Stupendous storms – Page 3

“Volcano” erupts north of the Tucson Mountains; California Niño, too, along the Cal coast

The documentary photos, below, of a modest-looking Cumulus congestus cloud yesterday afternoon that lept up to the stratosphere in the 20 minutes that cloud maven person wasn’t watching. Yours truly, while videoing it from start to finish, only got two still shots in those 20 min due to a distraction¹; was not taking photos of every cloud every three minutes as the “compulsar”, CMP likes to do:

1:51 PM. zzzzzzzzzzz. Not much likely to happen. Cloud is isolated over a flat area all by itself, no pals to group along with, so its certainly going to fade away after the itty-bitty amount ice on the right said produces maybe a sprinkle. — 1:51 PM. zzzzzzzzzzz. Not much likely to happen. Cloud is isolated over a flat area all by itself, no pals to group along with, so its certainly going to fade away after the itty-bitty amount ice on the right (frizzy part) produces, oh, maybe a sprinkle or slight rain shaft. Maybe I’ll take a nap while things are calm.

20 minutes later….something unbelievable has happened: a “volcano” of sorts erupted from this moderate, isolated cloud. I have never been so embarrassed in all my life not to have seen this coming. But it was also so wondrous at the same time.

2:11 PM. Wha? Can it possibly be the same cloud? It was. LOOK at that rain shaft! Also, in the middle,about halfway up, that dark thing almost looks like vortex. Kinda reminded me of the Mt. St. Helens eruption.

Also seen was the rarely seen Cumulus congestus pileus tops here and there indicating strong uprushing currents pushing into the air above the top, and rushing up so fast, the air above the top is pushed up and starts to condense into a cloud before the actual cloud top reaches it. See below:

2:18 PM. Pileus cap cloud tops Cumulus congestus turret. If you're in an airplane with instrumentation, you really want to penetrate this one to get high measurements of liquid water, maybe two or three grams or so. — 2:18 PM. Pileus cap cloud tops a rapidly rising Cumulus congestus turret over the Catalina Mountains. If you’re in an airplane with cloud instrumentation, you really want to penetrate this one right hear the top to get high measurements of liquid water, maybe two or three grams or so.

5:14 PM. This thunderstorm was almost in the same exact area as the "volcano." — 5:14 PM. This thunderstorm was almost in the same exact area as the “volcano.”

5:14 PM. It looked like a promising sitiuation was propagating down from N of Charouleau Gap, but the new bases ahead of outflow winds crept closer to the mountains instead of extending out over the lower terrain and Oro Valley. This led to a dramatic rainshaft scene that CMP missed because he didn't bail on a dinner situation at a restaurant. I guess it was quite a show when it cut loose a few minutes later, with a great rainbow, I hear. — 5:14 PM. It looked like a promising situation was propagating down from N of Charouleau Gap, but the new bases ahead of outflow winds crept closer to the mountains instead of extending out over the lower terrain and Oro Valley. This led to a dramatic rainshaft scene that CMP missed because he didn’t bail on a dinner situation at a restaurant. I guess it was quite a show when it cut loose a few minutes later, with a great rainbow, I hear.

7:06 PM. Did catch the lastbit of the show in these Cumulonimbus mamma clouds. So, something to show for having a good time with friends at a local Goose Plaza restaurant.

For the full day yesterday, see the U of AZ time lapse. Its a rolling archive and so it will gone if you read this after today.

Time of the hurricane, and of the California Niño

Those model generated ones, that is, that are shown to come close to Arizona; “close” being within 500 miles or so, which, astronomically speaking, is incredibly close.

This time of year, we look forward to the possibilities that one of the many hurricanes that affect the Mexican Pacific will rush up Baja coast, angle northeastward and cross the border into Arizona. Remember that one in 1976 that hit Yuma with 76 mph winds? Yeah, like that one. Go here to read about it if you don’t believe me that Yuma experienced hurricane force winds from a hurricane. Mt. San Jacinto in southern Cal got over 14 inches of rain, too.

While the computer models have a tough time generating hurricanes in their right places too far in advance, they are remarkable in how many they generate, considering that those hurricanes pop up out of loose-looking cloudy masses, with weak areas of low pressure associated with equally, loosely-organized upper level features. To have a tropical storm leap out of that cloud mass, the upper air pattern has to spread the air aloft over those clouds so that more air can come into the developing storm at the bottom. And, as more thunderheads (though they don’t usually thunder much) pile upward, more warming aloft occurs, and that helps the air spread away even faster.

Today, we have a coupla interesting predictions, one by our Canadian friends, showing a tropical storm roaring up the coast of Baja just next Thursday. This from their 5 PM AST model run yesterday. The remnant of that TS goes into southern California! This is just 5-6 days away, which, in model time, is not that far off and usually is fairly reliable.

But, USA model (WRF-GFS) from 5 PM AST last evening, has no such feature! See below. Boo-hoo.

Still, something interesting has shown up in our own USA model about two weeks out that seems to be due to something unusual that’s happening off the West Coast. A new phenomenon, reported in Nature (!) and akin to the “The New Niño” (the one in Pacific Ocean Region 3.4) and the “Classic NIño” (the one we heard about as kids where the water off Peru gets real warm), has recently been dubbed, the California Niño.

This is an oscillation caused by the slackening of the onshore winds along the Cal coast. Those winds, when as strong as they usually are, cause really cold water to boil up to the surface; when those winds become slackers, the water warms tremendously.

