‘Manda rain

BTT you read this, rain oughta be falling or near by as the remnants of  ‘Manda hurricane dribble into Arizona today.  Looks like there’s just enough rain upstream right now (4 AM) to produce, hold your breath, a MEASURABLE amount here in Catalina!  Likely will be just a few hundredths, though, as much as two tenths is about the top potential from this.  At this point, anything measurable is a fabulous rain!

Mods have been oscillating on whether it would rain here for many days, but last night’s run ended pleasantly with a “correct” forecast of measurable rain.  See green pixelation over Catalina below:

Valid for 11 AM AST today. Heart of rainband over us then, mod says.
Valid for 11 AM AST today.
Heart of rainband over us then, mod says.  From IPS MeteoStar.

Your Catalina cloud day

(Also, another great cloud movie from the U of AZ here....)

5:15 AM.  Cirrus
5:15 AM. Cirrus, leaning toward “spissatus”, heavy dense patchy Cirrus.
DSC_0236
7:42 AM. Cirrus fibratus/uncinus. “Cirrus” will do it.

 

DSC_0240
4:35 PM. What would a day be like without Altostratus? Here, “translucidus” because the sun’s position is visible. When the sun can’t be seen, its “opacus”, like a lot of science can be.

 

DSC_0244
5:27 PM. Walkin’ doggie and this seemed like a nice shot of the rustic neighborhood streets, the Catalinas, and up top, some glaciating Altocumulus, castellanus on the right side; hasn’t gone through the ice forming stage yet, or the ice hasn’t fallen out that’s in it.

 

DSC_0266
7:18 PM, Crepuscular rays show up as the sun sets due to smoke and haze under the clouds. The clouds? A mix of flakes of Altocumulus and Altostratus (the solid blob), some Cirrus on top of it all.

 The weather way ahead…

Not a lot showing up here for mid-June, so won't say anything about that.
Valid for June 12, 5 PM AST.  Not a lot showing up here for mid-June weather, so won’t say anything about that.  I suspect it will be warm, though.

Remains of Amanda (Cat 4 hurricane) to bring rain to Catalina…maybe

The tropical fetch coming to Catalina (shown here yesterday) is from the remains of now strong hurricane Amanda, unusually strong for May for that matter, a month in which tropical storms in the Mexican Pacific are pretty rare, let alone have a Category 4 hurricane down there.  Has sustained winds of 140 mph now, BTW.

When pointing out the tropical finches yesterday, was not aware that the low down there was, in fact, a hurricane.  (Maybe I shouldn’t point things like that out, causing the one reader to lose confidence…. Too late now.)  Check out this loop from the U of WA for the “pinhole” signature of strong hurricanes.  Really happy to report that rain is on the way as May closes out (29th-31st are best chances for rain here).

Reprising yesterday’s cloud day…

1) Your day began with sprinkles from a cloud deck based at around 12, 000 feet above ground level (remember, too, that you can skip the “added value”, incremental approach below by just going to your great U of AZ time lapse movie.  I thought it was really very pretty for yesterday):

5:32 AM.  RW--
5:32 AM. RW– (very light rainshowers) were falling from what could be called a Altocumulus opacus deck with scattered taller turrets embedded in it, ones that produced the sprinkles.

 

2) clearing from the north:

6:24 AM.  The shallow nature of most of the Ac deck is apparent as the backedge moves toward Catalina.
6:24 AM. The shallow nature of most of the Ac deck is apparent as the backedge moves toward Catalina.

3) once the clearing arrived, small Cumulus began developing on the Cat Mountains and “?”:

9:36 AM.  I have no idea.  Move along now to the next photo.
9:36 AM. I have no idea. Move along now to the next photo.

4) nice small Cumulus all around, sometimes filling in to make it seem like a Seattle day in spring, with patches of Cirrus on top:

10:16 AM.  Cumulus humilis and Cirrus.
10:16 AM. Cumulus humilis and fractus (those shreds) and that beautiful Cirrus seemingly spreading its icy arms out (spreading likely due to perspective).

