About real clouds, weather, cloud seeding and science autobio life stories by WMO consolation prize-winning meteorologist, Art Rangno
This is a new category
But, on second thought, people who have nothing to say, often say it anyway….and that’s pretty much what happens here everyday anyway….to repeat “anyway” again anyway.
Things continue to roll along for a juicy dump of rain, snow and wind beginning here on Monday.
Its windy outside now.
OK, a coupla clouds from yesterday….
The End
Immediately, “BS” is for “Big Storm” ahead, not something untoward.
OK, first a piece about yesterday’s unusual clouds at Cirrus levels; you wouldn’t want to be flying in, or underneath these:
You can also these specks fly by in the U of AZ time lapse film. If you look at the film when they do, you can see them twisting around. Cirrus at that level (CM estimated 25,000 to 30,000 feet above the ground) are normally like sculptures; frozen in time as they pass by this time lapse camera with little or no internal movement.
You could also detect internal movement from the ground in real time in these specks (as we can with Cumulus clouds all the time, since we’re so close to real Cumulus fractus) so it must have really been churning up there.
This patch of specks only took a few minutes to pass by, so you were lucky if you say them.
Of course, you’re only interested in the Big Storm just ahead, not turbulence….probably have grown impatient by now, not wanting to read about itty bitty specks in the sky that might have been associated with strong turbulence. Well, its still “in the bag”, no need to worry. See below this map from our Canadian friends’ model. I really like this map, so no need to look farther. Also, I wrote some things on it for you:
That “kicker” trough just off the Cal coast is going to kick that trough “ball” just off Baja at us as in a field goal in American football, and we are the goal posts.
When a trough is booted out like this one will be out of its nest, the upward motion in front of it is in enhanced, so that the clouds and precip intensify, become more widespread. Its going to head right for us, as it accelerates toward the NE.
This means, in turn, that the very strong rain band already in place in western Arizona, will intensify as it moves east across the State. This is pretty darn exciting because from here it would mean quite the downpour, hours of rain, and almost certainly thunderstorms on March 2nd. However, flooding is likely as rainrates will likely get up to an inch an hour or even more as the band passes over us.
Still sticking with 0.9 inches as “best guess” here in Catalina, top amount, 1.50 inches, if band lingers longer. Secretly hope I’m low….
In one last forecast panel, this MONSTER approaching the Cal coast. Its pretty far out there, as I am being today with the notes on band favorite, Oingo Boingo and sociobiology below, to be reliable, but its shown up a couple of times now in our model runs. It is unbelievable in strength to be forecast as far south as off central Baja, and I wanted to show you what an amazingly strong storm for so low in latitude would look like, if nothing else:
The End.
PS: A powerful jet stream is near us now, so more strange clouds, lenticular-sliver clouds, and fine granulations in Cirrocumulus and such, are likely to be seen over the next couple of days. Have camera ready.
PPS: Still some flow in the Sutherland Wash as of yesterday.
——————————-
1The genius of Danny Elfman, that is, composer of the Simpson’s theme song, and the only composer to be nominated for two film scores in the same year, and also the leader of Oingo Boingo, an LA punk rock/ new wave band in the early 1980s, formerly known as , “The Mystic Nights of the Oingo Boingo”, more like a Spike Jones gag band. An early influence on Elfman was the concept of sociobiology, as represented in “Only a Lad“, a song about an inherently bad “lad”, satirizing some popular, widely held concepts on the causes of mischievous behavior in that song. A sample below, if you care2.
“The lady down the block,
She had a radio that Johnny wanted oh so bad,
So he took it the first chance he had.
Then he shot her in the leg,
And this is what she said
“Only a lad. You really can’t blame him.”
“Only a lad. Society made him.”
“Only a lad. He’s our responsibility.”
Oh, oh, oohh oh oh oh
“Only a lad. He really couldn’t help it.”
“Only a lad. He didn’t want to do it.”
“Only a lad. He’s underprivileged and abused.”
Perhaps a little bit confused?”
2Being a rad-lib in those days, I thought it was INCREDIBLE to hear such a song with THOSE lyrics in the early 1980s on the University of Washington student radio station, KCMU-FM, again, if you care.
