Category Archives: The weather WAY ahead (10 days or more)

Trace of rain ruffles drought in Catalina! New storm approaches in five days or so followed by a several day dry, warm period followed by more storm threats a few days after that; January beginning to look wetter than December though it wouldn’t take that much rain to exceed Deember’s meager total of just 0.27 inches

Yep, unless you were outside yesterday morning, you probably missed the few drops that fell.   But fall they did, giving us officially a trace of rain for January!  In case you don’t believe me, here is a shot of the incoming shafts of rain.  OK, “veils” of rain.

8:22 AM. Rain reaches the ground from thick Altostratus/Altocumulus clouds.

Now, a historical forecasting criteria note after that paragraphical blog title, a criterion that still holds true:

In the 1950s and 1960s, the Los Angeles forecast office used the 564 decameter height on  500 mb weather maps (those made for about 18,000 feet above sea level)  to delineate where the rain line was for incoming troughs.  North of that, rain fell; south, no rain.
It was remarkable how well that worked.
Don’t know it that height criteria holds here in AZ, probably not, but the 500 wind max seems to be a good discriminator for TUS for rain; under or north of that max seems to be a necessary (though not sufficient) criteria in wintertime.  (That wind max does not hold in Cal; rain often falls south of the 500 jet max; only east of the Sierras and coastal ranges does it hold.)
Lately, as winter gets colder,  the NOAA spaghetti factory has recently lowered the red line heights to 564 dm in their 500 mb spaghetti plots, you can see that in 5 days from last night’s 00Z run, rain is virtually assured in southern Cal using that criterion, and we hope that rain gets here, too.
Check out where red lines are in the plot below.  I’ve helped you to find red lines on this plot by annotating them with an arrow:
Valid at 5 PM AST. See red lines. See red lines move east from California.
But after that trough whooshes by like a Nike logo, in ten days (2nd plot), we’re doomed again to be in the midst of a long warm, dry spell:
Valid on January 14th, at 5 PM AST.

But what about after that next warm, dry spell?  The weather way ahead

 In a less professional comment than the usual ones posted here, reaching beyond the 10 day forecast limit, that domain of the models where things that are forecast beyond ten days often go to hell with just the next model run, these spaghetti plots foretell a collapse of that big fat, storm blockin’ ridge after our next warm, dry spell!  It collapses into a muddle down, oh, I dunno, way down in subtropics somewhere.  Yay!  I can feel your happiness as I write this for you!
That ridge collapse means, first of all, that strong storms will blast Cal with needed flooding (well, big rains, anyway), and its likely that those Cal blastin’ storms will reach into all of Arizona providing a much needed hiatus in our drought, that is, will bring appreciable rains right here into Catalina as well.  You can see if I have made this up by looking at the whole sequence here, keeping an eye on where those red lines are foretold to be.
So, that’s it, that’s my take on the longer term weather pattern:
A Change Gonna Come,” as so eloquently sung by the master, Sam Cooke, when that 500 mb criterion was being used in LA, and apropos here because a change is gonna come, not that long from now.    (Warning:  The historical video scenes with Sam’s heartfelt tune will bring tears I just learned…  Everyone should see it.  Yep, we’ve been through a lot since he sang that song….)
Will keep you up to date every so often if it looks like my take, cribbed from the spaghetti plots is going to be correct in that  drought bustin’ part I’ve described beyond ten days. In the event this “take” goes bad,  it will, of course,  not mentioned again.  May have to fall back on writing about aircraft ice production in supercooled clouds to distract you.
The End

Less data; but more filling

A “storm”, one with “rain,” has at last shown up in the numerical prognostics for late on Thanksgiving Weekend.  It appears for the first time on last night’s 11 PM AST model run.  At that time (11 PM AST) we have less global data to work with when the model crunches out its forecast, and so it is generally thought to be less reliable.  But, it has a storm for us….