5)  Was there artwork in the sky?  You bet.  A niche developed here I immodestly remind you,  is that of cloud bottom photography, something I enjoy, and I think you do, too.  Below is one of the best ones of the day from the Cloud Bottoms Collection:

10:16 AM.  Cloud bottom of Cumulus humilis, maybe mediocris even, that was over ME.
10:16 AM. Bottom of Cumulus humilis, maybe mediocris even, that was over ME.  You look up, wondering, how deep is it?  Will it form ice and rain on ME?    Maybe graupel will fall out….since those are the first particles out the bottom of a growing Cumulus that is transitioning to a Cumulonimbus…  So much to think about when a bottom is over you.  Yours for $1,800,  if you call now.

 

6)  Late morning fill in:

11:23 AM.  Cumulus and Stratocumulus dominated the sky for a time; looked threatening, but no frizzy ice seen around the edges, so as dark as they looked, no ice, no precip.
11:23 AM. Cumulus and Stratocumulus dominated the sky for a time; looked threatening, but no frizzy ice seen around the edges.  No ice;  no precip or virga.  Pretty, though, with those shadows and sun breaks on the Cat Mountains

7) Smoky sunset (not a western singer, though it would be a good name for one):

7:06 PM.
7:06 PM.  Drifted down from the north.  Likely hours old, judging by the striations in it (not well mixed out and homogeneous  as would be smoke that’s days old).  Could not find source in satellite imagery right off.  I see that some of that layer is still visible to the SW this morning.

 

The End.

 

 

 

 

 

 

 

 

5)

6) Wildfire smoke drifts down in a thin layer from the N to spoil our sunset.  Note the reddish orange sun, a good sign of smoke and smog particles, tiny ones (typically, if you really want to know, that are 0.01 to 0.1 microns in size) that eviscerate the shorter wavelengths of sunlight so that only the reddish ones get through.

Nice weather we’re having; snowbirds ejected to the north too soon

Sure, there was a little mischievous wind in the early afternoon, BUT, as a day in late May in Catalina/Sutherland Heights zone of Arizona, wherein the temperature is less than 100 F, well, it was pretty darn great.  Another one is on tap today just like yesterday today, too.  Feeling sad about the early, northerly ejections of “snowbirds” who thought because of the warm winter, May would be an inferno here and are missing some splendid weather.  Doesn’t work that way.  You just don’t know.

Lot of interesting clouds yesterday, too, real cold ones.  Those Cumulus that formed in the late morning and afternoon started producing ice almost immediately.  Wonder if you caught the first ones over there beyond the Charouleau Gap around 11 AM?  They did not look as high-based as they were, thus, as cold overall, dad-gum, those cloud bottoms were running around -10 C (14 F)!

How high off the Catalina ground were they?  Oh, about 13,000 feet, or about 16,000 feet above sea level (about 550 millibars).  I woulda guessed, as you would have, about 8,000 feet off the ground when I first saw them forming (and not looking at the temperature and dewpoints, from which you can make a pretty good calculation of the cloud base height).  From the Cowboys at the U of Wyoming, this sounding for TUS yesterday afternoon:

The Tucson balloon sounding for yesterday afternoon, launched around 3:30 PM, ascends at about 1,000 feet a minute.
The Tucson balloon sounding for yesterday afternoon, launched around 3:30 PM, ascends at about 1,000 feet a minute.

——————–

Weather Hints for Every Day Use by “Art”:  You can calculate the height of a Cumulus cloud base by taking the difference between the temperature and the dewpoint, dividing it by 5, square that number, add the number you started with, and subtract the square root of  2.

DId I get the number you started with?

(Actually, stop at “dividing by 5”, multiply that number by 1000, and you’ll come out just about right.  Yesterday, 85 F temp, 20 F dewpoint, leads to 65 F difference, divide by 5, you get 13, and times a thousand is an estimated CUMULUS cloud base of about 13,000 feet above you, not too bad).

———————-

Continuing…..  Since bases were so cold, tops were exceptionally cold, too, for shallow Cumulus and started producing ice when they were only about 1,000 to 3,000 feet thick, with cloud top temperatures of -15 C to -20 C (about 4 F to -4 F).  Some of the highest tops, all east of us, and mostly on the east side of the Catalina Mountains, were likely as cold as -30 C (-22 F).

