Cloud-maven – Page 89 – About real clouds, weather, cloud seeding and science autobio life stories by WMO consolation prize-winning meteorologist, Art Rangno

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.

Old “Joe Trough”; cool temperatures move into Catalina later today

Mr. Cloud Maven person tried to trick you by titling his “piece” (“piece”, hah!) using a popular but not quite proper weatherspeak phrase, “cool temperatures”; something he ranted about a few days ago. Properly, and we try to be quite proper here, but probably aren’t, its cool “air” that’s moving toward Catalina.

As a demonstration of this assertion about cooler air moving thisaway, here, from our friends at Intellicast Inc., ones who hate Accuweather I’ve heard, is today’s 24 h temperature change chart (like to throw in some gossip from time to time, helps build ratings):

That blob of blue is associated with the encroachment of a cold front, where cooler air is replacing warmer air. Its the cold front that came ashore with Joe Trough (that trough that was so well predicted in its path across the Pacific Ocean for more than a week in advance) and his big low pressure center that brought hurricane force winds to some portions of the Oregon coast yesterday.

Unfortunately, both the warm side of the cold front (east of the cold front’s windshift line) and the incoming Pacifc air are both too dry for precip here. However, there should be a few small Cumulus later in the day as that cooler and more moist air arrives here in Catland. Also with a bit of moisture at mid and high levels, we could also see an Ac or Cc lenticular–keep an eye toward the NE and downstream from Mt. Sara L. Expecting a nice gold-lined small Cu sunset.

201204010900_500mb — "Joe Trough", the one we've been following, goes from Vancouver Island to San Diego here.

201204010900 — Joe Low, or just J-Lo, is trying to reform around Tonopah, but the main center is way over there in eastern Montana.

Where Joe T is this morning, brought to you by the U. of WA, is shown in the next panel, and the third one shows that Joe’s Low, or “J-Lo” for short, is all the way into eastern Montana! However, a second low is attempting to form around Tonopah, of course.

As Joe Trough ages, moving SLOWLY across the Southwest today (passes over Catalina at 8 PM AST), it will cast off by the main jet stream and will eventually become an isolated, enfeeble-ized meandering cut off low with a weak circulation over Texas, finally ending up, like so many old things, in Florida six days from now.

Not a great way to go, but with more moisture rising up from the Gulf of Mexico, this moisture being something of an age enhancer for “Joe”, huge amounts of precip will fall in the southern Plains food basket of the US. You don’t need so much strength as a weather system to generate huge clouds when you have Gulf air to play with. Think of our summers. No lows required, just that high dewpoint air and a blazing early sun for a good downpour here and there.

Note the new header today, along with an AZ Cat color scheme implemented by my web page person, Jenny Rink. She’s great! Go Wildcats! Huskies, too, though.

Speaking of summer and humid air….

Longer range models have something akin to a summer rain regime breaking out on April 10th, blazing hot with lots of tropical clouds streaming up from Mexico. Rains in SE AZ for three days, ended by a sharp trough and cold front on the 13th. Something to keep an eye on, dream about.

Will have some April precip climo tomorrow.

Cirrus altocumulus castellano-floccogenitus

We had a rare form of Cirrus yesterday, whose name I have made up in the title as a hint of where they came from, due to the very high altitude and low temperatures of some Altocumulus yesterday. Those Ac morphed to Cirrus, hence the strange, unpronounceable title.

Reminder, weatherscience mavens, its more proper to say “low” temperatures; not “COLD” temperatures, FYI, though you constantly hear it. (“Things”, like coffee, air, chairs in the sun, etc., are hot, warm, cool, tepid, and cold; temperature is not a physical thing, and is high. moderate, or low, etc.))

Still bristling over some unexpected clouds yesterday, so I wanted to complain about something minor, bring some discipline to the field.

Mr. Cloud-maven person was not paying attention, asleep at the wheel, etc., when some Altocumulus castellanus and Cirrus castellanus came a truckin’ over the horizon and floated over Catalina after dawn yesterday, but had not been mentioned in this blog in advance. I am sure, since they had not mentioned from this keyboard, you may have been in some distress yesterday when they showed up and you weren’t sure what was happening. My apologies. It will almost never happen again.