If you thought those high clouds were moving faster than usual, you were right. The winds were about 120 mph at that level, about 28,000 feet above sea level, and just over 150 mph a few thousand feet above that level.
You may have noticed two things, if you are good, that there were repeated formations of delicate Cirrocumulus clouds, likely starting as liquid drops, but quickly transitioned into Cirrus. Sometimes, it was just flocculent Cirrus the whole way to us from the west.
The second thing that you may have noticed was that there was always an upwind clearing zone that remained stationary until late afternoon when it finally passed overhead. Yesterday’s high clouds formed at that back edge.
How can you tell that the upwind edge of that sheet of clouds was initially composed of liquid droplets, but then froze naturally within a minute or three as it jetted downstream?
Perform an experiment to demonstrate the two phases.
In this case we will have an ice producing aircraft fly through both regions, the droplet region, and also the region where no droplets exist because they have frozen and are growing larger and larger as ice crystals.
What will be the predictable result of two ice-producing aircraft flying through these two different phases?
In the liquid cloud region, an ice canal will develop as the appearance of ice in a droplet cloud results in the evaporation of liquid droplets, the molecules of vapor from the evaporating droplets provide “food” for fattening ice crystals, where “deposition” takes place. Under a microscope you would see the crystals getting larger, growing extensions; you would not be able to see the molecules producing that, of course.
The result of our experiment, something you likely will never see again in my lifetime:
Was holding breath, thinking about that CV enhancement, waiting for the TUS sounding, which was already in the air when these last few photos were taken, and, more importantly, it was going up near where the clouds were forming, so the moist level intercepted and its temperature would be pretty accurate for this shots. Now, if its -40 C, oh man, we got a pub! -36 C, maybe. Temperature greater than about -35 C? No pub, well, except here, which is something. That’s because liquid drops at temperatures between -30 and -35 C have been reported by remote sensing and aircraft repeatedly. Nature abhors forming an ice crystal in clouds without going through the liquid phase first.
Within a couple of hours the TUS sounding was in, and here it is:
Jet core at 18,000 feet now passing overhead and DRIZZLE or very light rain from warm processes now (4:15 AM) evident on the Catalina Mountains. The passage of that jet core at that level (500 millibars) seems to be an almost black-white measurable rain or no rain discriminator in the Southwest US, so as that happens right now, chances of some measurable rain are good. Still not expected to be more than 0.25 inches, but will now at least be 0.01!
The low clouds are pretty shallow now, and, if they rain, shallow clouds with tops warmer than -5 C (23 F) have to be pretty clean for that to happen. Clean clouds is got bigger droplets, ones that reach the Hocking-Jonas threshold of between 30-40 microns in size and can collide and stick together forming still much larger drops that collect more and more tiny cloud droplets, kind of a chain reaction, as Nobel Laureate in chemistry Irving Langmuir described it back in 1948 after he got interested in clouds and rainmaking.
However, the “collision with coalescence process will be short-lived as cloud tops go up to well below freezing level this morning, and real rain falls (as is happening now (7:18 AM) down in TUS and to our NW.
Measurable rain should be just on the doorstep, and it will have to develop in upwind clouds as they approach us and the air begins to rise as it goes uphill from the lower deserts and encounters the Catalinas’ there isn’t much in the way of radar echoes upwind of us now.
The development of rain in clouds as they approach us in marginal rain situations like this one is not terribly unusual. Sometimes, as a friend pointed out, new echoes in deepening clouds can appear over and over again near where I-10 runs to the SW and W of us in a purely orographic situation.
This is what CMP is hoping for, and the result of that might be a tenth of an inch or more.
Actually, there are no thoughts about the Super Bowl here. The title was just another cheap attempt to attract a reader that might be both cloud-centric AND a football fan, creating a moneyful increase in web traffic for this blog.
First you had your Cirrus, the highest of all clouds except for stratospheric nacreous clouds which kind of mess things up up there by eating ozone. We will not display n-clouds.
Cirrus, as you know, ALMOST always precedes lower clouds since they’re moving so much faster than the lower ones. So we get a sequence of clouds before it starts to rain that generally is the same, over and over again as in that movie about weather, Ground Hog Day. But let us ramble on…
First, patchy Cirrus, then maybe a sheet of Cirrostratus, then the lower stuff as Cirrostratus thickens downward to become that gray sheet called Altostratus. Throw in a few Altocumulus clouds that become a sheet underneath, and voila, your in Seattle, with rain on the doorstep. Yep, that’s the Seattle, and well, the Middle Latitude Pre-Storm Cloud Sequence (MLPSCS)2.
