Category Archives: Stratocumulus clouds

Your cloud dairy for May 9th

Haha, most readers won’t even notice! But maybe some cow-centric, instead of cloud-centric, folks will drop by, raising the worth of this blog to above $35 if sold….that according to a “biz” site.

Had a rainbow yesterday. Hope you noticed. It was pretty early and overhead west. I think the clouds did not have ice in them. The rain echoes were not showing up on the radar, suggesting the beam went over the tops. Sounding suggested tops might have been as cool as -5°C.    In any case, the drops were able to tip the bucket a couple of more times, and along with yesterday afternoon’s brief, light rain showers our total has climbed to 0.37 inches for the storm. Not bad, though as in money, you always want more.

These storm breakup days are always our prettiest, and that’s often what this site is about, being pretty. Yesterday had some fabulous scenes;  couldn’t stop shuttering cam. It is a real neurotic compulsive behavior pattern, as afflicts some of us cloud and storm-centric folk. Check Mr. Olbinsky’s work; his work goes beyond phenomenal whether you want a wedding photographer or want to see a storm chasing video.  But it takes that kind of eccentric energy to be special, to stand out as he does.

Here, though, we let the storms and cloud scenes, such as they are, hope for the best, and let them come to us….  Kind of a lazy storm chaser’s attitude.

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5:49 AM. I really do think this rain came out of clouds that had no ice…maybe 70% sure.
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6:27 AM. Stratus fractus springing to life as Cumulus clouds lining the sides of Sam Ridge (Samaniego). Showed how much instability, the ease of which the slightly warmer air in these clouds could jut upward yesterday
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6:49 AM. Just pretty and so green after the rain.
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6:50 AM. Same scene, focusing in on a highlight.
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7:01 AM. More prettiness in a highlighted baby turret.
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7:01 AM. In case you missed it, here it is again, a little zoomed.
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9:03 AM. Rise of the Cumulonimbus capillatus incus (has anvil). This scene had a lot of portent for the day. You knew more would be forming, maybe drift over us later.
9:33 AM. I thought this was a pretty neat scene, though its just a cloud shadow lining up with the rise of the Catalina Mountains.
9:33 AM. I thought this was a pretty neat scene, though its just a cloud shadow lining up with the rise of the Catalina Mountains.
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9:36 AM. Hmmmm. What the HECK is happening now? Low center was off in the direction, headed for us, with still cooler air aloft. But where are the Cumulonimbus clouds that should come with it? (They formed rapidly, but later.)
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2:23 PM. By mid-afternoon, things were swell all around, lots of Cumulonimbus clouds. They seemed to fade, though, as they marched toward Catalinaland, as this complex did. The rather sharp line in the lower part of the photo, and beyond which you can see distant clouds, is where the melting level was. This is often appears to be the “cloud base” but its really not in the sense of having cloud droplets. If you were to fly in it, all you would see is rain and melting snow just below this line, and just snowflakes above it. If the whole sky was covered in this, we’d call it Nimbostratus, and say the base was at that melting level.
3:42 PM. Another pretty major band appears to be headed this way. DIdn't make it.
3:42 PM. Another pretty major band appears to be headed this way, rotating around that low center, shifting northward.  Didn’t make it.
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6:35 PM. Somewhat promising that a nice dark line and heavy shafts were out there, thinking they might shift northward again. Nope. Fizzled.

Still cold aloft, so having some nice Cumulus today is in the bag, the early Stratocumulus devolving into Cu, that is.

The End

Sprinkly clouds passed over during night; check dusty cars for drop craters and evidence of a trace of rain

Honestly, I gave up on the chance of rain overnight into this morning at sunset yesterday due to the absolutely clear skies.   And, like you, woke up to not one cloud within a 100 miles!  How could this be, given the synoptic situation?  Started slicing apples for some humble pie, but then, when looking at a radar and cloud loop (this one from IPS MeteoStar) saw that lower clouds had magically erupted to our west before midnight,  and by the time they got here in the early morning hours, had little showers coming out of them!

I did not park my own dusty car out from the carport, either. I thought I would at LEAST see a pile of clouds on Ms. Lemmon, too, this morning!  Sure wrong there.  Here are a couple of images from what has to be considered a tiny weather miracle:

201704290745_SWR 201704290830_SWR

Chances of rain increasing (imagine!), for  just over a week from now as actual model outputs begin reflecting what spaghetti (the many outputs) was indicating, i.e., a big upper trough in the West-Great Basin area.  At the time that spaghetti was indicating that, the actual model outputs were not, indicating that they were outliers.

Check this out from last night.  Since this model output is more in agreement with that crazy spaghetti plot, it inherently has more credibility, and is likely not an outlier model run.   That what the NOAA spaghetti factory is used for, getting a handle on those runs that might be wild, and those that are more likely to verify.

Its valid on the morning of May 8th and shows a trough coming out of the Pacific ahead of the one from the Pac NW, shown at this time over northern Cal.  The hope here would be that the one from the SW would have a generous amount of sub-tropical clouds with rain in them.

2017042900_WST_GFS_500_HGT_WINDS_228

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6:04 AM, 28 April. About the only lenticular seen. Oh, well, there were a few weak ones off to the north, but that was it. CIrrostratus is the higher cloud, too thin to be Altostratus.

Cloud shots will be posted later this morning of the next day….. (i didn’t get to is as I had planned)

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12:52 PM, April 28. There can hardly be a better shot of Stratocumulus. While it looks dark, it was partly because of the Cirrostratus or Altostratus overcast; it was that thick, not thick enough to reach temperatures where ice would form in it, and rain would come out.  And no rain did, and soon this whole overcast was gone, as was the higher Cirrostratus that shadowed it.
4:09 PM. No ice came out of these clouds, but they did allow those beautiful sunny highlights on our Catalina Mountains.
4:09 PM. No ice came out of these clouds, but they did allow those beautiful sunny highlights on our Catalina Mountains.
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4:40 PM. Its remarkable how after weeks and weeks of no rain that so much of our mountains and desert vegetation remains as green as it is.

Yesterday afternoon, the 29th.  Here’s what shallow, icy clouds look like, reflecting the unusually cold air above us.

4:44 PM, April 29th.
4:44 PM, April 29th.
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5:43 AM this morning. In an unusually timely post, here’s a leftover ice puff from yesterday over there beyond Charouleau Gap. You’d be guessing, if you cared, that the tops of both of these icy clouds was colder than about -20° C (4°F) since there seems to be so much ice.

 

The End

PS:  Chance of rain still holding for the 8th.  See below for new depiction of big “cutoff” vortex over AZ from last evening’s model run:

Valid at 5 PM, May 8th.
Valid at 5 PM, May 8th.

Catalina WY progress report; Cal WY update, too, since I grew up in Cal

I thought you’d like to see this:

As of the end of February 2017. We're pretty average, but it took some "heavy lifting" in December and January to get there.
As of the end of February 2017.  You can see were right about at the average for the Water Year,, but it took some “heavy lifting” in December and January to get there.

Doesn’t look promising for much rain here in Catalina in March, however.  No rain in sight through the next 10 days at least.

Let’s check our 7 inches with what’s happening upwind, say, in CALIFORNIA, and see if there’s been any drought relief there, through February,  via the CNRFC:

California water year totals through the end of February 2017. Note one station in the central Califorina coastal range is already over 100 inches!
California water year totals through the end of February 2017. Note one station in the central Califorina coastal range is already over 100 inches!  There are 20 stations already over 100 inches as can be seen from the table at right.  March looks to have substantial rains north of SFO, which will add appreciably to those highest totals.  Amazing!  You can go to the CNRFC and expand these interactive maps, btw.

As you are likely to know from many media stories last year, Cal was in a drought siege of five straight years,  with but got a little relief last year in the northern part thanks to help from  the giant Niño, one of the strongest ever.

Alas, it was one that failed to deliver as the big rain producer for the south half of Cal and the SW in general as was expected.

In case you’ve forgotten how bad things were in Cal, let us look back at what was being said, those horrific appearing drought maps,  and also how hopeful were were at the time  that the Big Niño would take a bit bite out of drought.  This is a really good article:

https://www.climate.gov/news-features/event-tracker/how-deep-precipitation-hole-california

Then, when the Big Niño faded away like maple syrup on a stack of buckwheat pancakes last spring and summer,  we were surely doomed for more dry years.  And, for a time, the dreaded cold tongue of water in the eastern equatorial region, the so-called, La Niña, started to develop, which would be no help at all for  a good rain season like a Big Niño is, usually.

The Niña faded away, too, to nothing as the winter went on, so we really didn’t have much going on in the tropical Pacific to help us figure out what kind of winter rainfall regime we were going to have om 2016-17.  Not having anything going on meant winter rainfall could go either way, a difficult to figure out situation for season forecasters.

In retrospect it is pretty astounding how big a signal must have been out there SOMEWHERE that this winter was going to be one for the history books on the West Coast in general, and in particular, for Californians.  Californians saw their drought chewed up and spit out in a single winter, including snow packs so high the height of some mountain peaks have been revised.  (I’m kidding.)