This year the water temperatures offshore of the Cal coastline, are way warmer than usual. No wetsuits needed off Monterey this year (a friend says)! These warmer waters will help tropical storms stay together a little longer when they are directed north and northeastward toward southern California and Arizona. Yay!

This may explain why a hurricane/strong tropical storm is shown drifting to the NW only a few hundred miles SW of San Diego, as shown below, in about two weeks. The eye-popping stat in that model projection, is that the low pressure in the center is still as low as 982 millibars when its fairly close to San DIego! This shows that the models knows about the water temperatures out there (that kind of data is always being fed into them), and it thinks that a pretty good sized tropical low can exist that far close to San Diego with water temperatures as warm as they are.

All we have to do now is wait for the right upper air “steering” pattern, to keep the western motif here, so that those stronger storms are directed thisaway, to continue yet again with the western theme.

The prediction shows that the model thinks that conditions are warm enough to support such a storm relatively close to southern California. What grabs your attention is the 982 mb central pressure in the eye of that predicted storm two weeks from now. Let us not forget the near hurricane that blasted southern California in September 1939, likely having occurred during “Cal Nino” conditions.

Check these predictions out, first from Canada, where a magnifiying glass will be required to view details:

Valid Thursday morning, Aug. 21st at 5 AM AST. The storm is moving N.

Valid for the afternoon of August 29th. This one is moving NW.

The reason for the excitement is that troughs and jet streams are beginning to creep farther south and when they do that, sometimes they can “steer”, to use a western term again here, a storm toward the north and northeast. In June, July, and into much of August, the many hurricanes that form off Mexico and central America drift west and west-northwest only to die over the cooler waters north of the Equator.

More showers and thunderstorms are buiilding on the Catalinas! And late afternoon or evening rains are foretold here.

The End.

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¹Ironically, the distraction was having his computer almost stop working because he had filled up the “C” hard drive with too many photos and almost nothing worked any more! Note: Put photos on a different HD. Leave at least 10 percent of the C hard drive “file-less”, so’s it can work properly.

Good muddy morning, Mr. and Mrs. Catalina!

Well, it finally happened, we got shafted royally (as CM likes to say, referring to getting rain shafted) yesterday afternoon with a badly needed 1.09 inches here in Sutherland Heights. More than 2 inches fell nearby, too, such as near the intersection of Hwy 77 and 79! The highlight of the storm was, of course, all of those several close lightning strikes between 2 and 3 PM yesterday. If you weren’t out watching them, here’s one for you, one that popped Lago del Oro. (Mr. Cloud Maven person reminds his reader that during lightning, do not stand outside by a tree outside as here. Hmmmph, a new thought…. Maybe that’s where the expression, “Death warmed over” comes from, a person unlucky enough to have been struck by lightning…and then somebody finds him right away!

2:06 PM. Looking northwest; a literal highlight of the day.

6:17 AM. The remarkable site of a Sc lenticularis stack over Catalina due to strong easterly winds up there. This is more like a scene from the front range of the Rockies in wintertime. It hovered up there in place for a couple of hours before withering. One almost started looking for infamous “rotor cloud”, filled with severe turbulence. You can see this remarkable cloud for summer and the things it did, courtesy of the U of AZ time lapse film for yesterday, a real keeper! Still have that lenticular cloud over and downwind of Ms. Lemmon today. Interesting.

6:23 AM. After a few drops, a little rainbow was seen off to the NW. Quite nice.

7:56 AM. Of concern after awhile is whether we might have a gloomy, but dry Seattle-style day, or maybe light steady rains as a disturbance moved toward us, or would that disturbance be potent enough to generate deep storms sans heating? For those who live here in the summer, we know that the sun is potent enought, even with dense clouds, especially ones that are NOT compose of ice crystals, the vaporize pretty heavy overcasts. This would be a good thing, because a little heating goes a long way when you have deep, and low based moisture as we had yesterday. The clouds shown here are composed of droplets, not ice crystals, but, of course, I have just now insulted your Cloud Maven Junior intelligence because you can see the sharpness of the cloud features, and more importantly there is no virga, a site that would mean there was ice inside the clouds, ice that would grow into major snowflakes, melt and fall out as rain. So, there is hope here, to continue this novella, for a "burn off" in spite of the heavy, and dark looking clouds because its early in the morning still and they probably have higher concentrations of droplets in them and that in turn cause more of the sun's light to be reflected off'n the top. — 7:56 AM. (Caution-long, sleep-inducing caption ahead. If you’re driving you’ll want to pull off the road.) Of concern after awhile is whether we might have a gloomy, but dry Seattle-type spring day, or maybe only light steady rains amounting to only a few hundredths or tenths as a disturbance moved toward us. Or, would that disturbance be potent enough to generate deep storms sans heating? For those who live here in the summer, we know that the sun is potent enough, even with dense clouds, especially ones that are NOT composed of ice crystals, to vaporize pretty heavy overcasts. This would be a good thing, because a little heating goes a long way when you have deep, and low based moisture as we had yesterday. Doesn’t have to get that hot. The clouds shown here are composed of droplets, not ice crystals, but, of course, I have just now insulted your Cloud Maven Junior cloud intelligence because you can see the sharpness and detail of the tiniest cloud features; they are not “blurry-looking as ice clouds would be, and more importantly there is no virga, a site that would mean there was ice inside the clouds, ice that would grow into major snowflakes, melt and fall out as rain. So, there is hope here in this sighting of droplet clouds, to continue this novella, for a “burn off” in spite of the heavy, and dark looking clouds because its early in the morning still and they probably have higher concentrations of droplets in them and that in turn cause more of the sun’s light to be reflected off’n the top, and that’s why they look so dark, a darkness that has been enhanced that bit by a little trick of photography called, “underexposing.” Oh, the cloud type? Stratocumulus stratiformis (the second descriptor because there’s so much of it.)

