Cirrus clouds – Page 8

“Oh, what a beautiful morning”; and day its going to be

1) I like to refer to songs about weather, though the musical references I’ve used are somewhat dated, as here, a song from 19th Century I think. BTW, tapping on the link above, you’ll see a guy riding a horse AND singing at the same time because he’s so happy, so it really fits the big western life we’re all leading here in old Arizony in the wintertime and seemed apropos. I wouldn’t recommend singing AND riding at the same time, however, unless you know you’re horse reel good. Might get spooked if it was you or me singing and not the cowboy, Gordy MacRae¹.

BTW#2, if you watch that entire song link above, you’ll see whole crowds of people getting carried away with the State of OK at the end of it. But…you’ll also notice in that scene that there is a MOUNTAIN on the distant horizon in the background. I don’t think they were in Oklahoma for that song! So, maybe they didn’t really like Oklahoma as much as they claim in song…. Now, where was I?

Man, the clouds are going to be spectacular today, zipping along like a dragster on nitro! Expecting some real great lenticular clouds, those hover ones, downstream of the Cat Mountains, too. Lots of wind, as well, to add to the drama with a Big _Cold Front (B_CF) getting closer during the day, then passing us during the evening-overnight with some rain by morning. Likely to be a 10-20 degree F drop in temperature within an hour or less, as this real “bad boy” cold front and wind shift go by. Ely, NV saw a 56 degree drop in temperatures in 24h. We Need more rain; always. Cold? Not so sure about that. All in all, a “beautiful” day² coming up.

How much rain here in old Catalina?

We’re on the edge of the jet stream up there, and you know what that means, on the edge of the precip, too. So, if you’re telling your friends how much rain you expect, and as a CMJ, they will expect you to comment on it, you’d best not go overboard and say, “a half an inch between tonight and Friday morning”; play it down some.

On the plus side, this is a storm type (flow pattern type, more westerly up there) that we Catalinans get MORE rain than surrounding areas, other than the mountains. So, on the edge means a low rain prediction; but the flow pattern suggests pushing a little on the greatest amount possible for an edge storm. Here’s the range I would tell you to say to neighbors:

Bottom (since it might miss), 0.08 inches (the “8” for faux accuracy); top, 0.50 inches (yep, has a high potential due to the storm type; that is, the angle of the winds impinging overhead on our mountains). Average of these guesses, which likely is the more accurate guess-amount, 0.26 inches.

Later we will compare the U of AZ supermicro Beowulf Cluster model prediction, one that takes our best model’s overall prediction for Arizona, the one WRF-GFS, and then breaks it down into our local areas better, like here and on the Catalina Mountains, because it uses much more detailed terrain. (Not available yet here at 4:45 AM–to Hell with it then!) ((Still not available as of 6:24 AM. It is finished..publishing now.))

There’s another cold blast on the heels of this one. Hits on the 8th. Poor TUS marathoners… ‘Nuf said.

The weather way ahead

2) With the upcoming storm and cold well in hand, that is, well described by our excited met men and women, both at the NWS and on TEEVEE, where in the latter case they make a LOT of money, really, its incredible how much (well, maybe not in TUS, but LA? Oh, my) Let’s see, where was I? Oh, yeah, I thought I would look WAY ahead, two weeks, which in weather model terms is like an astrologer looking through a telescope at the giant star, Betelgeus, its that far away in model prediction terms.

Still, I REALLY think you need to see this forecast even though its so far away because its pretty giant, too, in weather terms. If you’re too lazy to click on “this”, I have gifted you with the highlights below, highlights that might be the best forecast maps I have ever seen (again). Yes, to quote the song, “Everything’s (weather-wise) going my way.” ( “My way”? To Catalina, Arizona.)

Drum roll……

Well, there they are. I hope you’re happy now. Its quite an orgasmic sequence from a weather standpoint.

Why? There’s about THIRTY-SIX hours of rain in our area are foretold from these maps, 14-15 days from now! That last one has heavy rain throughout Arizona! BTW, I’ve posted them in sizes that are proportional to their credibility, thumbnails.

Now, since I’ve been learning you up on spaghetti, I’ll let you decide whether its a Big_Outlier (BfO). Take a look here and at where the”blue” lines are. They would have to be clustering down around Rocky Point-Puerto Penasco for this forecast to have any serious credibility.

Yesterday’s clouds

Cirrus ones. As always with our deep blue skies now days, so pretty up there. A few shots:

8:01 AM. The ever-present, rarely seen Cirrus castellanus (bubble Cirrus). — 8:01 AM. The ever-present, rarely seen Cirrus castellanus (bubble Cirrus lower center).

8:02 AM. Cirrus fibratus (long, more or less straight trails, at least from this overhead view).