No one saw such an astounding winter coming.

This winter sure makes one think of the QBO (Quasi-biennenial Oscillation, one up there in the Stratosphere where there’s almost no air (haha, well, practically none)…  Did the QBO have a role in this astounding winter;  was there a delay in the effects of the Big Niño even without a bunch of convection in the eastern Pac tropics?  Doesn’t seem that could be right…

But, William “Bill” Lau, U of Maryland scientist,  reported some statistical evidence of  such a lag way back in ’88 due to a QBO connection of some kind and ENSO, no physical cause could be discerned, however,  not yet,  anyway.  Lau, 1988, is reprised below for readers who want to go deep:

Annual cycle, QBO, SO on global precip J Geophys Res 1988ocr

Sure has looked like the Big Niño WY we expected last year!

Some recent clouds; after all, this is CLOUD maven, not RAIN maven:

I’ve been kind of holding out on you.  I dropped my camera and busted it.  Its no fun taking pictures when you don’t have a real camera.  Still doesn’t work right, but take these anyway:

March 4th, afternoon. Hope you logged this; the rarely seen CIrrus castellanus (almost "congestus" in size) or, informally, "Cumulo-cirrus."
March 4th, afternoon. Hope you logged this; the rarely seen CIrrus castellanus (almost “congestus” in size) or, informally, “Cumulo-cirrus.”
Poppies are out, btw. Nice display on "Poppy Hils" just across and southwest of the Pima County Pistol Club, off Bowman.
Poppies are out, btw, in case you haven’t noticed. Nice display on “Poppy Hils” just across and southwest of the Pima County Pistol Club, off Bowman.
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March 4th, late afternoon. Nothing terrifically special in this tangle of Cirrus spissatus (“Cis spis” to cloud folk) but I thought it was just a really nice scene

Moving to the next day, Sunday, that REALLY windy day:

March 5, Sunday morning 6:13 AM. Altocumulus lenticularis alerts cloudwise folk to the possibility of windy conditions although it was already windy.
March 5, Sunday morning 6:13 AM. Altocumulus lenticularis alerts cloudwise folk to the possibility of windy conditions although it was already windy.
3:55 PM, March 5th. After a day of solid Altostratus overcast with underlying Cumulus and Stratocumulus, a layer of Altocumulus began to move in to add a little more interest to the sky.
3:55 PM, March 5th. After a day of solid Altostratus overcast with underlying Cumulus and Stratocumulus, a layer of Altocumulus began to move in to add a little more interest to the sky.
3:57 PM. Looking to the north revealed that some of the lower Cumulus/Stratocumulus complexes reached heights where ice could form. That smooth region on the bottom and right side of the cloud is a fall of ice from this cloud with a RW- (text for "light rainshower") if you like to text stuff) right below that. This is not a lot of ice and so you'd be thinking the cloud barely made that ice-forming temperature.
3:57 PM. Looking to the north revealed that some of the lower Cumulus/Stratocumulus complexes reached heights where ice could form. That smooth region on the bottom and right side of the cloud is a fall of ice from this cloud with a RW- (text for “light rainshower”) if you like to text stuff) right below that. This is not a lot of ice and so you’d be thinking the cloud barely made that ice-forming temperature.  CMP doesn’t think it was caused by an ice fallout from that higher layer, which sometimes can happen.  Let’s look at the most timely sounding, just to check.  From the real Cowboys at the University of Wyoming, this:
Ann 2017030600.72274.skewt.parc
The TUS sounding which I only now just saw, showing a vast separation between the lower Stratocumulus and the higher layers of Altocumlus and Altostratus on top. Note, too, that over TUS the tops of the lower cloud is not quite at -10°C the temperature we start to look for ice formation in AZ. However, our clouds were NW of that balloon sounding, and it would have been that tiny bit colder, and tops were also lifted some when they passed over the Tortolitas earlier, meaning that the tops of this complex were colder than -10° C (14° F) at some point.

Wow, too much information….after a hiatus in blogging I feel like that  Oroville Dam in California, metaphorically overflowing with too much hand-waving information.

6:03 PM, March 5. Its still real windy. Line of virga brought a few drops when it passed overhead at 6:30 PM.
6:03 PM, March 5. Its still real windy. Line of virga brought a few drops when it passed overhead at 6:30 PM.
6:04 PM. Nice dramatic shot toward Marana as the backside of the middle cloud layer approached allowing the sun to shine through.
6:04 PM. Nice dramatic shot toward Marana as the backside of the middle cloud layer approached allowing the sun to shine through.
6:09 PM. Virga getting closer. May have to park car outside to make sure I don't miss any drops!
6:09 PM. Virga getting closer. May have to park car outside to make sure I don’t miss any drops!
6:22 PM. SW-NE oriented virga strip about to pass overhead. Drops fell between 6:30 and 6:40 PM, but you had to be outside to notice, which you would have been as a proper CMJ eccentric.
6:22 PM. SW-NE oriented virga strip about to pass overhead. Drops fell between 6:30 and 6:40 PM, but you had to be outside to notice, which you would have been as a proper CMJ eccentric.  You would have WANTED that trace of rain report, maybe slackers would not have observed.
6:30 PM. Climax; the great sunset allowed by that backside clearing.
6:30 PM. Climax; the great sunset allowed by that backside clearing.

The End, at last!

Lots of interesting clouds yesterday; partial double rainbow, too

Light rain showers overnight, just before midnight, and again just after 1 AM AST,  raised our Sutherland Heights storm total to 0.33 inches, decent but disappointing in view of model and personal expectations (0.60 inches).

What was especially interesting is that those nighttime light showers didn’t show up on the TUS radar, suggesting very shallow tops, perhaps a “warm rain” event, one not having ice, or an “ice multiplication” event with tops warmer than -10° C, about where the tops were on the 5 PM AST TUS sounding.

By this morning, the tops were barely below freezing (about -3° C).  Don’t expect to see ice today, except at Cirrus levels!

5:53 PM.

5:53 PM.

5:52 PM. Drawing back a little.
5:52 PM. Drawing back a little.  Pretty dramatic scene I think with that sun break running along there underneath the Stratocumulus clouds.
7:06 AM. Had another round of amazingly shallow Stratocumulus clouds precipitating on the Catalina Mountains. Hardly any depth at all to this cloud, and yet there the precip on the mountain!
7:06 AM. Had another round of amazingly shallow Stratocumulus clouds precipitating on the Catalina Mountains. Hardly any depth at all to this cloud, and yet there the precip on the mountain!  Tops were hardly higher than Ms Mt Sara Lemmon!  Must have been drizzle.  Let’s check the sounding nearest this time, see what’s up:
The NWS at the U of AZ balloon sounding, launched around 3:30 AM. Seems to indicate cloud tops were colder than -10°C, plenty cold enough for ice formations, so not as exciting as if they were, say, at -5°C.
The NWS at the U of AZ balloon sounding, launched around 3:30 AM. Seems to indicate cloud tops were colder than -10°C, plenty cold enough for ice formations, so not as exciting as if they were, say, at -5°C.  So, I retract my excitement excitedly!
11:00 AM. Still overcast with Stratocumulus clouds, but occasionally ones showing precipitation, making them the whole scene, Stratocumulus stratiformis (covers a big portion of the sky) "praecipitatio" (is emitting precip, here maybe drizzle) or it may be very light snow. You can just make out the snowline, around 6,000 feet on the Cat Mountains.
11:00 AM. Still overcast with Stratocumulus clouds, but occasionally ones showing precipitation, making them the whole scene, Stratocumulus stratiformis (covers a big portion of the sky) “praecipitatio” (is emitting precip, here maybe drizzle) or it may be very light snow. You can just make out the snowline (center), around 6,000 feet on the Cat Mountains.
2:01 PM. Eventually the sky broke open to reveal that deep blue we see in the wintertime as Cumulus clouds began to take shape. Aren't these scenes tremendous, so clean looking, like you're out at sea, far away from land.
2:01 PM. Eventually the sky broke open to reveal that deep blue we see in the wintertime as Cumulus clouds began to take shape. Aren’t these scenes tremendous, so clean looking, like you’re out at sea, far away from land?
3:51 PM. Gradually the tops of the Cumulus clouds reached up to lower temperatures where ice could form and something resembling our summer rain shafts began to appear here and there.
3:51 PM. Gradually the tops of the Cumulus clouds reached up to lower temperatures where ice could form and something resembling our summer rain shafts began to appear here and there.
5:12 PM. The front side of somebody's nice rainbow.
5:12 PM. The front side of somebody’s nice rainbow over there toward Marana.
5:45 PM. And a little before the rainbows, some nice, dramatic lighting on our desert vegies under a dark overcast of Stratocumulus.
5:45 PM. And a little before the rainbows, some nice, dramatic lighting on our desert vegies under a dark overcast of Stratocumulus.