You can see yesterday’s small Cu spewing ice in the great U of AZ time lapse movie here.  Only plays for one day, though.

You may also have noted in your cloud diary the bifurcation in the Cumulus array of yesterday.  Almost no Cumulus west of Catalina, and plenty in the east half of the sky, appearing to be largest in the distance in the east.   We were literally on the edge of the moist plume from the south that was hoped to end up been west, with us deeply embedded in it, and where measurable rain might have fallen here as it did east of us yesterday.  Oh, well.

Today, with a low center passing over us tonight and a blob of Pacific Ocean air in it, and while that air is cold and pretty dry aloft, it will be a little more moist and so cloud bases today should be a little lower, and warmer, than yesterday’s.  That means a little more water condensing in them than in yesterday’s clouds, and a greater chance of sprinkle here.  Hoping for measurable, but its probably less than a 50-50 shot at that.  Likely will be some thunder in the area of SE AZ, too.  And, as always with high cloud bases, gusty winds that arise due to virga and rain falling through the dry air below cloud base. (Yesterday afternoon’s gales in the Sutherland Heights, momentary blasts of 40-50 mph,  were NOT due to virga, but a rather to something I didn’t see coming, maybe a smallish low center–nothing really showed up on the maps.)

You can see the forecast trajectory of that upper low coming toward us, from the University of Washington’s Huskies, whose #14 softball team plays away, really away, at  #1 Florida in Gainesville this weekend–how crummy is that except for the great Cu there and its important enough to be on TEEVEE Saturday?) computer output by clicking on this informative sentence.

You will also see in the above loop that our low takes its time moving along, and will keep the skies interesting with Cumulus and weak Cumulonimbus clouds today and tomorrow, along with temperatures below seasonal norms for late May (aka, less than 100 F) ((Snowbirds left too soon; ice still melting off some areas of the Great Lakes!))

From the cloud vault; yesterday’s clouds

10:28 AM.  Small Cu began forming in the lee of the Catalinas during a horseback ride with a friend, in case you didn't think someone as cloud-centric as me could have a friend.
10:28 AM. Small Cu with lenticular type tops began forming in the lee of the Catalinas during a horseback ride with a friend, in case you didn’t think someone as cloud-centric as me could have a friend.  Calm winds, then, too.
11:08 AM.  First ice!  Can you spot it?
11:08 AM. First ice! Can you spot it in the distance? Horse can’t believe that ice is forming already, and is rolling around in ecstasy, thinking about what it might mean for the afternoon.
1:43 PM.  Approaching low with air moving upward ahead of it, triggers a batch of Cirrus and Cirrocmulus lenticularis (really high lenticularis)  upwind of Catalina and above some Cumulus fractus.
1:43 PM. Approaching low with air moving upward ahead of it, triggers a batch of Cirrus and Cirrocmulus lenticularis (really high lenticularis) upwind of Catalina and above some Cumulus fractus.
3:18 PM.  One of the more remarkable sights yesterday, were the small Cumulus clouds (humiilis or mediocris) that iced out.  Look at ll the ice that formed in this small cloud, exiting on the left side, but dominates the whole cloud from this viewpoint.  When you see this, it tells you how COLD those clouds are.  First guess should be around -20 C at top when you see this much ice in a cloud this SMALL. Clouds having warmer bottoms, can have warmer tops that look this icy because ice forms in clouds at higher temperatures when the drops in them are larger.
3:18 PM. One of the more remarkable sights yesterday, were the small Cumulus clouds (humiilis or mediocris) that iced out. Look at ll the ice that formed in this small cloud, exiting on the left side, but dominates the whole cloud from this viewpoint. When you see this, it tells you how COLD those clouds are. First guess should be around -20 C at top when you see this much ice in a cloud this SMALL. Clouds having warmer bottoms, can have warmer tops that look this icy because ice forms in clouds at higher temperatures when the drops in them are larger (see Rangno and Hobbs 1994, Quart. J. Roy, Met, Soc.) Oh, yeah, baby, have some pubs!

