About real clouds, weather, cloud seeding and science autobio life stories by WMO consolation prize-winning meteorologist, Art Rangno
What a gorgeous day yesterday was with deep blue skies dotted with Cumulus and one or two shallow Cumulonimbus, highlighted by our snow-capped Catalina Mountains. After the brief warm up, more storms ahead for Catalina!
Explanatory module below
After the brief warm up ahead, still looks “troughulent” and stormy in the SW as December closes out, continuing into January.
The End
Been dreaming about a white Lemmon for quite awhile, ever since the New Year’s Eve snowstorm here. Finally got one yesterday, as we saw. Here are a few extra Lemmons for you:
Looking closer, I hope you recorded the slight fall streaks (fallstreifen, ger.) in the scene above. It would have been quite an important observation for you to have acquired since these small clouds had not shown ice prior to this time. See below for the VERY delicate trails emanating from this Cumulus mediocris cloud; look between and above the orangish rock faces on the top of Sam Peak and a bit to the left:
Next rain chance in about a week. Looks like May will start out hot, but “too hot not to cool down”, to quote Louis Prima and Keely Smith doing the Porter songbook, and pretty much that cool down before the month is hardly underway. I am sure lingering snowbirds, not wanting to have their feathers singed, will be glad to receive this news.
How can we say that with any acuity?
Check the spaghetti! Looky below at how troughy the flow is by about the 8th of May (red lines dipping toward the Equator along the West Coast). No extreme heat then, just normal warmth or below average “warmth.” This is a circulation pattern that persists, too. And with “troughy”, there’s always the chance of a rogue rain.
The End.
Remember Consumer Reports, “Quotes Without Comment” page? Well, I am lying like anything here1.
Only ONE comment today (I’m lying again), but its about wind today. It will pick up suddenly from the north later this morning or in the early afternoon, and be gusty and cold. We here in Catalina get more of this north wind than, say, TUS, which is blocked from this wind by the Catalina Mountains. A big high is bulging into Utah, a state north of us, that’s why.
Next rain chances, a weak one late Wednesday or Thursday, and a stronger one around the 20-22nd, the latter as spaghetti has been suggesting for some time now.
Your cloud day below in case you were inside watching football television all day:
The End, at last. You can wake up now, horsey!
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1It comes pretty easily to weather forecasters, but you do have to speak with conviction; a certain degree of authenticity has to be imparted when lying. :}
Let us first begin first by NOT exulting too much over our own rain, but let us revel in that rain that has fallen in the Plains. New Mexico, too. From WSI Intellicast this beauty for the past 7 days:
Below is our national drought status at the onset of the week above (for July 30, 2013), and indicates why so many of us should be thankful for this past weather week:
Here are some area-wide 24 h totals, ending now, from the Pima County Alert system.
Yesterday’s clouds
Well, they didn’t get so big, so soon over the Lemmon, as foretold by one model referred to yesterday, but there was something later in the afternoon near the top of Lemmon. Can you detect whether that the turret shown below is mostly “glaciated” or not? You know, that’s why I do this, to learn you up on clouds and when they got ice and therefore are precipitating out the bottom even though here you can’t see the bottom. It all for YOU. Its no problem for me, of course.
Nice sunrise this morning….
Another morning of remnant rains moving through right now, rather than the full blast. As usual, these clouds and rain showers are likely to be dissipating in the later morning before doing much.
Looks like one last day of possible big showers here….check this out from the U of AZ, 11 PM run (WRF-GFS mod).. Lets hope so, cuz its gonna be dry after this for a few days.
The End.
AKA, Cumulus humilis virgae, or, with virga. While there were plenty of small Cumulus around yesterday, it wasn’t until after 1 PM that trace amounts of virga could be seen starting to emit from them as they got colder during the day. I think I did, too. By the end of the day, cloud BOTTOMS of those little clouds were about -20 C (-4 F)! Poor guys. Tops were likely only a little cooler, at -22 or -23 C. Those Stratocumulus bottoms topping the mountains in the third photo were about -5 C (23 F) already.