9:46 AM. Within only an hour or two, the thought of a heavily overcast all day could be jettisoned as the normal mid-morning to mid-day thinning occurred. But, now, would the storms be clustered enough to hit Catalina, or would they end up being too scattered as in the day before where big dumps missed us? It was, however, now in the bag, that huge clouds would rise up later in the day due to some heating. Note Ac lenticular slivers.

1:47 PM. While doubts arose as the sky filled in again with dark, lackluster Cumulus and Stratocumulus clouds over Catalina, powerful storms were ripping across Tucson and points S leading one to believe that there was a chance these clouds would pile higher until reaching the ice-forming level in spite of moderate temperatures. Sure enough, one of the Great Moments in clouddom, is catching those first strands of rain.graupel that fall from such a cloud. Really, its like seeing a marbled murrelet streaking in from the coast in a redwood forest, its that rare (see Rare Bird, Marie Mudd Ruth, award winning author, in keeping with a mud theme here today. — 1:47 PM. While doubts arose as the sky filled in again with dark, lackluster Cumulus and Stratocumulus clouds over Catalina, powerful storms were ripping across Tucson and points S leading one to believe that there was a chance these clouds would pile higher until reaching the ice-forming level in spite of moderate temperatures. Sure enough, one of the Great Moments in clouddom, is catching those first strands of rain/graupel that fall from such a cloud, as here. Really, its like seeing a marbled murrelet streaking in from the coast whilst in a redwood forest, its that rare (see Rare Bird, Marie Mudd Ruth, award winning author and friend who likes clouds a lot, in keeping with a “mud” theme here today. Remember, too, you only got a couple of minutes to catch this stage as the large drops and soft fall out at about 15-20 mph.

1:59 PM. Moving rapidly westward, unloads west of Saddlebrooke. Worried here, since it missed. — 1:59 PM. Moving rapidly westward, unloads west of Saddlebrooke. Worried here since it missed.

2:00 PM. More rain and thunder appeared upwind on the Catalinas leading to renewed hope. In fact, the whole sky at this point seemed to be turning into one huge Cumulonimbus. It was great!

3:27 PM. An inch had fallen and it looked like we were going have a lake side property. Next time will get kayak out! Sometimes toads erupt from the earth when this happens, but I guess they like it darker than this.

4:01 PM. One of the prettiest sites after our major rains is this line of Stratus fractus clouds that cuddle up against Samaniego Ridge. Yesterday was no exception, and it was another memorable site of the day.

The weather ahead

Well, drying. Unfortunately we’re in for another long dry spell likely beginning after today. Hoping we can squeeze out one more day with rain this afternoon. Today’s storms will move from an unusual summertime direction from the south-southwest and southwest, so you;ll want to be watching toward the Tucson Mountains to Twin Peaks for stuff that might come in in the afternoon, more of a fall pattern as the winds are shifting aloft today to from the SW. The Catalinas get active with Cu and Cumulonimbus piling up by late morning, but they drift toward the north and not over us as they did yesterday, all this from the U of AZ model run from 11 PM AST last night.

While waiting for the rain….

Started to rain here in at 3:45 AM…have 0.01 inches so far. :{

So far in AZ, Flagstaff area leading the way Statewide with about 0.90 inches. You can check out those amounts in real time here from the USGS, and here for Pima County. Also you can look at those amounts reported in real time at PWSs (personal weather stations) throughout Arizona on the Weather Underground “Wundermaps” as this exciting, much awaited day develops.

Point forecasts from the U of AZ “Beowulf “for today, based on 11 PM AST data, here. (Graphical version not yet completed.) You’ll see that a mighty amount of over 4 inches of water content is forecast for the top of the Lemmon (Summerhaven) from this storm. These calcs are usually a little high, but even 2 inches would be fabulous up there. Catalina, per se, does not appear in the point location list, but Oro Valley is expected to get around half an inch. We should do better than that here in Catalina/Sutherland Heights.

———-SC rain doings———

Forecast “10 in 24” at Opids Camp; got about 8, same for favored locations in Ventura County. Working on 10 for storm there as I write; another round of pounding rain moving into the LA Basin now. NWS tornado warning for east central LA expires at 4 AM today. (They saw rotation in a severe thunderstorm around Covina earlier this morning.)

BTW, go here to see how excited the Los Angeles branch of the NWS is today. You’ll see that their domain is a kaleidoscope of colors for warnings and advisories of all kinds! Ninety five percent of the time, they really don’t have that much to forecast in southern California, pretty boring really, so this is a great time for them to show their stuff, be excited, “show the colors.” (Me, too!)

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Some of yesterday’s cloud scenes

6:46 AM. Sunrise on the Gap. — 6:46 AM. Sunrise on the C-Gap.

6:57 AM. Two levels of ice clouds, an rare site. The darker on just above the mountains is some icy remnant of an Altocumulus cloud that converted to ice. The whiter clouds are at Cirrus levels, likely some spot of droplets before almost instantly glaciating. The different colors give away the different heights, and also the difference in movement; one level moving relative to the other tells you this, too.