But, a storm here helps fill dreams of a green desert washed of dust, and stimulates the thought of wildflower seeds springing to life for the spring to come.  So, to HECK with opinions on a 11 PM run having less skill!  Let us dream of rain and poppies!  Here it is below, from IPS Meteostar:

Valid on Saturday, November 25th, at 11 PM AST. As shown, rain would be imminent or underway with this upper level configuration. If it verified, might produce half an inch or so in Catalinaland.  That next trough would tend to follow in its path for a second rain a few days later.  This is so far out from now, we often call these kinds of depictions, “mythical.”  Take under advisement.  Also, this kind of depiction of a deep trough marching across old AZy wasn’t there on the prior run at 5 PM AST.  Going on a  hunch is all , that something will come through then.
From the NOAA spaghetti factory: Not a lot of support, either. Those blue lines (contours of the flow) should be bunched down in the SW if the forecast above, so far out in time, is going to have any reliability at all. It really doesn’t. Going on a hunch based on wishful thinking, like thinking Washington (former company team) was going to defeat Stanford last night….   🙁


Pretty Cirrus lately, often at multiple levels, as here:

12:13 PM yesterday. What’s a cloud-maven site without a cloud, at least one shot?  Can you tell that there are Cirrus clouds at different levels?  Notice crossing patterns, one clue.

The End

Goodbye summer storms; new book out about clouds!

First, I will shamelessly plug a book on clouds, “A Sideways Look at Clouds”,  by a well-published and acclaimed author friend, Maria Mudd Ruth.   Its about her odyssey into them,  mentally and physically,  after she realized they were something she really had not paid much attention to before mid-life,  then she had to know EVERYTHING about them!  Its a great read, infused here and there with humorous anecdotes.

You can sample the contents here.


Now, on to Catalina’s  clouds and weather…

6:43 PM yesterday.
6:43 PM yesterday.  If you look hard you can see there wasn’t much of a rain shaft with these guys.  Bases were too high, updrafts pretty weak, so not a lot of water “topside” to come out.

Not that there have been that many rainstorms since the end of July.

But it would seem that today marks the meteorological end of the summer rain season as dry westerly winds sweep our remaining tropical air to the east today.  The mods think there is a chance for a couple of high-based thunderstorms in the area around Catalina late in the day.  But bases will be so high that not a lot of rain will reach the ground even if one passes right over us.  And, they’ll be moving in from the SW or W today due to encroaching westerlies.

In a little over a week, too, you’ll be hearing about early snow in the Rockies and West!  We’ll have a day or two of those gusty, dry southwest winds that accompany our winter storms as well.  You’ll get a real feel for the season change then.

Check out this plot from the NOAA spaghetti factory showing (blue lines) that an unusually strong upper trough will absolutely dominate the West in just over a week

Valid on Thursday, September 21st at 5 PM AST. As this develops it draws a tropical storm northeastward out of the Mexican Pacific into New Mexico. Lucky for them!
1:48 PM, September 11. Nice to see those blue skies again after so many smoky days! Here Cumulus humilis, Cumulus fractus (shred clouds) dot the sky.
4:56 PM, September 11. The remaining smoke is still enough to produce crepuscular rays below Stratocumulus and Cumulus (blob on the right).
6:30 PM. Orangey sunset speaks to remaining smoke. The clouds are a Stratocumulus with Cu underneath on the right.
4:46 PM yesterday. The drama of lighting and shadows is about the only drama we might see now for a LONG time! Still these kinds of scenes are so wonderful; never get tired of them, which is strange.
4:57 PM. Even yesterday, amid all the blue, you could still see a lofted layer of haze, typically thickest near cloud base and within cloud layers where the relative humidity is highest and some of the haze particles have “deliquesced”, adsorbed water, fatten up and scatter the light more effectively helping to produce that hazy look in toward the sun (called, “forward scattering.”)  Can you see the slender icy top protruding down there in Mexico.  We’ll go zooming next so you can see it.  Good for you if you entered it in your cloud diary!
4:57 PM. Zoomed view of that little protrusion of ice. Only a few drops would come out something like that as it developed. Here its pretty much in its dead phase, likely no base under this ice cloud. The horse icon wind vane is that of a trotter racing horse. Mom was a horse trainer and this is hers!  In case you don’t believe me again, see below:
Mom in 1957 or so.
Mom in 1957 or so.  She passed a year ago in July.
4:58 PM yesterday. More shadow drama.  Expect more of this later today.


The End


May to have measurable rain in Catalina and environs!

This is great news, heard here first of course (haha),  after a pitiful April with no measurable rain.  Poor desert.

