The weather ahead – Page 25

Dream maps in latest prog series; RAIN foretold for southern Arizona!

Every so often something stupefying comes up in the models, such as the extraordinary upper low predicted for over southern California on June 17th. Well, that low disappeared on subsequent model runs, but as of the 06 Z (11 PM AST) run from last night, its back!

But, in that run from yesterday, it wasn’t going to have any tropical air flowing over us; that air was going to end up over New Mexico and Texas.

Things have changed! Now, no less than a hurricane remnant is foretold to scoot up the Mexican coast and be swept up by this low so that its remnants and all that moist air get into Arizona! Check these two maps out from IPS Meteostar. First, the surface weather map. The hurricane remnant is shown just off the tip of Baja Cal (red arrow).

The green areas are those where the model thinks rain has fallen in the prior 12 h ending at the time of this forecast map, 11 PM AST on June 18th, ten days from now. As you can see, the moist plume associated with the dying hurricane, and the entire tropical fetch around this low have been moved westward from the prior model runs and are shown to be entering SE California and Arizona. Fantastic.

Next, is the forecast map that goes with the surface map, the one for the 500 millibar level, around 18,000 feet above sea level. This level shows the steering of the moisture and that hurricane remnant, and that steering (red arrow) is going to take hurricane remnant northward into the Colorado River Valley during the 24-48 h after this map.

Will this happen in 10-12 days?

Almost certainly not like this, but it COULD happen like this. The model outputs have been fluctuating wildly from run to run. But, the ensemble (spaghetti) plots are making the overall situation of a trough along the West Coast in the time frame of 10-12 days, “pretty solid.” And having any trough there is a good thing when tropical storms are along the Mexican coast. They could, along with a good moisture plume, be directed into Arizona.

Hoping there’s some model truth in this exciting display.

The End

Dr. Dust Devil, Peter C. Sinclair

With no weather in view for the next week or so, and with June being “dust devil” month in Arizona, it seemed appropriate to reference the work of Dr. Peter C. Sinclair, University of Arizona, Institute of Atmospheric Physics, 1960s. Read all of his journal articles because I liked dust devils myself…. Don’t we all like to see them, are fascinated by them, when we don’t have a jumping castle about to be tipped over by one?

I know a lot of you out there, too, are fascinated by dust devils and even while driving, take snapshots of dust devils you’re particularly fond of. The photo below is from a friend who’s particularly fond of dust devils, as an example.

Here’s one of Dr. Sinclair ‘s pioneering efforts from 1964. Also, from a Google image collection, these . Some are fantastic!

Dr. Sinclair put stuff on his car, the kind of stuff shown in this article above, and drive into dust devils, getting measurements of the temperature, pressure and winds inside them. He was the first person to do that, to get measurements inside them, and so was making a real contribution. He was kind of a hero of mine since I, too, had a fascination with dust devils, though of a more visceral nature; I just jumped into them sans instrumentation when they crossed our San Fernando Valley school yard. Its a gritty experience. Hair gets messed up, too, but who cared about girls then?

Here’s a post-dust devil kid shot, entitled, “little Artie’s hair” for some reason. (I hope it was a post dust-devil shot! I always laugh when I see this photo and hope you do, too.)

Note that in the article referenced above, Dr. Sinclair, shown standing next to his equipment, has hair that is perfectly in place. I don’t think he jumped into them, to really KNOW them, like I did…

Plenty of sun all day, high sun angle, with resulting surface temperatures that could melt lead leads to tremendous instability at the ground and “superadiabatic” lapse rates here in Arizona. In these situations, the air right at ground level, within inches, might be 120 F, and the air just above, “only” 100 F.

The atmosphere gets rid of that excess heat at the ground via thermals, bubbles of warm air that lift off and is replaced by cooler air overhead. Our afternoon winds, ones that come up suddenly, then die out, and repeat that sequence over and over again, are evidence of those thermals. Leads to a very bumpy temperature trace since its warmer, then cooler, warmer, then cooler, etc.

Sometimes, when the bubble lifts off, perhaps suddenly, air swirls in to take its place, and by conserving its angular momentum, develops a tube as the air spins more rapidly as it approaches the the central lift off point. A more recent explanation is that small volumes of air already have rotation and become tilted upward over hot surfaces, as shown here.