 

6:58 PM.  Iced out Cu/weak Cumulonimbus beyond the Gap, the Charouleau one, end the day.  Shoot, a slight change in trajectory from the south, and they woulda been here.
6:58 PM. Iced out Cu/weak Cumulonimbus beyond the Gap, the Charouleau one, end the day. Shoot, a slight change in trajectory from the south, and they woulda been here.
7:00 PM.  Meanwhile, all quiet to the NW, no Cu whatsoever demonstrating the moisture edge we were on.
7:00 PM. Meanwhile, all quiet to the NW, no Cu whatsoever demonstrating the moisture edge we were on.

The weather ahead and WAY ahead

Now what I think is really interesting, which is almost everything to do with weather, is that the models are suggesting a tropical injection again at the end of MAY into early June, with a chance of a decent rain again.  As you can see in the plot below from the NOAA spaghetti factory, a trough to the west of us and over California is a virtual certainty now at the end of May.  That means the air above us will be, while quite warm, originating from the deep Tropics with the likelihood of clouds and precip coming up from there.  Nice.  Will keep me posted on these developments, in case no one else is reading this far.

Valid at 5 PM AST, June 1st 2014.
Valid at 5 PM AST, June 1st 2014.

 

The End.

Canadian model wetting it up for Catalina and environs

http://weather.gc.ca/model_forecast/animateweb_e.html?imagetype=model_forecast&imagename=00_054_G1_north@america@zoomout_I_4PAN_CLASSIC@012_….jpg

Had maybe a pixel of “rain” over us prior to last night’s run based on global observations made at 5 PM AST yesterday.  Now, from those obs there’s widespread rain in SE Arizona from the little low that drifts across SE Cal and just to the S of us.  First showers now shown to move in overnight Thursday, continue off and on, for about 24-36 hours.  Expect to hear thunder.  Sticking with best rain total prediction, generated when the models had none, of between 0.05 to 0.25 inches.  Tongue of moist air now seen to be injecting from tropics into that upper low!

Who cares what other mods calculate?  We just hope the Canadian model results above are not some kind of confluxion.

———-

Off on another tangent:

The “strangely believe it” side of science, cosmology:   Two weeks ago, in a Science mag editorial, it was pointed out that the entire Universe (!) as we know it today, even with those 50 billion new galaxies that the Hubble telescope disclosed back in the 90s, began with a particle SMALLER than a proton!  The Science Editorial, however,  did not disclose how that incredibly dense (!) particle got there, what was it doing before that, nor why, in 10-35 seconds, it blew up to be a couple hundred light years across, the very parts I was hoping to learn about.  This is,  perhaps, a more amazing scenario than one that brings rain to Arizona in May!

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The End.

After the rain, the oven

First, pretty nice sunset yesterday evening, which is redundant because sunset always occurs in the evening.

7:18 PM.  Altostratus with slight amounts of virga, underlit by the evening sunset. Haha, "evening sunset."
7:18 PM. Altostratus with slight amounts of virga, underlit in the evening sunset. Haha, “evening sunset.”

 

7:19 AM.  Only the virga is highlighted over here.  Liked the way was splayed over a house in the foreground.
7:19 AM. Liked the way was splayed over a house in the foreground. Sort of perty.

 

7:42 AM.  Thicker Cirrus clouds are Cirrus spissatus, or "Cis spis" for short, though not in polite company.  Should be the State Cloud of Arizona, we see so much of it, white or gray patches of ice cloud.  Kind of fed up with just "Cirrus-ee" skies these days.
7:42 AM. The thicker Cirrus clouds are Cirrus spissatus, or “Cis spis” for short, though not in polite company. Should be the State Cloud of Arizona, we see so much of it, those white or gray patches of ice cloud. Kind of fed up with just “Cirrus-ee” skies these days.

 

7:43 AM.  Looking north-northwest from Catalina toward Mt. Humphries, a delicate blend of Cirrus uncinus fibers (upper half of photo) with thicker Cirrus spissatus in the distance (thicker appearance not due to perspective).
7:43 AM. Looking north-northwest from Catalina toward Mt. Humphries, a delicate blend of Cirrus uncinus fibers (upper half of photo) with thicker Cirrus spissatus in the distance (thicker appearance not due to perspective).