5:26 PM. Subtle color in Cirrus and distant Altostratus layer (deep ice cloud). — 5:26 PM. Subtle sunset color in Cirrus and in a distant Altostratus layer (deep ice cloud).

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¹Not wearing a helmut, either, which is also a bad example besides singing while riding a horse.

²Words can mean different things to different people, and here, “beautiful”, as in the title, may not be the “beautiful” day you were expecting to be described.

Severe weather pattern ahead for West and central US

Summary statement: Begins in 5-6 days in the northern US, then expands southward; goes on and on, like the discussion below, after that. Cloud pics WAY below the “novella” on spag plots.

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Our docile weather in the West for the past few months is about to end, as well as for those in the Rockies and Plains States. Wasn’t gonna blog on TG day, but looking at mods, and realized that I am the SAME person that I was as a 6-year old in Reseda, California, on January 10, 1949, that ran up and down Nestle Avenue knocking on doors to tell people it was starting to snow that afternoon (!), I realized that same “gotta tell ya” impulse lives on.

The trigger for THIS “gotta tell ya” is how bad the cold, snow, rain, and wind look for the western half of the US starting in about 5-6 days from now as cold air and storminess works its way south from the Pacific Northwest and Rockies at that time. I am sure you have heard something about this developing pattern already from your favorite media weathercaster, but I’ll try to take it a bit farther out in time, and tell you why I think you can do that in this case.

I haven’t looked at the models per se with the exception of the Enviro Can one, one in which the lasted posted output is at the start of this episode, but rather the excitement for Mr. cloud maven person was triggered by those chaotic looking, “errorful” plots we call spaghetti plots, “Lorenz plots”, if you will, posted by NOAA that tell us how sensitive a pattern is to small errors.

It seemed, too, like there was something to be learned from them, as well demonstrating a high confidence pattern of a severe weather pattern more than a week away. Many forecaster, maybe most, shy away from forecasts beyond a week because we know how often they are faulty. But there are exceptions and this is one coming up.

ann dec 4 5 pm spag_f192_nhbg — Valid at 5 PM AST, December 5th. This map shows a high confidence of a mammoth, cold trough at 500 millibars covering most of the US. Its “ginormous” as a friend used to say. You really don’t see anything like it, that is, like that black “quiet” zone extending so far south anywhere in the whole northern hemisphere!

OK, here we go.

Above I have added boxes in this plot to show you where the forecast is highly reliable and in another one, where its not. This is indicated by the bunching of those lines, height contours, the same ones, from many model runs starting with the introduction of slight errors. At first in these plots, with errors being tiny, there is no difference in them in the first day or two. But, as time goes on, the errors have greater impact. A metaphor: when you hit a ball off the tee, the error in the first inch of travel is nil in magnitude. But 5 seconds later? Oh my.

Here, the bunching of lines in most of the US is what got me going. Continuing the metaphor above, after 5 seconds and 300 yards of travel in this case, its analogous to 2 yards from the hole! In other words, the were essentially no effect of errors in the model runs; you slugged that golf ball perfectly.

But what does it mean, in terms of weather? That trough (the curved area where the “high confidence zone” is located, means a tremendous plunge of cold air into the West and Plains States. Don’t need to look at future maps to know this. You all know that a trough is a tongue, a wedge, of DEEP cold air that drags cold air at the surface southward on the west half of it, and drags warm air northward on the east side (in this case, toward the eastern US. The size of this wedge indicates a gigantic area of high pressure from the Arctic will be pushing DEEP into the West and Plains States as this pattern develops in the few days before December 5th.

Once established this pattern lasts for several days, a huge, deep and cold trough dominating weather throughout the US. And where the air masses clash at the ground presents ripe conditions for low centers to spin up, given a trigger aloft, like a traveling, much smaller wave in the jet stream where the lines are bunched.

Below, farther along in the sequence, these plots each one day later than the one above that illustrate how a confident pattern begins to erode. In this case, “uncertainty” in the central and eastern Pacific begins to spread eastward into our confident pattern; the blue lines start to go goofy (highlighted by boxes):

Last, here is the plot for 15 days (360 h) out in which those little errors have had their biggest effect, really done a number (haha) on the forecast confidence game, everything’s pretty unreliable except maybe in eastern Asia and the extreme western Pacific, and along the East Coast.

But, even with all of this chaos below, we can see that the model still thinks a trough (a bend in the contours to the south) will still be present in the mid and western sections of the US. Since we know that weather, once changing into a new pattern likes to stay in that pattern for weeks at a time (with brief interruptions), a reasonable forecast for December would be colder than normal in the Southwest and West overall, and in the central US, while its warmer than normal in the East, particularly the southeast US.