8:37 AM. Micro-versions of Cirrus uncinus suddenly blossomed overhead; almost missed 'em. What was unusual was how tall the vertical parts were with tiny hooks at the bottom. That vertical part indicates a layer of air with no wind shear, a phenomenon almost always observed at cloud tops. The wind shear may have been "mixed out" by the up and down motions associated with cloud formation and dissipation. — 8:37 AM. Microversions of Cirrus uncinus suddenly blossomed overhead; almost missed ’em. What was unusual was how tall the vertical parts were with tiny hooks at the bottom. That vertical part indicates a layer of air with no wind shear, a phenomenon almost always observed at cloud tops. The wind shear may have been “mixed out” by the up and down motions associated with cloud formation and dissipation.

8:37 AM. Close up view of those tiny Ci unc.

9:12 AM. Webby Cirrus. Has no official name that I know of. — 9:12 AM. “Webby” Cirrus. Has no official name that I know of.

9:35 AM. Though the natural sky is slightly marred by a contrail, in general it was a thing of beauty all morning in particular with the high visibility, complex goings on in the cloud structure, deep blue sky with moderate breezes and temperatures in the 70s. Here, more of that "webby" Cirrus, and on the horizon, the rarely seen Cirrus castellanus which I report seeing almost every week here in AZ. — 9:35 AM. Though the natural sky is slightly marred by a contrail, in general it was a thing of beauty all morning in particular with the high visibility, complex goings on in the cloud structure, deep blue sky, moderate breezes and temperatures in the 70s. This view, toward the Charouleau Gap, shows more of that “webby” Cirrus, and on the horizon, left of center, the rarely seen Cirrus castellanus which I report seeing almost every week here in AZ.

10:37 AM. Less complicated Cirrus fibratus patches moved in, followed by the development of small Cumulus clouds. Still very pretty though. — 10:37 AM. Less complicated Cirrus fibratus/uncinus patches moved in, followed by the development of small Cumulus clouds. Still very pretty though.

2:50 PM. Your afternoon. The Cirrus thickened into a solid layer with gray, transitioning to Altostratus with these small Cumulus ("humilis") below. — 2:50 PM. Your afternoon. The Cirrus thickened into a solid layer with gray, transitioning to Altostratus with these small Cumulus (“humilis”) below. TYpically thickening is due to the bottoms of clouds lowering (in this case, where the ice crystals falling out evaporate is perceived as cloud base) while the top stays about the same height. As the air moistens during the approach of a storm, the crystals fall farther toward the ground and the cloud thickens downward.

The End.

All’s not quiet on the western front

Rain beginning to pile up again in Cal as behemoth Pac storm moves in. See an actual, professional level weather map below, not a mickey mouse one. It will be good for you to see a complex weather map with all kinds of weather symbolia on it:

Surface weather map with satellite overlay from the University of Washington Huskies Weather Department. High clouds from this storm are already above Catalina!

0.01 inches at Opids Camp, LA area mountain site, already (at 5:30 AM AST) out of predicted by C-M of 10 inches or so in the next 24 h; highest totals somewhere in central and southern Cal mountains likely between 10 and 20 inches for this one storm! California dreamin’¹? Will keep you posted if I am right.

Here?

Really tough to forecast more than an inch in one winter’s day in a desert. Goes against the grain and the cactus, for that matter. Thought I would get some help from the great U of AZ Beowulf Cluster, but its still crunching the 11 PM AST data away as I write here at 5:30 AM. So, can’t wait for a really accurate answer. You should go there, though to get one….

Being crude, then, and I mean using a model with a huge grid spacing compared to that of the U of AZ Cluster model, the Canadian GEM indicates about 36 h of rain, 5 AM AST tomorrow to about 5 PM on Sunday, and even at a average of 0.05 inches over that time, you get 1.80 inches! Good grief. So, maybe now that BIG forecast by a BIG atmos sci faculty member at Colo State, “1.5 to 2 inches”, might be right, closer than my dinky 1 inch max forecast of yesterday. Its great to be wrong when you under forecast precip, but that’s about the only time!

Higher resolution US WRF-GFS mod run from 5 PM AST last evening has fewer hours of precip, BTW, partly because it DOES resolve the forecast in 6 h blocks, not 12 h ones like the crude Canadian model.

Also, the winds above us, being more westerly than southerly during the coming storm, is better for us here in Catalina. Deep southerly flows have to go over Pusch Ridge, and rain can be diminished locally that bit due to the downslope effect off the Ridge. Won’t have that tomorrow and Sunday, so that’s a plus.

The cut to the chase: minimum from this typewriter now HAS to be much higher than 0,25 inches as was indicated previously. Will go to 0.75 inches as the LEAST we’ll get (things don’t go well, main bands just miss Catalina, etc), with 1.5 inches as max by Sunday evening 5 PM.

Will not mention this forecast again, of course, if the rain in Catalina is outside these limits.

Yesterday’s clouds

Nice patterns and nice small Cu yesterday with great visibility again.

1:53 PM Finely granulated, and with a bit of color (iridescence) Cirrocumulus. Here, the Cc is at mid-levels, not at Cirrus levels. In our cloud classification scheme, which is a little funky, its only the tiny granulations that make it Cc and not Altocumulus. Happens a lot.