Of course, everyone, including media weathercasters, are all over the incoming stupendous storm event. For a more technical discussion, here’s one by Mike L., U of AZ forecasting expert, who got excited enough about our storm to come to send out a global e-mail. I think you should read it, though I left out all the graphics. I’ve already been too graphic today.
———–Special Statement by Mike L———————————-
“A very unusual heavy precipitation event is forecast for the next few days across Arizona and New Mexico as extremely moist air interacts with multiple short waves. As seen in the below data from the NWS, the maximum monthly IPW for Jan is about 28-29mm. If the various WRF forecasts verify, the upcoming storm will set new a new January IPW record.
The 12z WRFGFS indicates very high moisture levels being advected towards Arizona due to a low latitude low located west of the Baja spur. While IPW has slowly decreased from the previous storm over much of the area, La Paz is seeing a upturn in observed IPW.
As seen below, at 5pm today, some convection is forecast near to the low. Lightning data has indicated there has been some strong convection during the day today. Model initializations are normally suspect so far from any upper air stations, but it seems that both the NAM and GFS seem to have the intensity and location initialized well. One item of note is that during the past few days, the models have had a trend of moving the heaviest precipitation back to the west. Initially, the heaviest band was well in to NM whereas you’ll see later, it is now over much of eastern/central Arizona.
By late tomorrow afternoon, the low has only moved eastward slightly, but IPW continues to increase over NW Mexico and into Arizona. Precipitation begins mainly over the higher terrain of eastern Arizona.
By Wednesday morning, the mid level low has intensified as a strong short wave dives down behind the mean trough along with CAA into the back side.
Significant synoptic scale lift is present over southern Arizona and into northern Mexico by this time.
Extreme IPW is forecast to be present during the morning hours on Friday and combined with the favorable dynamics, widespread moderate to heavy rain is predicted. As the low becomes cut off, there will be an extended period for precipitation.
Precipitation rates are forecast to be above .25″/hour in some locations during the morning hours.
Partial clearing is forecast by Friday afternoon which allows some heating. Combined with cooler air aloft and high IPW, moderate amounts of CAPE are present during the afternoon.
By later in the afternoon, as Bob Maddox pointed out, convection forms and results in some locally heavy precipitation.
Tucson’s vertical profile is quite impressive with 700 J/Kg of CAPE and some vertical shear to support organized convection. Hail is also a threat.
Convection continues into the evening over southern Arizona with a continued threat of hail and some lightning.
The 3 day QPF is very impressive with widespread 1 inch amounts with some areas receiving over 3 inches. Some of these areas are associated with the strong convection present on Friday afternoon/evening. Confidence is low to medium due to the lack of upper air data and lack of run to run consistency as discussed previously. Also, the output in this discussion was solely from the 12z WRFGFS. The WRFNAM from last night had the heaviest precipitation somewhat to the east. It will be informative to see the next suite of model runs overnight to see if this westward trend ceases. There is a chance that it could continue and the heaviest precipitation is actually farther west than depicted below.
Very little of this precipitation falls as snow except at the very highest elevations, above 9k feet due to the sub tropical air-mass and lack of cold air.
Note that this discussion will only be available for organizations who are (or have) supported the Arizona Regional Modeling Program. This change will take effect before next monsoon season. Private individuals not associated with commercial/governmental agencies will continue to receive the discussions. If your agency would like to support the Program, please email me for details. “
————–End of special statement by Mike L—————————
The End!
1Let us not forget Simon and Garfunkel’s telling descriptions of Patterns of life; they repeat in clouds, too. (Pretty funny lead in commercial where Bryant Gumbel is asking, “What is the internet?”)
2Back in the old days when cloud forms were used to tell weather, Cirrostratus sheets, those high thin sheets, often with a halo, foretold rain 70% of the time here in the US (see Compendium of Meteorology, 1951). Deserts don’t much see this sequence. Cirrus are mostly meaningless in them, just indicating some withering tail of a system with rain that’s far away most of the time.