Here are some photos of the interesting clouds that passed overhead yesterday. I was quite excited to see them partly because I had not prepared myself mentally for them. Now, there is something strange in the first caption. But I wrote it that way on purpose because I REALLY want to know if YOU know WHERE the HELL you are, and where the mountains are around here. Next, after that outrage, some interesting banded Cirrus. Then a hint at where those Cirrus came from in the background of the 3rd shot.

SONY DSC — First, this sunrise over the Tortolita Mountains with Cirrostratus nebulosus (vellum-like cloud) and a hint of Cirrocumulus (tiny, brighter, flocculent specs).

DSCN1187 — This banded Cirrus gave some hint as to its origin. Might be termed, Cirrus uncinus, or floccus, or fibratus, its a pretty complicated set.

Caption function not working now for this third shot in WP, so here it is:

3) A nice example of Cirrus uncinus in the foreground, tufted or hooked ice clouds trailing tiny ice crystals. In the background, a clue to the origin of the patchy, banded Cirrus.

4) Another shot of the approaching Altocumulus castellanus (Ac cas) and (Ac floc) floccus clouds as they arrived overhead, some of which have morphed completely into ice (Cirrus) clouds, such as that larger element over the house in the foreground! In the upper left quadrant of this shot are Ac clouds that, to this eyeball, are still liquid.

Droplet clouds have more sharply defined edges because droplet clouds have MUCH higher concentrations of particles in them than ice crystal clouds (which tend to make them “fuzzy”, ghost-like, striated, fibrous, etc.

Why this visual difference, which I want you to learn, to see for yourself and impress your friends?

There are more cloud droplet condensation nuclei than there are ice crystal nuclei. For example, liquid Altocumulus clouds might have 100,000 to 500,ooo drops per liter in them, while ice crystal clouds may have only tens to a few thousand per liter (and then only in newly formed elements) of ice crystals. In general, there are more cloud condensation nuclei than ice nuclei, too.

Today

While “Joe” is spinning up into his little hurricane-like self in some kind of weather tantrum off the California coast today before heading to Oregon, our skies over Catalina will be marked by various forms of Cirrus clouds, ice clouds well above 25,000 feet above the ground, and not much else. BTW, you can follow Joe’s progress here from the U of WA, if interested.

If you’re interested, instead, of following our Cirrus clouds as they approach and go overhead today, go here, also from the U of WA. You see the Cirrus clouds pealing off the main frontal band in the Pac NW and then fading as they head this way. (I would increase the speed of the loop for maxium excitement.)

The End.

Joe the Transformer

“Where’s Joe?”, a new game for kids and adults. I’m talkin’ “Joe Trough” here, that little big boy we talked about a coupla days ago that’s going to bash the West Coast now in a little over 48 h. Try to find “Joe” here.

Did you find him in the satellite clouds on these weather map? He’s entering the scene, “stage left” as a hint. If this was a silent film, there would very a dramatic and dark organ accompaniment at this time: “Joe” is a villain, about to transform into a monster. Yes, that’s right, “Joe” is a “Transformer”, to recall movies that we’ve all enjoyed where things turn into bigger things (I am so kidding here). But, “Joe” WILL destroy some stuff in a couple of days.

For us little older weather-centric folk, it was obvious where “Joe” is. Of course, I know you, too, are weather-centric, hungering for more information, thinking about quitting your current job to become a weatherman, “why did I chose my current profession in the first place?”, the kinds of things that TRULY weather-centric folk ruminate about all day.

So, I will tell you. “Joe” is that comma-shaped cloud in the north Pacific almost due north of the Hawaiian Islands at this time (5 AM AST, 12 GMT today), and oddly, separate from and to the north of the long bank of clouds that stretch from Duckville (sometimes called “Oregon”, sorry Beavs) and northern California into the central Pacific and then on to Okinawa I think.