5:13 PM. Delicate Cirrus uncinus (hooked Cirrus).

6:18 PM. Sunset Cirrus uncinus, so pretty.

The End, except for a little peak at Opids Camp rain just now… Wow, was just 0.01 when I looked at the 3 AM ob, and at 6 AM is already over an inch!

Hope, too, you caught the beautiful sunrise just now. Will reprise it tomorrow.

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¹Some of you will instantly recall the initial words to this pop tune:

“All the leaves are brown, and the sky is gray, I went walkin’ for awhile on a winter’s day.”

These words were inserted after the “Mamas and the Papas” poke at LA smog in the original words were deemed by producers as less desirable in seeking a commercial hit. The original words that the song began with, before it was commercialized, were” “All the leaves are gray, and the sky is brown”, words that might offend Californians. Thought you’d like to know.

BTW, this video above is a PERFECT paradigm for this year’s sunny, warm and dry weather in the West, and the brutal winter back East. Take a look! Its great!

On the Catalina trails with lenticularis

First, Cal drought bustin’ rain update:

As much as 1-2 inches as far south as Ventura County so far, 3-4 inches in the coastal mountains of central Cal as of just now (4 AM AST). Rolling 24 h Cal State archive here. LA area rain here; keep an eye on Opids Camp and Crystal Lake FC. Totals in NW LA County just now going over an inch. Following this drought bustin’ sequence, while just a” two shot wonder”, will be like watching….I don’t know..something really exciting, a weather kind of Olympics, where the favored team “drought” is taken down unexpectedly by some upstart storm. Yes, I will play the Olympics card.

And remember, this is just the lightweight division today; up next, beginning Friday in southern Cal: “Sumo wrestling”, as a 400-lb storm moves in next to push aside “Team Drought” at least for the moment. (Is Sumo wrestling an Olympic sport?) Still expecting some jumbo rain totals in the mountains of southern Cal, such as more than 10 inches at places like Opids Camp in the San Gabriel Mountains.

Speaking of jumbo totals, a friend and expert weather forecaster (and big atmos sci faculty member at Colorado State who now lives part time in Catalina), sent a stunning e-mail to me yesterday expressing his opinion that Catalina will get “1.5 to 2 inches of rain” from the second “Sumo” storm, the one that eases into Arizona late Friday and arrives here by dawn on Saturday, and then continues for around 24 h. Cloud maven here can’t go that high in his guess, doesn’t have the “testicularis” you might say, to go that high; 1 inch max is all I can come up with, but would be ecstatic if in error!

Still, this is going to be FANTASTIC! Saw some perennial wildflower blooms on the trails yesterday (see below), ones in need of a little pick-me-up–actually a big one, and this will be great for them. Fauna, too, will be happy! It may be too late for the annuals…not sure. Poppies are few, and awfully stunted this year, as many of you know.

Don’t forget, too, before our storm; those gorgeous skies! Have camera and pen ready to document and make notes about them in your weather diaries Those skies we’ll be fantastic, too, like yesterday, which was a great day to be on a horse, watching the sky.

Even when its raining the skies will be fantastic!

How many of us, even if we’re from Seattle, are STARVED for low gray, dank and dark daytime rainy skies, clouds chopping off the Catalinas a thousand feet above us, listening to rain pounding on our roofs, then running off roof making puddles, those richer shades of desert green after the rain ends, the glistening, water-covered rocks on the Catalinas in the morning sun after the storm? Its a real treasure when rain falls here.

Yesterday’s clouds

12:23 PM. You got yer Cis spis (Cirrus spissatus) topping a few Cu fractus and humilis, if I may. It was so great to see those Cumulus clouds, reminding us that July and huge clouds are only about 125 days away!

12:23 PM. You got yer Cirrus uncinus. Note fine strands hanging down. Amazing they can be so perfect, not erratic, when the wind up there is about 100 mph! — 12:23 PM. You got yer Cirrus uncinus. Note fine strands hanging down. Amazing they can be so perfect, not erratic (see arrow), when the wind up there is about 100 mph!

3:54 PM. A great line of a Ac lenticular advanced over Oro Valley. This shot was about the best I got and its not that great.

3:55 PM. Not all about clouds.... Here, a wild onion bloom maybe. — 3:55 PM. Not all about clouds..wanted to show you that I have more than one dimension. Here, a wild onion bloom maybe, slightly out of focus. Prickly pear is in focus, though.

3:55 PM. Very nice Altocumulus lenticularis formed later downwind from the Catalinas. — 3:55 PM. Very nice Altocumulus lenticularis formed later in the afternoon downwind from the Catalinas.

6:25 PM. Another very nice sunset due to some Cirrus spissatus and a few lower Altocumulus clouds.

On the weather horizon

Mods still have unusually warm weather here in the storm after life, 8-12 days out (cold in the East continues, too). But, then some Catalina rains continue to show up after that hot spell when you think May is already here.

The End.

Dull Altostratus-ee day yesterday, but big Pac storm continues to move toward Catalina!

That thick (likely more than 3 km, or more than 10,000 feet) and steady gray sky diet of Altostratus opacus clouds didn’t provide a lot of visual highlights most of yesterday, in contrast to the many Altocumulus flocculations of the day before. An example of yesterday’s sky for most of the day:

3:50 PM. Altostratus opacus. Or is it? Not much going on here¹.

Virga hung down here and there, and some radar echoes during the day suggested a sprinkle here and there reached the ground, but none here.

