No NWS sounding from the U of AZ Weather Department yesterday afternoon, so’s we can’t really tell with solid data what the temperatures of yesterday’s frosty clouds were.
However, with a max here in the Heights of Sutherland of 71°F, and with a dry adiabatic lapse rate to the bottoms of the clouds (as is always the case on sunny afternoons with Cu), if we estimate how high the bottoms were with any accuracy we can get that bottom temperature.
You already know as a well-developed cloud maven person that they were WELL below freezing which could see by noticing how far the snow virga extended below the bases of the Cumulus, at least 3,000 feet. and more from the larger clouds later on. So we have something,
Let’s say bases were at 14,000 feet above the ground over Catalinaland–they were way above Ms. Mt. Lemmon at 9,000 feet which you could probably tell. That would make the bases at about 16,000 to 17,000 feet above sea level in the free air, pretty darn high above us.
From a ground level of 3,000 feet, and with the dry adiabatic lapse rate of 5.4°F per 1000 feet, that would make the cloud bottoms a cold, cold, -2°F, or about -17° to -18°C! COLD! Then, tops, of clouds only 3,000 feet thick (about 1 km), would be -28° to -30°C (assuming a mix of the dry adiabatic rate with the “moist adiabatic” rate, given yesterday’s conditions, or about 4° per 1000 feet, “plus or minus.”
Addendum–corrections, hope nobody see’s ’em:
Later analysis and the next morning’s NWS sounding from the U of AZ suggests that bases were closer to -10°C because they were not as high as CMP estimated. Rather they were closer to 12,000 feet ASL. Tops would not be quite as cold, too, more like -25° C and colder in the deeper clouds, plenty cold enough for ice in even the small clouds, and for the long snow virga trails.
Below, some samples of Frosty the Cumulus (Cumuli, plural):
Not much ahead now. Maybe a few more frosty Cu will form today… before things dry out and heat up.
Later yesterday morning, some interesting “Altocumulocirrus”, a rare breed indeed, mocking/mimicking Altocumulus.
Maybe Cirrus floccus would come closest to the true name, but to every eye but that of a genuine cloud maven person, it would be deemed just “Altocumulus”. Check these out to see how good you were–and NO correcting your cloud diaries!!!!
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:
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:
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:
As Einstein wrote, “Things are not always as they seem.”
Q. E. D.
Now, for the snow report
…from the Lake Tahoe area (after all, we made a BIG DEAL out of the incredible NWS, Reno, forecast in the prior blogulation):
0822 AM HEAVY SNOW NORTHSTAR 39.28N 120.12W
01/11/2017 M42.0 INCH PLACER CA PUBLIC
NORTHSTAR AT TAHOE REPORTED 42 INCHES OF NEW SNOWFALL IN THE LAST 24 HOURS. 48 HOUR TOTAL OF 78 INCHES AND A 7 DAY TOTAL OF 122 INCHES1.
1This note passed along to the Arthur by Mark Albright.
Looks like a bite has been taken out of the Cal drought this water year, a drought it was said would take years to end! Folsom Lake, near “Sacramenta”, Cal, has risen 30 feet in the past 30 days! Oh, my.
Now for some more of them cloud pictures…
Been holding out as other chores fill up the day:
The weather just ahead
U of AZ latest mod output (from 11 PM AST last night) has a substantial rain on the doorstep. Starts here in Catalina Saturday afternoon with projected totals over half an inch nu mid-day Sunday. Check it out:
HECK, this storm wasn’t even predicted 10=12 days ago! The major weather change was indicated about the 20th, plus or minus a day. Those storms, indicated in the NOAA “spaghetti” plots more than 12 days ago, are still in the pipeline after we have a brief “recovery” from the “surprise” storm about to arrive on Saturday! Yay.
This sequence of storms is so great for the AZ water situation, too, as well as giving it to Cal good again around the 20th as well. No doubt, as the humans we are, the peoples of Cal will be complaining about TOO MUCH WATER!
This will lead to apathy about water issues, you can bet on it! See the well-known “cloud seeding cartoon” about drought and apathy posted so many decades ago in a journal article on cloud seeding by editorial nemesis1, Bernard A. Silverman, J. Appl. Meteor., termed the “Hydro-illogic Cycle”:
——————————- 1Nothing yours truly submitted during the era of BAS as Editor of the J. Appl. Meteor. “got in”, including the benchmark paper reporting that our own aircraft was creating ice in clouds at temperatures as high as -8° C. Three sole-authored papers critical of cloud seeding that I submitted were rejected in 1983 alone! All or parts of them were published years later.