Last of the Cal rain blasters is making its way across the State today, with another 5-10 inches expected in favored Sierra and coastal ranges in the next 24-36 h. Numerous sites north of SFO have now logged over 100 inches since October 1st!  Imagine.  Great to see that Cal drought vanquished in a single year, so unexpected.  Let’s hope the Oroville Dam, N of Sacto, holds.

The End

PS: Using point and shoot cam now with “real” camera in the shop for awhile.

Rain clouds drop more rain on Catalina; 0.24 inches logged as of 7 AM

But what kind of rain clouds?

That’s why you come here, to answer important questions like that.  After all, those precipitating clouds could have been Nimbostratus, Stratocumulus opacus praecipitatio, Cumulonimbus capillatus incus flammagenitus,  or even just “plain” Cumulonimbus capillatus (no anvil),  and possibly, Stratus opacus nebulosos praecipitatio.

Of course, with no large fires around, we can at once rule out Cumulonimbus capillatus incus flammagenitus….(the new name for clouds on top of fires, formerly referred to by the more accessible terms,  “pyrocumulus” or “pyrocumulonimbus.”

For the curious, and since I broke my camera and don’t have the dozens upon dozens of photos to regale or bore you with, I will reach into the archives for a shot of “flammagenitus” and show you one from the pyromaniacs’ paradise,  Brazil!:

Brazil, 1995: Cumulonimbus calvus flammagenitus. Shot taken by Arthur In flight shot, Porto Velho to Maraba.
Brazil, 1995: Cumulonimbus capillatus flammagenitus. Shot taken by Arthur on flight from, Porto Velho to Maraba.  The black at the bottom is mostly smoke.  Where it starts to turn a little white is where cloud droplets are forming.  Smoky ice is just above the aircraft’s wing and a little behind it.  You probably didn’t expect to see a “flammagenitus” here today, but, here it is.

 

Now, on to more recently viewed clouds, like yesterday’s:

9:16 AM. Stratocumulus praecipitatio line the tops of the Catalina Mountains. What's
9:16 AM. Stratocumulus praecipitatio line the tops of the Catalina Mountains. What’s “wrong” with this scene?  Very shallow clouds are precipitating, ones likely exhibiting, yep, the rare phenomenon in Arizona of “ice multiplication” wherein ice forms in clouds with tops warmer than around -15° C or so in great concentrations (often 10s to 100s per liter.)  Here, probably not that high, maybe several per liter of unaccounted for ice.  Happens when the cloud droplets are larger than usual–so when you see shallow clouds precipitating, but ones with tops still below freezing, -5° C, say, you can report in your cloud diary that you saw some “ice multiplciation on that day.  You would definitely get some accolades for such a report if cloud maven club members were to read  it, perhaps, an “Observer of the Week” award.  Of course, you get a mountain of extra credit for stating that those crystals falling on side of our mountains (Sam Ridge here), “look like needles and hollow columns” those ice crystals that form at temperatures higher than -10° C (14° F).
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10:52 AM. The actual cloud that produced this mist-like precipitation has literally “rained itself out.” What’s interesting here for you is that there seems to be no demarcation of the melting level. Hmmmm. Was this all drizzle then that fell out of that cloud, starting at cloud tops noticeably below freezing? It happens, though usually that phase is short lived as ice takes over.
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10:52 AM. A wider view of this intriguing scene. You can see all the glinting rocks, too, due to a little water on them. So pretty, the highlighting and all.
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11:08 AM. This shot, not taken out the window whilst driving since that would be crazy, gives a nice profile to those shallow, precipitating clouds. Sure would have liked to fly through them, see what the precip actually was. However, we do know that it was snowing on Ms. Mt. Lemmon, so that implicates the ice phase. If you were up there, you may have seen those needles and hollow columns, of course, mostly in aggregates (snowflakes). And, to trigger the “ice multiplication” process, you may have seen some tiny snowballs falling, too, ones we call graupel or soft hail.
The U of AZ balloon sounding for 5 AM AST yesterday morning. May have been valid for those shallower preciping clouds.
The U of AZ balloon sounding for 5 AM AST yesterday morning. May have been valid for those shallower preciping clouds.

Later these scenes were overtaken by a slab of Nimbostratus and steady light rain for a few hours.

A note on the recent southern Cal rain blast

As you know, up ten inches fell in some mountain locations in southern California as a monster low pressure system smashed into the coast near San Francisco1.  You might recall, too,  that the shift of the jet stream (and thus storm track) into the southern portions of California was well predicted two weeks in advance in those crazy spaghetti plots.   You can’t always get much out of those plots except maybe the degree of uncertainty in  weather patterns a couple of weeks out, but that was a rare case in which the signal far upstream for something strong barging into southern Cal also strong.  And, of course, we are experiencing the residual of that storm, also as was indicated in those plots (“…the weather change around the 18th.”

Presently, a another sequence of extremely heavy rain is in the pipeline for central and northern California starting today, which will take a few days for it to come to an end.

Following a  break, what was intriguing in the model outputs, and a little scary was that it appeared that yet another scoop of tropical air was going to jet across the Pacific under another blocking high in the Arctic  and Gulf of Alaska  into California. Take a look at this prog:

Valid Sunday, March 4th, at 5 PM AST.
Valid Sunday, March 4th, at 5 PM AST.

Here’s where spaghetti can shed some real light:

From last night's global data, this output for March 4th at 5 PM with writing on it.
From last night’s global data, this output for March 4th at 5 PM with writing on it.

So while it is still possible that some model runs will indicate a blast from the sub-tropics affecting Cal, they can be pretty much waived off as outliers (not impossible “solutions” but rather unlikely ones.  Breath easier Califs!  At least after the current onslaught ends.

BTW, can you see what kind of weather is indicated in this plot for the SW and old Arizony?

Cold; temperatures below normal, precip likely at times.

The End.

——————————–
1The low pressure center that passed over San Francisco yesterday was not  as deep (988 millibars) as the notorious “Frankenstormmaggedon” of 2010 which barged into Frisco with a 979 millibar center.   You may recall, too, that spaghetti had strongly suggested a “Frankenstormaggedon”, as it was later called, also more than ten days in advance.  Recall, too, if you can recall, that 2009-10 was an El Niño winter with this kind of thing pretty much anticipated.

For history buffs, I reprise that January 2010 storm as seen on our national weather map.  You may recall that, if there’s anything left in that noggin up there, that Catalina experience no less than THREE inches of rain as this system went by, taking a couple of days:

11 AM AST, January 21st, 2010.
11 AM AST, January 21st, 2010.
Valid at 2 PM AST, February 17th.  Junior.
Valid at 2 PM AST, February 17th. Junior.

Iridescence, jet streak Cirrus warn of overnight “middlin'” storm

I guess “billows” (“undulatus” in cloudspeak) two days ago in the late afternoon wasn’t enough of a sign that the weather was changing. Yesterday we had fast moving Cirrocumulus with rainbows in it, and as the sun was setting, “jet streak Cirrus”, a line of Cirrus clouds often seen in the very core of high altitude, powerful jet streams passed overhead.

How hard was the wind blowing up there in that Cirrus last evening? Oh, our Tuscon balloon sounding, lifting off around 3:30 PM, going up about a 1000 feet a minute to, indicates that the max wind up there at Cirrus level was 146 knots (just under 170 mph)! Yikes. Poor balloon.  Must be in France by now.

The storm has been a bit of a disappointment in rain production. We’ve only logged 0.22 inches1.  Not as much as foretold here, 0.33 inches, but that forecast was a better prediction than  by “Weather Underground Robotics” (0.58 inches).  Its great to beat a robot!

We had another sign yesterday in the fastest moving Cirrocumulus clouds I think you’ll ever see around here (about 100 mph), ones at just 18,000 feet above sea level, 15 kft above Catalina:   rainbows of color near the sun called iridescence (also called “irisation”).   Here, as is the norm here,  are a few too many shots of the same thing2.

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10:54 AM. The fist of weather is used as a prop to indicate that these colors are forming a ring around the sun.
10:54 AM. The fist of weather is used as a prop to indicate that these colors are forming a ring around the sun. Usually you try to find a light standard somewhere…maybe a “gopro cam on a stick” might do it. Just don’t look at the sun when you do this.
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10:57 AM.
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10:57 AM, pulling back some for perspective. As we often say here, “so pretty.” And look at how tiny the granulation is in this Cirrocumulus cloud is!

The colors themselves, of course,  don’t warn of something about to happen, but the fast movement from the southwest did; a powerful jet stream is over you.   That strong stream, the result of temperature gradients in the atmosphere, is dividing deep warm air from deep cold air, and steers the alternations of high and low pressure centers, and with those alternations of lows and highs along the jet stream, air is drawn from different latitude zones and the boundaries where those different masses of air meet at the surface, is called fronts.  Here, such as last night, its nearly always cold ones.

The rest of the day was pretty exciting, the wind arising suddenly yesterday morning, along with our usual great visibility, and darker blue wintertime skies, made the clouds stand out more.