Below, one taken by the arthur on a U of WA research flight over eastern Washington where dust devils are particularly numerous as well. You might think about spending some time in the desert there, since you could get into quite a dust devil, but it wouldn’t be as hot. Still have to have those superadiabatic lapse rates at the ground, however.

The weather ahead…

Man, the models of late have come up with an exceptional trough in the West. While no rain is expected here, it is quite extraordinary, and is pretty much supported by the ensemble plots (aka, spaghetti plots). Here is the upper air anomaly plot showing how extraordinary this forecast for the heights of the 500 millibar surface are for June 17th, ten days from now. This would mean exceptionally cool air over southern California and Nevada, and some cooling here, though not so much is indicated for us at this time since the low stays west of us. Inside the strongest winds around this low at this level would be the areas having precip, or in Nevada and central California only.

At this time of year, we need a tropical fetch for us to get rain, and that isn’t forecast right now. But the models are having a hard time with this situation, and it may be that some tropical air can be caught up on the faouter boundary of this low if it moves off to the west. Such moist air is already foretold to invade over New Mexico and west Texas, lucky guys.

The End.

Layered smoke, not clouds yesterday

From dawn til dusk, Catalina was plagued by a smoke layer from the fires in western New Mexico, ones you wouldn’t ordinarily think that smoke would get here from.

SONY DSC — An example of the mid-day smoke that looked so much like a cirrostratus layer.

Here is a loop of the water vapor imagery that will show you the air movement from where those fires are to us in Catalina. Also, even more dramatic, showing this is the visible satellite image from the Atmos. Sci. Dept at the U of WA, whose sports teams are not involved in NCAA baseball or softball playoffs, BTW. The arrow points to Catalina, and you can see that by the time of this image, 5 PM AST, we were not in the thickest part.

Now, as many of you know, air flowing down from the northeast is often a VERY good thing for rain here in mid-July since the afternoon thunderstorms over the White Mountains coming bopping on down in the evenings from that direction, driven by driving outflow winds from the northeast, pushing over and around Charoleau Gap. Can’t you just see the blackening July sky, the cloud-to-ground strokes to the northeast, then as close as they are to us, parts of the Catalina Mountains beginning to disappear, no longer visible through the dense rainshafts! Ah, yes, our great July weather…

In the sat image, you can also see that thunderstorms, best represented by the whitest dots in this image next to duller, smooth regions, are not so far away from us. Those whitest parts likely represent the regions of the storms where there are liquid cloud drops and updrafts, the cumuliform part. Those less white zones that appear so smooth, the “stratiform” or anvil portions composed solely of ice.

Rain is usually not occurring at the ground in most of the anvil regions; its just icy fluff, ejecta, and in many cases, counterproductive you might say. That’s because anvils can shade a huge area and kill of the Cumulus that might otherwise grow into storms.

Any rain indicated in the models for Catalina in the next 15 days?

No.

The End.

Dusty cool snap at hand

In MINUTES, the temperature will head downward as our long foretold (remember the spaghetti plots?) , “dusty cool snap” finally arrives. This time, from Intellicast, you can see below the blob coming, that blob of much lower temperatures with an epicenter at Las Vegas. Unfortunately, there are few clouds with this system, oh, maybe enough for a scruff over the Catalina’s a little later this morning and in the afternoon, Cumulis humilis, that sort of thing, and THEN we’ll get some nice cloud shadows on the mountains for awhile.

If you have a barometer, though, you will get to enjoy the “pressure check”, that sudden, sharp rise in pressure as the air over the barometer gets cooler and denser, mashes down on it more as the cold front goes by! You could be informing your neighbors about it. (Actually, “on further review”, with the temperature in descent now (5:18 AM), and barometer on the rise, I think the cold front has gone by already. )

BTW, while its windy here in Catalina right now, down in Tucson, they’re only reporting 7 knots, no gusts. This is kind of usual for this situation for us to get the brunt of the winds funneling up the Oro Valley while TUS is protected for the time being.

Still enough wind/pressure gradients around for dust today, but those gusty winds should really be gone by tonight and tomorrow in Catalina as that deep low, still in the Great Basin fades. See below for a neat looking weather map from where else, the University of Washington. In case you want to see more maps, go here.