Later, as usually happens, the tops of the clouds lowered, as did the bases, and we had some pretty Altocumulus again, some with long trails of virga, indicating a deep moist layer below cloud bottoms. For a time, as dewpoints rose, it looked like Ms. Lemmon might be topped with Sc, but those lowest clouds did not get quite low enough.

5:14 PM. Two layers of Altocumulus are present, the lower one having spires (Ac castellanus). Nice lighting on mountains.

5:08 PM. Two layers of Altocumulus are present, the lower one having spires (Ac castellanus), to repeat.

6:23 PM. Heavy virga issues from an old Altocumulus cloud, its once higher, pyramidal top has collapsed as snow developed in it and in essence, hangs down in an upside down version of what it once was — 6:23 PM. Heavy virga issues from an old Altocumulus cloud, its once higher, pyramidal or mounding top has collapsed as snow developed in it and in essence, hangs down in an upside down version of what it once was (though not as tall as the virga is long here).

The Tucson balloon sounding (rawinsonde) for 5 PM AST (launched about 3:30 PM, rise at about 1,000 feet a minute.) BTW, takes about an hour and a half to get the whole depth normally measured, to around 100, 000 feet. During that time, or even during the first hour, the atmo is changing, so when its at 40,000 feet, what is measured at 3,000 feet isn't the same anymore. Introduces slight error into models into which these data get fed. Models think its an instantaneous view of the atmo over Tucson. I think you should know this. — The Tucson balloon sounding (rawinsonde) for 5 PM AST (launched about 3:30 PM, and rise at about 1,000 feet a minute.) BTW, takes about an hour and a half to get the whole depth normally measured, to around 100, 000 feet. During that time, or even during the first hour, the atmo is changing, so when its at 40,000 feet, what is measured at 3,000 feet isn’t the same anymore. Introduces slight error into models into which these data get fed. Models think its an instantaneous view of the atmo over Tucson at 5 PM AST (00 Z time). I think you should know this. Note tops of that Ac with heavy virga were about -30 C (-22 F)! Notice, too, that some of those higher, colder Altocumulus flakes are not showing virga in the sunset photo above.

Weathering just ahead….

Rain One (“Little Bro”) is moving onto California coast as I write. Residents in towns like the very-expensive-to-live-in Monterrey rejoicing as drops patter on rooftops now! The negative news here is that the Canadian model has lessened the area of rain in Arizona as Rain 1 passes over us, confines the rain to central and northern AZ mountains now, still light, but not as widespread as before.

At the same time, the US WRF-GFS model has been adding rain in AZ from Rain 1; previously it had NONE. Now, these mods have now come together over us² to quote a song title from the last century, both showing about the same thing, so that’s probably what will happen. Just rain to the north of us. So, a little less of a close call to Catalina tomorrow as Rain 1 goes by. Just middle and high clouds for us, and probably some virga, nice sunrises and sunsets.

Rain 2, “Big Bro” moves into southern Cal tomorrow night, and still looks like a real and necessary pounder for southern Cal before moving on and drenching little Catalina. Will report on those SC amounts to see how big they get, too.

Rain should be falling here in Catalina by Saturday dawn and continue all day. Range of amounts, still a not-so-great quarter inch on the bottom (if things don’t go well), but top (if things go really well) still an inch! How great would that be? So, best guess about 0.60 inches here in Catalina, from averaging those two “extrema.” Later today, our U of AZ Beowulf Cluster model computations will start to have some quantitative amounts from actual calculations, not just a SOP guess from yours truly. Check here at the U of AZ later in the day for accumulated totals based on this morning’s 5 AM AST data.

Way out there

While our drencher on the weekend seems to be a one-shot wonder for at least a week after it passes, the longest view from our WRF-GFS, valid way out on March 13 at 5 PM AST, 360 h from last night’s model run, has another major storm moving into the SW, but this time it doesn’t come from the west, but from the NW. This is a climatological norm; storms tend to move from NW to SE during the spring months in the western US, and so there’s SOME climatology to hang your hat on that the rain forecast below for us may be a real event, not a fantasy storm, as so often happens that far into the future in our models. See the map below, from IPS MeteoStar’s rendering of the WRF-GFS to brighten your day that bit more, knowing one good rain is coming, and maybe, just MAYBE, the pattern is shifting to a normal one with an occasional rain here in Catalina beginning after mid-March.

Valid at 5 PM, March 13. Green areas denote those regions where the model thinks it has rained during the prior 12 h.

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3:50 PM. Actual Altostratus opacus. I've been talkin' clouds here for quite awhile, and in a clever kind of a test, wanted to see if you could tell the difference between the side of my gray car and an Altostratus cloud. — 3:50 PM. Actual Altostratus opacus. I’ve been talkin’ clouds here for quite awhile, and in a clever kind of a test, wanted to see if you could tell the difference between the side of my gray car and an Altostratus cloud. Its pretty important to me that you get this right.

Rains moving closer to Catalina; whopper LA rain ahead

It doesn’t get any better than this if you need rain and want 10 inches:

Valid at 5 PM AST, Friday, February 28th. Arrow points to massive sweep of sub-tropical air into southern Cal, the whole SW really. — Valid at 5 PM AST, Friday, February 28th. Arrow (upper right panel) points to massive sweep of sub-tropical air into southern Cal, the whole SW really. This from the Canadian Global Environmental Model (GEM) based on last evening’s data.