7:56 AM. Looking to the west at a scattering of Stratocu patches.
7:56 AM. Looking to the west at a scattering of Stratocu patches.
7:57 AM. Highlight on the hills above Saddlebrook. Stratocumulus overhead.
7:57 AM. Highlight on the hills above Saddlebrook. Stratocumulus overhead.
8:42 AM. This patch of Stratocumulus was the result of a lift zone that often produces clouds headed our way in southwesterly flow. The difference here is how limited in size this patch was allowing you to see where that lift zone was. Downstream, though, descending motions creamed this cloud, one that sat there most of the early part of the day. Usually a whole layer is over us, with a clearing visible toward the SW horizon.
8:42 AM. This patch of Stratocumulus was the result of a lift zone that often produces clouds headed our way in southwesterly flow. The difference here is how limited in size this patch was allowing you to see where that lift zone was. Downstream, though, descending motions creamed this cloud, one that sat there most of the early part of the day. Usually a whole layer is over us, with a clearing visible toward the SW horizon.
11:02 AM. Still out there, still limited in size. Wind here now 20-30 mph with stronger puffs.
11:02 AM. Still out there pretty much near the same spot, still limited in size. Wind here now 20-30 mph with stronger puffs.

 

DSC_1904
11:40 AM. By this time it had shifted closer to us, still forming on the southwest end, dissipating at the downwind end where the cloud is so ragged due to mixing with dry, descending air.
12:42 PM. Creeping closer, but still a standing wave, dissipating as it came toward us.
12:42 PM. Creeping closer, but still a standing wave, dissipating as it came toward us.  It was about this time that it disappeared, the sky becoming more complex with no simple standing waves.

The sky at last, considering the power of the trough approaching, FINALLY began to fill in.  Started looking around for the first sign of ice having formed in these clouds as the air aloft became cooler. Along with this filling in by Cumulus and Stratocumulus clouds, some sun highlights began to appear on our mountains, contrasted by the darkening skies above.

1:55 PM. Stratocumulus banks up against the Catalinas, Samaniego Ridge.
1:55 PM. Stratocumulus clouds  bank up against the Catalinas, Samaniego Ridge.
2:03 PM. While Stratocumulus banked up against the mountains, huge temporary clearings occurred elsewhere. Notice how shredded the tops of these clouds are and how the tops lean to the right. They're revealing the great increase in the wind with height, and yet, how dry it was above this layer (that, by the ragged cloud tops mixing with the very dry air just above them.)
2:03 PM. While Stratocumulus banked up against the mountains, huge temporary clearings occurred elsewhere. Notice how shredded the tops of these clouds are and how the tops lean to the right. They’re revealing the great increase in the wind with height, and yet, how dry it was above this layer (that, by the ragged cloud tops mixing with the very dry air just above them.)
3:38 PM. Here comes the Jet Streak Cirrus! Also about this time, the frontal windshift line, marked by low scud clouds in the cold air, began to appear on the NW horizon. It was an exciting moment. Here we go! FROPA within a coupla hours maybe. Well, took longer than that....
3:38 PM. Here comes the Jet Streak Cirrus! Also about this time, the frontal windshift line, marked by low scud clouds in the cold air, began to appear on the NW horizon. It was an exciting moment. Here we go! FROPA within a coupla hours maybe. Well, took longer than that….
3:52 PM. A little ruffle of Cirrocumulus leads the advance of the jet streak Cirrus.
3:52 PM. A little ruffle of Cirrocumulus leads the advance of the jet streak Cirrus.
4:11 PM. Cloud line forming above the frontal windshift line. Was progressing this way at this time, but was to stall, maybe back off.
4:11 PM. Cloud line forming above the frontal windshift line. Was progressing this way at this time, but was to stall, maybe back off.
4:11 PM. Zooming, floating over Saddlebrooke, this close up of our FROPA and windshift line. Ended up backing off, dissipating, maybe reforming later after dark.
4:11 PM. Zooming, floating over Saddlebrooke, this close up of our FROPA and windshift line. Ended up backing off, dissipating, maybe reforming later after dark.  These lowest clouds form in the colder air associated with the windshift line at the nose of the front as the moist air ahead of the front  mixes with it and is lifted.  We see this with most of our incoming cold fronts, and in our summer thunderstorms.  The best cases  form “arcus clouds”, a solid line just above and behind the windshift at the ground.  These kinds of ragged clouds, in cloudspeak, are called “pannus.”  Was pretty excited here, as no doubt you were, that FROPA (frontal passage) was imminent, might happen within the hour.  Nope.
4:40 PM. In the meantime, our jet streak CIrrus moved overhead, the clearing behind this thin band leading to some memorable fading sun highlights on the Catalinas.
4:40 PM. In the meantime, our jet streak CIrrus, above the Stratocumulus clouds,  moved overhead, the clearing behind this thin band leading to some memorable fading sun highlights on the Catalinas.
5:40 PM. No words needed.
5:40 PM. No words needed.
5:43 PM. "Fading sun and rain gauge." Another one of those exceptional scenes you won't find anywhere except on this blog. Tell your friends. A small mammal, termed a "packrat" is decimating my prickly pear wind protection for this gauge! A lot of rain loss occurs due to wind. drops missing the collector! It very upsetting to see this happen.
5:43 PM. “Fading sun and rain gauge.” Another one of those exceptional scenes you won’t find anywhere except on this blog. Tell your friends. A small mammal, termed a “packrat” is decimating my prickly pear wind protection for this gauge! A lot of rain loss occurs due to wind. drops missing the collector! It very upsetting to see this happen.
5:43 PM. Even the often despised teddy bear cholla can be so beautiful in this fading sun, the spines capturing it so well.
5:43 PM. Even the often despised teddy bear cholla can be so beautiful in this fading sun, the spines capturing it so well.

Eventually our jet streak Cirrus provided the background for another great sunset scene:

5:56 PM.
5:56 PM.

 

 

A 300 millibar (about 30,000 feet above sea level) with an IR satellite image for yesterday at 5 PM AST. Arrows denoted the jet streak Cirrus cloud, enhanced in the downwind region of the Baja mountains.
A 300 millibar (about 30,000 feet above sea level) with an IR satellite image for yesterday at 5 PM AST.   The Cirrus layer extended from about this height to around 35, 000 feet above sea level.   according to our TUS balloon sounding.  Arrows denoted the jet streak Cirrus cloud thatpassed over us,  enhanced in the downwind region of the Baja mountains.  Note that the wind at San Diego max wind was even slightly stronger than our wind max was at this level at152 knots.  This map is the courtesy of the University of Washington Huskies Weather Department.

Today’s clouds and weather

From that map above, you’ll see that there’s a “tail-dragger” trough still to the west of us and about over Sandy Ego (haha). That’s going to keep the air over us extremely cold, and with some sun, the Cumulus clouds that arrive are expected to have tops colder than -15 to -20° C, plenty cold enough for the formation of ice.
Ice means precip, snow up there, rain down here in spots. So, we could still pick up a few more hundredths if a shower happens to drop by. The chance of isolated very light showers in the area is 100%, but no one can tell you if one will actually land on us. You’ll have to be watching, mostly after 12 noon. Look to the west toward the Tortolita Mountains, terrain that ought to spawn one or two of those.

Looks like a longer dry spell ahead; several days to a week, maybe more.

The End

—————————-

1CoCoRahs gauge, btw. NWS-style gauge had only 0.20 inches, likely due to enhanced wind loss associated with my collapsing prickly pear protector.
2 I was driving and had to park and jump out of car to get these.  You only have seconds or maybe a minute or three to capture stuff like this.

Thunderblasts after midnight awaken sleeping Catalinans with 50 mph winds, graupel, and R++; latest storm total now 1.38 inches!

In case you don’t believe me that over an inch fell, this digital record from Sutherland Heights with writing on it:

20170120-21 rain day
Your last 24 h of rain in the Sutherland Heights, Catalina, Arizona, USA. Total resets at midnight.

Probably a little more to come, too.  Got some blow damage, I’m sure.  Will be looking for roof shingles around the yard today.

12:45 AM. Your radar and IR satellite imagery for our blast last night from IPS MeteoStar
12:45 AM. Your radar and IR satellite imagery for our blast last night from IPS MeteoStar .  That tiny red region near Catalina represents hail and/or extremely heavy rain.

And, as everyone knows from their favorite TEEVEE weatherperson, “New Storm to Pound SE Arizonans!”  Begins Monday night, Tuesday AM.  May have snow in it as it ends.

Your know, its no fun telling people what they already know, so lets look ahead beyond the normal forecast period of great accuracy, beyond not seven days, not eight, but beyond TEN days!

First, we set the stage with a ten day look ahead (from last evening) in a NOAA spaghetti factory plot:

Valid for 5 PM, Monday, January 30th. If you've not seen this, you'll be screaming "warm in the West, and damn Cold in the East." Its a common pattern often associated with some of the driest years in the West when it recurs over and over again during a winter.
Valid for 5 PM, Monday, January 30th. If you’ve not seen this, you’ll be screaming “warm in the West, and damn Cold in the East.” Its a common pattern often associated with some of the driest years in the West when it recurs over and over again during a winter.