Feels great to be in the circulation of a big low, that one centered in Utah right now (5 AM AST. People all around the country are probably talking about us and all the weather we’re having hereabouts, at least the ones watching The Weather Channel.

Not much ahead to talk about, just a few very pleasant clear days and rising temperatures.

HOWEVER, updating here at 6:11 AM, and having just checked the NOAA spaghetti factory, it does appear, but with moderate confidence, that another dusty cool snap is ahead for 11-12 days from now in a pattern remarkably like the current one with a “Big Trough” along the West Coast again. That event would center around June 7th plus or minus a day or so. It will be fun to keep an eye on this every coupla days.

The End.

Wind pummels Catalina again and again and again

Thinking about buying into the wind turbine thing….

Also, I’m hearing complaints about Catalina weather from anonymous sources. First, in late winter, it was “too dry.” Then recently, it was “too hot.” Now, I am hearing, “its too windy, I can’t take my horse out, my baseball cap blew off, etc.”

What have we become?

Hot, dry and windy, as in haboobs, dust devils, straight line thunderstorm winds, happen all the time in DESERTS. I am trying to think of a word for it, oh, there it is, we have become, “crybabies.” Yes, we have become “weather crybabies.” Me, too. It doesn’t rain enough in the desert and I haven’t really seen a good dust devil yet this spring.

OK, look for more dirt in the house today as winds perk up to 40-50 mph in momentary puffs over the next 24 h or so. However, for perspective, Hurricane Bud (110 mph sustained max winds) is about to strike the Mexican coast, so we really don’t have much to complain about in comparison except the fact that the remnants of Hurricane Bud will not come up here, but instead go over to Texas after crossing Mexico. Had this Big Trough causing all the low pressure and winds been a few hundred miles farther west, little Bud might have been swept up this way. Pretty upset by the bad “weather” draw we got so I didn’t want to miss an opportunity to complain a bit.

Take a look at this behemoth trough on the University of Washington 500 mb map for 5 AM AST this morning. Its truly gigantic, and has a really cold core over northern California with snow levels down to. The full loop is here. The clouds of Bud are in the extreme lower right hand corner.

Below this map is the surface pressure pattern showing the huge low center in the Great Basin, like a giant vacuum cleaner up there that is sucking the life out of the air around it and that air to the south of us, hence why that air is rushing northward across us with such enthusiasm; it wants to go right into the center and fill it up.

So why are there clouds and precip? Its too dry, of course, darn it. No tropical air can get to us with such a strong jet stream coming out of the Pacific and around that trough. The Pacific air, where it is deep and moist enough for rain and snow, is constrained within the jet stream core at 500 mb, and that core air will never reach us! Below, this morning’s sounding from Tucson, courtesy of the Wyoming Cowboys, in case you didn’t believe me that it was too dry. If the two heavy lines come together, it would be moist and clouds would be present, and as you can see, that doesn’t happen on this morning’s balloon sounding. And won’t happen, except for maybe rogue lenticular cloud, or, as the Beowulf Cluster at the U of A sees here, a scattered Cumulis humilis of no consequence this afternoon except maybe to produce nice shadows on our glorious mountains. Naturally, cooler air is on its way, too. More details here at the NWS.

The End

Windy, windier, windiest

Pretty much like that title will be the scene for Catalina for the next three days, particularly during the afternoons as temperatures moderate slightly to more normal values in the mid-upper 90s today, while the series of “Tonopah low” pressure centers that will form in Nevada and then move away, are stronger and stronger. The strongest one one is expected to form on Friday. Of course, “as always”, there was a low over Tonopah, NV, earlier today; now its down around Blythe, with cooler air following behind it.

Check our NWS excitement here where you’ll see maps and warnings galore. Also, here, where you can see the 24 h temperature change, a good tool for where cold fronts have passed. At this point, the major invasion of cold air stays to the north. Its later on the weekend it barges down thisaway.

Here are the current satellite and surface pressure map, and the “jet stream” maps (for 500 mb), both from the U of WA. What’s pretty unusual in our domain at 500 mb is how “warm” it is south of the jet stream (where the contours are bunched the most) over central California and Arizona. Its only -5 C at Tucson right now, hardly below freezing, up around 20,000 feet! This suggests that the racing around and outside the jet core on the south side has been subsiding like mad, and in doing that, compressing and heating up.