Precip? Always more dicey than temperatures, but CM is going with above normal in the interior of the West and in the Southwest, near normal to above normal here in SE AZ. Remember while reading this, Mr. Cloud Maven person is NOT an expert in long range forecasting, like for a month, and, he likes to see precipitation in the desert, and those wildflowers that follow. (“Truth-in-packaging” clause.)

In a couple of days, the Big Boys at the CPC, that is, the NOAA Climate Prediction Center, will be issuing their temperature and precip forecasts for December. It will be interesting to see what they make of these patterns, combined with other factors like sea surface temperature anomalies and northern hemisphere snow cover.

BTW, with a pattern like the one coming up, snow that falls during the storms is going to remain on the ground for long periods due to the lower than normal temperatures, those that snow cover helps to maintain (strong feedback loop, as we would say).

Your clouds of yesterday

If anyone is still with me, you had your Altostratus, your Altocumulus, and some Cirrus. Here they are:

8:31 AM. Altostratus, an ice cloud consisting of single crystals and snowflakes. Slight falls of snow (virga) can be seen at the bottom, that rumpled look. WAY too high above the ground to reach it, estimating 18 kft here.

3:41 PM. Altocumulus perlucidus (left), opacus center and right where they get solid. These clouds are comprised soley of liquid droplets; no virga is showing for one thing, and the greater detail, sharper edges goes with a droplet cloud composition. Droplets are almost always in far higher concentrations that are ice particles in clouds, thus, they have sharper edges.

5:22 PM. Pretty nice sunset, Altocumulus overhead left; in the distance Altocumulus floccus with heavy, funnel-looking virga fall, and extreme distance, some following Altocumulus castellanus, no virga yet.

5:24 PM. Close up of prior scene. Last row visible on the horizon is a nice little row of Ac castellanus.

Rain, and more of it

AZ Map of USGS gauges here (takes a couple of minutes to load); USGS AZ amounts here.

Pima County ALERT gauges here (Mt. Lemmon already at 0.67 inches at this hour!)

Rainlog.org here (best if used after 7 AM AST).

CoCoRahs here (best if used after 7 AM AST)

NWS rain totals here.

AZ agmet rain totals here.

I’m trying to keep you busy today. Maybe you’re retired and you don’t know what to do with yourself. Well, today you can look at building precipitation totals in Arizona all day! It will give you something to talk about.

In fact, occupying retirees with searches for precip data is why we have so many different sites that record precipitation. We have a lot of retirees in AZ, low temperature refugees, and we need to keep them occupied and out of trouble.

Imagine how awful it would be if we had ALL of these rainfall amounts in ONE place and you could look at them all immediately, or have a map plot of all these sites and amounts? Imagine just CoCoRahs and Rainlog.org being friends and cooperating together and just having one site for their rainfall collections? It would be like the Berlin Wall coming down, precipitationally speaking. Oh, well, that’s not gonna happen.

Oh, yeah, the Heights of Sutherland here in wonderful Catalina, AZ?

Got 0.17 inches overnight. “Main bang” still ahead, quite a long ways ahead, considering the passing showers we have now. Doesn’t look like the major band will get here until after midnight, then pound on us most of the day tomorrow. This prediction from the Huskies of Washington’s Weather Department model seen here.

So being on the toasty side of the cold front, should be a pleasant, mostly day with dry spells in between showers, and maybe, if the low clouds break a little, with fabulous middle and high cloud patterns associated with the powerful jet stream overhead (winds at Cirrus levels today and tomorrow should be over 100 mph!) Have camera ready.

Range of amounts from this front, a little in the withering stage as it goes by tomorrow, here in The Heights of Catalina, 0.4 to 1.5 inches, median guess 0.95 inches. Just too cellular in nature to be sure you get hit with all that’s possible, so you fudge on the downside some.

HOWEVER, just viewed the accumulated precip from our great U of AZ mod and it shows about 1.5 to 2.5 inches here, with the model run ending at 1 PM tomorrow–with more still falling! Wouldn’t that be fantastic! Certainly we’d have water in the CDO.

: Precip totals ending at 1 PM tomorrow!

These mod forecasts do tend toward the high side, but I would be very pleased if more than my highest estimated amount (1.5 inches) fell.

So, what’s happening now? Check this loop of radar-sat imagery combo map.

As you will see, rain’s piling up like mad in central AZ just to the west of us. Amounts, according to radar, already well over an inch just for the last few hours according to NWS storm total radar loops from PHX and Yuma. Hah, Yuma! How often does that radar see amounts over an inch in winter?

Below, the Intellicast 24 h radar-derived precip totals ending at 5 AM AST:

24 h rain from radar, ending at 5 AM AST.

I suppose we’ll be complaining soon about too much rain….

Yesterday’s clouds

So much was happening skyward yesterday! So much so, its probably best seen through the U of AZ Weather Department’s time lapse movie here. Its really great and shows all the complications of a day where clouds are moving in at different levels, and there are lots of wave clouds (lenticulars) over the Catalinas to marvel at.

