The weather ahead

Cooking with solar; dusty cool snap still ahead (25th or so)

It was 99 F here in Catalina yesterday.

Spinning entity in AZ today. See it here in the water vapor imagery from the Huskies, the Washington ones. Not much moisture with it, but we did see a couple of….. of…..yes, “Cumulus fractus” yesterday, maybe one big enough to be a humilis, if “big” and “humilis” can be used in the same sentence. In case you missed them:

No ice.

The zoomed shot is because Mr. Cloud-maven person could detect a “pyrocumulus” on top of the Crown King fire on the horizon. Can you?

Here’s the sat image, also from the Huskies, and you can see the tiniest little white spec on the top of the smoke on the left side.

Likely more Cumulus today. Yay.

At least some hot air relief is on the doorstep as a couple of weak troughs buzz the State in the next couple of days, but then its back to The Oven for a couple more.

However, after that, a much bigger cool down is still ahead…

Dusty Coolsnap coming to town

I wish there was a western singer by that name because I would probably buy his/her records.

Anyway, he’s coming to town around the 24-25th-26th, and its going to be real windy, REALLY windy with a lot of dust around, but then we won’t be cooking with solar so much then.

This is due to “big trough” implanting itself in the Southwest then. Will cause a lot of weather mayhem in the West for late May. Here are some scenes from the upcoming “show”, courtesy of IPS Meteostar: Opening the show will be The Ovens, with their hot rendition of 102 degrees (or more) here in Catalina on the 21st.

It will be so great to see “Dusty” after that! Hahahaha. Oh, well, I’m trying really hard here.

OK….now look at all the isobars in the maps below, valid for the afternoon of the 24th and then the 25th! Bunched in the State of AZ those days around that huge low center, first in southern Nevada and then, the next day, over Needles, CA! Wow. It just sits there! This is going to be fun, something besides hot air to think about.

Note, too, all that precip that creeps down into southern Nevada on the 25th. Sadly, that’s about as close as it gets to us here in Catalina. Oh, well, maybe things will “improve” for us as the event gets closer in the models. The real cool down is after the low goes by, after the 25th.

The End.

Scattered showers coming to a mountain near you

I wanted to get your day going on the right foot, one filled with the thoughts of a few scattered Cumulus and Cumulonimbus clouds next week, with almost a certainty of hearing thunder in Catalinaland, along with brilliantly colored sunsets, and some shafts of rain.

How do I know this so confidently, and am feeling good about myself also having those thoughts whizzing around?

Model “convergence.”

Both the USA (!) and the Canadian model (a version of the European Center for Medium range Forecasting, “ECMWF”) are both showing rain around here, and the little baby low center that forms going along the same track, one to the south of us.

BTW, a quite illustrative cartoon discussion of models (USA vs European) after Dreamworks has been released recently. You’ll want to bone up on models here, perhaps before reading on. This cartoon was brought to my attention by Mark Albright, the former WA State Climatologist who wants to live in AZ but can’t make up his mind on a house, to give credit where credit is due. This is so funny; brilliant!

The GFS (the US Global Forecast System) explained. Rated “R” due to language near the end.

Contnuing on to what the models are saying, the chances of rain falling here are more better when the low center is a little to the south and moisture from the tropics can wrap around the low from the east side of it. Here are two prediction maps for about the same time. The first from IPS Meteostar for Wednesday May 9th, midday.

You can see a low center at 500 mb (18,000 feet or so in the atmosphere) is over the north portion of the Gulf of Baja California, Sea of Cortez. The green represents moisture at that level streaming in from the east on that day. Cool! We will certainly get a boatload of Ac cas with this, something that Mr. Cloud-maven person likes to see and frequently, as a result, forecasts its occurrence wrongly because he is not being objective, but SUBjective, which as the name applies, is below “objective” and being “disinterested” in what you are talking about, to go on and on about it. It happens in science. Remember when…, oh, never mind.

OK, below this chart, from Enviro Can, is also one for Wednesday, May 9th at 5 AM AST-PDT. The low center at 500 mb is shown by the little red dot in the upper left panel. You can see that both models have now (after being “divergent”) have put the low center in the same spot. The USA model had it farther north for several model runs, which were quite bad for rain here in Catalina.