The paper on our aircraft, submitted originally in 1981, was rejected twice before being accepted and published in 1983. The effect was confirmed in experiments conducted in the Mono Lakes area in 1991, by the president of Atmospherics, Inc. mentioned above! Aircraft produced ice particles at unexpectedly high temperatures is a now well-known phenomenon that researchers have to be aware of when re-sampling the same cloud with an aircraft at below freezing temperatures.
Soap box: It really is the editor of journals that determines whether you’re going to get in or not. They know, or should know, those who are going to keep you out or not, those with axes to grind, and those who are more objective. However, let me say this, I like Bernie. Has a great sense of humor. Below, Bernard A. Silverman. You can see the twinkle in his eye:
Oh, well. Was expecting at least 0.25 inches a few days ago, and thought maybe a heavy shower last night might pull that expectation out of the trash bucket. Monthly total now up to 0.70 inches (updated after reading NWS-style and CoCo gauges here), still significantly below average (0.96 inches). Not much else elsewhere, either. Double dang.
Mostly Cumulus humilis and flat Stratocumulus yesterday. Was looking for ice as the temperatures aloft cooled during the afternoon and evening, and only as the sun went down was a slight bit of virga visible to the west. That Stratocu deck over us was deepening upward, and began reaching the magic point where ice begins to form, probably around or a little below -10° C (14 °F) in clouds such as yesterday’s. Let’s look at a sounding from the U of AZ (as displayed by IPS MeteoStar) and see what it says about those evening clouds and see if the above is just a bunch of hooey (I haven’t seen it yet, either):
Still looks like a chance for some light showers before the month closes out, but will be hard to get enough to bring the total to an above average value. Dang.
Will update my reader on December’s early cold outlook as new information that agrees with my assessment comes in. Right now, that information is not available.
Here it is. You may need an optical enhancement tool to see the radar echo speck nearest Catalina, and its not the one nearest the arrowhead below, but continue in that direction:
You can also check on all the rain that fell overnight in the region here, courtesy of Pima County ALERT rain gauges. BTW, they aren’t capable of reporting traces, so if you see bunches of zeroes, it doesn’t mean some drops didn’t fall somewhere in the network.
Non-verification of this rain can also be found via our fine TUS NWS “storm total” view, 10:30 PM to 4:30 AM this morning:
In the meantime, all those rainy cloud blobs to our NW right now (first image) look like they will be able to just make it to Catalinaland after all.
In our last chapter, it looked like the strong cold front would move through tomorrow as just a dry cold one, but now the chances of having a little rain (a wet cold one) have been zooming up. The models have readjusted their thinking and now that critical ingredient, the core of the jet stream (at 500 mb) passing over us ahead of the trough core itself is being predicted.
And with that configuration as the front goes by Catalina, and believe me you’ll know by the 10-15 degree temperature drop, a tiny amount of rain might fall. Also, look for a pronounced lowering of cloud bases to the W-N of Catalina as it gets close, something in the way of an “arcus cloud”, marking the leading edge of the windshift to the N. Could be nice and dramatic looking tomorrow. Those cloud base lowerings are pretty common with fronts here.
How much rain?
Oh, possibilities range between 0 (a complete bust is still possible) to only about 0.25 inches, tops in the “best” of circumstances. But, this keyboard would like to see ANYTHING measurable; that would bring happiness.
There are some more rain blobs showing up in regular intervals in the days ahead for you to think about, as rendered by IPS MeteoStar. Arrows have been added to show you where you are, if you are in SE Arizona:
In the storm below, which is pretty much going to happen now, the range of amounts as seen from here, at least 0.15 inches, top, 0.50 inches, best guess, therefore, 0.33 inches (from averaging the two.)
There’s great uncertainly in whether this last storm will actually occur, so range of amounts are zero to 1 inch. :} See reasons for uncertainty below, besides being too far in advance or our models to be reliable anyway.
While a significant storm on the 1st is virtually assured according to spaghetti, this last major event in the panel above is doubtful. See below, in another lesson on consuming weather spaghetti:
Yesterday’s fine clouds
The End, though I COULD go on and on and on, and then on some more. Its who I am….
The low that plunks down off the coast of Baja this weekend from southern California, circles around out there for a couple of days, before deciding to move back over southern California with clouds and rain. If it was a song, it would be The Wanderer. Yes, that fits. Its expected to scoop up a generous helping of middle and high clouds from the deep tropics as extra baggage. The “extra baggage” (model predicted rain) arrives here late on the 26th (Monday) and continues off and on through Tuesday night. The first clouds, of course, high ones like Cirrus, will begin arriving a day ahead of the actual rain, on Sunday.