DSCN6320 — 6:59 AM. Altocumulus patches and pastel Cirrus announce a new day.

DSCN6326 — 7:06 AM. A few minutes later, Altocumulus perlucidus join the color display.

11:07 AM. Once again, the rarely seen Cirrus castellanus ("cumulus in a Cirrus) that I seem to notice every week here... — 11:07 AM. Once again, the rarely seen Cirrus castellanus (“Cumulus in a Cirrus) that I seem to notice every week here…

11:44 AM. Hover clouds (Ac len) over the Catalina. — 11:44 AM. Hover clouds (Ac len) over the Catalina, Altostratus above.

1:14 PM. Barging in from the south, the next lower layer, Stratocumulus and Cumulus, bases touched Ms. Mt. Lemmon. — 1:14 PM. Barging in from the south, the next lower layer, Stratocumulus and Cumulus; bases touched Ms. Mt. Lemmon. Sky darkened rapidly and almost eerily right after this.

4:22 PM. The occasionally seen Seattle June sky, overcast with threatening clouds that don't do anything, and with mild temperatures. Tops 0f these clouds were right at the normal ice-forming level here, -10 C (14 F), and by evening, virga and light rain began to fall from them as they deepened up a bit more. — 4:22 PM. The occasionally seen Seattle June sky, overcast with threatening clouds that don’t do anything, and with mild temperatures. Tops 0f these clouds were right at the normal ice-forming level here, -10 C (14 F), and by evening, virga and light rain began to fall from them as they deepened up a bit more.

The weather way ahead

More rain as month closes out. If you don’t believe me, a theme here, check this image out:

Valid for 5 AM AST, November 30th. Of course, I'm not going to show you the actual rain map, I want you to go from this as a bonafide Cloud Maven, Jr. (CMJ). I've noticed that some of you have not yet ordered your "Dri-Fit" TM "I heart spaghetti" tee shirts... What's up with that? — Valid for 5 AM AST, November 30th. Of course, I’m not going to show you the actual rain map, I want you to go from this as a bonafide Cloud Maven, Jr. (CMJ). I’ve noticed that some of you have not yet ordered your sophisticated “Dri-Fit” ^TM, “I heart spaghetti” tee shirts… What’s up with that?

Clouds before the storm

First, let’s see how excited the NWS is about our upcoming major, drought-denting storm, now “in the bag”:

Tucson, here and a nice NWS YouTube presentation here.

Phoenix

Flagstaff

As you will see from these links, they’re getting pretty worked up, and have issued the SAME “Special Statement” for ALL of Arizona, that’s how big the storm is. We’re all in this together. BTW, the U of AZ model forecast from 11 PM AST last night had as much as 5-6 inches of rain indicated in the central mountains of AZ over the next 24-36 h! Will the washes flow here, eventually as the major rain moves east? Hope so.

But, must point that the range of amounts that will fall here in Catalina has to be considered quite large; something from “just a nice rain” (0.4 inches total) to a gully washer (1.5 inches total) due to the fine-scale of the heaviest rainfall bands rotating around the dawdling low over the next couple of days. Its really not possible to pin it down better than a large range of possible values in situations like this, but it does appear that most of it will fall on Friday night into Saturday.

In the meantime, more pretty skies today before the deeper clouds and rain get here overnight or tomorrow morning. Very little rain is indicated here, though, through tomorrow evening,in this latest U of AZ mod run. while inches pile up just to the west and in the AZ mountains.

Yesterday’s clouds

Had pretty skies all day yesterday, even saw some clouds that as far as I know, have no name, these ones below that LOOK like Altocumulus perlucidus but are all ice at Cirrus levels. Could be called, to make up a name, “Cirrus perlucidus” I guess:

7:46 AM. "Cirrus perlucidus." It may be hard to tell for most folks, but these flocculent clouds are all ice. There's a patch of Altostratus in distance. — 7:46 AM. “Cirrus perlucidus.” It may be hard to tell for most folks, but these flocculent clouds are all ice. There is no WAY I would call an all ice cloud, “Altocumulus.” There’s a patch of Altostratus in distance, and an Ac lenticular to left of pole on horizon.

9:49 AM. Altocumulus virgae. Great example of the "upside down" storm; droplet cloud at the top, ice and snow underneath as ice forms amid the droplet cloud, grows like mad and falls out. — 9:49 AM. Altocumulus virgae. Great example of the “upside down” storm; droplet cloud at the top, ice and snow underneath as ice forms amid the droplet cloud, grows like mad and falls out. This finding, first made in the 1950s was surprising because the clouds were liquid at the lowest temperatures.

12:04 PM. Cirrocumulus lenticularis, a bit too thin to be Ac lenticularis.