Its been suggested by the NOAA spaghetti factory for some time, but now actual precipitation is showing up in the models pretty regularly for around May 8th and thereafter, and so we can gleefully start dusting off our umbrellas, seeing if we have enough change for the car wash afterwards, etc.

Even WU (Weather Underground) is starting to catch up, showing about a 3% (THREE percent!) chance of rain at that time from last night’s model output.   Its “waymore better” (a nice name for someone) than that, I think, though its not 100% yet.   That percentage should be climbing as the days get closer.

WU chances of rain for Catalina, as posted early this morning. Watch it rise, I hope....
WU chances of rain for Catalina, as posted early this morning. Watch it rise, I hope….


BTW, Have never seen such a pronounced “retrogression” as that shown today  over such a vast region of the globe in those spaghetti plots, and that’s why I’ve taken to the air today.

The good news for AZ-ians is that we get placed in a trough in the lower latitudes, albeit a weak one;  a dip in “jetty jet stream” to the south over us  (meaning cooler temperatures than average aloft should prevail) with some enhanced chances for rain after our main chances coming right up on the 8th and beyond for a couple of days.

As you know already, ovenly weather for this time of year,  with temperatures far above average,  is just ahead,  which takes a big, fat high pressure dome aloft over us.  That high will dissipate as “troughy” conditions begin to shape up toward the weekend.

So, venturing farther,  it would seem a reasonable temperature first half of May is ahead, with RAIN,  after the “meltdown” later this week.

Time for a random thought before closing:

A cactus can be a beautiful thing, can’t it?DSC_3390The End

Best chance for April showers in Catalina around the 20th

Cooling off now after the Big Review of NAS 2003…and finally getting back to the lighthearted, carefree, playful, well, silly,  mode normally found here (he sez).

As a brief follow up, I have yet to receive a “thank you very much for your absurdly late review of our tome on cloud seeding; had you submitted it in a timely manner, perhaps one thing you wrote MIGHT have been considered” note from the National Academy of Sciences for all the work I put in on it.   Must be pretty busy back there.

Also, if it didn’t go out “like a lion”,  as foretold here weeks ago utilizing weather lore,  March at least went out as something of a “bobcat” with the severe winds, series of cold fronts, we Catalinans experienced, along with several traces of rain.  “In like a lamb, out like a bobcat.”

The weather way ahead

Spaghetti lovers will INSTANTLY recognize from those maps, of which ONE is shown  for April 20th, that other than wind and “fluctuating temperatures” as dry cold fronts pass by, that there’s no chance of rain until the 20th.  Check it out if you don’t believe me again:

Valid at 5 PM April 20th. Need one say more? Probably.
Valid at 5 PM April 20th. Need one say more? Probably.  Note extreme dip in reddish lines, indicating a high probability of a big trough in the SW US at this time, if you can find the SW US.


The End (at least for now)

“Peru’s Niño”

I thought you’d like to read this (Peru’s Niño), forwarded to me by Niño expert, Nate M.   Pretty incredible to read about what is happening down there in the wake of the Big Niño of 2015-16,  which really turned out to be more of a couch potato in terms of weather production in the Great SW.

But, all this winter,  along the Equator near the coast of South America, there has been something we used to call an “El Niño”,  but is downplayed or ignored these days because of a new definition that seemed to explain more weather when it occurred, “Region 3.4” a large zone along the Equator WAY out in the Pacific rather than something near the South American coast (that zone now called, “Regions 1 and 2”),  as nicely illustrated by NOAA here.

But what has been the effect of what we might call the “Classic Niño”, a warm strip of water along the South American coast, one that doesn’t extend too far into the Pacific?  “Read all about it”, as they used to say.   Its pretty remarkable.

And here’s what the SST field looks like.  Its boiling down there off South America!  (Speaking figuratively, of course):

Sea surface temperature anomalies as of yesterday from the Navy!
Sea surface temperature anomalies as of yesterday from the Navy!  Wow.  That hot water is fueling giang Cumulonimbus clouds, ones that spew out huge anvils that can affect the weather in the mid-latitudes, disrupt the normal winter patterns of where highs and lows like to go.  Could such a warm anomaly, limited to the near coastal region of South America, have created this astounding winter in the West?