3NOT a reference to an untoward sex act.
The report below was supplied by stalwart metman, Mark Albright, U of WA, who snooped around to see if a forecast of 50-100 mph in southern Cal made from this blog on JANUARY 18th had any credibility at all for a 50-100 mph wind event in southern California:
“Looks like your forecast of 2 days ago1 has already verified. Sill Hill, 20 miles NE of San Diego at 3556 ft, reported a gust to 86 mph (75 knots) at 13:50 UTC this morning.
“0430 AM NON-TSTM WND GST 9 SSW JULIAN 32.95N 116.64W
01/24/2015 M75 MPH SAN DIEGO CA MESONET
MESONET STATION SILL HILL /SILSD/
24 SILSD sd 1300 55 8 89 37 60 (last number is max wind gust, in knots) RH=15
24 SILSD sd 1310 55 10 88 43 63 RH=16
24 SILSD sd 1320 54 9 91 43 59 RH=16
24 SILSD sd 1330 54 9 87 41 57 RH=16
24 SILSD sd 1340 54 9 87 40 66 RH=16
24 SILSD sd 1350 54 9 85 38 75 knots (!) RH=16
24 SILSD sd 1400 54 9 94 40 61 RH=16 ”
-mark”
Its rare when forecasts go the way they should, and I thought I would put on a display of exceptional exultation today.
Now comes the time that the upper air disturbance that produced that 50-100 mph wind sits off the Baja coast, scoops up some moisture from the deep tropics and sends its back over southern Cal and the Great Southwest. Still looking for a thunderstorm or two in that cloud mass somewhere, most likely west of us, as it rolls northward tomorrow.
Here is a satellite loop from the University of Washington Huskies Weather Department. In this loop, entitled, “Scoop, there it is!” paraphrasing a skit from “In Living Color“, you will see how that tropical moisture is beginning to wrap around the low off Baja, prepping it into a rain-bearing system that will be pulled northward by a disturbance approaching the West Coast.
The bottom line in this loop is the Equator, and that cloud band just north of there is the Intertropical Convergence Zone, where the trade winds meet. The water is a little warmer than normal down there, not enough to qualify as more than a minimal “New Niño (the “Classic Niño, the one next to Peru, is completely gone). But modestly warmer than normal water temperatures still helps a little to send up Cumulonimbus clouds which eject moisture from the Tropics into middle latitude and sub-tropical latitude disturbances and that’s what’s happening in that sat loop; an ejection of clouds and water vapor into that formerly dry, 50-100 mph Santa Ana wind forecast-verifying-producing upper low, a forecast that was made 6- days before it happened! Really incredible.
A view of sea surface temperature ANOMALIES, with important annotations:
We’re sticking with the range of amounts previoulsy foretold here that could occur in Catalina, that range being pretty high due to model vagaries. From this keyboard, the least that could fall is a puny 0.05 inches, and the most remains at 0.50 inches, which would be very nice. Averaging those two gives 0.275 inches, also quite nice, and the most likely amount if averaging like that has any credibility at all. This is the fun part of weather forecasting.
It has to be mentioned that the WRF-GFS nested model from the U of AZ indicates that the larger total is going to occur, this from the 11 PM AST run from last night. That would be so GREAT! Take a look at these great totals as they pile up, ones accumulated over the 24 h from mid-day tomorrow to mid-day on Tuesday. So fine.
And, to make the news even better, more rain is increasingly likely two or three days after this episode!
Yesterday’s sunset:
Today; mostly high ice cloud (Cirrus, Cirrostratus, Altostratus) broken to overcast skies with thin spots from time to time. Nice sunrise, hope you caught it.
The End
———————————————-
1It was on January 18th, not “two days ago”, that that astounding forecast was made, so long before it happened I might get an award of some kind, maybe the Amer. Meteor. Soc. Rossby Medal… That would really be great!
Friends, arriving this afternoon from Seattle for a sunny and warm couple of vacation days, will find that Catalina weather today is exactly like the weather they left in Seattle; poor Tommy and Patty.
Clouds will fill in as the day goes on, becoming pretty cloudy at times, especially in the afternoon hours. They will starting to ice up, too, and you know what that means; they’ll produce virga and light showers in the area, with breezes and a high of only in the low 50s.