So, how do we know “Joe” will become a monster? Our computer models are so good these days, they just never miss a situation like “Joe” is presenting to us. All the ingredients are there, sharp air mass contrasts, STRONG upper level trigger (“Joe Trough”) on top and approaching the long frontal band mentioned above, and starting to make it expand and swell up. The most incredible thing to us weather folk, is that now, “Joe” doesn’t even have an eyeball (no low center) on these maps above and in the latest one below for 5 AM AST today! I will show you that latest map with a “no eyeball Joe” below, it’s just a bend in the isobars (yellow lines of equal pressure); his power comes from above. Soon, JT will cause the air to start wrapping around itself and a hurricane like eye-center will form out of what was just a long, almost straight band of clouds.

But look below at what the models say will happen in but 48 h! The transformation is into practically a cold season hurricane striking Oregon. Certainly hurricane force winds and pounding rains of several inches will strike northern California and the Oregon coasts in but two days. There are so many isobars I can’t count them all, and, as you know, the more tightly packed a lot of isobars are, the stronger the winds.

Two things are exceptional about this storm, the time of year, and that its so far south with this kind of intensity. Very rare to see such an intense low strike the West Coast south of Seattle at any time, but in late March? Wow.

Look for some damage reports in the Pac NW and Cal beginning on Saturday.

Here?

Just some friendly, non-threatening Cirrus clouds (ooops, and maybe a lenticular or two since I just saw one–something we meteorologists call, “retrospective forecasting”–really helps your accuracy ratings…and here at 8:03 AM, seeing Ac cas with long virga trails. Better predict those, too, now).

Not much else for the next few days in the skies, but we’ll get a part of the remnant of “Joe Hurricane” on Sunday. Expect a lotta wind and dust in the air, and then a SHARP drop in temperatures after the dry (boo-hoo) cold front goes by. Also, go here to experience more excitement at the Tucson NWS when it gets a bit closer.

The End.

What’s up? Smoke, most likely

You may have noticed, if you’re from around here, that we did not exactly have an “Arizona Highways sky” yesterday. The sky was an awful whitish color tinged with blue (I’m fussy here). Below are examples of smog from the ground and from satellite. from yesterday afternoon. (Where there are clouds, BTW, the satellite can’t tell if there is smog under them.)

As you can see, the sky is not good over Catalinaland in this mid-afternoon shot from yesterday. And, it was not aloft in a layer as we have sometimes seen, but is partially obscuring the hills and mountains in the distance. It is also what we would call a well-mixed smog, which indicates its not generated locally. In that case of a very local source, there would be obvious thick and thin regions. Yesterday, it was homogenous, pretty much the same looking smog in every direction. (Tends to look worse toward the sun.)

In the aerosol satellite image, you can see we are in a blob of smog as indicated by the light turquoise area over Arizona and extending into northern Mexico. BTW2, dark blue in this graphic is a good sky, while a red one is awful. Our smog level here, as indicated by a parameter we call, “aerosol optical depth” (AOD), was around o.3 or so according to the satellite image below (probably on the high side). AOD measurement doesn’t know the height of the smog; its just how much is in the air between the top of the atmosphere and the ground.

For comparison, if the sun is NOT visible due to smog, the AOD would be about 4.0. Yikes! A really clean sky has an AOD of less than o.o5; its a really blue one and on such a day, from here you would be able to see Mt. Humphreys near Flagstaff if it went up to 40,000 feet or so, it is THAT clean. (You can actually see the tops of Cumulonimbus clouds near Flagstaff in the summertime from here in Catalina on these kinds of days with no intervening clouds.)

So where is it all coming from, I’d like to know?

To get an idea, we go to our trusty NOAA Air Resources Lab and their “HYSPLIT” model and run back trajectories for the air at the levels we estimate the smog is at. Of course, you can do this yourself; in fact, I have to say that it seems like I have to do everything for you.

Anyway, below are a couple of plots for various heights above the ground from ARL, 500 m (1500 feet), 2000 m (6600 feet), and 3000 m (10,ooo feet) for the past 4 days before the air arrived here.