This plot indicates that the pattern of a towering, storm-blocking ridge is certain along the West Coast by ten days–will be developing for a day or three before this,  That ridge represents an extrusion of warm air aloft over the entire West Coast extending all the way into Alaska.  The couple of red lines in and south of AZ are due to the change of a minor, likely dry, cutoff low in our area about this time (plus or minus a day).

In other words, this plot suggests a warmer, dry period develops over AZ, and storms are shunted from the Pacific Ocean, located west of the West Coast, all the way to Anchorage and vicinity,  They will  be welcoming a warm up in weather up thataway at some point in this pattern.

Is that it, then, for the AZ winter precip?  It could happen.  Just one more storm after the current one fades away today?

Hint:  Sometimes anticyclone ridges like the one in the plot above get too big for their britches, and fall away, or, break off like a balloon from a tether, and a warm blob of air aloft sits at higher latitudes, often floating off to the northwest.

The exciting ramification of this latter scenario is that in the “soft underbelly” of the “blocking anticyclone” (as in American football), the jet stream throws something of a screen pass, goes underneath the belly of the blocking high,  and races in toward the West Coast at lower latitudes.  Having done so, such a break through pattern (“Break on through to the Other Side”) results in heavy rains in Cal and the Southwest.

Izzat what’s going to happen?

Let us look farther ahead, unprofessionally, really,  and see if there is evidence in spaghetti for such a development and you already know that there must be because it would explain why I am writing so much here.  Below, the EXCITING spaghetti plot strongly indicating break through flow breaking on through to the other side, i.e., the West Coast,  from the lower latitudes of the Pacific:

Valid on Thursday, February 2, at 5 PM AST. Flow from the lower latitudes of the Pac will, in fact, break on through to the other side, as told in song by the Doors1.
Valid on Thursday, February 2, at 5 PM AST. Flow from the lower latitudes of the Pac will, in fact, break on through to the other side, as told in song by the Doors1.  Who knows what they were talking about but here we’re talking about a jet stream….

Well, we’ll see in a coupla weeks if CMP knows what he is talking about..  I think this is going to happen, resembles what’s happening now, and weather patterns like to repeat, more so within the same winter.  However, how much precip comes with this pattern will be determined by how much flow breaks on through to the other side….

Yesterday’s clouds

Let us begin our look at yesterday’s clouds by looking back three days ago before the Big Storm.  We had a nice sunrise.   Here it is in case you missed it:

DSC_1680
7:21 AM. Altostratus sunrise. Virga is highlighted showing the precipitating nature of Altostratus. Amount of virga can vary.
DSC_1686
7:31 AM. Same kind of view, different colors.
DSC_1689
7:40 AM. Highlight on the Tortolitas. This is why you carry your camera at all times.
9:04 AM. Pretty much solid gray after that nice sunrise for the rest of the day with cloud bases lowering and raising. Early on, cloud bases were well above 10,000 feet; i. e;, above Mt. Lemmo, and would be called, "Altostratus opacus." The virga is very muted, and there are embedded droplet clouds as well as a droplet cloud layer (Altocumulus) encroaching on the right. Estimated ceiling here: 12,000 overcast." (Pronounced, "one-two thousand overcast" if you want to make your friends think that maybe you were a pilot at some time in your life.)
9:04 AM. Pretty much solid gray after that nice sunrise for the rest of the day with cloud bases lowering and raising. Early on, cloud bases were well above 10,000 feet; i. e;, above Mt. Lemmo, and would be called, “Altostratus opacus.” The virga is very muted, and there are embedded droplet clouds as well as a droplet cloud layer (Altocumulus) encroaching on the right. Estimated ceiling here: 12,000 overcast.” (Pronounced, “one-two thousand overcast” if you want to make your friends think that maybe you were a pilot at some time in your life.)
12:58 PM.
12:58 PM. Clouds began to appear on Samaniego Ridge as the moist air above us lowered steadily.  However, due to lowering cloud tops, the ice in the higher overcast layer was gone. Here there are two layers above the scruff of Stratus fractus (I would call it) on the ridge.  The lower one looks like its a Stratocumulus, and the higher one a solid layer of “Altocumulus opacus.”  Its already rained some, and we were in between storm bands.
2:48 PM. Looked like the Altocumulus opacus (stratiformis, if you want to be exactly correct) was breaking up just enough for a sun break. But no, kept filling in as it headed this way from the southwest.
2:48 PM. Looked like the Altocumulus opacus (stratiformis, if you want to be exactly correct) was breaking up just enough for a sun break. But no; it kept filling in as it headed this way from the southwest.  No ice, or virga evident, so tops are pretty warm, probably warmer than -10° C (23° F) would be a good guess. Hah!  Just now looked at the TUS sounding and tops were indicated to be at -11° C, still very marginal for ice (absent drizzle drops in clouds, which causes ice to form at much higher temperatures, but you already knew that.)
4:24 PM. Small openings allowed a few highlights to show up on the Catalinas underneath that Altocumulus opacus layer.
4:24 PM. Small openings allowed a few highlights to show up on the Catalinas underneath that Altocumulus opacus layer.  And  clouds were still topping Ms. Mt. Lemmon, indicating a good flow of low level moisture was still in progress.

Moving forward to only two days ago, the day preceding the nighttime blast:  a cold, windy day with low overcast skies all day, shallow, drizzle-producing clouds, something we don’t see a lot of here in Arizona.

8:08 AM, January 20th, 2017, btw. "Gray skies, nothin' but gray skies, from now on", by Irving B.
8:08 AM, January 20th, 2017, btw. “Gray skies, nothin’ but gray skies, from now on”, by Irving B.  Stratus fractus underlies an overcast of Stratocumulus.  Some light rain is falling toward Romero Pass on the right.
8:10 AM. A really special shot. Stratus with drizzle is a very difficult photographic capture. I can feel how enthralled you are with this view toward Oro Valley. You know, I do this for YOU.
8:10 AM. A really special shot. Stratus with drizzle, shown here,  is a very difficult photographic capture. I can feel how enthralled you are with this scene toward Oro Valley. You know, I do this for YOU.  Look how uniform the gray is!  It just takes your breath away!
9:44 AM. Before long, drier air down low moved in, eradicating our beautiful Stratus layer, leaving only holdouts (Stratus fractus) along the Catalina foothills below the heavy layer of Stratocumulus.
9:44 AM. Before long, drier air down low moved in, eradicating our beautiful Stratus layer, leaving only holdouts (Stratus fractus) along the Catalina foothills below the heavy layer of Stratocumulus.
10:20 AM. The wind had now shown up, and these ragged, shredded shallow Stratocumulus shedding drizzle or very light rain showers stormed across the Catalina Mountains. This was quite remarkable sight, since such shallow clouds as these are more often seen in clean maritime locations like Hawaii. Scenes like this suggest that the cloud droplet concentrations were very low, and that there were larger than normal cloud condensation nuclei on which the drops could form, getting a head start in the sizes needed to produce collisions with coalescene (larger than 30 microns in diameter (about one third to one half a human hair in diameter, for perspective.)
10:20 AM. The wind had now shown up, and these ragged, shredded shallow Stratocumulus shedding drizzle or very light rain showers stormed across the Catalina Mountains. This was quite remarkable sight, since such shallow clouds as these are more often seen in clean maritime locations like Hawaii. Scenes like this suggest that the cloud droplet concentrations were very low, and that there were larger than normal cloud condensation nuclei on which the drops could form, getting a head start in the sizes needed to produce collisions with coalescene (larger than 30 microns in diameter (about one third to one half a human hair in diameter, for perspective.)

 

3:12 PM. Lower, drier air moved in, eradicating the Stratocumulus and revealing the rarely seen Nimbostratus precip-producing layer. This layer, considered a mid-level cloud, is usually obscured by, you guessed it, Stratocumulus clouds.
3:12 PM. Lower, drier air moved in, eradicating the Stratocumulus and revealing the rarely seen Nimbostratus precip-producing layer. This layer, considered a mid-level cloud, is usually obscured by, you guessed it, Stratocumulus clouds.

By the end of the day, the clouds had lowered again, and we were about to have a very interesting night!

5:01 PM.
5:01 PM.

The End

———————-
1Remember how great we hippie relics thought that first Doors album was? Later, the Doors, and that era were to be made fun of by 80s punk and humor group,  The Dead Milkman in “Bitchin’ Comaro.” (Its worth a listen.)

 

 

Storm-weary Catalinans prepare for more strong storms, cold, and storm weariness

Catalinans experienced a FOURTH cloudy day in a row, and, over the past few days, including yesterday’s few drops that fell at 4:24 PM, have experienced over an inch of rain!

Some grumbling has started concerning muddy,  pot-holed and puddled up dirt roads, about the washes running across roads lately, water and mud splashing on the car day after day,  and brutally low temperatures dipping to well below 50° degrees in the morning now for several days in a row.  Its 40° F here as I write this.

While a brief respite is in progress now,  Catalinans were discouraged to learn that more strong storms are due in this weekend, bringing possibly damaging winds and heavy rains that will augment the poor road conditions.