OK, enough great information on clouds and things we can see from Catalina/Sutherland Heights, now for the rain ahead….

Rainshowers, some thunderstorms wrap around this low that drifts from over San Diego to over Puerto Peñasco, Mexico (aka, Rocky Point) by Saturday.  Here the Canadian version of what the weather configurations will be this coming Saturday morning:

Valid at 5 AM AST, Saturday
Valid at 5 AM AST, Saturday

 

As you can see, a little bit of tropical air gets whirled into this low from someplace down Mexico way, and, viola, showers and a couple of thunderstorms erupt.  This could happen anytime between Thursday night and Sunday morning, maybe even a couple of days of scattered showers.

Rain here in Catalina?  I think so.  Likely range, not a lot, but from a low end of just 0.05 inches, to as much as a quarter of an inch by Sunday morning (10% chance of less; only 10% chance of more, as a first take on this).  Gorgeous, dramatic skies are guaranteed, and likely some strong winds here and there emanating those high-based thunderstorms we can get this time of year.

BTW, not reporting on the US model forecast since it shows the low next weekend passing a little farther to the north, i. e., doesn’t take as favorable a track for rain here as the Enviro Can model shown above.

The weather way ahead

After the little “lowboy” goes by next weekend (producing some great, badly needed rains in NM and TX), the Arizona oven is turned on.  Look for a string of 100+ days beginning in about a week.

Coming to weather theaters next fall and winter, “The Ninja (?) Nino.”  Looks warmer and warmer down there in those key “Classic” and “The New Nino” equatorial ocean zones off South America to Hawaii.  CPC’s (Climate Prediction Center) is getting pretty worked up about it, too.   Check it out below and here:

Sea surface temperature anomalies from NOAA, valid for May 19, 2014. OK, here we go!
Sea surface temperature anomalies from NOAA, valid for May 19, 2014. OK, here we go!CPC

 

 

 

 

 

 

 

 

 

 

Of course, as we know here, the effect on the summer rainfall season is not really well documented.  But things can wetten up in late summer and fall due to tropical storms that drift farther north toward us, remaining a bit stronger because the ocean temperatures that maintain them are a bit warmer.  This enhances the chance of a wet spell or two then.  Mainly, with a good Nino,  the chances of a wet winter go up a lot, particular the mid and later parts.

In the meantime, let us dream about September and October 1983, as the Great El Nino of 1982-83 was fading, but still was associated with colossal rains in Arizona those two months.  In case you forgot, this recap about those days and TS Octave.  During that water year of that Great Nino, October 1982 through the first couple of days of October 1983, just a year and a couple of days, Catalina recorded a Seattle-like 32 inches of rain!

The End

Everyone knows its windy

Well, its not windy1 yet, but it will be, and everyone knows it.  The infamous “Tonopah Low”,  as the ancient weathermen called it, is now in formation over Tonopah, Nevada,  as a big bad trough roars into California, over the Sierras, and into the Great Basin today and tomorrow.  We should have noticeable winds by mid-day, a dramatic accompaniment to some pretty Cirrus clouds, ones that will be chugging along up there at 100 mph or so.  The U of AZ mod also suggests a few mid-level clouds, ones likely to be brief Cirrocumulus patches (those clouds having tiny granulations that make them look higher than they really are) or Ac lenticulars NE of Ms. Lemmon;  also off to the north of Catalina, as the moistness aloft increases later in the day.  Cirrus likely to devolve into thicker Altostratus.  Watch for a great sunset today, since holes far to the west of us in these higher clouds are possible that would allow the fading sun to light up the bottoms of the high and middle clouds after it sets.  Hope so, anyway.

I am really happy for you today since this will be the really first interesting cloud day in awhile.  You might consider leaving work around lunchtime so you don’t miss anything, like some iridescence around the Cc.

Of course, the late April cold air blast, mentioned here so long ago in a blog that I might get a forecasting award of some kind2, will hit tomorrow as the cold front (sudden drop in temperature, barometer rises instantly, and wind shifts) hits later tomorrow morning.  Have jacket ready.