3:59 PM. Ac lenticular stack in lee of Catalina Mountains. Ac perlucidus in foreground. — 3:59 PM. This view from atop horsey, an Ac lenticular stack beyond the Gap, in lee of Catalina Mountains. Ac perlucidus in the foreground.

4:00 PM. Looking S; buttermilk skies due to Ac perlucidus; lower layer of Ac opacus advancing from the the west below those mottled clouds.

5:31 PM. Brief sunset "bloom" due to a small break in the overcast just over the horizon. — 5:31 PM. Brief sunset “bloom” due to a small break in the overcast just over the horizon.

The weather way ahead

2013112100_CON_GFS_500_HGT_WINDS_276 — Valid at 5 AM AST, December 2nd. A near twin of the upcoming situation.

Now showing up on mods, as November closes out, a low center that looks an awful like the situation we’ll have tomorrow and Saturday, another vortex aloft tracks S along the coast, settling in around San Diego, then moving along to the east very slowly. As you know, weather patterns like to get in a groove and repeat themselves for awhile. Could be we’re in that phase where the SW is a low “magnet” and that would mean above normal precip over a spell of a few weeks. Above, a map for December 2nd at 5 AM AST that looks a lot like what we have coming right up. For that reason, you tend to place a bit more credibility than you might otherwise in a forecast that far away. The exact day this occurs will be most likely be off, but it is likely that a troughs/clouds and precip will to affect the SW over the next couple of weeks or more. Good bye dry spell!

If you don’t believe me, check this 10 day outlook from the NOAA spaghetti factory:

"Lorenz plot" from NOAA, valid at 5 PM AST, November 30th. Its pretty plain to see that there is a strong likelihood of a cutoff low in the extreme SW US. — “Lorenz plot” from NOAA,
valid at 5 PM AST, November 30th. Its pretty plain to see that there is a strong likelihood of a cutoff low in the extreme SW US, if you can find it. (The vast number of contours is due to a software glitch today. Usually only a few upper level contours are tracked.)

Heavenly model

From our friends in Canada, this fabulous sequence for AZ. An example:

Valid for Friday afternoon, 5 PM,m November 22nd. Arrow points to beau coup eastern AZ precip amounts — Valid for Friday afternoon, 5 PM AST, November 22nd. Arrow points to beau coup eastern AZ precip amounts.

The loop above, generated by last evening’s global obs by the Enviro Can “GEM” model might be the best a numerical model can put out for Arizona. It might even be the best model day of my life ever here (which hasn’t been that long, but still…).

Why?

1. Trough races into the precip “Red Zone”, located immediately SW of AZ. Rain moves in on Friday into Catalina and environs.

2. Trough forms circular, spinning low aloft there, that wanders slightly in place. Cloud and precip rush into Arizona, and it just doesn’t quit as wave after wave of clouds and rain move up from Mexico, the Gulf of Cal-Sea of Cortez, and the Pacific off Baja while the low center dawdles.

3. Low crosses into AZ and departs AZ late Sunday after showery day.

In sum, showery rainy conditions beginning on Friday, continuing into Sunday.

Amounts should be several inches in the mountains of AZ. Here, sans the great U of AZ calcs for the whole storm period, will go with the same “seat-of-pants” estimates of the botttom and top amounts made a couple of days ago: at least 0.4 inches (even if things don’t work out so great; low doesn’t dawdle so long). But as much as 1.50 inches on the high end here in Catalina if it DOES dawdle as this model run from last night shows and we get nailed by recurring rain bands. Best estimate, “therefore” he sez, is the average of the two, or about an inch.

It would seem some thunder now and then would also be in the mix, and BTW, we remind our reader that snow and rain mixed together is NOT SLEET, dammitall! SLEET is frozen raindrops, ones that have frozen on the way down and usually requires two to three thousand feet of below-freezing air temperatures before that happens. Also, they BOUNCE when they hit, are usually clear, and often have spikes where the water was trying to get out since they mostly freeze from the outside inward, and because water expands when it freezes, a spike or ejection of ice splinters results as freezing takes place. Kind of neat really. But its NOT rain and snow mixed together! Sorry, getting into some “sleet rage” here; need to work on it; get it under control. I just don’t want my reader to sound ignorant when rain and snow are mixed together, but rather, “precipitationally erudite.”

Yesterday’s clouds5:20 PM. Jet’s ‘n’ Cirrus. The very short contrails, formed by moisture and carbonaceous crap, oops, black stuff, in the exhaust, are short here because the jets are flying ABOVE the Cirrus.

The moon's been HUGE lately, enough where you can see quite a bit of detail. — The moon’s been HUGE lately, enough where you can see quite a bit of detail.

More rain ahead as month closes!