Be sure to record the first sighting of ice in clouds today. Will be a nice test for you, and a great ob in your cloud diary.
Still expecting a pretty major storm next week.
Got 0.12 inches in the gauge last evening.
————————————–
In the meantime, meet members of the former Cloud and Aerosol Research Group at the University of Washington, Professor Peter V. Hobbs, director.
Tom, who arrives today from Seattle, was our group’s software engineer at the University of Washington. He was kind of recluse we learned after he was hired. Liked to have a lot of high vegetation around his desk in our lab where me and a grad student worked. However, unlike a prior software engineer, who was also brilliant like Tom, Tom really never fell asleep at his desk that we know of.
Our first software engineer was Doug, shown meditating below.He was great! Worked long hours that often took their toll in the daytime.
But, not to demean “Doug” whatsoever, who truly WAS brilliant, and his software helped enormously to grease the wheel of our group’s aircraft data analyses, and who also made a lot of money when he joined the then fledgeling Microsoft in the early 1980s, took his job especially seriously, He liked to let people know how seriously, and exactly how much he loved working with computers. And he dressed to show it.
Cloud and Aerosol Researcher, “Stan”, monitoring cloud particle data on a flight over the Washington coastal waters.
It was a fact, that as I got embedded into perhaps the best Atmospheric Science Department in the world, I also learned that science draws “unusual”, maybe even quirky folk, and “meditating” while on the job, perhaps “awaking” with new, substantive realizations of relationships, or ways of presenting data, was pretty common, not just with Doug:
But there were other quirky characteristics that turned up, like “Germophobe John”, shown below, who actually shared my lab room for many years:
Then there was that one guy who worked as part of the flight crew who specialized in looking like John Denver, and liked to come in to work in the morning and report that someone on the bus he rode thought he was John Denver. Seemed to get a lot of satisfaction out of that, which in retrospect is kind of sad when you think about it.
Me? I was pretty normal, really not too much affected by the various quirky people around me. From those halcyon days, a selfie:
There was some thought, however, that any quirkiness that was exhibited in our personnel might have been due to the various cancer-causing chemicals we worked with, one of which was Formvar, used to capture images of ice crystals that would hit the liquid Formvar on movie film rotating in the arm of a probe that stuck out of a pod, or a glass slide that stuck out a hole on a stick in the plane. In both cases, the crystal would hit the liquid Formvar, which would dry VERY fast, and then the impression of the crystal would be left in the plastic Formvar.
Below, “Diana”, and “Brad”, a brilliant grad student, at least before he started working with Formvar, examine a jar of the smelly stuff.
3:53 PM. This was about an hour before virga and falling snow began to obscure the tops of Samaniego Ridge and Mt. Ms. Lemmon. Here the streaks, crespuscular rays, are NOT caused by precip, but rather dust
Some additional scenes from a 4 h yesterday into the Sam Ridge foothills:
Stuck here, might reached a limit, can’t seem to add photos, and there are too many already.
The End
Like scientific opinion1, climate change happens. You may not know this, but only 15,000 to 20,000 years or so ago, a blink of an eye in light years, the earth was gripped by an Ice Age. No “hockey stick” handle back then! Snow and ice piled up over a kilometer deep on top of the Space Needle in Seattle. And the polar ice cap extended to places like Cahoga Falls, Ohio, while burying the Great Lakes, which didn’t exist.
NOW, of course, we’re in an “Interglacial” period called the Holocene, where its nice and toasty, for the most part, the way we like it as a people. Really, human beans do not like Ice Ages; they can really die off in a hurry2 and have to repopulate themselves afterwards! Well, I suppose that part might be fun.
The forecast models are foretelling something in the way of a flashback in the way of a pressure pattern over nearly ALL of North America that might well have been the average pressure pattern day after day during an Ice Age (there have been many), the last one, at its peak, not surprisingly, was called, “the Last Glacial Maximum.” I’d call it that, too.