Yesterday’s clouds

Just a few Cirrus ice clouds floated over as the upper level winds start turning from the southwest at high levels. These kinds of clouds should be seen over the next few days.

Baby cutoff low coming to a sky near you; is followed by June in May

Something to blab about at last. The computer models show a small area of low pressure breaking off the main jet stream and setttling over Arizona for a few days. Arrives on Monday, May 7th, then hangs around for a couple of days before moving off. Rain here? Doesn’t look like it now, but there should be some high based Cumulus, and one or two high-based thunderstorms over the mountains, maybe some Altocumulus here and there, too.

The happy part of this is that this time of year weak lows aloft like this one can produce a boatload of rain in the droughty areas of eastern New Mexico and west Texas when they interact with that Gulf air sloshing northward and westward into those areas. That happens after this forecast map. Let’s hope so. See below from our friends at Environment Canada for the afternoon of May 7th:

However, and pretty confidently predicted a huge bubble of warm air arises over us in the days. This in the longer term NOAA WRF-GFS model rendered by IPS Meteostar below. The last of the snowbirds will be scurrying off to their northern climes when this hits since temperatures are likely to ascend to over 100 F for a few days (a preview of normal June weather). Get ready.

Errata

Mr. Cloud-maven person misspoke recently when he asserted that May was our driest month. Below he reprises the Catalina monthly rainfall averages for himself and his two other readers.

JUNE is our driest month!

Cold one on tap for Catalina; tubes in Cal

First, this is not about BEER!

Usually when you get carried away and expect something unusual to happen, it doesn’t, like that girl I thought liked me but didn’t (there have been a number of those…) Yesterday, carried-away Mr. Cloud Maven person mentioned the possibility of tubes in Cal. Here’s the report in the Big Valley near Merced, CA, from yesterday. Big hail, too. I am pumped! Spiking fubball now!

0535 PM FUNNEL CLOUD ATWATER 37.35N 120.60W
04/12/2012 MERCED CA PUBLIC

3 DIFFERENT FUNNEL CLOUDS IN THE ATWATER AREA

0605 PM HAIL ATWATER 37.35N 120.60W
04/12/2012 M1.75 INCH MERCED CA AMATEUR RADIO

Official name of tube-producing clouds? Oh, something like, “Cumulonimbus capillatus incus (has an anvil) tuba.”

Actually, its not terribly unusual to have tubes in Cal when the air is extremely cold up top over Cal in April and May, and that’s what we have now. Take a look at this nice, compact map from San Francisco State Former US Hippiedom Capital Weather Department for last evening at 5 PM AST. At San Francisco, its -29 C at 500 mb, very unusual for mid-April. (Actually, they got some real nice maps there.) Combine that with the strong sun on land surfaces, and voila, Cumulonimbus galore!

Also, if you look carefully, you will see that where there is no data, over the Pacific Ocean, the 500 millibar pressure contours are nice and smooth . But notice how “nervous” they get once crossing the coastline where there is data. I think really it has something to do with the interpolation scheme that try to place the contours exactly at the right spot between the real data; that algorithm may be a little primitive. Kind of funny in a way.

That cold core of air is heading for Arizona, and no doubt some April low temperature records will be set, such as lowest maximum, and likely a few minimum temperatures before this passes on into the Plains, with no doubt true severe weather there the result of that. And we, too, will have some Cumulonimbus clouds, lightning here and there around the State.

Below the SFO State map is the forecast from IPS Meteostar showing where this mass of cold air will be later Saturday at 5 PM AST, northern AZ. U of WA WRF-GFS mod thinks rain will be occurring here just about ALL DAY on Saturday after beginning around dawn! That would be a heckuva cold day, winter-like, with temps in the 40s-50s here at 3,000 feet and we’d have those pretty white Catalina Mountains afterwards. Sure seems like 0.20 inches is in the bag for the bottom of this rain event, with maybe 0.50 inches being at the top here in Catalina.