The End

Keeps getting better..the storm on the doorstep, that is

“Better” means wetter, of course. You don’t read this blog to read about DROUGHT! You read it to read about rain and moistness; clouds, too. Let’s leave drought for the other guys…

Here is the latest model permutation from the Canadians, one that successively, and successfully, I might add, jacks up the amount of rain for AZ as the real deal gets closer on the November 21-23rd. Take a lot at these two depictions from Canada for the 22-23rd (sorry about the small size; the Canadians are shy about their model outputs and don’t like to post large gifs or jpegs; also remote areas of Canada mostly have dial up so big files are a problem I’m guessing):

Valid at 5 AM 23 November 00_054_G1_north@america@zoomout_I_4PAN_CLASSIC@012_132 — Valid at 5 AM Saturday, November 23rd. Note streamer of heaviest rain in central AZ, The colored regions are for those areas in which rain is forecast by the model for the prior 12 h.

Valid at 5 PM November 22nd. Very heavy rain indicated for central AZ mountains 00_054_G1_north@america@zoomout_I_4PAN_CLASSIC@012_120 — Valid at 5 PM, Friday, 22 November. Note streamer of heaviest rain in eastern AZ, and over our area with lots more ahead!

The colored regions are for those areas in which rain is forecast by the model for the prior 12 h.

Note round low near San Diego in the first panel, upper left:

“Round lows out of the flow; no one knows where they want to go.”

This old weather forecasting limerick I just now made up sums this situation well. Round lows sit, spin, wobble and jerk around for awhile, and so they shovel rain and clouds over the same areas for one or two days, sometimes longer.

So, instead of a nice sharp frontal band passing by within a few hours and then its over, as happens most of the time here, bands rev up and keep spinning around the wobbling low, often hitting the same areas and the rain/snow keeps piling up. Remember the giant cutoff low in December 1967, and the MOUNTAINS of snow it produced back then in northern and central Arizona, stranding hundreds? Well, this ones not THAT big, but its big deal anyway with lots of water in it, and not so cold as the one in 1967 when “album rock” was emerging.

So, this could put a real dent in our October-November rainfall deficit throughout Arizona, a real “worth billions of dollars storm” to agriculture! I am pumped, as are you!

Great storm, too, if you’re planning on getting those spring wildflower seeds in the ground; do it just before the storm arrives and you’ll likely get a colorful return in the spring this year.

What are the chances of measurable rain here in Catalina? Oh, right now, I’d say anywhere between 100 and 200 percent. Now the NWS is NOT going to give you those kinds of percentages I might add. You only get them here.

Amounts?

Let’s go for it. I say the minimum (10% chance of LESS) is 0.40 inches, maximum (10% or less chance of more), is 1.50 inches (big top side due to stationary aspects of storm, likely thunderstorms in area). Median of these, which might be the best estimate for Catlanders (those domiciled in Catalina): 0.95 inches, all falling between the morning of the 22nd through the morning of the 24th, likely in pulses. Goodbye dust!

But in those central AZ mountains, with flow more or less perpendicular to them from the south, their best rain producing wind direction, 1-4 inches is very likely. Yay for rain and snow, maybe some TSTMS, too, comin’ right up.

Didn’t mention the US mods but they are “on board” for a major rain event in AZ. Canadian one saw it happening first, so am sticking with it.

Still another pretty good rain chance as the month closes, but a far colder situation than the one coming up.

Yesterday’s clouds

Small ones, Cumulus humilis, no ice, but pretty anyway. Also, a little smidgeon of Cirrocumulus late, with Cirrus, too, invading from the SW, and a pleasant sunset.

5:11 PM. Cirrocumulus blossomed overhead as a moist layer way up top encroached. No ice indicated.

DSCN6228 — 2:46 PM. Cumulus humilis dot afternoon skies. No ice indicated.

DSCN6234 — 5:32 PM. Cirrus clouds provide target for fading sunlight.

Sequence in C; Cirrus spissatus

Some nice CIrrus spissatus and the rare Cirrus castellanus yesterday (something I say a lot here in old AZy). Here is half hour sequence of a patch of heavily precipitating Cirrus spissatus, kind of a cloud oxymoron. I thought it was pretty spectacular even if you don’t care one wit about it. (Hahaha, “wit” instead of “whit.”)

Those Cirrus clouds were up at about 35,000 feet above sea level, at around -50 C (-58 F), but snowing like mad. Don’t let folks tell you its too cold to snow; usually happens that way because here on the surface there’s a high pressure over you, the sky is clear, to wit; a fair weather pattern, and that’s why its not snowing here on the earth when its -58 F, except maybe when there’s a ice haze called “diamond dust“, tiny ice crystals floating/glinting in the air.)

DSCN6145 — 8:48 AM. Cirrus spissatus on the left with the little snowstorm trailing off to the left will pass overhead of Basha’s parking lot there on Oracle in about half an hour, a prediction made in hindsight.