How much rain?

Let us look below and see how much has been calculated by our best model at the University of Arizona’s Wildcat Hydro and Atmos Sci Dept  (I am so glad they provide this service; I donate to the Dept,  as we all should!):

Precip totals by 8 PM, January 23rd after a few storms have gone by.
Precip totals by 8 PM, January 23rd after a few storms have gone by.  As you can see lots of red and yelleows in Arizona’s critical mountain regions for snowpack, and we’re in the inch or so of rain, pretty much like the amount produced here by the last storm.  What a January this is turning out to be!

Hah!  We can’t complain too much about inclement weather compared to California’s pluvialities.  Here is a table and map of precip amounts for that State through just the first 14 days.  Prepare to gasp:

A map and table of the highest 20 rainfall totals in California and Nevada just through January 14th. Astounding! And 10-20 inches more are expected at some of these sites before the month is out.
A map and table of the highest 20 rainfall totals in California and Nevada just through January 14th. Astounding! And 10-20 inches more are expected at some of these sites before the month is out.  Yep, by Jan 14th, one station was closing in on 40 inches of rain!

The remarkable aspect of this rainfall anomaly on the West Coast and in the Southwest, which is also quite wet, is that it could not be seen in climate forecasts days to a couple of weeks in advance.  Its not that the folks at the Climate Prediction Center aren’t the best that we can get, its just a statement about how hard it is to get a longer term forecast right.  Many are right, but lately, recalling the “Big Niño Bust of 2015-16” where the forecasts of a wet Southwest and central and southern California went terribly awry, those forecasts have taken a beating.  Here’s what was expected this winter by the CPC, first, for January, a forecast made on the last day of December. when the forecast models we use day to day would have had some influence:

The precipitation forecast for January 2017 by the CPC.
The precipitation forecast for January 2017 by the CPC.

As can be seen, the extreme rains that hit California, and our own well above normal precip, though on the doorstep on December 31st, were unforeseen.  That’s how tough it is.

Below, the forecast for January through March, also going astray, though a recovery could be had by a very dry Feb and March in Cal and the Southwest, something not likely to happen now.

Below, the forecast for the three month period of January through March, also now going astray.
Below, the forecast for the three month period of January through March, also now going astray.

Glad I’m not forecasting for a month or three months!  Gads, yesterday we had ice galore here and there, and I had predicted that morning that it was doubtful that ice could form in our clouds yeserday and how about that rainbow yesterday afternoon, to change the subject quickly, but smoothly; hardly a ripple, something gleaned from the election debates:

4:59 PM. A rainbow.
4:59 PM. A rainbow, an implicit indicator of ice in clouds yesterday.  There was a lot in some areas, particularly over the Catalinas in the late afternoon.

Some additional views, including a horse, which should increase web traffic:

Horse, muddy corral, and supporting rainbow evidence for why the corral is muddy. Horse: "Why is that rainbow on my butt?"
Horse, muddy corral, and supporting rainbow evidence for why the corral is muddy. Horse “Chero-key”: “Why is that rainbow on my butt?”
Rainbow empties into a rain gauge.
Rainbow empties into a NWS-style, 8-inch diameter rain gauge.  Real weathermen have real rain gauges, not the cheap plastic toy types.  Just kidding, CoCo and rainlog, orgs that  use cheap plastic toy-type gauges.  Just kidding again, CoCo and rainlog. orgs.
5:09 PM. Here a completely different rainbow, because I moved a few feet, and the rain drops in the prior bows have fallen to the ground, empties into yet another 8-inch diameter rain gauge, a tipping bucket one which is online at KAZCATAL4. Its been under-measuring the rain, however, for some time.
5:09 PM. Here a completely different rainbow, because I moved a few feet, and the rain drops in the prior bows have fallen to the ground, empties into yet another 8-inch diameter rain gauge, a tipping bucket one which is online at KAZCATAL4. Its been under-measuring the rain, however, for some time.

OK, now for the rest of the day, your daily cloud diary:

8:09 AM. You got yer normal TUS exiting smog plume heading for Mark Albright's house in Continental Ranch over there on the right. There is some Stratus fractus in that plume as well. The damp air has caused some of the hygroscopic particles to swell up; be deliquesed, which increases the opacity of smog. Such an effect is particularly bad on the East Coast ahead of cold fronts when warm, humid, smog-laden air is brought northward ahead of fronts. Gads, its awful. Even when the sky is cloudless, you can hardly tell its blue!
8:09 AM. You got yer normal TUS exiting smog plume heading for Mark Albright’s house in Continental Ranch over there on the right. There is some Stratus fractus in that plume as well. The damp air has caused some of the hygroscopic particles to swell up; be deliquesced, which increases the opacity of smog. Such an effect is particularly bad on the East Coast ahead of cold fronts when warm, humid, smog-laden air is brought northward ahead of fronts. Gads, its awful. Even when the sky is cloudless, you can hardly tell its blue!  Above the smog, Stratocumulus.
9:36 AM. Had evidence of a little smog up thisaway, too. Again, the whitish haze is due to deliquesced partilces. As the air dries out and the day warms up, this effect disappears. even though the aerosol particles that were "deliquesced" are still around. The Five Satins, "Still Around." That takes me back aways.
9:36 AM. Had evidence of a little smog up thisaway, too. Again, the whitish haze is due to deliquesced partilces. As the air dries out and the day warms up, this effect disappears. even though the aerosol particles that were “deliquesced” are still around. The Five Satins, “Still Around.”  Gads, that takes me back a-ways when I was 2 inches taller than now….
10:10 AM. Smog plume, as sometimes happens, begins to drift northward as the mountains start launching Cumulus clouds and cause the wind to move toward them. Can't say too much about the central cloud feature, a gesture of some kind it would appear.
10:10 AM. Smog plume, as sometimes happens, begins to drift northward as the mountains start launching Cumulus clouds and cause the wind to move toward them. Can’t say too much about the central cloud feature, a gesture of some kind it would appear.
10:27 AM. Nice lighting scene I thought.
10:27 AM. Nice lighting scene I thought.  Cumulus turrets were rocketing upward at this time.
1:48 PM. Not much going on. Underlying Cumulus bases lifted, some Cumulus spreading out adding to the general Stratocumulus deck. No ice around, as was forecast.
1:48 PM. Not much going on. Underlying Cumulus bases lifted, some Cumulus spreading out adding to the slightly higher general Stratocumulus deck. No ice around, as was forecast.
3:02 PM. Something is going terribly WRONG with the anticipation of no ice producing clouds yesterday. Rain begins to fall on the Catalinas.
3:02 PM. Something is going terribly WRONG with the anticipation of no ice producing clouds yesterday. Rain begins to fall on the Catalinas.
3:20 PM. A totally humiliating, completely glaciated tiny Cumulonimbus remains breaks into view from the Stratocumulus deck.
3:20 PM. A totally humiliating, completely glaciated tiny Cumulonimbus remains breaks into view from the Stratocumulus deck.  On the other hand. another fascinating day of ice multiplication here in Arizona!  Look at that little guy, all ice, and tops almost certainly warmer than about -12° C from sounding data.  This would mean that those 10s to hundreds per liter of ice that you’re looking at are needles and hollow column ice crystals called “sheaths.”  Man, I wanted to sample that cloud so bad!  What happened to cause this cloud was that at one point its top got a couple of degrees Celsius colder than the surrounding clouds that did not produce ice.  Rain was reaching the ground at this time o er there even though it is in the dissipating stage, too.
3:43 PM. In the meantime, the showers emitting from the clouds over the Catalinas were getting more enthusiastic (read, "personally insulting"). No doubt if you could get on top, they would have looked exactly like that dissipating Cb shown above.
3:43 PM. In the meantime, the showers emitting from the clouds over the Catalinas were getting more enthusiastic (read, “personally insulting”). No doubt if you could get on top, they would have looked exactly like that dissipating Cb shown above.

But, then there were some great sun and lighting scenes in those showers, not to mention the brilliant rainbow that was to come:

4:47 PM.  Its a little crazy, I know, but I just love these rainy, sunlit scenes on our mountains, or those sun and shadow scenes that I post so many of.  Just never will get tired of them.
4:47 PM. Its a little crazy, I know, but I just love these rainy, sunlit scenes on our mountains, or those sun and shadow scenes that I post so many of. Just never will get tired of them.
4:51.  More of same.  Notice inclusion of man-sized rain gauge in foreground.  Its a nice touch if you, too, have one, which I hope you do.
4:51. More of same. Notice inclusion of man-sized rain gauge in foreground. Its a nice touch if you, too, have one, which I hope you do.  It really says who you are.

The End

Thanks, if anyone is out there….

Sutherland Heights 72-h storm total nears an inch

0.24 inches was recorded after 7 AM yesterday, bringing our voluptuous rain total to 0.95 inches1.  How nice.

Dry spell ahead now, maybe a LONG one.  “Fiddle-dee-dee.”