It is virtually certain that there will be some high-based Cumulonimbus clouds and thunderstorms in these masses from the tropics, though maybe not here. Most of the rain is projected for eastern California and western Arizona where rain is really needed–and how great is that?
However, we should be in for a quarter inch or so, anyway. Last time I guessed limits on a storm, even the lower limit of 10% chance of less than 0.05 inches wasn’t even realized. Pretty pathetic forecast. But, moving forward and forgetting past errors, this one seems to have a similar range of possibilities, the least amount 0.05 inches, the most, 0.50 inches. The chance of measurable rain here in Catalina in this first 36 h storm period is probably, from this typewriter, about 80%.
“But wait! There’s more!” “Maybe!”
A second system floats in right after that and from Jan 29th through early in Feb, and more welcomed showers are possible.
You can check out these prognostications in a more professional way at IPS MeteoStar, this link to the latest model run from 11 PM AST last evening.
In case you didn’t notice, there was a prolonged street of clouds emanating from possibly as far away as Kit Peak, or maybe just the Tucson Mountains. Lasted for a few hours.Happens only on days with relatively shallow clouds (cloud-topped boundary layer) with a little wind, meaning that the thermals from the surface heating ended up being capped by an inversion or other stable layer, and those thermals form clouds in some places. In this case, a long line of intermittent clouds formed from an initial air bump caused by those mountains far to the SW of us. CTBL is more often invoked as a term by cloud folks when the sky is much cloudier in low clouds than these shots from two days ago, such as when the sky is covered in Stratocumulus clouds.
These kinds of streets occur over the same places whenever a day like this comes along. Think of it, especially here in Arizona, as a row of shady air under which you might like to live compared to those areas on either side of this cloud “street.” In Seattle, where the “cloud topped boundary layer” is almost a daily occurrence, you want to avoid being under the cloud street, where it can block the sun, and instead find the clearer slots!
For those sharpies that day and logged in their cloud diaries that ice formed in those shallow Cumulus clouds, they will be a little chagrined by this TUS sounding. This sounding suggests the clouds around the balloon were topping at -8 C, too warm for ice formation in shallow Cu. Let us begin to explain this puzzle by presenting evidence of ice formation in those clouds on the 18th:
Simple answer to our connundrum; due to lifting of the air as it approached and went over the Catalina Mountains, the tops of the clouds reached those temperature below -10 C where is begins to form. We would guess even closer to -15 C in that cloud in the distance beyond Charouleau Gap due to the amount of ice. Ice increases with decreasing cloud top temperature, but the temperature at which ice onsets can change on a daily basis; higher onset of ice temperatures on days in which the clouds have larger drops in their tops (a phenomenon originally reported by Ludlam in 1952, then re-discovered by Rangno and Hobbs (1988) who did not, at that time, know of the Ludlam finding, and thus, did not cite it. Pretty embarrassing, really. Was cited later in an update, however.
The weather way ahead
Seasonal rains beginning to show up in southern Arizona now on models beginning around the 4th of July as a big anti-cyclone parks itself over the Four Corners area in the latest model run from 11 PM AST last night. Very excellent run.
5:31 AM: Moving ahead! Looks like we’re at the end of the sprinkle clouds, don’t see much upwind. BTW, could you see the clouds that produced the sprinkle? Not as easy as you think. You see, the wind is stronger, much stronger where those clouds are up there, and the rain that falls out trails behind them. So you have to look downwind a mile or two to see the clouds what done it! (ANOTHER few drops here at 5:37 AM!) Three sprinkles now! Those drops must be like HUGE water balloons to those ants out there on the pavement!
Here’s what those sprinkle clouds look like, the ones you missed while you were snoozing, but, as usual CMP is there for you:
Below, the same sounding without arrows:
End of rain chances now, darn, looking at withering clouds. (Last sprinkle, hardly noticeably unless you were outside, 7:20 AM, from an remarkably small cloud, ice not really apparent).
(Interrupted by having to get a flat fixed; Philips head screw in it.)
Yesterday was a great day to once again test your ice acumen. Here are examples of only those clouds exhibiting ice except that fat Cu over Pusch Ridge, a pic I took during BP2 at James Kreigh Park with ballplaying friend, Patrick.
Seems U of AZ mod sees this little moist street over us as able to generate Cumulus and isolated small Cumulonimbus clouds this afternoon. Very nice.
1Where would Yahoo be today without that “!”?
2It was 101 F during our 2 h session that began at 2:30 PM. Note to baseball people: the ball goes farther when you hit it when the air is less dense. The air is LESS dense when it is HOT, AND when their is moisture in the air (unless the baseball you’re using is hygroscopic, in which case it might absorb water vapor and get that bit heavier and not go as far. So, its great to practice when its above 100 F!