Looks like this cold front, with the jet stream sagging over us or slightly to the south, will be enough for a little rain now, a tenth of an inch likely the most that can fall.  Still, it will be something to break up the monotonous string of zero precip days.

Now I will look at the AZ mod precip output and see if there is any credibility to that rain amount mentioned just above.  (Oh, fer Pete’s Sake, accum precip run ends at 1 AM today here a few minutes before 5 AM AST.)

Well, the WRF GOOFUS model run,  based on global data taken at 5 PM AST yesterday, did have some rain here tomorrow morning.   Rain for Catalina and environs has been coming and going in various outputs for days on end.

The Cirrus will be gone tomorrow, but with lots on interesting lower clouds, some having  ice in them, will produce nice picaresque views of the Catalinas as clouds and shadows of clouds roll across them after the front goes by and the clearing takes place.

The Weather WAY ahead:

Very “troughulent”, in a word.

A lower latitude trough will be affecting this area not too long after this current big boy passes starting a few days into May.  With those lower latitude troughs usually comes just high and middle clouds with their spectacular sunrises and sunsets, and their presence keeps the temperature from spiking to astrological levels due to those clouds, but also because the air aloft is a little cooler in a trough than when an upper level high pressure area (a region of deep warm air) is squatting on top of us.  So, really ovenly weather will be MOSTLY held at bay as we roll into May.  Yay.

Once in a while, one of those persistent troughs, too, can scoop up some real moisture from the tropics and bring some rain here, so there’s even a chance of May rain as this situations develops.  This troughy situation begins to develop about 8 days out now, around May 4th, but persists beyond the 10th.

Check out the spaghetti for the morning of May 10th to see what I am talkin’ about:

See arrow that points to the general area in which you live.  Note, too, where all the red lines are, big gap over the West until the blueish lines, indicating a pretty darn reliable forecast even this far out.
See arrow that points to the general area in which you live. Note, too, where all the red lines are, big gap over the West until the blueish lines, indicating a pretty darn reliable forecast even this far out.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The End

————

1TItle is a pathetic reference to a popular but crappy IMO song from the 60s.

2Actually, I didn’t think it up by myself, that forecast of cold air late in April, but relied on the NOAA spaghetti factory to give me a heads up, so that if I was to get an award, I would have to acknowledge and thank the NOAA folks who produce spaghetti for their work in supporting my efforts, and I couldn’t have done it without them.

A recent sunset shot, and not much more if anybody’s out there

APril 12th, 6:57 PM.  In case you missed it or forgot about it already.
April 12th, 6:57 PM. In case you missed it or forgot about it already.

Still looking like a couple of pokes of cool air in the last ten days of April, no rain indicated with them, just wind.

Some sprinkles maybe on Friday or Saturday from mid-level clouds like Altostratus or large clumps of Altocumulus with virga, some of the latter likely large enough to transition in name from Altocumulus (castellanus) to Cumulonimbus clouds.  As with the last sprinkle a few days ago, any rain will be from clouds whose bottoms are well above Ms. Mt. Lemmon.

A great sunrise/sunset or two is almost guaranteed on Friday and or Saturday. This cloud action due to a weak wave/trough in the subtropics that creeps toward Arizona in the next few days. You can see it now in the sat imagery from the Washington Huskies Weather Department here. Its that little thing spinning around in this loop east of Hawaii with a big plume of high and middle clouds streaming NE from the Equator toward the West Coast to the east of the upper low.  Expecting nothing more than passing Cirrus before Friday.

The End.