9:07 AM. Taken while not driving down Equestrian Trail Road to Basha’s supermarket.

9:21 AM. Basha's parking lot. — 9:21 AM. Basha’s parking lot. Snow, composed of single crystals, not flakes or what we called “aggregates” because they don’t stick together at such low temperatures, pours out of this really cold cloud. The single crystals in the trail would be bullet rosettes, a complex looking crystal consisting of hexagonal columns that stick out from a center point. How much snow falls out? Just a dusting. You could blow it away off any surface. When flying through these icy clouds toward the top where the crystals are simpler, there are sparkles and glints when the sun hits the crystals just right. Very pretty.

The day ended up with lower Cirrus and few Altocumulus clouds with virga as the dry air aloft moved in, providing the clear western horizon that allowed the sun to highlight our clouds. That great sunset, as much as I could see anyway being “on the road” here:

5:37 PM. Heavy Cirrus with Altocumulus on the right. — 5:37 PM. Heavy Cirrus (spissatus) or Altostratus patch, either name OK, with Altocumulus on the far right horizon.

The weather ahead

Mods still showing rain in the area on Sunday the 17th pretty consistently now. And as we saw from the “errorful” NOAA spaghetti maps yesterday, a trough with cooler weather, clouds and scattered precip is pretty much in the bag for that time period (16th-18th). Can only hope that we get something measurable here. But, even without rain, those days will be pretty ones with Cumulus clouds around.

Upper trough with rain continues to march toward Catalina from Siberia and points west

…and maybe points north, too. Lately models have been foretelling rain in Catalina on the 17th or 18th. In case you don’t believe me, here’s the precip forecast from last evening’s (00 Zulu) WRF-GOOFUS¹ model run for the morning of the 18th as rendered by IPS MeteoStar:

Valid for Monday morning at 5 AM November 18th. The colored areas are those in which the model has foretold rain during the previous 12 h. As usual, the heaviest amount is foretold for my house here in Catalina/Sutherland Heights.

What are the chances this will really happen so many days ahead? Pretty good. Let’s check out the “Lorenz map²” below:

The Lorenz map valid for 5 AM, Monday, November 18th. Cold air? Its in the bag. Rain? No doubt showers in the area with a pretty low snow level. — The Lorenz map, a name I made up but he deserves it since he came up with the Chaos Theory due to which such maps like these are produced by our computer models; where little, itty bitty things can feed into the system and alter the whole thing, like the cliche of a butterfly flapping its wings in Brazil and affecting a tornado in Texas later, as a friend said in a SEA Times article a few years ago, a friend, BTW, that I played softball with on the Dept team and could really hit the long ball³… Oops, where was I? Oh, yeah, this map is valid for 5 AM, Monday, November 18th.

Cold air in Catalina? Having to put your jacket on for a few days? Its in the bag.

Rain? No doubt showers in the area with a pretty low snow level on the 17th-18th, but, with the long overland trajectory as presently indicated, not much, maybe a tenth of an inch or so, kind of marginal.

Yesterday’s clouds, high ones

There was some iridescence in a patch of Cirrocumulus about mid-morning, and then what might have been a bit of a parhelic circle in a patch Cirrus. That was it. More interesting clouds today as streamers of moist air at high levels sporadically invade Arizona, and today should be one of those. Get cameras ready!

: 10:56 AM. Sublte bright, slightly curved line in the upper part of this photo of a Cirrus cloud patch may have been a “parhelic arc.”

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¹ As the Global Forecast System is affectionately known.

²I think E. N. Lorenz deserves it, a map with his name on it that we currently call “spaghetti plots”, or by the uppity “model ensembles” name. You put little errors in at the beginning of the model run and see how different the end results are. Not too much effect at the beginning because the errors are so small, but usually end up producing a ball of yarn after kitty played with it, as one reader wrote, after a couple of weeks, meaning that the reliability of any specific prediction at that time is nil. You see, all instrumentation has some error factor, so we never really measure the exact state of the atmosphere. This is a technique of adding little errors is to see how much they can affect the outcome. Sometimes, when something really POWERFUL is out there somewhere, those little errors don’t have much of an effect, and that’s when we can make a pretty good prediction for more than a week out.

³In case you don’t believe me again, this time that I actually played on a softball team with someone that might be asked his opinion on something by a newspaper reporter from the Seattle Times, here is a picture of Dr. Nick “Blaster” Bond, my teammate. I took this picture him because I really liked him, and we both liked to play on teams with girls who could really play, too, then we would win co-rec titles because of how well THEY played. It was great! Nick always wore those ripped short-shorts no matter how cold it was, even if it was raining.