Yesterday: another day shallow precipitating clouds and “ice multiplication”

Seemed to be another day of “ice multiplication” here in southeast Arizona, a term that was coined in 1969 by Peter Hobbs of the University of Washington when he and his group reported that clouds were snowing on the peaks of the Olympic Mountains when the cloud top temperatures were warmer than -10° C (14° F).  They had a hut on the top of Mt. Olympus at 7,000 feet!  Lots of stories about that experiment, many swirling around Abdul Alkezweeny,  a Peter Hobbs grad student in those days.  An aircraft with skis landed up there to bring supplies!  Imagine.  (Yours truly was not embedded in the Hobbs group at that time.)  It was an exciting time in that group, prior to the acquisition of their first research aircraft, WWII B-23 “tail dragger.”  Peter himself, did not fly in this with RARE exception.  Many flights were quite sickening, bumping around in Cumulus and small Cumulonimbus clouds, spinning around power plants stacks, wings vertical to ground….

In a nostalgic mood, posting this photo of our venerable B-23 research aircraft in which I spent SO MANY hours!
In a nostalgic mood, posting this photo of our venerable B-23 research aircraft in which I spent SO MANY hours!

His group’s observations, however,  were not the first, but were among many airborne and ground reports in the mid and 1960s that left  jaws dropping about how much ice was in clouds at these moderately supercooled temperatures, even in clouds with tops as warm as -4° C.  It was believed, in various ways that ice nuclei measurements were made on the ground, or in aircraft measurements,  that not much ice would be found in clouds until the top temperatures was lower than -20° C.  In fact, it was generally believed that only about one ice particle per liter would be found in clouds with tops as cold at -20° C, while actual observations were telling a much different story.

This discrepancy between measured ice nuclei concentrations is a scientific  enigma that is still being investigated today!   And it appears that me and you cloud maven juniors out there got to see it again yesterday, the second day in a row to see an cloud-ice enigma (“nigma” for short)!

Let us continue this module by examining the assertion of “ice multiplication” with the TUS balloon soundings for yesterday morning and evening as rendered by IPS MeteoStar:

The TUS rawinsonde balloon data from yesterday morning. Launched around 3:30 AM AST.
The TUS rawinsonde balloon data from yesterday morning. Launched around 3:30 AM AST.
The TUS rawinsonde profile yesterday afternoon, balloon launched at about 3:30 PM AST.
The TUS rawinsonde profile yesterday afternoon, balloon launched at about 3:30 PM AST.

These soundings strongly suggest at the start and end of the day, that coldest cloud tops were warmer or no colder than -10° C.

However, the fly in the oatmeal here is that a cold front and associated wind shift came through in the mid-morning hours, heralded by an little arcus cloud, and cloud tops would have been somewhat colder during that period of rain; we don’t know for sure how much, and satellite imagery suggested lower temperatures, though possibly due to over-riding CIrrus cloud above the “Nimbostratus” layer that produced the steady light rain.

However, the rain before the front went by, and the very light rain showers that fell in the late afternoon were likely well represented by the TUS soundings.  That’s my case!  Wish I’d had a cloud-instrumented yesterday and the day before.  Woulda got a paper out of it:  “Ice multiplication rampant in Arizona!”

Yesterday’s actual clouds

No more hand-waving….  Let’s see if it really was raining near the time of the TUS soundings above.  Picture of the day:

5:18 PM. Rainbow goes into a RAIN GAUGE! Amazing. Proves that it was raining, though very lightly (RW--) at 5:18 PM.
5:18 PM. Rainbow goes INTO a RAIN GAUGE! Amazing. Proves that it was raining, though very lightly (RW–) at 5:18 PM, when the sounding profile was likely valid for these light showers.  Q. E. D.!  Yours for $2,000, today only.  Should get a lot of money out of this photo.  I had to practically have the camera on the ground to get the right alignment and illusion.
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8:08 AM. Misty, light rain showers shower on the Catalinas and in Catalina itself.

 

8:50 AM.
8:50 AM.  Misty light rain continues from relatively shallow clouds.  No shafting observed, something that would suggest much taller cloud tops.  These were likely “mounding” up there, like rolling hills, mounding the most prior to releasing slightly heavier rain.  Here’s where you would be thinking, “Could this be ANOTHER ice multiplication day?  Wow, if so.” And, of course, the thought of it being a warm rain process day (no ice, thank you) can’t be ruled out either, since rain can form at below freezing temperatures in clouds, though  supercooled raindrops are the most vulnerable to freezing at high temperatures, to go a little deep here, and complex the interpretation some.

That was phase one of yesterday’s weather, rain from shallow clouds.

Phase 2 is,  “The front marches in across the OV! Cloud depth not so certain, but is probably not real deep, as inferred from the disappointing amount of rain that fell so lightly from the frontal band in spite of its dramatic entrance, fronted by an arcus, wind shift cloud.”

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9:55 AM. Here comes the front and arcus wind shift cloud!
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10:06 AM. Here the approaching front and wind shift appeared to have jacked up a cloud top near Pusch Ridge. Was thinking, as you were, maybe we’ll get some thunder today.
10:14 AM. Arcus cloud rolls fast across the OV; rain follows.
10:14 AM. Arcus cloud rolls fast across the OV; rain follows.
10:19 AM. Arcus cloud passes over Sutherland Heights, and light curtains of rain begin to fall from it.
10:19 AM. Arcus cloud passes over Sutherland Heights, and light curtains of rain begin to fall from it.
11:26 AM. The end is near. The sun became visible after only an hour of steady, very light rain, and a tenth of an inch of rain. Thought there might be a gush in this, but, no. This also points to shallow, mounding or even flat cloud tops, not tall ones.
11:26 AM. The end is near. The sun became visible after only an hour of steady, very light rain, and a tenth of an inch of rain. Thought there might be a gush in this, but, no. This also points to shallow, mounding or even flat cloud tops, not tall ones.  This was not a good sight.

But, as those who live here know, some of our best scenes are AFTER after the rain has stopped and the skies partially clear.  Yesterday was no exception.  But first, the Stratus, which you don’t see too often:

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1:09 PM. Looking north at a Saddebrooke highlight. Stratus is beginning to break up out there.
1:11 PM. Stratus in the cold air following the frontal passage ("FROPA", in weather speak or texting).
1:11 PM. Stratus in the cold air following the frontal passage (“FROPA”, in weather speak or texting).  Not budging yet.
1:35 PM. Yep, only 25 or so min later, this! So pretty. Stratus fractus lining the area around Charouleau Gap.
1:35 PM. Yep, only 25 or so min later, this! So pretty. Stratus fractus lining the area around Charouleau Gap.
2:30 PM.
2:30 PM.
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2:57 PM. Cumulus puffing up by the minute. Will they form ice?
3:04 PM. Just a pretty scene of Cumulus over there toward Saddlebrooke.
3:04 PM. Just a pretty scene of Cumulus over there toward Saddlebrooke.
4:02 PM. A bit of a surprise as a group of precipitating Stratocumulus like clouds came rushing in. No shafts, suggesting tall tops were seen, so likely again just mounding tops up there.
4:02 PM. A bit of a surprise as a group of precipitating Stratocumulus like clouds came rushing in. No shafts, suggesting tall tops were seen, so likely again just mounding tops up there.
5:24 PM. As the last sprinkles ended and the sun peaked through an opening to the SW, our mountains and clouds lit up with an orange tint. As the air cooled the Stratus fractus clouds (highlighted) again were once again straddling the side of mountains near Charouleau Gap.
5:24 PM. As the last sprinkles ended and the sun peaked through an opening to the SW, our mountains and clouds lit up with an orange tint. As the air cooled the Stratus fractus clouds (highlighted) again were once again straddling the side of mountains near Charouleau Gap.

Looks like only streamers of  high and middle cloud from the tropics as California gets blasted with extremely heavy rains over the next two weeks.  Totals in favored central and northern California coastal ranges, and in the central and northern Sierras will fall between 20 and 30 inches of rain during this period.  A great place for you and me to be would be near the King Range, Shelter Cove (see below), or Honeydew to see those pounders.

Part of Shelter Cove, CA, with King Range in the background. A coastal jet rams the King Range and causes prodigious rains from ordinary looking storms. Average precip more than 100 inches, farthest south point for such a high average rainfall on the West Coast.
Part of Shelter Cove, CA, with King Range in the background. A coastal jet rams the King Range and causes prodigious rains from ordinary looking storms. Average precip more than 100 inches, farthest south point for such a high average rainfall on the West Coast.

The End

—————————–
1The online gauge is a Davis tipping bucket. It has been consistently under-measuring totals recorded in the NWS 8-inch diameter gauge, and the 4-inch diameter, ground-mounted (it sits on the ground among grasses and weeds) CoCoRahs gauge. CoCoRahs is a national organization of rain and snow measuring nuts (haha, just kidding-they’re really precipophiles like me) all over the country and overseas as well. You can find them here.  Part of the reason for the under-measurement of the Davis instrument is loss due to wind.  That tipping bucket sits up at about 6 feet off the ground, thus sees a lot more wind than gauges on the ground.   A gauge on the ground, away from tall objects, is always the best way to go!  The reason for this explanation is because if you go to Wundermaps or Weather Underground and see the total for this site, it is ALWAYS going to be low compared to the actual amount that fell.  This is a degradation that has come up over the past year or two.

