Retiree from a group specializing in airborne measurements of clouds and aerosols at the University of Washington (Cloud and Aerosol Research Group). The projects I participated in were in many countries; from the Arctic to Brazil, from the Marshall Islands to South Africa.
“Read ’em and weep”, as a Los Angeles Times sports scoreboard page used to say:
No joy ahead in “Dustville”, as a once mighty trough has struck out. An long-foretold, incoming trough for April 8th appears now to not have enough amplitude (i.e., the core of the jet stream won’t get to us, but will stay a little to the north of us). Only wind and a temperature drop is likely.
Should see some nice Cirrus from time to time though….maybe small Cu after the cold front passes. Oh, me, living in a desert can be hard.
But, “hey”, the northern Cal drought is getting squashed quite a bit by major spring storms, with some monsters still ahead. I guess we be happy for them as they recover from extreme drought. Snowpack around Reno/Lake Tahoe, to give you an example, has made its biggest recovery in some 41 years as of April 1st after the near record low on March 1st. Reno is near northern California. And, a whole lot of precip is in the pipeline. Might even make the news….
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.
No, this is not about Bonanza, the TEEVEE show, “Hoss”, or any of those ranching people, though that might be more interesting than a blog about clouds, gray ones. First of all, the word, “bonanza” would be capitalized (its not on my view of this edit, FYI) if this was a blog about it. Second, there was no “Bonanza” episode about Stratocumulus and drizzle, another clue.
Your cloud diary, for those of you still reading this blog:
Well, let’s move ahead to sunnier conditions, those pretty scenes we see on the mountains when a storm begins to clear out.
PS: The agonizing delay from typing then seeing words appear 5-10 s after you stopped typing, disappeared when I jettisoned Firefox for Safari. So, all these months of agony, were due to a Firefox bug, not a WordPress or GoDaddy hosting service problem. Unbelievable. This problem I think began when I downloaded the latest version of Firefox, which also came loaded with pop up ads and web site diversions it previously was free of. Dummy me never connected it to the venerable Firefox web browser. So, Firefox has been trashed from this computer!
Huh, Sounds familiar. Well, 50 shades of gray is a theme here at cloud-maven.com. Those various shades brought 0.02 inches of rain this morning to The Heights. Here are yesterday’s 50 shades:
This Altostratus invasion covered the sky within about 15 minutes, and that was it for sun, except some “filtered sun” at times (when this layer is called Altostratus translucidus (the sun’s position can be seen). Its an all ice or mostly ice cloud.
The weather ahead
Pretty much a sure-thing rain (we, unprofessionally forecast at least a 90-100% chance of measurable rain then) will move in late on the 16th or on the 17th. Should be a significant, vegetation-boosting rain, too–by that I mean at least a quarter of an inch–unlike this rain this morning. It looks,. too, like a second rain might move in a day or two after that one. Quite strong support in the ensembles (“spaghetti plots”) for that to happen, too. How great would that be? Very great, of course.
After that, the models are showing even more troughs affecting AZ, but the ensembles aren’t sure about it. Neither am I (CMP).
That means that a deep Altostratus overcast will be in place by tomorrow with a load of virga and sprinkles, not really much rain since the bases will also be cold and…high. Top possible rain amount from these high cold ones is a tenth of an inch, but more likely will be traces. Chance of a trace in the area? Oh, about 99% IMO.
But that’s not our full rain destiny.
On the horizon, only a week from now, is the likelihood of a significant rain. Check the models and the spaghetti:
Here’s the rain prediction which I have not looked at until posting now to make the point you don’t need to look at it:
Would say the chances of measurable rain from this “incoming” are at least 90%; i. e., virtually certain. (Note that “virtually certain” is not the same as 100% certain, but its damn close.)
Problems with hoster and connections to hoster continue–must wait seconds to see what I’ve typed, then have to go back and correct the gibberish. So, not doing much as a result.
But here are a couple of cloud shots from yesterday anyway:
Addendum: Coupla of days ago saw the rare “Cumulo-cirrus” clouds, ones that appear to be Cumulus but are fakes, up at Cirrus-levels. You might call them Cirrus castellanus. I feel these are worth sharing so that the young cloud maven person doesn’t embarrass himself or herself when making a cloud call to friends and neighbors, as you would do. They occurred on March 7th between 11:30 AM and Noon. Can you tell, upon “zooming big” that these are mostly ice clouds? If droplets were present they were there for only a short time, thus (is that still a word?) indicating that these rag clouds were at very low temperatures.
Its not a review of a new Stephen King movie where people turn green after eating too many vegetables. Its a status report on growing grass as of yesterday from a hike.
Got pretty excited yesterday watching grass grow. Below, some exciting examples of growing grass, mostly from the flats around the Canada del Oro wash near the Catalina State Park entry building, in case you’re thinking about rushing down yourself to see grass grow. Some areas are not so far along (last photo).
Nice to see this eruption of green after our 2 inches or so of rain recently. Even saw a couple of poppies popping up by the entrance to the Park.
Chance of measurable rain here in Catalina? 100% (IMO).