Here are a coupla panels from the venerable Enviro Can computer model with its FOUR panels of weather. Take a look at the pressure patterns in the right side panels, you may have to use a magnifying glass, both showing the predicted sea level pressure pattern. These forecast maps are astounding to C-M and will, therefore, be likewise to you, too: a high pressure area so expansive with cold dense air that it covers millions of square miles, even more in square kilometers, maybe billions, since the kilometer is a smaller Euro unit of measurement that makes everything seem farther away when you’re driving to someplace and the distance is in Euros. (hahaha, just kidding folks).
So, we have an historical treat coming when the average temperatures every day in the US were 15-20 F lower during the Last Glacial Maximum! (Ugh.) The oceans were at lot smaller then, too, because a lot that water was piled up on top of the Space Needle, etc.
You might have noticed in these panels that the Ice Age-like conditions are plummeting rapidly southward, and big trough is starting to curl over the interior of the Pac NW. Yes, since we are still in the Trough Bowl, that curling air pattern, containing frigid air is headed toward Arizona, and will be here or not in early January.
Why a bifurcated statement?
Models are confused. Two model runs, only 6 h apart (5 PM and 11 PM AST last evening have the low center aloft for the SAME time, January 1st at 5 AM AST over a) Pebble Beach Golf Course, Carmel, CA; b) over Gallup, NM! How funny, outrageous, and frustrating is that? See below:
========Learning Module=================
But, we are “gifted” with an opportunity to learn about chaos in the atmosphere, aren’t we, that is, those times when little errors can lead to huge differences in future states.
So, to resolve this weather conflict, and lose a few more readers, we go to the NOAA spaghetti factory, and examine the “Lorenz plot” for this time period and see which one is looney:
Well its pretty obvious that the goofy one is the one having the low over SFO and vicinity. Most of the circulation pattern has a center in Arizona somewhere. But this interpertation means that extremely cold air is likely to invade at least the northern half of Arizona as January begins. The good side is that there would be substantial, and later, reservoir filling snows in the mountains, and a good chance of substantial rain here in Catalina as the year begins.
The end of maybe solving a prognostic conundrum.
Well, its all “out there” by your favorite weathercaster, and they all do a pretty darn good job, and so no use hacking over what’s already known by everybody except to say that the jet streak at 18,000 feet (500 mb), that core that circumscribes precip from no precip areas during our winters, passes over Catalina (our area) around 5 PM AST according the latest model run.
And that’s, too, when the models expect the first rain around Catalina to arrive. As before, this ain’t gonna be too much unless we get real lucky, top amount likely below a quarter on an inch between 5 PM today and the end of possible showers later tomorrow afternoon.
And of course, there’ll be lots of wind, maybe gusts to 40 mph today, a windshift to the NW here when front goes by overnight, with a temperature drop of about 10 degrees almost simultaneously. Expect a frosty Lemmon on Friday morning when the clouds part.
You can follow today’s developments today best from IPS MeteoStar’s satellite and radar loop.
The interesting part is that echoes and clouds will appear out of nowhere as that big trough expands southward, cooling the air aloft, allowing cloud tops to rise to ice-forming levels. Also, if you go there now, you will see giant clear slots between those middle and high clouds that passed over last evening until right now (Ac castellanus visible to SSW now), and a tiny band in west central Arizona, and the echo-producing clouds in the NW part of the State. Those unstable-loooking clouds will be gone soon.; they’re more from tropical locations.
Keep an eye on that little band in the middle; it may turn into a bona fide rainband as clouds add onto it, widens and thickens. That’s probably what’s going to bop us this evening with rain.
Expecting to see a nice lenticular cloud downstream from the Catalinas today. They’re common AHEAD of the jet core since the air is much more stable then, resists lifting and so you get cloud pancakes that hover over the same spot. How you log them if you see any.
Will we see our usual, “clearing before the storm”? This is when middle and high clouds depart, there’s a big clearing followed by an inrush of low, precipitating clouds. Not sure, but will look for it if that little band of middle clouds ends up as only that as it passes by today. The invasion of low clouds would follow that. Too much speculating today!
Finally, the End. I’m sure you’re glad, too, if you got this far!
——————————-
1Remmeber back in the late 1960s and early 1970s when it was widely believed that a new ice age may be at hand because the earth had been cooling off for a coupla decades? It was also being pointed out that an ice age could onset in a hundred to a few hundred years from past ice age onsets! Yikes. Scary times on earth then when the Beatles were popular.