Yesterday’s line of enhanced virga in As deck at sunset

Now here’s an odd feature. Looked at first that it might have been due to an aircraft passage in that streak of Altostratus, but then I rejected that thought, as I can do. I came to believe somewhat confidently, odd as it is, that it was natural. Natural linear features in clouds are fairly common. Here it is, in case you missed it:

Rain and cold foretold for Catalina on Saturday as big, long-foretold storm bops Cal then moves on to AZ

Things are falling into place. Remember the spaghetti from a week or more ago, in which it was clear, or at least at attempt was made to explain to both readers of this blog, that a large trough was almost certainly going to be along the Cal coast? We intuited that from the lack of spread in some contours in that “spaghetti” plot along the West Coast some week or more in advance.

Well, that trough is truly turing out to be a behemoth, a gigantosaurus for April. The people of California are going to be very excited today and tomorrow about cold, showery weather, mountains of snowfall in the mountains, maybe a funnel cloud or two in the Sac or San Joaquin Valleys. Here is that trough as shown on today’s 5 AM AST 500 millibar map from the U of WA weather department, the one prophesized with high confidence so long ago:

However, for many days after that, the models did not think the rain in Cal was going to get here. Of course, still being in the cool season, our rain is nearly all dependent on whether the jet stream in the middle levels (500 millibars or about 18,000 feet above sea level) is able to be over or especially, south of us here in Catalina.

But lately, in the forecasts, been shifting the jet southward and rain has started to show up in two or more recent model runs, always a good thing. You may also remember that in our spaghetti plots back a week ago, it was not clear in the models where the Cal trough was going to go after it bashed the West Coast. Hence, while things were clear for Cal (actually, they were going to be cloudy and rainy), they weren’t so clear for here until lately.

From the U of WA, this for Saturday morning (colored splotches denote where the model thinks precip has fallen in the prior 3 h); below, the jet stream at 500 mb from IPS Meteostar for the same time.

Yesterday’s clouds

In case you missed them…. Cumulus and Stratocumulus, punctuated with a splash of Cirrus fibratus undulatus (Cirrus with rolls, showing something akin to swells in the ocean in the atmosphere). The wind at Cirrus level in that shot is blowing from left to right. No ice falling out in Cu and Sc; too warm at cloud top. Only about -5 C (23 F) or warmer.

The End.

Pretty skies, but no castellanus (again)

Apparently the castellanus formations went over during the nighttime hours when we couldn’t see them…

But it was a fabulous day again of interesting high and middle cloud flecks anyway. Below, a reprise of yesterday’s clouds starting with that delicate patch of Cirrus passing over the Catalina Mountains with its tiny fibers of Cirrus uncinus embedded in it. I have also included two sinister crossing contrails. Who knows what evil lurks there? Perhaps they’re marking a target of some kind, or filling out a questionnaire with crosses instead of check marks. Oh, well.

Later, as the sheet clouds of various Cirrus, Cirrostratus, and even Altostratus with virga cleared off, we got into some scattered lenticulars, some of to the distant north, and with our usual friend downwind of the Catalinas, shown in the last two shots. It was able to hang on for several hours, right past sunset.

Again, for the whole day’s cloud excitement, a great place to go is to our very own U of AZ Wildcat time lapse movie. In the late afternoon of this movie, you can see some great Altocumulus lenticularis clouds hovering over and downwind of the Catalina Mountains, occasionally shooting upwind as the air moistens in the humped up airflow, and you can get a sense of how little the air is pushed up in lenticular clouds from this movie.

(Once again the caption function has quit in WP before I got to some of these. My apologies.)

Gee, “dusty cold snap” is beginning to look more like “muddy waters” as the later model runs dip the jet stream farther and farther south over us on the 14th and 15th. Check this forecast of the precip hereabouts from the U of WA’s WRF-GFS model run from last night, showing a bit of rain HERE Saturday morning (colored areas of map). Sure hope so. Terribly cold air with this, too, for mid-April. Likely some low temperature records will be set in the State somewhere for this time of year with this.

The End.

SONY DSC — Tiny Cirrus uncinus, top center, Cirrocumulus top right with,oh, maybe Cirrus fibratus (has linear fibers) lower left.