Actually, 10 inches in a day is not so unusual in the mountains of southern California, which is something that’s going to happen if this model output verifies this weekend. Also, the storm takes a couple of days to go through, and so mountain totals of 10-20 inches are likely in the favored locations. Coastal areas would likely see 2-6 inches I think now with this configuration.

Twenty four hour totals of more than 25 inches of RAIN were observed in the southern California mountains in January 1943, and again in January 1969, to put a forecast of “just” 10 inches in one day in perspective.

Thinking about driving over there, to say, Hoegee’s Camp in the San Gabriel Mountains, where they once got 26 inches in a day (back in ’43). Would really like to see what heavy rain looks like in this basher; rocks coming down onto highways, windy, giant waves along the coast, a real weather hullaballoo. Maybe we should organize a storm tourism trip? Think of all the happy people we’d see, too, in this muttin’ bustin’ drought bustin’ bustin’ bustin’ bronc bustin’ storm, to kind of get in the rodeo frame of mind here to emphasize to the people of Tucson just how rough it will be on the city folk of southern Cal.

The good news here is that predicted rains have been increasing here in Catalina and throughout Arizona in the models as well. Maybe it won’t be too late for our spring greening to green up a little more. An inch is now possible here on the top end, minimum likely to be as much as a quarter of an inch (even if mods really off) ending on the 3rd.

Still looking at a close call, maybe some sprinkles before that from the first slug of rain that hits Cal, on Thursday, the 27th of Feb. Much of Arizona should get something from that first rain intrusion.

What a great cloud day it was yesterday! Fabulous.

Here are a few cloud shots:

Can you name them?

Today? Sat imagery makes it look like our middle clouds will be thick enough to produce isolated drops. Be sure to log any that you see.

The End.

Final storm total here 2.31 inches

0.48 inches fell after 7 AM yesterday, a nice addition to the 1.83 inches already “in the (raingauge) can”, with a 0.01 inches dollop overnight here in Catalina/Sutherland Heights, slightly more and less here and there, with several inches in the local mountains. That addition brought our storm total to 2.31 inches, about 2.5 times normal for the month of November which averages only 0.96 inches.

Recall that at the beginning of the month, it was deemed by the Climate Prediction Center of NOAA that we in SE AZ would experience below normal precip. But this just shows how HARD it is to predict monthly precip anomalies in semi-arid and arid regions where ONE good storm of just a day or two, can blow the forecast (thank goodness!)

Much harder to blow a monthly forecast in places like Seattle where monthly totals are based on many rain days, and if you only had 25 days with rain in a month instead of 30 due to some storm deflecting pattern, then it might turn out to be a droughty one (hahahahaha, kidding my Seattle reader). Those CPC forecasts have a greater chance of verifying in wetter areas where one rogue storm won’t blow those forecasts up.

Also recall that this season we have no La Nina nor an El Nino to hang our climate forecasting hat on. Makes it tough as well.

If Carl Sagan was a meteorologist today, he would be describing our 2-day November drought bustin’ storm as one worth “billions and billions and billions” where nearly every corner of our drought-impacted State got substantial rains. Should help, too, with wildflower eco-tourism in the spring; at least some wildflower blooms now guaranteed.

Should be a gorgeous day today with deep blue skies punctuated by fluffy Cumulus clouds, some tall enough to form ice and produce virga and light showers here and there; not likely to measure here, though. Lots of Stratocumulus¹ around early before breaking up into Cu.

Next rain chance? As November closes out into the first coupla days of December.

Yours and mine; the weather and clouds of yesterday

7:31 AM. Doggie Zuma notes R- OCNLY R, decides to return to house. — 7:31 AM. Doggie Zuma notes R- OCNLY R (light rain occasionally moderate rain) forming puddles, decides to return to house. Dog photo likely to increase web traffic…..

DSCN6449 — 10:48 AM. Light to moderate rain continued for another few hours while the back edge of the band was just over the horizon to the west!

12:12 PM. Clouds beginning to lift above ground, Catalinas plainly visible. — 12:12 PM. Clouds (Nimbostratus) beginning to lift above ground, Catalinas plainly visible. SOmetimes this scene is described in aviation parlance as, “Ceiling ragged”, cloud bottoms becoming visible because not much precip is coming out anymore. So this is a horrible report to read, “CIG RGD”, often due to cloud tops descending in height, and/or much drier air moving in, both suggesting, as it did yesterday, that the worst of storm is over.

2:40 PM. One of the great sights after a storm are the sun glints due to water on the Catalina Rockies. Hope you caught some of this yesterday.

2:41 PM. "Standard issue" crevice cloud. You'll see this over and over again on Sam Ridge. And, as suggested, a great place to hike to, then go in and out of cloud, one that can remain there for hours. — 2:41 PM. “Standard issue” crevice cloud. You’ll see this over and over again on “Sam” (Samaniego) Ridge. And, as suggested, a great place to hike to, then go in and out of cloud, one that can remain there for hours. Remember how you used to play hide and seek in the fog when you were little? BTW, fogs are real dense when they’re full of pollution, more fog droplets to cut visibility down. So that’s the kind of fog you want to play in and see if you can run away in and disappear in it from your brother.

3:56 PM. And as the storm clears, we get these wonderful highlights on the Catalinas.