Peru’s Niño can be thought of as a “classic Niño”, the ones written about in the decades before about 1990 or so when the definition of what constituted a  NIño (or Niña) was expanded and delineated more sharply among several definitions that were floating around. We ended up focusing on a region WAY out in the Pacific Ocean called, “Region 3.4” that SEEMED to explain more over the prior years.

What’s so interesting about this is that the “Classic Niño” has been underway pretty much all this winter, and we’ve had, especially in California, a classic Niño response; that is,  abnormally heavy precip farther down the West Coast that no one anticipated.


Well, the correlations with Cal precip and “classic Niño” occurrences will take a huge jump upward after THIS winter!

End of Statement (hand-waving)  on Niñoes.


Local weather statement:  for immediate release

Cooler, fluctuating weather foretold here for that latter part of March, I don’t know how many weeks ago, is on the doorstep after the long, anomalously hot dry spell.  Poor wildflowers have been suffering, too, fading, looking a little stunted after a great beginning, one rivaling the great displays of 2010.

All of the local weatherfolk are on top of this now, and so no point recasting that stuff.  HECK, you can go to Weather Underground1
and get as “good as can be” forecast for Catalina (Sutherland Heights) out to ten days!  And, there’s nothing worse for a weather forecaster with forecasting in his blood, than to be excited about an “incoming” and when you mention it to a neighbor he replies, “Yeah, I heard about that already.  Supposed to get a quarter of an inch.”  There is no air whatsoever in the “balloon” after that.  So, if you have a weather-centric friend who says something about the upcoming weather, pretend that you haven’t heard about it yet, “DON’T say something as hurtful, as “Yeah, I heard about that already.”

So, here, we go the long route because most weatherfolk are afraid to go too far into the future because its often WRONG.  Our models tend to lie a lot after about even a week, so only the brave go out even ten days!

However, here, we go out as much as two weeks and more because its not a truly professional site but rather want to get something out there earlier than other people, sometimes called a “scoop” in the news and weather business.  That’s why our motto here is, “Right or wrong, you heard it here first!”  Furthermore, if a longer range forecast posted here is WRONG, you won’t hear about it anymore!

Cloud maven person will say this about the first incoming of several fronts:  comes in early Thursday morning, its strong!    Rainfall potential:  10% chance of less than 0.12 inches, 10% chance of more than 0.75 inches.  Best of those is the average, or about 0.4350 inches in this one.  It has great POTENTIAL to be a soaker, but mods have been all over the place; hence, the large range of potential amounts.  At least some measurable rain seems to be in the bag, a paper one please, because plastic is insidious.  Note, CMP’s forecast is more generous than that found in WU’s latest forecast for Catalinaland.

The weather WAY ahead, unprofessionally so

Let us look beyond the professional forecasting limits to April:

We know we got several storms/fronts zipping across AZ as March goes out like a lion, but what about April?

Looks like that pattern will continue into April with temperatures below normal for the first part.  The end of the unprofessional forecasting portion of this blog, though we do have our NOAA spaghetti to hang our umbrella on….  Check it out for about two weeks ahead.

Some clouds recent clouds, including a couple from yesterday

2:33 PM.  Yesterday afternoon saw a few globs of lenticular forming on top of mini_Cumulus clouds, ones that made you think the summer rain season could be at hand, given the 90+ heat of yesterday around these parts.
12:52 PM.
12:52 PM.  A high  (above 30 kft above the ground) and cold (less than -40°C patch of Cirrocumulus cloud that is going to transition to CIrrus over the next 10-20 minutes.
1:12 PM:  Later that same patch as those cloudlets spread out and merge into just an ordinary Cirrus after being that delicate-looking patch of Cirrocumulus. Most Cirrocumulus clouds are not this cold, but rather evaporate or fatten into larger elements of “Altocumulus” clouds, rather than transition to Cirrus.
Had a nice sunset a couple days ago (15th), some liquid Altocumulus cloud slivers with higher Cirrus.