Addendum; yesterday’s and today’s clouds

Addendum on beer

BTW, if you’re still interested in beer and clouds after yesterday’s blog about CIrrus being “on tap”, get this book:

Clouds in a Glass of Beer: Simple Experiments in Atmospheric Physics, Dover Publications, by Professor Craig Bohren. In spite of having an interest in beer or perhaps because of it, he is a Distinguished Professor Emeritus of Meteorology at Penn State University, one of the leading party schools in America. Writes about optics, too, a real atmo optician. Kidding aside, his book above is one of the best you can get on how the atmo works and has been popular for decades; was updated in 2001.

I forgot about it, darn, but added it to yesterday’s blog to “go with the theme….”

Yesterday and today

Nothin’ but filmy Cirrus clouds yesterday enhancing the skies over Catalina. Here’s are two examples. BTW, if you were really noticing, they tended to be thicker and more widespread to the north, as in the second photo, closer to the main jet stream up thataway.

Same stream of moist air at high levels continues over us, but, what happens over time with these high level streams of moist air? They tend to lower in height as time goes by. Here’s the stream in this loop from the U of WA Huskies Weather Dept.

So, today, we’ll likely see some mid-level droplet clouds, not all ice clouds like Cirrus ones of yesterday, and because its relatively warm up top, those droplet clouds tend to be turreted, i. e., Altocumulus castellanus (has a base) and floccus (base is evaporating upward). Both types indicate the same thing, really, that the atmosphere is a little “unstable” up there; updrafts are easily produced when the cloud forms and a little heat is released in the condensation process.

It looks, too, like those Altocumulus clouds will be around with the Cirrus at at sunset today, and you know what that means: lots of color so charge those camera batteries, cross fingers. Could be especially spectacular.

Cal-AZ storm update

The long, and confidently predicted (think spaghetti here) and unusually strong trough and storm for April 12th is still in the cards for Cal. AZ pcpn, though plentiful for April over a couple of days in the north, may not reach us here in Catalina, and if so, will be minimal it now appears, maybe a few hundredths. Look for dusty breezes for sure after the 12th. Check this loop out for all the details, again from the Huskies.

The End

Dusty parhelia

No, that’s not a baseball player that played for the Dodgers or Giants back in the 1950s, that was Dusty Roads; though Dusty Parhelia would be a nice name for a baseball player. Yesterday, with our slightly dusty skies, and on the 22 degree halo ring, and horizontally from the sun’s position, was a couple of sun dogs (parhelia) late in the day associated with those cirriform clouds we had. You know by now that those high clouds are comprised of small ice crystals. Here’s a few shots of those clouds, which were often CIrrostratus with embedded other Cirrus cloud species like spissatus, fibratus, and uncinus.

The ice crystals in those clouds are typically hexagonal (six-sided) plates, ones that fall face down. If you could be there in them, and see them falling, at eye level you would see only the sliver side of them, but if you looked down at one that went by, you would see the whole hexagonal plate. The way that they fall is why aircraft laser imagery, when the laser is oriented in the vertical, captures such beautiful, full images of plates and other flat crystals in ice clouds as the aircraft flies through them.

The sun’s white light is separated into its colored components in these hexagonal crystals (but only at certain specific angles) and for this reason, the bright spots are at the same locations relative to the sun. Since I am not an atmo optician, I am relying on the links above to provide more complete, comprehensible explanations.

Note: Caption function stopped working again in WP for the fourth photo, and after half a dozen tries, will write it here:

Photo 4 caption: An especially vivid parhelia can be seen just above the horizon at lower left. The brightest ones like this are usually associated with aircraft contrails since those have high concentrations of pristine crystals. A flying saucer, or a bird with its wings closed at the instant the photo was taken, is also visible.

Continuing….

Sat image loop from the U of WA weatherfolk show lots more cirriform clouds in route to AZ next few days with occasional breaks. So, keep your camera ready for optics and sunrise/sunset color.

The weather ahead? Dusty cold snap.

“Dusty” is kind of the word of the day today.

Long foretold big Cal storm on the 12th-13th affects southeast AZ mostly with wind and dust on the 13-14th followed by unusually cool weather for mid-April. A hint of rain excitement for Catalinians has begun to show up in model runs, such as this one from the U of WA for early Saturday morning on the 14th. Yay.