You can forget about the one that starts at 3000 m (green line) above ground level in the Pacific. These plots also estimate the amount of lifting and descent the air went through, and you can see that the green parcel was caught up into a low center, got spun around in a circle, thrown upward to above 20,000 feet (7 km) and then descended on the back (west side) of the low. In going upward so much, clouds and precip forming in the upward moving air would have removed all untoward aerosols, so we can pretty much rule out something from Asia having crossed the Pacific, as happens from time to time.

Looking at those lower level trajectories (500 and 2000 m above ground level, blue and red lines in the plot) the likely culprit is found. Those ones represent back trajectories in much slower moving air that arrived over us, air that apparently spent a day or two in northern Mexico before getting here. That the of smog over us extended into northern Mexico and you start to think that the smoke probably was captured there and then eased northward across the border. This seems to be hinted at in the cloud wind field available through the University of Wisconsin and the US Navy’s Research Lab here. There are a couple of “wind barbs” (yellow colored ones) in northern Mexico that suggest southerly and southeasterly winds at levels where the smog was. Not an airtight case, but it probably drifted up from Mexico.

Enough about smog!

The case of the spaghetti plots; an update

In our last episode, it was foreseen that a confidently predicted, “Joe Trough” , was going to bash the West Coast on the last day of this month with a strong storm, little doubt about it. He had been tracked nicely by the computer. Looked the same, “buff”, potent, day after day 4-5, ten days away as he crossed the Pacific Ocean. But after entering the USA at the end of March, “Joe” lost control of himself, it was unpredictable about what he would do next. At that time, displayed here on this blog, one computer guess was that he was going to break up into pieces, one piece over Arizona for days, sitting around, dawdling really, producing scattered showers in the first week of April thoughout Arizona. It was an unusual pattern, but there it was on the model outputs.

Sadly, from the spaghetti factory at our NOAA Super Weather Computer weather center, and the wild fluctuations it showed, indicated “Joe T” might do a lot of different things after he entered the USA. We could see that this rainy Arizona forecast was just one of many possibilities for “JT”, he was “unreliable” after approaching the West Coast no matter how badly we wanted that forecast that came out to come true; we just couldn’t count on it.

Now “JT” is only a few days away from crashing into the West Coast, still well predicted. But how about after he enters the West Coast? What will happen now? Will Joe break up into pieces and dawdle over AZ? Will there be rain? Or will we have just a dust storm and a dry cold front?

Let’s look in on the spaghetti factory and see what happens to Joe on the way in now, only few days from possibly affecting our weather.

From last evening’s spaghetti plots (“ensembles” in weather higher ordered weatherspeak) this 96 h forecast showing “Joe Trough” as it is about to hit the West Coast. As you can PLAINLY see, the entire earth’s weather north of the equator is well predicted as far out as 96 h, valid the evening of March 30th, 5 PM AST. In case you’ve forgotten, when all of the lines run almost on top of each other, things are well predicted, little chance of a busted forecast. The southward bulge in the turquoise and red lines just off the West Coast is our incoming “Joe Trough.”

The next panel, for later, valid for 5 PM AST, March 31st, shows that “Joe” is now in the Great Basin doing his thing, and the southern part of “Joe” is over us! Yay! Or not.

Remember the Red Zone, not in fubball, but in these plots? The red lines represent pretty much the southern edge of the jet stream at this level, 500 millibars pressure, around 18,000 feet above sea level. The turquoise lines represent pretty much the northern side of the jet stream at this level.

So, what’s wrong with this pretty picture (2nd panel)? Joe’s Jet (sounds like a singer I’ve heard of), doesn’t pass south of us by all reasonable expectations. Those little “perturbations” they put into the model at the beginning of the run to see how they might change the prediction, and thus get a handle on its reliability in case of errors, missing data, chaos in general, have the Red Zone (where the red lines are grouped) north of us. Jet north of us, as these red lines indicate, means no precip no where ’round here.

Well, unless you count dust as precip, and it certainly will pile up some.

“Joe” is strong and cold, but passes too far to the north. But as he does, a huge, intense low forms in the Great Basin, drawing dusty southwest winds across southern Arizona before the dry cold front goes through with quite a chill.