So what you might say?

Well, thinking of others here, normally, gobs of precip break out in the central and southern Plains States when these big troughs settle into the SW and Great Basin, but this one, on the models for the next few days, hardly produces ANY precip! Its pretty upsetting, really, because this could have been a real soaker out there in those droughty regions; instead the rain is mainly in Montana, the Dakotas and Canada.

And the likely reason is that the air is too hot above all warm and humid air from the Gulf of Mexico that is racing northward in the southern Plains right now to allow deep convection except in isolated areas. So, as warm as the Gulf air is, there will be an inversion that just won’t break down as they often do when they are not so strong as this one will be.

Nice sunset yesterday due to some passing Cirrus spissatus. Today will likely see more examples of those, along with Altocumulus or Cirrocumulus lenticulars, probably more off to the north of us because I see some over there to the north now (6 AM AST).

Bad trough! No precip, just a dusty cool snap ahead

Making its entrance today into the Pac NW is the first stage of that MASSIVE trough, foretold long ago by your NOAA spaghetti factory to begin happening about now, and peak out between May 25th-26th.

Now you’ll understand why, if you want to get a handle on the exceptional things that might be in the weather pipeline, you have to have some spaghetti every day. (Note: right now, 5:10 AM, the “factory” is down, has a bug in the sofware that REALLY makes it look like “spaghetti” because too many lines are shown. Its kind of a hoot. I will have to inform NOAA again, as I did a few days ago, or maybe you can, that something is wrong. Their answer to me back then was that they had not yet noticed the problem; made me think I was the ONLY one looking at them, also funny!) It is a powerful tool, one that also foretold the excessive heat we are experiencing today–recall the “June in May” writeup based completely on spaghetti.

OK, onward…

That second pulse of cold air aloft, the one shown below in the forecast map for the afternoon of May 25th (upper left panel) over Reno, NV, is REMARKABLY strong for this time of year, and will bring exceptionally low snow levels to northern and central California for later May.

And look at how much the surface map (upper right hand panel) is in a dither with the circulation around the low pressure at the surface extending all the way from Illinois to California! Its HUGE!

But what about us? What does all this atmo commotion mean for you and me?

Briefly, just Dust in the Wind, to allude to an old, sweet song by that heavy metal, huge hair group, Kansas, that hit the scene in the 1970s and were quite something I thought. Yep, the dryness in this HUGE trough makes me as sad as their song does about being only a spec of dirt.

Look at the lower left hand panel in the forecast chart below to see what the moisture expected at 700 millibars, about 10 k above sea level, or a little above the top of Mt. Sara Lemmon, for the afternoon of May 25th. It’s grim.

As you can see there are two but regions in the SW and West that have moisture at 10 K; that in central and northern California extending northward and expanding eastward, and a TINY stream from the tropics hundreds of miles to the east of us in western Texas.

Thus, there is no HOPE whatsoever of rain in southern Arizona with this huge system, because, like almost all of our cold winter systems, the core of the jet stream at 500 millibars, that band of wind that circumscribes the Pacific moisture over northern Califonia below, NEVER gets here, dammitall!

And those powerful winds around the outside of the trough core, really representing trajectories of subsided air from the cold Pacific, just race around it, preventing an intrusion of tropical air. The normal tendency for upward motion on the EAST side of all troughs trough is totally inadequate to produce clouds and precip with such dry air. About the only thing you could expect to see is a few filaments of rapidly moving CIrrus, maybe a lenticular or two on the 25th-26th, and, after the cool air moves in on the 26th, a couple of Cumulus humilis. And maybe the same kinds of cloud fragments off and on before that. Otherwise, the only “precipitation” will be “lithometeors”, dust particles. I suppose they might add up to an eighth of an inch over several days. Hahahaha.

Sure looks like the Catalina area will be raked with winds above 40 mph in gusts with this system before its over.

Check the excitement at the NWS here in Tucson here.

The End.