While these photos popped in in a rather timely manner after changing ISPs, typing text remains an unsolved buggabo; must wait several seconds to see what’s been typed, making any writing, such as it is, a real debilitating slog. Thanks for sharing my pain.
The weather way ahead
Doesn’t look so great for more rain after this upcoming event. The ensembles (spaghetti plots) show the trough bowl we are in now retrograding to offshore of the West Coast. This will be great for droughty California, but downstream over the SW will be a ridge leading to a long dry and warm spell as this regime change takes place after our rain.
One branch of a seemingly bifurcated plume, spread north along the side of Samaniego Ridge. The other branch appeared to moved out of Tucson to Continental Ranch, “thence” northward toward the east side of the Tortolita Mountains. It’s happened before, but is pretty rare, maybe once a year occurrence.
(Took an hour for these first three jpegs to be uploaded to WP, btw.)
Quitting here due to slower than dial-up service, hosting service, “godaddy” has confirmed its not them….
Have cameras ready for interesting clouds today as yet more storms approach. Winds at 500 mb (around 18,000 feet above sea level) are forecast to approach 100 kts by tonight (oops, TOMORROW NIGHT! Egad). With winds like that, likely will be some nice lenticulars around to add to your collection. Oh, I already see one downstream of the Catalinas….
Maybe some photos later if the upload problem can be resolved.
Its not resolved…. But, trying to look at the bright side, while this ONE photo was uploading, I got some more coffee, read a book (Cadillac Desert, Marc Reisner, and got a good start on, Mythical Rivers by Melissa Sevigny–both highly recommended for cloud maven readers.
Some more on the upcoming rain and wind event in the next 24-36 h:
From this keyboard, 10% chance of less than a trace (pitiful forecast), in other words, a zero from this storm, and 10% chance of more than 0.40 inches. The average of those two, which helps center a forecast in the forecaster’s mind, great or small, would be, say, 0.21 inches.
But the wind max during this storm event will be the most “interesting” part of it: 10% chance of puffs less than 35 mph, 10% chance of more than 65 mph , in this forecaster’s opinion. The average of those would lead me to think that very momentary gusts will reach 50 mph (averaging those extremes to center a forecast). So, the wind in the next 24-36 h is really the most interesting thing to keep an eye on; stuff will blow around, shingle fragments likely to come off. This is NOT a NWS forecast.
——————— 1“Puffs”: almost instantaneous blasts of a few seconds.
Toot, toot, drip, drip. Rain fell on Catalina, Arizona, for the third day in a row, bringing our three day total, at least in Sutherland Heights, Catalina, to 2.18 inches, and over NINE inches at Ms. Mt. Lemmon, subject to quality control later.
Here’s a nice map, courtesy of the Pima County ALERT network, whom I haven’t actually asked to post this but you can go here and see it in the original:
No photos, still suffering from WP or godaddy hosting chokehold. Even text takes seconds to appear! Worse than dial up. The above jpeg, just 1.4 mb, took several minutes to upload!
The weather way ahead and soap-boxing the erroneous, “warm temperatures” expression
While the NOAA ensembles let us (me) down in mid-January when it appeared that troughs would dominate in late January through early Feb (it wasn’t even close to that interpretation, and the first time I’ve seen those crazy plots do so badly, will go with them now and present a couple that strongly suggest the drought pattern has been decimated for Arizona and the Southwest; no more weeks of no rain or rain threats, with ridiculously warm days (note, not days with “warm temperatures”, a temperature is a unit of measurement, not a thing that can be cold or warm—-got it? Its the AIR that’s warm or cold, or a day, a month. What if, when a high pressure sat on Arizona, that I said we had really “dense millibars today”, to make a comparison showing how WRONG it is to say, “warm temperatures.” Its HIGH temperatures or LOW temperatures, etc. Tell your friends….
OK, will go through that bit more of uploading misery with these stupefying spaghetti factory plots. Inspect them and be happy if you like unsettled weather, storms threatening or actually occurring every few days. The first one is a week from nows, then ten days from now, and the last one two weeks from now. Exult over the troughulent regime we’re now in! Yay!
This “ensemble” approach, where tiny errors are deliberately input into the model data as the computer run begins is deemed one of the great advances in forecasting, this due to more powerful computers that can crunch so much global data so fast. There are always errors in the data, and we can’t measure the atmosphere over the whole globe in an instant, and this is a way of determing what the errors might do to the forecast. Heck, we don’t even know what the real errors are. So we input some and see what happens.
The greater the effect errors have, the more spread out and chaotic the patterns are. When the red and blue lines stay close together, it indicates that at least, tiny errors, don’t have much effect. Normally, after ten to 15 days, the lines are kind of a mess, with only general patterns discernible. (Sure is annoying typing and waiting seconds to see what it is you’ve typed!)
In last evening’s global data runs, the red lines in our domain stay pretty bunched up, indicating a strong indication of troughing over these next two weeks, even out to 15 days! So, cloud maven person is pretty excited thinking that maybe a wildflower or two can now pop up, and our spring greening will go forth.
Just yesterday on a dog walk to the Sutherland Wash, tiny plants were bursting forth from the ground. What a miracle that is. (The wash had no water in it.)