Now, for a little humor to end this blurb, a real laugher spaghetti plot, that for 15 days from now. You’ll go into conniptions, burst out laughing, like I did I am quite sure with your knowledge of spaghetti plots when you see this one and what virtually “unforecastable” weather looks like in a spaghetti plot. They should put these in the newspaper as kind of weather cartoon.

Actually, after 15 days, they mostly look like this.

Ending on humor, The End.

The lenticular that came for breakfast and stayed for dinner

Some of you already know that there is a favored position for a lenticular cloud downwind from the Santa Catalina Mountains. Yesterday, a little fluff of Altocumulus lenticularis kept reappearing all day! It didn’t have the “classic” look of a lenticularis early on, but that’s what it was, hovering over the same spot, changing size some, disappearing then reforming over the same spot. That rough bottom early on suggests turbulence. You don’t want to fly there. Often, flying IN lenticular clouds is, as the smoothness suggests, completely lacking in turbulence. Its when you come out the downwind end of those clouds that you can experience some nauseating bumps.

Why was the lenticular cloud there all day?

Because there is a standing wave, or hump in the airflow downstream of the mountain that raises a moist layer to its saturation level where a cloud must appear, and not much changed in wind direction and moisture all day up there. The morning and evening sounding for Tucson were almost the same. Also, while that lenticular cloud was nearly always there, it was often “buried”; obscured inside that sometimes thick layer of Altostratus with its virga that moved in during the afternoon hours.

Some photos. (BTW, since I started adding captions, WYSIWYG has gone bonkers in the Word Press edit page. So excuse the strange organization and text in odd places–still learning here.)

Below, photos of some of the other clouds of yesterday. I have to say if there was a disappointment, it was that there wasn’t as much Altocumulus as I thought, and virga trails were not as long as I expected, either. They were barely hanging down from that Altostratus layer, an indicating of smallish snowflakes in the Altostratus layer as well as very dry air below it.

DSCN1173 — "Altostratus over horse arena".

Lastly, a sunset shot, indicating the back edge of these high and middle cloud layers was over the horizon to the west.

Cloudy with snow above 15,000 feet

On deck, this cloud stream for today, as presented by the University of Washington Huskies Weather Department. As you will see, the whole stream rotating around that low off southern California has been thickening up overnight, a process that will continue, and so it looks like it will be a frequently gray day with Altocumulus, Altostratus, and Cirrus of various types piled on top of each at times. Don’t look for much direct sunlight today. Virga (snow), too, but no rain beyond the slight chance of a sprinkle. Most of the clouds you see will be composed of ice crystals and snowflakes. Also, with the wind picking up aloft today, lenticular clouds are likely again. Look to the NE of Mt. Lem.

Don’t miss a nice sunrise shot this morning.

Yesterday’s clouds

Below, after you have read all the captions, yesterday afternoon’s sounding from our friends in cowboy-on-a-bucking-horse-license-plate-land which, BTW, I think is a pretty cool looking license plate since I’ve been bucked off horses myself a few times and when I see that license plate can say, quite haughtily, “been there; done that”, and tip my hat to the driver. In fact, the horse I was bucked off most recently kicked about as big as the one rendered on that WY license plate, and while I ended up in the hospital with a big bill, HELL it was worth it when you can say things like this and show that you are truly embedded in western culture, which I love after leaving the Temperate Rain Forest-Starbuck’s culture of Seattle:

What do you see in this sounding?

The pinching together of the two heavy lines (temperature to the right, dewpoint to the left) tells you the height of the moist layer in which these clouds formed.

How high was that, you ask, or not?

The “300” line (refers to millibars of pressure) is about 30,000 feet above sea level (27,000 feet above Catalina) and the top of the moist layer, about at the “200” line, is 40,000 feet above sea level, 37,000 feet above Catalina.
So, they were damn high yesterday, running between 27,000 and 37,000 feet above the ground. The bottom temperatures were about -35 C (-31 F), and the top about -63 C. What’s interesting is that lenticular cloud was almost certainly comprised of liquid water drops on its upwind edge before glaciating (turning completely to ice a short distance downstream from that upwind edge.) One of the mysteries of ice formation in clouds is that Cirrus clouds don’t generally form until the conditions for a droplet cloud have been met. This means that when ice is present, it is in a highly supersaturated environment with respect to ice and in spite of the very low temperatures, the crystals can grow and fall out producing trails or fallstreaks as you could see in the Cirrus uncinus clouds.