Here’s what happened yesterday. First, the tail of the frontal cloud band came by, dropped a few flakes on the Catalinas before rushing off. Here is that precip, barely detectable on the Tucson radar:
Answer: Probably less than 5 per liter of those larger than, say, 150 microns in maximum dimension in 6-9, likely 10s per liter in photos Nos. 10-11.
Because it impresses the neighbors, for one thing, because then you can go on and on about the Wegner-Bergeron-Findeisen precipitation mechanism in “mixed phase” clouds, or simply impugn them, with the words from the Walt Disney Studios science song lyric in “Water Cycle Jump1“;
“Your brain is on vacation/if you don’t know about precipitation.”
Second, if you’re into “vigilante science”, as Mr. Cloud Maven person was in parts of his science career, knowing concentrations of ice in clouds by sight will help you clean up some of the messes in the domain of cloud seeding when people report concentrations of ice that are too low. But an extra low ice concentration report benefits them because it helps make the clouds seem like they need some of that seeding to make ice and then more precipitation. Then a big contract is let based on bogus cloud reports, ones that you damn well know are goofy just by looking at the clouds, or checking out rawinsonde cloud tops when its raining from them… I could go on, and on, and on….. Someday…will tell those stories.
I hope that helps explain why this is important. If not, oh well.
Well, you all know about the hot ahead. Now some rain pixels have shown up on March 10th. Not worth showing, but will keep an eye on them.
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I am euphoric that this song is now online! I loved that song! Gritty but great, except the part where it is asserted that condensation leads to precipitation. Condensation (and the ice form of “deposition”) is only the first step. Also, if you like easy listening, boring music, don’t go to this site; it might be too much for you.
Condensation by itself can NEVER lead to precipitation. You got to have ice or those larger cloud droplets (again, let us call to mind, Hocking, 1959, Jonas and Hocking 1970 was it?) that cloud droplets do not stick together UNLESS they are around 38 um in diameter and larger, and then there have to be quite a lot of those that size and larger to “bump and stick” (sounds like volleyball) to form a true raindrop (mm sizes). You see, cloud droplets pretty much stop growing due to condensation at sizes TOO SMALL to fall out of a cloud as precip! They’d evaporate in the first 50 feet out the cloud bottom. NEVER forget that as a cloud maven junior!
Very exciting day ahead as the south to southwest winds pick up this afternoon to gusty proportions with some dust-haze in the air. Cold front coming, as you you know. Surface low pressure center passes to the north. Very exciting, to repeat for emphasis.
Rain? Oh, yeah. This time ALL of it After Midnight (different “reminder” version of this song of when-the-rain-will-start than the one I used last time; different comments, too, on YouTube by people who drink beer late into the night instead waiting for rain… In fact, not one person mentions that he/she was up waiting for rain to start “after midnight”, as you and me might do today.
How much rain here in Catalina this time?
Well, let’s start out by guessing…from weather maps, pattern recognition, and stuff like that. Oh, bottom (estimated 10% chance of less than this): 0.10 inches (namely, it shouldn’t be a dud with no rain at all).
Top amount potential, if everything goes well (only 10% chance of more): 0.40 inches. It doesn’t have the potential of the last blunderbuss of a storm (day 1 of that one where the top of 1.00 inches was realized), but “hey”, its a nice rain in the desert again, helping to plump up those just-ahead spring flowers and grasses.
Best estimate, most likely amount: the average of those two guesses, 0.25 inches1.
OK, now I have JUST looked at the “B-Cluster” output from the U of A 06 z (11 PM AST) model run for OBJECTIVE guidance, not SOP stuff as above: Rain begins here in this model at 1 AM AST (probably too soon by a couple of hours), and the total amount, as predicted by a computer that might have cost billions? Pretty much the same as me, 0.10 to 0.25 inches! I must be wrong! (hahahahaha).
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Serious note: the U of A could really use a donation from you to help keep stuff like the Beowulf computer cluster going; I’ve contributed. See online U of A Department notice in RED letters, calling out a dire situation here. It would be a shame if some of their stuff goes away.