Cirrocumulus on display; icy Cumulus later today

6:05 AM.  Pretty ripples in Cirrocumulus below some Cirrus.
6:05 AM. Pretty ripples in Cirrocumulus below some Cirrus.  What a fantastic and subtle scene this herring bone pattern was!
DSC_0008
9:34 AM. Pretty much a whole Cirrocumulus morning, punctuated by a few Cirrus clouds. Why isn’t it Altocumulus? Granulation is too tiny; no shading. BTW, no ice evident though this layer was colder than -20 C (-4 F).
DSC_0013
10:30 AM. An aircraft has punched this very thin Cirrocumulus layer and left a tell-tale ice trail that looks like natural Cirrus. Same cause for that second, white ice patch farther to the west. Its almost impossible to detect something like this since the ice trail from the aircraft is almost exactly in the form of a Cirrus uncinus.  The absence of natural Cirrus is a clue about what happened.
10:34 AM.  Aircraft-induced Cirrus is passing overhead, and if you look VERY closely you can see the tiny "supercooled" cloudlets of Cirrocumulus are still there around it.  The ice crystals fell below the Cc layer and disappeared over the next 15 minutes.
10:34 AM. The aircraft-induced Cirrus is passing overhead, and if you look VERY closely you can see that tiny “supercooled” cloudlets of Cirrocumulus are still there around it. The ice crystals fell below the Cc layer and disappeared over the next 15 minutes.
DSC_0025
2:27 PM. Later that day….widespread natural Cirrus overspread the sky, with a very thin patch of Altocumulus on the right (granulation is a bit to large for Cc).
DSC_0029
3:44 PM. Those Cirrus clouds thickened and lowered some, trending (as we would say today) toward Altostratus (translucidus–the thin version).

Today’s clouds

Today our passing cold-core trough is overhead and in the middle of it, the moisture is low enough to trigger Cumulus and small Cumulonimbus clouds as the middle and high clouds exit “stage right.”  Should be an interesting day since these cumuliform clouds will be so high-based (above the Lemmon summit) and cold that  lots of ice will form, producing virga, and in some places, sprinkles.  A hundredth or two is possible, but that’s about it.  Heck, I guess there could be some lightning here in southern Arizona as well.

This will be the last interesting cloud day for awhile, as you likely know.

Below, your weather map for 5 PM AST when there should be plenty of ice action all around:

Valid at 5 PM AST today.
Valid at 5 PM AST today.  This from NOAA and the GFS-WRF model run from 5 PM AST yesterday.

BTW, our trough, as it passes to the east, will trigger yet another strong storm with a massive cold air outbreak behind it in the eastern US.

Our next interesting cloud days will be on the 11th and 12th as another trough passes overhead. Slight chance of rain again.

The End.

Upper low to pass over us later today and tomorrow with pretty clouds and that’s about all

You can see it highlighted in red on forecast maps here from the Huskies, the Washington ones.  Have cameras ready for various forms of Cirrus and Altocumulus clouds, the latter later.

U of AZ Wildcats local model thinking just pretty Cumulus tomorrow as central region of low up there passes overhead.  Some with virga, maybe reaching small Cumulonimbus size, with some wisps of precip on top of Ms. Lemmon;  a little measurable rain is even foretold for east central  and northeast Arizona tomorrow!  Nice.

In the meantime, a nice poppy photo for your enjoyment from a hike just a coupla days ago .

Logged on a hike on March 22nd.  Its not a poppy.  Is anybody out there?
Logged on March 22nd1. Someone’s inside it.

 

 

 

 

 

 

 

 

 

 

 

 

The End.

 

__________________

1Its not a “poppy”, for Pete’s Sake, but rather a Calochortus leichtlinii.  Wanted to see if you were paying attention and know ANYTHING at all about the fabulous wildflowers we have here.  A quote from the Flower Essence Society about this flower:  “The nurturing qualities of Mariposa Lily draw the soul (and apparently, the worm in the photo above) into a deep interior space like the chalice of the flower itself.”

Rain shows up here in a model run!

Looky here, valid in only about 9 days, that is, just off the forecast confidence horizon, predicted rain for SE AZ!  Valid for April Fool’s Day, at 5 PM AST.  We hope its not another model cruel joke, since time is running out on the chances of cool season (Oct-Apr)  rains.

Ann gfs_namer_240_1000_500_thick

SInce I know you love spaghetti, here’s some for about that same time, the evening before the map above, and it has a strong indication of a strong trough moving into the SW from the Pacific.  Count on it.  At the least, it will get real windy when this happens, count on it, and with a little more luck, there will be enough amplitude in the jet stream, that rain WILL occur.

Valid at 5 PM, the day before the predicted map, that is, 5 PM on March 31st.
Valid at 5 PM, the day before the predicted map, that is, 5 PM on March 31st.