Arriving in local skies today: clouds, high and middle ones

Now that your camera battery is fully charged, you will be ready for the panoply of high and some mid-level clouds that will be arriving overhead today. Should make for some great sunrise and sunset shots, but also daytime shots due to the interesting twists and turns in the Cirrus (ice) clouds that will float by. Maybe later today, Cirrocumulus and Altocumulus clouds will show up adding that extra dimension to sunset color. Typically, in these situations, the first clouds on the scene are Cirrus at the highest levels (30,000 to 500,000 thousand feet above ground level (hahaha-just checking to see if you are reading this)–OK, 30,000 to FORTY,000 feet above the ground here on a warm day in Catalina-Tucson like today.

Next, with the moisture layer thickening downward from those high CIrrus levels as the day goes by, there might well be some Cirrocumulus (Cc) cloud patches, ones between about 15,000 and 25,000 feet above ground level. Some times they evolve to Cirrus clouds within minutes after they form when they’re colder than -30 C (-22 F). Cirrocumulus are short-lived clouds usually in thin, isolated patches. They can have no shading by definition and they can display the most delicate granulations imaginable.

But those patterns change in seconds to a few minutes, and you have to have your camera by your side to get the best shots of that sort of thing, like other nature photographers who shoot birds and stuff like that. Did you realize that by shooting clouds that you were becoming a “nature photographer”? Often these patches can be higher level lenticular clouds (thin sliver clouds) that have smooth portions on the upwind side and then break into tiny elements downstream.

Finally, as the day comes to a close, some Altocumulus clouds might arrive on the scene; if not today, then by tomorrow at daybreak. They may also be in the form of sliver clouds, lenticulars that hover downwind of mountains–look to the northeast of Mt. Sara Lemmon today. But, given the high temperatures aloft, indicating that the Altocumulus clouds will have more water in them than on a cold day, look for some sprouts and little turrets. That extra warmth, say at 15,000 feet, results in an enhance updraft when clouds form at those levels because condensation releases a small amount heat to the atmosphere inside the clouds. That bit of extra heat is likely to lead to those itty bitty turrets (castellanus species of Ac)

Here is an example of the delicate Cirrocumulus (Cc) clouds we may see today and tomorrow.

No rain seen in models for two weeks now, but remember the wild chaos of the predictions beyond six days now, as indicated in “spaghetti plots.” That means rain for southern AZ may well show up again soon, along with that horrific early April cold spell.

The End.

Weekend slider, cloud excitement ahead, more about spaghetti

Check out these forecast maps from IPS Meteostar from last night’s 5 PM AST global data (less data from GOES-15, the satellite that covers the eastern Pacific and western US, which has gone belly up lately):

A ludicrous baseball metaphor for today; after all, its almost baseball season:

Let’s say your a very tall person with a bat a few hundred miles long standing in the batter’s box somewhere around Hermosillo, MX. A trough, like a baseball, has been thrown by the Pacific Ocean. Its coming down the “middle of the plate” (see panel 1) with the trough easing into southern California with a lot of rain). This one is gonna be jacked (will bring rain to all of Arizona!) It can’t miss. If it rains in southern California it can’t miss bringing rain to AZ!

You take a mighty swing (forecast rain), to go back to this silly metaphor. You didn’t noticed the “red dot”, something batters can see on the spinning ball when a pitcher throws a “slider”, a curving ball that, from a right handed pitcher to a right handed batter, veers away from the plate.

In this case the “red dot” to stretch this metaphor, is that the north winds on the backside of the southern California trough will be weakening as a new trough from the Gulf of Alaska roars down toward California and begins to catch up to it. The “ball” (trough) veers suddenly to the outside corner of the “plate”, Arizona, and spins into the dirt over Nevada and Utah. But you have swung anyway and struck out with the bases loaded (if you had thought rain from southern California was going to get here and water our wildflowers). The fans are booing now.