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Now if you’re a pattern person, you will be noticing that this trough is the type in which Catalina amounts are significantly greater than those to the south, such as in Tucson and the surrounding lowlands, and often this comes toward the end of the storm when we see the rain hanging on for an extra hour or two and the clouds pile up against the Catalina Mountains on our side of them as the wind turns more perpendicular to them as the trough goes by. Always a nice time to look at radar because you see little echoes popping out of a no-echo but cloud filled sky, ones that then head toward us. Here where that trough is at 5 AM AST tomorrow morning, its apex right over you and me!
Note above, in timing the onset of the rain, that by 5 AM AST, the strongest winds of this trough (at this level, 500 millybars) has gone by–forecast the rain to have begun by this time; nice rain beginning time window, with the Beowulf being a bit fast (as per usual): Between 2 AM and 5 AM AST tomorrow morning. Set alarm clock. This is so much fun! For extra razzle dazzle for your neighbors, tell them the rain will start between 2:08 AM and 4:32 AM. You can’t get this kind of forecasting precision elsewhere! This is so much fun!!!
As you know, too, the temperature will PLUMMET during the frontal rainband early tomorrow morning as it always does, maybe 10 degrees F or more in an hour, along with the familiar pressure check (sudden rising pressure, one that occurs just about the instant the wind at the ground shifts from wind from the southwest to northwest zephyrs (sounds like a soccer team).
There weren’t any. Hahahahahaha. From the 16th, a picture of a “frosty Lemmon.” (Its amazing how you can just be sitting here, and after one or two cups of coffee, this kind humorous creativity just bubbles up from below. The brain is really something, as the special issue of Science mag will tell you, talkin’ about the hippocampus and neocortex and the mysterious things they do, like thinking that “frosty Lemmon” is funny. You really should read this whole issue to find out what’s going on up there in that cranial cavity you have.)
————Footnote in middle of blog for a deliberate change in normal protocol—————
1Kind of like footnoting, makes me feel like a real author or librarian… I came up with this technique in Durango, Colorado, in the early 1970s with the Colorado River Basin Pilot Project, a gigantic randomized cloud seeding experiment covering much of the San Juan Moutains. Its based on the fact that we meteorologists often have a better idea, a more concrete one, of what’s NOT going to happen. By estimating the extremes of a storm (the crude weather models of that day off this way or that some), it turned out that you could engineer in a way, a better forecast of the amount that would actually occur. In a sense, doing that was performing a “mental ensemble” or mental spaghetti plot have two members (outputs)1(kind of like footnoting…).
Of course, in Durango, CO, we had an objective forecast scheme based on the work of the late Dr. J. Owen Rhea, former chief project forecaster in Durango, who came up with the basic idea behind what is now called the PRISM method of estimating rainfall between gages in complex terrain. Used today to present statewide rainfall averages such as this one for Arizona, courtesy of the Western Region Climate Center. This is a very nice guide if you’re unhappy about the rain/snow you’re getting and want to live where there’s more, a true precipophile:
They’re definitely in the pipeline…. (Here you can feel the confidence slacking that bit from “count on it” yesterday to “definitely” today. Was chagrined by model outputs during the day yesterday, that, while having many AZ rains, were ones having reduced amounts, and were less numerous.
Still, will ride the “Big Storms Wave” right into oblivion if necessary because that’s what I saw in the “ensembles of spaghetti” and they have NOT let me down once that I know of (another fudge phrase).
BTW, what happens after you have seen those wavey lines in the “ensemble members” (each line is called a “member”) is that you come to expect a disappointing output or two–but you don’t really worry TOO MUCH about them, because the Big Boys will be back if the ensembles are correct, as well as your interpretation of them.
So while yesterday during the day the outputs backed off so much rain here as foretold at this very blog, during the night, with the 00 Z (5 PM AST run) not too surprisingly those big rains came back.
In sum, watch for strong storms and big rains in the last week of December into early January.