The End

1Although “Weather Underground” might sound like an org has a radical origin, maybe something left over from the late 1960s, this particular one was NOT formed by 60s “weatherman” terrorists like Bill Ayers and Bernadine Dohrn (the link is for those of you who may have set trash cans on fire, as happened at San Jose State to protest the Vietnam War, to look back at those days in horror or nostalgia; take your pick) , but rather by genuine weather geeks (haha, I count myself among them, those that can’t get enough of weather, there can never be too much, like the guys mentioned in this “Cloud City” article.)

March 2017: In like a lamb, out like a lion? Yep.

The title represents one of the great forecasting lores of our time, developed over centuries, really, that will once again verify.   BTW, this particular lore has a “skill score” up around 0.9011.   Its unbelievable,  really.  If March “roars in like a lion” count on the opposite at the end of the month.  Many of you will harken back to March ’83….as an opposite example if what’s a ahead for us this time around.

So, since March 2017 started out tranquil (docile, like a lamb) and a little too warm, “out like a lion” means not just cooler, but even cold, windy, turbulent, unsettled days,  rain here  and there in Catalina, snow in Catalina Mountains; in other words, a lot of weather fun!  And, all this happening a time or three during the last ten days of the March as the month rolls to an end.

Count on it2.

Next report:  when rain threatens here in March.  Well, maybe sooner.

The End.


1Perfect predictability would be 1.00

2The exact days of rain, wind and cold are still pretty uncertain, but they will roar in.  You can’t expect “lore” to nail down the days!

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).
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.
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.
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.

Dry, dry, hot, dry, all mixed up, then, blammo, the storms roll in again

Well, it will be pretty obvious, ludicrously so to spaghetti lovers, the sequence shown below.  It goes from “warm in the West (again);  cold in the East pattern to another undercutting flow from the Pacific, the kind we’re having right now under the “soft underbelly” of a big blocking high, except that the tropical flow from the Pac this time is a little too far to the north to give us anything.

But, it will be another floody situation for northern Cal in the coming days.   Some places, mainly north of “Frisco”,  have already picked up 4-6 inches in the first blast which hit yesterday.  Ten to 20 inches more is likely over the next week at favored locations.  Having quite the water year there, really a lot of water year.

You may recall that the current situation, alluded to in the “break on through to the other side” refrain used here about ten times,  was well predicted about two weeks in advance!  That’s what spaghetti can do for you!

OK, enough jabbering, let us move on to the current exciting examples that popped out from last night’s global data ( there are outputs after adding little errors at the start of the model run, to see how the flow is changed with them in it.  Sounds crazy, I suppose, but is considered a huge advance in forecasting, a stupendous tool, that is, to make errors in models at the beginning of the run).  Heck, they even do that in climate models that simulate 30-50 years from now, and you’d be amazed at how the tiniest fraction of a degree change the beginning makes (see Deser et al 2012).

Valid on
Valid Sunday evening, 5 PM AST, February 12th (TIme at the top is Zulu Time, as we used to say,  or CUT, Central Universal Time, which takes in a lot of territory IMO.  This is one you look at and say, “Its gonna happen.”  What?  A big blocking high pressure ridge along the West Coast in a little more than a week.  Done weather deal.  Period. The dip to the south in the blue lines over there by the Great Lakes says that cold air will be extruding into the eastern US.  So, we have a Nike swoosh in the jet stream across the whole Pacific and then it makes a sharp left turn up into Alaska, and NW Territories of Canada.  They must be jumping up and down now, seeing this.

Well, the first one’s not so exciting since we’re dry and hot for this time of the year, and its a common one that can get stuck for weeks at a time, so you REALLY hate to see models project a bulging ridge poking north along the West Coast.  It could mean a rainless February here, if it persisted.

Here’s the exciting follow up, though, pretty unexpected given the above, showing a sudden collapse of the West Coast ridge regime, and strongly suggesting that wet spell has begun in Arizona, including regions of Catalina and Saddlebrooke:

Valid at 5 PM AST, Friday, February 18th.  Given a day or so off, we would be looking at a rainy spell beginning somewhere about this time or a day or around it.   The thing that really jumps out is the clustering of the red lines (564 decameter) contour lines. ALL the way across the Pacific right into central Cal and the Great SW.  This means that the jet stream will once again break through a ridge at lower latitudes just as its doing now, but in this case, a little farther S, which should mean periods of rain for us, keeping those washes going, or restarting the flow in them if we’re lucky.