El Nino may be in the works for next winter; stories from the field

Here you can read the latest statement from the Climate Prediction Center on the neutral conditions that have developed in the eastern Pacific Ocean–La Nina is gone–and what it sees for next winter from their computer models. While things are not clear because they are so difficult to foretell, they are talkin’ El Nino some. As we know, the Southwest can benefit tremendously in rainfall when an El Nino develops, and so it is uplifting news to hear ANYTHING about an El Nino in the future and I though you would want to read that, too. Here you can see the last few weeks of global ocean temperature anomalies and how they are changing.

Why talk about next winter now? We should always be looking ahead in life, planning retirement, vacations, what football games to attend next fall, the important things in life; besides, there are no clouds to talk about, only hot air currents, maybe a dust devil, so I need some filler material. Remember when newspapers used filler material to make columns come out even, add some little fact? Those were great.

Too, I may have to dredge up some “stories from the field” to fill in the boring gaps in weather we have today, like that time they almost rolled over our VW microbus on that big boulevard in Madras (now Chennai), India, in August 1975. That big boulevard was reserved that day for the funeral parade of freedom fighter, Kamaraj, (against the British) with Indira Ghandi leading it. We should not have driven on it. Hundreds of thousands of people lined that boulevard for miles that afternoon! You would not have believed that scene!

The crowd. What I look like when I am in India (on the right)

I am still white-knuckled thinking about our knuckle-headed project leader who thought it was going to be OK to drive on that funeral route so we would get back to the hotel faster. He ordered our driver to go onto that boulevard, and then told him to, “just wave at the police”, guarding the route as we drove down it. We were returning from the Madras airport at Meenambakkam where we had been on standby to seed some clouds if they developed over a nearby reservoir catchment area. We were the only vehicle on that boulevard as the people waited for the official parade.

But then some of the crowd, maybe just a dozen or so, took exception to our driving down that boulevard and rushed our microbus. Our driver, sped up and slowed down in spurts, swerving left and right as well trying to shake people off his van. And the ones trying to climb on it did fall off, thank god, but fortunately no one was injured (or run over!)

In another bit of luck, the windows of that microbus were completely opaque due to heavy condensation on the inner surface of the windows, and so the crowds could not see that it was three Anglos in the back of that damn bus violating that boulevard. Heart pounding now as I relive that drive.

A bit farther, the driver somehow found a side street among the crowd and drove ever so gradually through all of those people lining the boulevard and finally onto the side street he knew was there.

That was an awful thing to have done and still regret being a party to it. But, somehow, too, my life was spared so I could write this blog in Catalina, AZ. Interesting. It better be good!

The latest map below (May 9th conditions) shows that the “warms” have it overall in the global oceans, and what’s important for us is that the cooler-than-normal water in the eastern half of the Pacific along the Equator (representing La Nina conditions) has dissipated.

For comparison, shown this map for May 9th is one for February 1st conditions when our La Nina was holding forth. Note the below normal temperatures along the Equator westward from South America across the Dateline on that map, and then look to the new one.

So there are no strong forcing factors at present to alter our climate from “normal.” Still means that the weather machine will continue doing its thing, hot, cold, rainy, extremes, etc., but there won’t be a dominant pattern, the kind that leads to a greater chance of drought in the Southwest and southern states as La Nina’s tend to do in late winter and spring. Yay! Summers don’t seem to be much affected by either of these conditions.

The Big One, that giant trough, is still on the way for implantation in the West, but only wind projected here

Dang. No rain. Likely we’ll hear about low temperature records in parts of California, Nevada, the Pac NW, extreme winds at various places, and hot and windy conditions here and in the Plains States. Very little rain is projected out there as well, at least in the early going of this enormous trough and low system. Starts affecting us on Wednesday; the TEEVEE weather presenters will be all over this one!

Cooler now, but windy, ovenly conditions just ahead

Here is the temperature change from yesterday morning at this time to today at this time, courtesy of The Weather Channel and due to that dry cool front that went through yesterday. Its about 8 degrees cooler this morning here in Catalina compared to yesterday at this same time. Nice.

But, its back to above normal temperatures for a few days after this respite. Normal is around 90-92 F here in Catalina for this time of year, but a 100 F is just ahead I’m afraid. No rain seen in mods for the next 15 days, too. Feeling glum.