The End

Big storm to strike California on April 12th; maybe it’ll bring some rain here though I doubt it

If you have had your spaghetti this morning, you would be able to write headlines like this. Here’s the plot, no, not like in a detective story, but an actual plot from the Spaghetti Factory at NOAA, valid for 192 hours from last evening, or in plain speak, next Thursday afternoon at 5 PM, April 12th, AST:

SInce you’ve had lessons in spaghetti, you should be shrieking when you see this one, “My gosh, look at that potent, powerful storm about to strike California! I can’t believe one that big would strike in the middle of April. Quite unusual.”

OK, calm down that bit, but still stay excited. Yes, the Dark Void radiating from approximately where Santa Claus lives in this plot shows you where there can great confidence that a big trough is going to be present where the Dark Void ends. Notice the dark tube extending from Nome-Anchorage, AK, all the way SSE to off northern California. And another one in eastern Canada, etc. That, as you know, is where a trough will be at 00Z on Friday, April 13th (in ordinary time, 5 PM AST on the 12th, and with that, a strong low center is coiled and ready to strike. Exciting.

Let’s go to the next chapter of this plot, one but a day later, valid for 5 PM Friday the 14th and see if the Darkness is able to extrude (I really like that word because its fun to stretch it out and make it sound like what it is describing–“ex-TRUDE”, you can feel it oozing along, its an onomatopoeia, like “thunder”). Now where was I?

Oh, yeah, the plot, revealing the plot (story-line goes), for the next day is below.

Sorry you you have to see this. After explaining the above plot, and with the background on spaghetti plots I have provided you in ealier blogs, I don’t have to tell you how disappointing the one below is. Only a slight chance of rain here exists, and there is not much confidence in configuration of the trough and jet stream around it after it rockets up to the Cal coast on the 12th.

There is another chance of rain indicated from last night’s run, that on April 19th, a day in which it has not rained in 35 years here in Catalina. Odd. Are we due? Or are there climatological factors at work to minimize rain around the middle of April? I really don’t know the answer. However, it is not a very reliable prediction at this point. It will likely come and go in the model runs in the days ahead.

In the meantime, today’s clouds

Here are a couple of shots of the Cirrus/Cirrostratus-with-contrails¹ mesh we have overhead this morning, ice clouds, as you now, with a hint of lenticulars off to the distant west. Should have nice Cirrus-ee clouds all day, and again, a chance of Cirrocumulus or very high Altocumulus lenticulars. Not much chance of anything below about 15,000 feet above the ground today.

¹I HATE contrails except when I am flying to some fun place I want to get to in a hurry!

The End

April precip climo; yesterday’s cloud

Well, no surprises here. The chance of rain continues to diminish overall in April, with an especially dry period in the current 35 year record in the middle of April. It has not rained on the 9th and 19th in all those years! Odd.

Since rain at this time of year has to be associated with cold troughs (like the Joe T of yesterday), these frequencies also tell you when a passing trough is more likely. We had one go by yesterday evening, and its still nearby, fitting the pattern above of an enhanced chance of rain day or trough passage in the first few days of April.

BTW, most of these data are from the folks at Our Garden in Catalina, who happen to be very weathercentric, thank heavens. You should really go there and buy everything they have as a “thank you.” (hahahah, sort of.)

Today’s upper level configuration from the U of WA is shown below. You can see that “Joe” is still around; in fact, he’s in the process of forming a closed center just over the horizon in New Mexico. This will eventually be a great rain producer, as mentioned yesterday, for portions of the southern Plains States. It would be great to be there during those downpours. Anyone for a road trip to OK? (hahahahah, sort of#2).

Yesterday’s cloud and its shadow

Here it is, in case you missed it. Well, OK, there was more than ONE, but not too many more. And, disappointingly, they faded before sunset! What were those clouds? Cumulus fractus, maybe as “large” a one that it could be termed a Cumulus humilis, but that was it. No ice, of course, not cold enough, only about 32 F at top; just droplet clouds.

The weather ahead? Dry now

That mid-April chance of rain has disappeared on the models, now seeming to fit the 35-year climatology of it being VERY hard to get measurable rain here in mid-April. Dang. Nothing in sight now for the next two weeks in the latest model calcs.