So, you’ll want to get outdoor work done before this.

Historical note of interest, added value content,  etc.

Some of you may remember that the 564 decameter contour (those red lines) at this level (500 millibars or around 18,000 feet above sea level on average) was used in the early years of forecasting before computer models (50s and early 60s) by southern California forecasters to demarcate where rain would fall in California–at and north of where that 564 decameter contour intersected the coast when upper troughs came in.    The Old Forecaster remembers, though not much else…

So those red lines barging into southern Cal after a LONG fetch from the subtropical Pacific in the plot above mean central and southern Califs better watch out for some major rains a little before we ourselves get a dousing around the 18th of Feb.

Isn’t it great what spaghetti can do, that is, constrain our future weather to fairly certain outcomes two weeks in advance!

There was a sunset yesterday, btw:

6:06 PM. Altostratus with tiny virga illuminated by a setting sun. haha Guess I didn't need to say the sun was setting
6:06 PM. Altostratus with tiny virga illuminated by a setting sun. haha Guess I didn’t need to say the sun was setting.

Upper level snow flurry passes south of Tucson!  Trying to generate some excitement here….

8:56 AM, Feb 1st.
8:56 AM, Feb 1st.

The End

Future shock

From IPS MeteoStar,  this “YIKES!”

Valid at
Valid Saturday morning, 5 AM, January 21st.  Spaghetti was indicating a big change about then, but this is ridiculous (maybe not credible).  This scenario would bring a very violent storm into southern Cal and Arizona about this time.  That white region represents wind velocities of over 100 mph at 500 millibars, around 18,000 feet above sea level, and EXTREMELY unusual occurrence for that region off San Diego, CA.  That would provide the energy for an exceptional lower level storm.

Is this the Big Niño pattern we’ve been waiting for all these years (well, one, anyway)?  Its the kind of thing we looked for last winter during the giant El Niño and there was all that publicity about how much precip the Great Southwest would likley get.  Then it was pretty much a “no show.”

Could this really be a lagged Big Niño pattern caused by a stratospheric phenomenon known as the Quasi-biennal Oscillation or “QBO”?

It was posited years ago by a researcher in a peer-reviewed journal article (not The Atlantic or Reader’s Digest) that I have been too lazy to look up, that the QBO can induce a lag in El Niño effects.


Personally, I blew it off when I read it, but now have hope that person was onto something.

Also, in Science mag recently, it said that the “QBO was positioned to produce heavy rains in Europe”, the first time I have heard that the QBO was associated with weather in the Weathersphere where all weather occurs, clouds and storms and sh… like that.  Hahaha, it is so funny to cuss right there, out of science context!

(Its not really called the “Weathersphere” but rather, the “Troposphere1“,  but thanks for reading that anyway. )  ((Too much laughter-inducing caffeine imbibed this AM…))

The Troposphere is  BELOW the stratosphere as my one blog reader might already know, but its generally thought that doings in the stratosphere don’t have much effect on the Troposphere.  Well,  unless there’s a lot of smog up there produced by a volcanic belch (like Pinatubo, which cooled the earth for a coupla years back in ’92-’93).  That’s 1992 and 1993.

Will be fun to see what REALLY happens.  And, oh, I guess things are collapsing sooner than around the 20th, too.  But will defer to Bob and the other fine professional meteorologists to let you know about that happenstance.  (There are some great photos from Yellowstone by Mike L in Bob’s last post!)

The End

1It was suggested by this keyboard pounder  in a scintillating article, oh, 50 years ago or so,  in the Spartan Daily student newspaper, San Jose State, not Michigan State,  that the “Troposphere” be renamed, “The Pollutosphere” due to all the crap we put in it and that we rename Earth, “Polluto”).  Think of what the other civilizations out there think of us as they see things flying off the planet  into outer space; “There they go, littering again….”, besides their evaluations of the increasing aerosol depth of the atmosphere.

Polluto?   Fits doesn’t it , with all we’ve messed up;  microplastics throughout the oceans, smog most everywhere, invasive plants and species wiping stuff out, burning up forests, etc.  Perhaps  renaming Earth could be seen as an honorarium of sorts for the late planet, “Pluto.”   Well, that was a depressing summary.   Need more coffee…and more thinking about storms!