Famous scientist, quoted in newspapers, Blaster Bond, about 25 years ago. I took this picture because I liked him so much. — Famous scientist, quoted in newspapers, Blaster Bond, looking askance at some lollipop softball pitcher, about 25 years ago. Not the same Bond responsible for “Bond Cycles” in paleoclimate proxies, though I wish he was because then I would be more important as a person having more important friends I could mention.

Pretty skies; pretty Cirrus

Here are some shots:

SONY DSC — Cirrus fibratus, straightish fibers of CIrrus lacking a tuft or hook at the top, in this case toward the left. For fussy folks who detect a slight hook, Cirrus uncinus would be OK, too. Not really too important to differentiate between these species. Just shows its moist up there, and, like yesterday, there was a trough going by; air sliding up ahead of it, going down and clearing things off behind it (as happened late yesterday).

The weather ahead

Tried to find some rain for you in the models, but only one had rain, and that was the low resolution (big grid spacing) Canadian GEM model posted here. It had the rainy panel (lower right) for SE Arizona calculated from last evening’s global data:

Valid for Wednesday morning, 5 AM, October 30th. The colored areas in the lower right panel are those ones where the model thinks it should have rained in the prior 12 h. Note heavier, red-blobs in AZ! How great would that be? Again this rain is the result of a westerly trough grabbing the moisture out of a tropical storm off Baja, a very “iffy” situation, to quote a term oft used by the much honored, late atmos sci Professor Richard Reed of the U of WA¹.

Also, I am really learning about how much the WRF-GFS model likes to bring hurricanes and tropical storms into the Southwest. Yesterday’s model run at 11 AM AST, had another doozie coming up the coast in two weeks still having tropical storm strength and its about to pounce on northern Baja, southern Cal, and maybe AZ. Here is that depiction for your amusement, valid at 11 AM, Saturday NCAA football day, November 9th.

: the stuff of dreams for Saturday, November 9th, 11 AM AST.

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¹

The late Richard Reed, a man that did not mince his words. The nicest thing he ever said to me was, "Those guys have gotta be stopped." — The late Richard Reed, a man that did not mince his words. The nicest thing he ever said to me was, “Those guys have gotta be stopped.”

Not likely to verify, but a wonderful map (but, “trending up” in twitter-speak)

This is definitely not the same title as was a few days ago for a similar map, one also valid for Nov 3rd-4th. That title was quite different: “Not likely, but a wonderful map.” The rainy Arizona map back then from our best model showed a tropical storm and moist plume being drawn northward into AZ.

Almost the exact map as that one a few days ago has shown up again out of the blue, if you can say that when you’re talking about clouds and precipitation. There’s been nothing like that former map since that first time it showed up, and, in view of how odd it was, you tend to write it off as something you’ll not see again. But there it was again, now only 10 days out.

Below, the happy, rainy AZ map churned out by last night’s model run based on global data taken around 5 PM AST yesterday ( from IPS MeteoStar):

MOdel outpur valid for 5 PM November 4th. Shows tropical storm remnant being sucked up toward Arizona with lots of rain already here. — Model output valid for 5 PM AST, Monday, November 4th. Shows tropical storm remnant being sucked up toward Arizona with lots of rain already here. Green blobs denote where the model thinks rain has fallen in the prior 12 h, which here is the entire State of AZy!

Below is the pattern aloft that steers (hahaha) all that moisture into our water-challenged State, one that has a lot of steers.

HOWEVER, this rainy situation requires a lucky conjunction of a Pacific trough coming in out of the Pacific onto the southern California coastline, while a tropical storm/former hurricane is off Mazatlån at that same moment. If these two features of interest are just about anywhere else than is shown here in these model projections, forget it.

The flow pattern in the middle of the troposphere, around 15,000 to 20,000 feet above sea level. Yep, that's right, half the air is gone by the time you get to only about 17,500 feet! — The flow pattern in the middle of the troposphere, around 15,000 to 20,000 feet above sea level. Yep, that’s right, half the air is gone by the time you get to only about 17,500 feet!

The first time this rainy map was shown for Nov. 3-4th, back about five days ago, the chances of it actually happening were probably somewhere around 0.2 percent. Just too much had to fall into place. Coming up twice, however, jacks the lucky numbers up to, oh, maybe to an 8 percent chance of actually happening as a wild guess. Not a great chance, but one that’s trending upward. You know, after the rainless October that’s about to finish up, we really deserve this storm in early November. The NOAA spaghetti factory has good support for a trough along the California coast at this time, so its likely THAT ingredient will likely be in place on November 3rd-4th.

Yesterday’s clouds; yes, there were a couple, some patchy Cirrus and a little band of Altocumulus, some of the latter trending toward lenticularis-ee ones. later on. Here they are.

2:37 PM. Patches of Cirrus drift across the southeastern sky.

The End