4:42 PM. As the sun set, our second band of showers approached, consisting of heavy Cumulus (i.e., congestsus) and small Cumulonimbus clouds with shafts of rain. — 4:42 PM. As the sun set, our second band of showers approached, consisting of heavy Cumulus (i.e., congestus) and small Cumulonimbus clouds with shafts of rain.

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¹ Stratocumulus: “flat Cumulus”, a cloud name oxymoron

1.77 inches in Catalina and counting

….as of 6 AM.

And we might even end up with TWO inches total for this storm! Amazing! I couldn’t imagine it, even as a precipophile with a known bias, that more than 1.5 inches would fall from this situation (10% chance of more than that I wrote), with a best guess of only about an inch.

Even the mods grossly underestimated the amount of rain that would fall during the day yesterday, and THAT was the huge surprise in this situation, with several inches falling in the Cat Mountains in the first 18 hours. It appeared in the models that the major rains would occur overnight and this morning, rather than during the day yesterday.

Three to five inches of rain have fallen in the Catalina Mountains since the storm began about 36 hours ago. Is the CDO flowing? Sutherland Wash? Streamflow reports for the CDO don’t show anything at this hour, surprisingly.

Here are the latest totals for just 24 h from Pima County.

We’re now in the main cloud and rain band wrapping around the upper low near San Diego and more showers, maybe a roll of thunder, will continue through this evening. This band was supposed to be the major rain producer, in the mods, but likely won’t now, though won’t be as great a rain producer as yesterday. Probably a tenth to half an inch likely during the day as the band continues over us for another few hours. And here is your U of AZ mod rain forecast, hour by hour.

While not forecast in this U of AZ mod run, sometimes secondary bands develop separate from, and behind the main one we’re now in, and I think there is a pretty good chance of that happening today. Often, there’s a nice sunbreak as the main band departs and before the second separate one comes through, so watch out for that possible surprise in case you think the storm is over.

Pity the poor Oregon Donald Duck^TM football team, playing in “Eugene weather” against the Cats today in Tucson, Arizona. Imagine what they expected the weather to be here even a week or two ago! And those poor Tour de Tucson bicyclers, too, peddling around flooded streets!

Upper low passes overhead later in the day tomorrow, which means a day with the coldest air will be over us then, and with that, we’ll have some great looking Cumulus and small Cumulonimbus clouds, scattered showers, maybe enough depth for some graupel and lightning before the weather dries out again for a few days.

Sometimes in these situations like we have today, dramatic line of showers/thundershowers with a fronting arcus cloud can develop to the west and southwest and roll across Marana and Oro Valley in the afternoon. Will be looking for something exciting like that today.

Coming up, another forecasting conundrum….

While the US model has a trough passing over Cal as November closes, while the GEM Canada has the SAME trough offshore of Baja at the same time, a huge dispersion in model results we don’t see very often when they start with the SAME global data and its only five or six days away!

Recall the USA model was in error for the current storm early on, showing it to come inland and be rather dry when the Canadians came up first with a monster using that same global data. So, leaning toward the Canadian model this time around; that the incoming low at the end of the month has a good potential to produce more rain here by having a more offshore and southerly trajectory before arriving.

Below, the Canadian solution, and below that, the USA one, FYI as an example about what weather forecasters have to deal with sometimes:

Valid at 5 PM AST, November 28th. Low of interest (LOI) off Baja Cal. In USA GFS mod, its over Fresno, Cal at this same time! Can't be two places at the same time. Believe this depiction will be closer to the truth. — Valid at 5 PM AST, November 28th. Low of interest (LOI) off Baja Cal. In USA GFS mod, its over Fresno, Cal at this same time! Can’t be two places at the same time. Believe this depiction will be closer to the truth.

Valid for the same time as the map above. Quite a difference, huh?

Yesterday’s clouds

11:43 AM. Characteristic cloud shot for November 22nd, 2013.

And with the massive amounts of rain and puddling, the desert quickly responded. — And with the massive amounts of rain and puddling, the desert quickly responded in unexpected venues. Here on Equestrian Trail Road, prickly pear cacti emerge from a road puddle.

Yesterday, too, after the light to moderate rain in the morning, was a rare episode of Arizona drizzle. I am sure the best of the CMJs noted this. And what does it tell you? The clouds overhead are exceptionally “clean”, droplet concentrations are LOW, likely less than 150 per cubic centimeter, or 150,000 per liter, which we consider low, though it probably sounds high to normal people.

The aerosols on which cloud droplets form on, called “cloud condensation nuclei”, or CCN, got pretty much wiped out by rain, as you would guess yesterday, and so air involved in cloud formation hasn’t got a lot of CCN available. Normally in inland areas, clouds with 300, 000 to a million droplets per liter are common.

When droplets are few, the water that condenses in the cloud is dispersed on fewer drops, and so each drop tends to be larger than in polluted clouds. When they are larger, and reach diameters of 30-40 microns (about half or so of a human hair) they can collide and stick together, form a much larger droplet that falls faster and collides with more and more droplets until it falls out of the cloud. In this case, because its a thin Stratus cloud, the droplet only can grow to drizzle size, one by definition that is smaller than 500 microns in diameter (about five human hair widths. They don’t or BARELY make a disturbance in a puddle. So, when you saw those drizzle drops falling out, you KNEW that the largest droplets in that shallow Stratus cloud overhead had attained 30-40 microns in diameter.

Do you need to know this? No.

12:33 PM. Very exciting scene. The rarely seen Stratus deck, AND a drizzle occurrence in progress!

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.