2Of course, if you were to die in an Ice Age, you might end up being well-preserved and then people would see what you looked like, the hair style you had, tattoos, etc, as we’ve seen with a few dead people that have been found from those glacial times. I guess that’s something positive to say about cold times.
Check these out in yesterday’s “Olympics of optics” where all kinds of goofy optical things were seen:
Thickening and lowering, ho hum, the usual as a trough aloft (bend in the jet stream winds up there) off southern Cal and Baja approaches today. Ahead of the bend in the winds, seen in the map below, the vast layers of air rise ever so gradually, something like cm per second. But, its enough to produce sheets of clouds.
What kind of clouds?
Heavy, dense and gray ice clouds we call Altostratus (As), with thicker and thinner spots should dominate the day. Then as the moist layer lowers, that is, as the As “bases”, really just comprised of falling snow that only looks like a solid bottom, get lower, patches of virga will start to reach the ground later today. Altocumulus ought to be around, too, water droplet clouds not cold enough to be completely iced up. Expecting those layer clouds, or undercutting layers to be low and lumpy enough to be termed Stratocumulus late in the day.
The strongest winds at 500 mb (around 18,000 feet above sea level) will be to our south beginning today, a necessary condition for virtually ALL wintertime rain here. CM is expecting some rain to fall in Catalina later today, or tonight as this bend in the winds aloft goes by. Expected amounts in this first wave, trace, minimum to 0.25 inches max by mid-day tomorrow.
Its really dicey situation since its not clear how deep the moisture is off Baja now, but looks potent enough for as much as a quarter inch from this keyboard, though less is more likely. Sorry the range is necessarily so great.
BTW, the WRF-GOOFUS model didn’t have ANY rain predicted for this time frame period in both of the 5 AM AST and 5 PM runs of yesterday. So, we’re out on a bit of a limb.
After tommorow….
After 5 PM AST tomorrow, all peoples and models see more rain for Catalina as two waves/troughs barrel in right behind the first one that goes over tonight. The 2nd and 3rd ones produce a couple of rains through Thursday with big breaks likely in between.
The total amounts for Catalina between now and Friday morning still look like they will be contained within the range of 0.25 inches (things don’t go so well; disappointing really) and an inch (things go really well). Best guess is average of those, for a few day total of 0.625 inches.
The End
———————————
1Remember “Wrong Way Corrigan”? Picked up that fumble and scored a TD for the other team? Maybe it was an early sign of the effects of concussions in fubball.
Due to some kind of server meltdown, the NOAA spaghetti plots, better, “Lorenz plots” in honor of “Dr. Chaos”, Edward N. Lorenz, the ones my fans1 like so much, have not been available.
But they’re back today!
But what are they telling us? Gander this for Christmas Day:
Don’t need to tell you that the weather looks like there’s a good chance of cold and threatening weather for Christmas Day. Big trough implanting itself in the West around then. Maybe those easterners who hogged all the cold air last winter will share some of it this winter. The warmth we had last winter made it bad for horsey with all the fly larvae that survived.
Kind of bored now with the rain immeidately ahead, but only because everybody else is talking about it, too. Its no fun when you don’t have a scoop and you’re just saying things that other people are already saying. Even my brother in North Carolina, who knows nothing about weather, told ME that it was going to rain here on Thursday! How lame is that? Of course, it is true that you won’t here anywhere else that the chance of measurable rain is more than 100% this week in Catalina ; at least I still have that. Tell your friends.
When does it fall? Sometime, maybe multiple times, between Tuesday afternoon and Friday morning. Hahaha, sort of.
Looks like the first trough and weather system will go over on Tuesday through Wednesday, chances of rain then, and yet another colder one on Wednesday night into Thursday. So, 100% chance of measurable rain falling sometime between Tuesday afternoon and Friday morning, probably in several periods of rain. Look for a frosty Lemmon Friday morning.
Predicted amounts from this keyboard? Think the bottom of this several day period of individual rain events will be only a quarter of an inch. Top, could be an inch, if everything falls into place. Canadian mod from 5 PM AST global data yesterday, for now has dried up one of the storms, that on Thursday, the day the USA! model thinks is our best chance for good rains based on the virtually same global data! Of note, the USA model based on 11 PM AST data, has begun to lessen our Thursday storm that bit.