Well, enough baseball for today. The season is too long anyway.

Recall the AZ “jet rule”; no jet here and to the south of us as troughs go by; no rain no how in this cooler time of the year. Whilst the jet is south of our latitude on Sunday’s map (first panel), you can see that by Monday night at 11 Pm AST, the high velocity core has oozed over the NW corner of AZ (brownish regions in the second panel). The strongest winds are now on the east side of that trough, telling you its going to rocket off to the NE.

Cloud prognostication: get yer cameras ready!

The great thing about our “missed” storm is that the skies should be especially fabulous over the next three days (make sure all cameras are charged) because of having marginal moisture in the mid and upper levels of the troposphere as our “miss” goes by. That should mean interesting and photogenic clouds of all kinds up there: Cirrus, Cirrocumulus (fine grained clouds), Altocumulus (probably castellanus, lenticulars), and probably a spate or two of Altostratus clouds. Gee, you’ll have to get a cloud chart to know what I am talking about here! (Maybe you should get this one; it seems better than some of the other ones I’ve seen, and I don’t just say that because if you do get it, I will get some money.) ((Or go here, if you like to shop around)). Is this crass or WHAT?

The great thing, too, is that the Altocumulus clouds are likely to have nice virga trails, and it that kind of cloud (Altocumulus castellanus virgae) or Altostratus occur at sunrise or sunset, you can get the MOST fabulous photos. I like’em during the daytime, too, though. OK, so very excited about the cloud prospects ahead. Will be scanning skies.

The weather ahead

Another giant cold spell has erupted in the models. Check this big boy out over Az, valid for Sunday morning, 5 AM AST, nine days from now. Yep, you got yer low snow levels again, some showers, too. But the really interesting part is that it gets cut off out of the stream and sticks around for a few days. Look at the second panel, for FIVE days later! A remnant of it is still there, producing showers! In April? Seems unlikely, but could happen.

How do we check out how likely this cold spell and rain/snow is?

We think about spaghetti. Now remember, too, with GOES-15 out, there is also the fact that the models are working without as much information as they usually have. So, right off the bat, you have to downgrade anything “strange”, more than you normally would.OK, here’s some spaghetti for 168 h out, valid for a week from last night. This map was SHOCKING to me, because its telling you that the set up for our big boy is virtually guaranteed! I couldn’t believe it, its amazing!

So what am I ranting about?

This plot below says that a gigantic trough in the eastern Pacific between Hawaii and the mainland is virtually guaranteed. Look at how closely the contour lines are spaced in the eastern Pacific! This closeness says that the “signal” for this to happen is huge in the global data. Compare this spacing in the eastern Pacific, with the bowls of rubber bands, say, in the Atlantic and western Europe. The models are clueless about what is going to happen there. Conclusion: a few days before our forecast trough shows up, it is out there, and at least has the potential to be realized here in AZ two or three days later. Somebody on the West Coast is going to get whacked, little doubt about that.

But what happens on the days we are concerned about, April 1st and beyond? See next panel of spaghetti plots (2) for the afternoon of April 1st. The yellow lines are a couple of the contours in the forecast map for April first above.

The confidence factor has gone to HELL! Sorry for having to cuss. In the western Pacific, you can still be pretty confident of where the troughs will be, but look at the MESS now in the central Pacific to Moscow! Nothing is assured. All is hazy, fuzzy, out of focus, dimly lit, a drunken spider’s web, DAMMITALL, to cuss that bit more. While our trough has been foretold as of last night’s data, and it will maintain itself right up until reaching the West Coast (spaghetti 1), after that its anyone’s guess. Chances are good for a cool spell, but will it be historic with rain and snow, or a slight drop in temperature under sunny, breezy skies?

No one knows, but that first dish of spaghetti (1) has to make you at least hopeful that something strange will happen in early April here. Go here if you want to see the full animation.

The End.