The last batch of spaghetti was disappointing, that shown here about two weeks ago. Sure, there’s been  a “trough bowl” in the SW as was predicted way back then; that’s what was producing the pretty clouds we’ve been seeing, the passages of weak troughs aloft over us, ones that have been also keeping the temperatures reasonable.

But, that predicted “trough bowl” so far back did not have the amplitude necessary to bring rain as was thought could happen back then.  “Trough bowl” turned out to be more of a “plate”, than a “bowl.”

Here’s what I mean, below, from the first panel of spaghetti from last evening:  see the little dent toward the south in the contour lines passing over Arizona? That represents a trough where clouds like to form, such as yesterday’s Cirrus clouds..

spag_f000_nhbg
Map for last night as model runs begin.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

But we need the big polar jet stream over us to get rain in the cool season, not a wispy jet up at Cirrus levels as we have been having. You may have noticed how fast the Cirrus clouds were jetting along up there. Well, for the past couple of days, they were zooming along at over a hundred miles an hour.

What we need are deep, cold troughs where the red height contours (5700 meters in the above map) are way south of us.   Here’s why rain is predicted in the first map, as an example.  Below is the configuration of the jet stream for that day that rain is predicted, showing that the 5700 meter contour and the core of the jet stream is over central Baja California.  Now THAT is a rain map for AZ!

Ann 2014032300_CON_GFS_500_HGT_WINDS_240
Valid at 5 PM AST on April 1st from an IPS MeteoStar rendering of the NOAA NWS model. Note to mod: don’t pull another cruel hoax on us.

 Yesterday’s clouds

Let us begin by breaking up the weather talk monotony with a photo of a bee evaluating a thistle1, this from a hike yesterday to some weather petros2, to resume the weather talk.

10:31 AM.
10:31 AM.  “Sentient Bee-ing and Thistle”  $1800.  (See link to Sci Am article below if you don’t think bees think about stuff.)
DSC_0179
8:46 AM. Crossing strands in CIrrus fibratus. Indicates that they have formed at different heights in layers of air with vastly different wind shear (change of direction with height). Rarely do you see this because at Cirrus levels (here around 30-35 kft above ground level, the wind direction usually does not change much.  The strands running from left to right across the photo is the higher Cirrus cloud.

 

9:14 AM.  Several species of CIrrus here; fibratus, uncinus, and spissatus (lower right).
9:14 AM. Several species of CIrrus here; fibratus, uncinus, and spissatus (lower right).

 

9:35 AM.  After the delicate Cirrus forms passed, lower blobs of dense Cirrus spissatus followed.
9:35 AM. After the delicate Cirrus forms passed, lower blobs of dense Cirrus spissatus with some castellanus *turreted” versions) followed.

 

9:45 AM.  Cirrus fibratus radiatus--last of the delicate Cirrus clouds left a memorable scene.  However, the look of radiating fibers may be due to perpspective, not sure.
9:45 AM. Cirrus fibratus radiatus–last of the delicate Cirrus clouds left a memorable scene as they disappeared past the Catalina Mountains. However, the look of radiating fibers may be due to perpspective, not sure.

 

11:32 AM.  Strands of Cirrus fibratus mimic the branches of a mesquite tree, both seemingly reaching out.  A blob of the rarely seen Cirrus castellanus is on the horizon, lower left.
11:32 AM. Strands of Cirrus fibratus mimic the branches of a mesquite tree, both seemingly reaching out. A blob of the rarely seen Cirrus castellanus is on the horizon, lower left.

The cloud day pretty much ended with a brief appearance of Cirrocumulus overhead, enhanced by iridescence:

12:07 PM.  CIrrocumulus and iridescence.
12:07 PM. CIrrocumulus and iridescence.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The End.

 

 

 

 

 

 

 

 

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1Apparently bees think a lot more about stuff than we think.

2Below, an early weather forecasting icon petroglyph indicating that the forecaster was anticipating a sunny day except for some Cirrostratus clouds, ones expected to produce a halo.  Pretty sophisticated I thought.

10:17 AM.  One of several weather forecasting petroglyph icons.
10:17 AM. One of several weather forecasting petroglyph icons.