This is the reason that the certainty of measurable rain here in Catalina is spread over such a several day period.
Just various forms of Cirrus, most seemingly from old contrails that produced exceptional parhelias (sun dogs, mock suns).
Very contrail-ee sunset, too, as contrail lines advanced from the west. They were likely more than an hour old when they passed over Catalina yesterday.
The End
—————–
1Why just recently C-M had a comment from a fan in Lebanon3, that country near Israel, not the one in Ohio2! Said it was warm there now, but normally it rains for days at time in the winter, and gets real cold. You see, the eastern Mediterranean is, climatologically speaking, a trough bowl. Troughs just hang out there a lot, creating something called the “Cypress Low.” Though it only rains in the cool season, October through May, as in Israel, places in Lebanon get 25 -40 inches of rain during that time, and its exciting rain because it almost all falls from Cumulonimbus clouds, many with lightning! C-M is getting pretty excited, since he’s on record as wanting to go Lebanon to study the clouds there! See Lingua Franca article from 1997! He loves those Mediterranean wintertime Cu. Hell, you probably threw it out, so here it is: Lingua Franca _1997. See last sentence. last page. Thanks.
2Speaking of Ohio, who can forget that great 1980s rant against urban sprawl in Ohio by Chrissie Hinds and the Pretenders! Will it happen to Catalina after the road project? An insurance agent told me that Catalina was to be absorbed by Oro Valley after it was completed. Oro Valley says they know nothing about that.
3“Its great when you’re global!”
Front will roar across like a mouse, not a lion, as hoped for a few days ago. Not too many rain “calories” in it. Measurable rain will still occur, starting sometime between 9 AM and 10 AM AST–oops. raining now at 7:10 AM! Check out U of AZ model for rain timing. First drops fall here in that model output (from 11 PM AST last night), between 8 AM and 9 AM. The frontal band, such as it is, is almost here! However, the model rain tends to arrive a little fast here, though not always. FYI, be on guard.
C-M is holding firm with a minimum of 0.15 inches today, but previous foretold possible top of 0.80 inches a few days ago is out of the question. Will be happy with 0.25 inches at my house. Since I am also measuring the rain as well as forecasting it, I have a feeling things will turn out fine.
There will be a nice temperature drop, windshift, and simultaneous rise in pressure as the cold front goes by–it’ll be fun for you to watch the barometer today and see the minute the front goes by as higher pressure begins to squash down on you.
Rain might reach briefly moderate intensity (defined by official weatherfolk as 0.10 to 0.30 inches per hour). It would be great if it lasted an hour at that rate, but it likely won’t. Its moving pretty fast, and it doesn’t seem like more than 2 h of rain can occur today. Look for a nice clearing in the afternoon, and a COOL evening.
Drive south if you want to avoid rain today. Jet core (in the middle levels, 500 millibars, 18, 000 feet above sea level) is almost overhead, and just to south, and that core is almost a black-white discriminator of rain here in the cool season. So, we’re on the edge of the precip today. More to the north; less to the south.
The weather ahead and WAY ahead
Speaking of bowls, and let’s face it, with only a 100 or so we could use a few more1; we here in all of Arizona are in the “Trough Bowl” now.
This means that troughs (storms and cold fronts) that barge into the West Coast will gravitate to Arizona instead of bypassing us and they will do that over and over again. Being in the Trough Bowl is great fun! Lots of weather excitement for weather-centric folk like yours truly. When you’re in the Trough Bowl, the weather is “unsettled”; is NEVER really nice (if you like sun and warmth) for very long because a new front/trough is barreling in at you.
So, while today might be a little disappointing, we will have many chances to get the “real thing”, i.e., a behemoth of a trough among the many that affect us in the weeks ahead.
In the longer view, a behemoth of a trough for the Great SW has just popped out of the models1 just last night in the 11 PM AST run! Gander this monster truck trough for AZ. Where’s that monster truck event announcer, we need him now!
OK, enough weather “calories” for you today. Hope you’re excited like me.
The End
———————————————
1Furthermore, why don’t we have bowls for women’s teams, what happened to Title IX there, maybe Beach or Sand Football? )
2As rendered by IPS MeteoStar, which is about to go from “free” to “fee” in January. Dang.