Yesterday’s clouds

Had some nice supercooled Altocumulus translucidus clouds yesterday after the Cirrus departed. Here’s a shot that was taken as an aircraft flew through a patch of it. Note fine contrail. These clouds, from the Tucson sounding at 5 AM AST, appear to have been at temperatures between -15 and -20 C, ripe for aircraft to produce icy canals or holes, and that’s what happened. Below is the rest of the sequence, taken from different locations. In the last shot, the tip of that icy contrail began to light up and I thought I might see some color due to refracting ice crystals, but it didn’t happen. These aircraft effects on supercooled clouds are receiving more attention in the scientific community, BTW.

For a time, too, we had our lenticular cloud friend downstream of the Catalina Mountains in its normal position.

Powerful, but dry system progged for later next week

Check this “four panel” out, bottom of blog, from the Canadians from their model run last night. Its valid for the afternoon of Thursday, May 24th at 5 PM AST.

My first thoughts: Egad! Holy Smokes!

Looks like low temperature records will be broken in the West and Pac Northwest as this comes through those areas. However, the thought of the ovenly air over the Southwest at this same time, being drawn into the western High Plains States was alarming. This is because it could get superhot over there as our hot air comes down out of the Rockies. Fortunately, the models don’t show the 120 F temperatures in the Plains my alarmist mind was generating.

What WE will get here in Catalina as this giant trough settles in the West for several days is a LOT of wind and dust in a lot of hot air before the cooler air arrives sometime after May 25th.

This period of wind and hot air will be awful for the fire situation. No rain is indicated with this giant low, too.

I dread these days because you’re thinking about how much is on the line as far as our forests go.

The End.

Cooler hot air riding in from the West later today

Should arrive by later this afternoon as foretold in models, unfortunately, in view of fires, with a lot of wind before and after a dry cold front gets here, too. Check the NWS forecast for Catalina here.

The Cirrus clouds this morning? The only trace of clouds we’ll see with this trough and “cold front” today, if you can call it “cold”, with temperatures still in the 90s. Those clouds will be gone by mid-day.Tomorrow morning we’ll notice a temperature difference!

The weather ahead, as you likely know, fiercely hot early next week, after our little cold front goes by today, followed by another dry, windy, “cool” front around May 25th.

Of course, if you’ve had your NOAA spaghetti plot this morning, you probably already know about that weather change eight days from now. Here’s a chart from last night’s spaghetti run.

What do you see in the map below?

Except here at this blog, you have NEVER seen a weather map like this before! Imagine your TEEVEE weather presenter showing you something like this! Heck, where’s the land? Well, you can see Florida and Communist Cuba in the lower right hand corner. Just remember that Arizona is somewhere to the west of Florida. The outer dotted line is the Equator, where the date changes. (Just kidding, want to see if you are paying attention. Eyebrows should be raised on a couple of counts because TWO things are wrong in that ONE sentence.) OK, on to the map and no silliness….

First, those yellow lines are where the actual weather map contours of 576 and 552 “decameters” at 500 millibars pressure are predicted to be in last night’s run, on the afternoon of May 25th. When those yellow lines bulge southward, as they do in our domain in the West, a trough was foretold in that run. All the other red and turqoise lines help determine how reliable where those two yellow lines will be.

Look at all the red lines pushed down toward the Equator in our sector! There is nowhere in the northern hemisphere where so many red lines (576 decameter contour) extrude so far toward to the south! These red lines are from the same model, but run with slight changes in “initial conditions” (you might think of it as with a couple “bad balloon” readings) to see how robust the “signal”, the predicted features in the model are.

So, when all the lines, as wobbly as they are, do the same thing (extrude to the south, or bulge toward the north as they do northeast of the Hawaiian Islands) then the “signal” is quite strong, and the foretold feature more reliable. So eight days from now, a pretty long time in model predictions, we can be pretty darn confident there’ll be a MAJOR trough in the West that will affect Arizona. See how the turqoise lines also dip southward for the most part.

And what does that mean as far as Catalina weather? Dust, wind, and cooler weather for awhile; “dusty cool snap.”

No rain is indicated at this time, though the summer thunderstorms will be close prior to the dusty cool snap.

OK, I think I have confused things enough.

The End.