Sutherland Heights storm total now 0.71 inches as of 7 AM; soil turning green as moss look alike growth reminding one of Seattle spurts from bare ground!

First, in blogging for dollars, this:

3:55 PM. Rainbow fragment and solar home. Yesterday's visual highlight. Yours for $1995.95. If you call now, we'll throw in a exact same photo FREE!
3:55 PM. Rainbow fragment and solar home, an extraordinary combination.. It was yesterday’s visual highlight. Yours for $1995.95. And, if you order now, we’ll throw in a second,  exact copy of this extraordinary, magical scene FREE!

Here’s a nice one from the day before as the clouds rolled in, starting with Cirrus and Altocumulus, lowering to Stratocumulus later in the afternoon.

5:04 PM, 30 Dec.
5:04 PM, 30 Dec.  Sun break amid Stratocumulus.  Stratus fractus topping mountains.

Yesterday’s clouds; an extraordinary day with a little drizzle amid light showers

Hope you noticed the true drizzle that occurred yesterday, namely, fine (larger than 200 microns, smaller than 500 microns in diameter), close TOGETHER (critical to the definition of “drizzle”) drops that nearly float in the air. They may make the least impression, or none, when landing in a puddle.

When you see drizzle, you have the opportunity of chatting up your neighbor by educating them informally to what drizzle really is (many, maybe most,  TEEVEE weatherfolk do NOT know what “drizzle” is, btw), and 2) by telling your neighbor, if he/she is still listening to you, that the droplets in the clouds overhead must be larger than 30 microns in diameter, or better yet, “larger than the Hocking-Jonas diameter of 38 microns, at which point collisions with coalescence begins to occur” and  “drizzle is not produced by ice crystals in the clouds overhead; they’re not enough of them to produce ‘fine, close together drops.'” Your neighbor has likely left the building at this point, but, oh, well, you tried.

Here, in Arizona, shallow clouds, such as we had yesterday, hardly ever can produce the broad droplet spectrum in which clouds have droplets larger than 30 microns in diameter.  Its because this far inland from the ocean, where the air is very clean,  the air has picked up natural and anthro aerosol particles that can function as “cloud condensation nuclei” (CCN).   As a result of ingesting dirt and stuff, clouds have too many droplets here as a rule for the droplets in them to grow to larger sizes.   They’re all mostly less than 20-25 microns, sizes in which even if they collide, they can’t coalesce.

In “pristine” areas, if you go to one, such as on a cruise out in  the oceans, droplet concentrations in clouds are much lower, and even a little water that might be condensed in a shallow cloud can produce a broad spectrum, one that extends to droplet larger than 30 microns.

So even little or shallow layer clouds can precip over the oceans, produce drizzle or light rain showers (in which the larger drops are bigger than 500 microns in diameter).  Of course, here we recall that the (whom some consider “villainous”) geoengineers want to stop drizzle out over the oceans so that clouds have longer lifetimes, are darker on the bottom, and reflect more sunlight back into space.

Those guys can be lumped into the same ilk as those who want to change the color of the sky from blue to whitish or yellowish by adding gigantic amounts of tiny particles in the stratosphere, again for the purpose of cooling the planet!  Unbelievable.  Please ask before doing this!!!

A Pinatubo sampler for what “geoengineering” would do to our skies,  say, sunsets in particular.  I took this photo from the University of Washington’s research aircraft in 1992 off the Washington coast in onshore flow.  But we saw these same sunsets, sunrises, yellowed by the Pinatubo eruption of June 1991 everywhere we went, including in the Azores in June 1992.

AB469_mf9193_1517_ontop Sc_Pinatubo above

OK, pretty boring, whiney, really, so inserting picture of a nice horse here to make people feel better if you’ve been depressed about what our scientists have been pondering to do about global warming other than controlling emissions:

8:57 AM. Zeus. Led cloistered life for 13 years; likes to bolt now that he's getting out.
8:57 AM. Zeus. Led cloistered life for 13 years; likes to bolt,  now that he’s getting out on the trails.
7:40 AM, yesterday, Dec. 31st.
7:40 AM, yesterday, Dec. 31st.  The low hanging Stratocumulus clouds, about 1500 feet above Catalina, and the mountains had a bit of an orange tinge.  It was probably due to sunrise color on a separate much higher layer.

Later….drizzling Stratocumulus, same view:

10:30 AM. Stratocumulus praecipitatio, if you want to go "deep" into cloud naming. "Stratiformis", too, covers a lot of the sky.
10:30 AM. Stratocumulus praecipitatio, if you want to go “deep” into cloud naming. “Stratiformis”, too, covers a lot of the sky. Note misty-like view, lack of shafting.
12:48 PM. More Stratocu P., an example of those clouds in the distance that kept dropping little and light rain showers on Catalina.
12:48 PM. More Stratocu P., an example of those clouds in the distance that kept dropping little and light rain showers on Catalina.
1:01 PM. Highlighting amid the RW-- , (weather text for "very light rain showers").
1:01 PM. Highlighting amid the RW– , (weather text for “very light rain showers”).  Stratcu P., with maybe Stratus fractus or Cumulus fractus below.  The shadowed,  dark shred clouds  in the mddle would be Stratus fractus IMO.
3:55 PM. Zooming in on that pretty rainbow. You know, this is a cloud heaven here. I hope you all appreciate it!
3:55 PM. Zooming in on that pretty rainbow. You know, this is a cloud heaven here. I hope you all appreciate it!  Maybe that’s why I get upset over “geoengineering” and changing the sky anywhere.
3:57 PM. Between showers, but new ones erupted upwind. This one have a shaft, implying a higher cloud top than the prior, non-shafting clouds that brought us semi-steady RW--.
3:57 PM. Between showers, but new ones erupted upwind. This one have a shaft, implying a higher cloud top than the prior, non-shafting clouds that brought us semi-steady RW–.

The second extraordinary thing about yesterday was that the top temperatures of these clouds was around -10° C (14° F), temperatures that ice does not form act as a rule in Arizona.  To get ice at temperatures that high, you also need larger cloud droplets, and they have to occur in the -2.5° C to -8° C range.  In this range, it was discovered that falling ice crystals, mostly faster falling ones like “graupel” (aka, soft hail) when colliding with larger drops, ice splinters are produced.  The cloud droplets must be larger than 23 microns in diameter in THAT particular temperature zone, something that would occur more often in our warm,  summer clouds, but would rarely be expected in our winter ones.

Why?

Again,  it goes back to clouds in inland regions ingesting lots of natural and anthro aerosols that cut down on droplet sizes in clouds (by raising droplet concentrations in them).  Our recent rains have helped cut down on that process on ingesting dirt, for sure, and was a likely player yesterday.  Furthermore, our winter clouds are moisture challenged relative to the summer ones with their tropical origins and high cloud base temperatures, a second reason not to expect larger droplets in our winter clouds.

Here  is the TUS sounding with some writing on it for yesterday afternoon from IPS MeteoStar.  (Satellite imagery was also  indicating warmer than usual tops for precipitating clouds yesterday.):

The TUS balloon sounding ("rawinsonde" in techno speak) launched at about 3:30 PM yesterday afternoon. Balloon rises at about 1,000 feet a minute, FYI. Typically they pop up around 100,000-120,000 feet! Instruments are parachuted down. Sometimes they are found and returned to the NWS and re-used! How great is that?
The TUS balloon sounding (“rawinsonde” in techno speak) launched at about 3:30 PM yesterday afternoon. Balloon rises at about 1,000 feet a minute, FYI. Typically they pop up around 100,000-120,000 feet! Instrument package is parachuted down so it doesn’t conk somebody on the head. Sometimes they are found and returned to the NWS and re-used! How great is that?

Here’s the punchline:  If clouds are drizzling, then they are ripe, if the tops get to lower temperatures than about -4° C for what we’ve termed “ice multiplication” or “ice enhancement”.  A very few natural ice nuclei at temperatures between -4° and -10° C, say, starts the process, those forming “soft hail” which then leads to ice splinters.  This is the leading theory of this anomaly of ice in clouds at temperatures only a little below freezing, if you think 23° to 14° F fits that definition.

There are exceptions where this process did not explain the ice that formed at such high temperatures, so standby for further elucidation about how in the HECK ice forms in clouds at some point in the future.

As usual, no time to proof, so good luck in comprehending what’s been written.

The weather just ahead:

The second main rainband is just about here at 9:25 AM.  Cloud tops will be deeper and colder than in the prior rains, raising the possibility of some thunder today, and maybe another third of an inch of rain.  Watch for an windshift line cloud (“arcus” cloud) might well be seen today.  That’s always dramatic and exciting here in Catalina cloud heaven.

The End at last!

And a happy, weatherful year to all!