Nimbostratus – Page 2

Trough, combining with Simon’s remains, delivers 5 inches to Ms. Mt. Lemmon! Clouds now clean and shallow!

Looked for a time that the rain might be over by mid-afternoon and early evening here in Catalina with only a disappointing 0.40 inches here, but the rains kept coming overnight, piling up a nice 0.98 inches 24 h total for the storm. In the meantime, Ms. Mt. Lemmon has gotten 4.29 inches! Check out these eye-popping totals from the Pima County network, ending at 7 AM AST today (just updated. These are so great in view of last October’s trace of rain:

Gauge    15         1           3          6            24         Name                        Location
ID#      minutes    hour        hours      hours        hours
—-     —-       —-        —-       —-         —-       —————–            ———————
Catalina Area
1010     0.00       0.00       0.00        0.24         0.71      Golder Ranch                 Horseshoe Bend Rd in Saddlebrooke
1020     0.00       0.04       0.04        0.28         1.06      Oracle Ranger Stati          approximately 0.5 mi SW of Oracle
1040     0.00       0.08       0.12        0.43         0.94      Dodge Tank                   Edwin Rd 1.3 mi E of Lago Del Oro Parkway
1050     0.00       0.16       0.20        0.67         1.26      Cherry Spring                approximately 1.5 mi W of Charouleau Gap
1060     0.04       0.16       0.20        0.83         1.93      Pig Spring                   approximately 1.1 mi NE of Charouleau Gap
1070     0.00       0.08       0.20        0.59         1.14      Cargodera Canyon             NE corner of Catalina State Park
1080     0.00       0.00       0.00        0.31         0.91      CDO @ Rancho Solano          Cañada Del Oro Wash NE of Saddlebrooke
1100     0.00       0.12       0.28        0.55         1.06      CDO @ Golder Rd              Cañada Del Oro Wash at Golder Ranch Rd

Santa Catalina Mountains
1030     0.00       0.04       0.08        0.55         1.57      Oracle Ridge                 Oracle Ridge, approximately 1.5 mi N of Rice Peak
1090     0.08       0.31       0.67        1.42         4.96      Mt. Lemmon                   Mount Lemmon
1110     0.04       0.12       0.12        0.71         1.61      CDO @ Coronado Camp          Cañada Del Oro Wash 0.3 mi S of Coronado Camp
1130     0.00       0.24       0.47        1.89         3.46      Samaniego Peak               Samaniego Peak on Samaniego Ridge
1140     0.04       0.12       0.24        0.39         1.73      Dan Saddle                   Dan Saddle on Oracle Ridge
2150     0.08       0.12       0.28        1.14         3.50      White Tail                   Catalina Hwy 0.8 mi W of Palisade Ranger Station
2280     0.00       0.04       0.12        0.31         1.93      Green Mountain               Green Mountain
2290     0.04       0.08       0.20        0.75         2.40      Marshall Gulch               Sabino Creek 0.6 mi SSE of Marshall Gulch

Misty drizzle with very low visibilities is still falling here in Sutherland Heights, Catalina, at 3 AM. The Catalina Mountains are not visible from just a couple of miles away. This suggests the clouds overhead are now “clean and shallow” and rain is forming via collisions of cloud drops with coalescence rather than because of ice in the overhead clouds, often called “warm rain,” a rare occurrence in Arizona. You’ll definitely want to log this in your cloud diary!

“Clean” means that the clouds have low droplet concentrations, viz., are not choked with anthro and natural “continental” aerosols but are more “maritime”, almost oceanic in composition, something that easily leads to “warm rain/drizzle” formation. In oceanic clouds far from pollution sources droplet concenrations usually are less than 100 cm^-3. They average about 60 cm^-3 in Cumulus clouds in onshore flow along the Washington coast, as an example. Cloud appearance should look a little different to the discerning eye, too. With low droplet concentrations, the clouds appear “softer” than usual, not a hard.

Normally, our clouds likely have a few hundred per cm^-3 or more and appear darker from below since higher droplet concentrations is also associated with bouncing more sunlight off the top of the cloud¹.

With vort max (aka, curly, or curling, air) still well to the west of us at this time (3 AM AST) as seen here. This sat imagery also shows plenty of shallow clouds upwind of us, so it seems like the very light rain and drizzle will continue well into the morning, likely adding a few more hundredths to our generous totals. Remember that the air likes to slide upward as curly air approaches, that is, produce a lot clouds, and today, a last bit of precip. Did pretty good last night, too!

Honestly, you really want to get out and experience our misty, drizzly rain (drop sizes mostly between 200 and 500 microns in diameter; a few human hair widths), before it ends; the kind of precipitation that makes riding a bicycle even with a big hat impossible. You might even try the near impossible trick of photographing the drizzle drops, too, as they land in puddles, see if you can catch the tiny disturbance made by drizzle drops. That would be great photo! I know, too, that experiencing real drizzle will give you a bit of a chuckle as you think of all those less informed folks, some of whom are even on TEEVEE, who call a sparse fall of raindrops, “drizzle.” Oh, my, WHAT has happened to our weather education?!

Yesterday’s clouds

Lots of gray cloud scenery yesterday, including a stunning example of Nimbostratus (Ns), the steady rainmaker (at least here we had that, anyway.) In other places, Cumulonimbus clouds were also contained within that rainy cloud mass and dumping an inch or so in an hour in TUS with LTG (weather text for “lightning²“), as you likely know. Didn’t hear thunder here, but coulda happened since I was off to the new Whole Foods market at Ina and Oracle as the steady rain from Ns moved in it because it said online that they had Brother Bru Bru’s African Hot Sauce which I had been looking for for a long time but when I got there they didn’t have it! The grocery manager apologized profusely and then we started talking about haloes and the ice crystals that cause them. So, you never know when your cloud mavenhood will come in handy in everyday conversations, maybe make that friend you’ve been looking for:

7:14 AM. The many layered remnants and distant rain creeping toward Catalina from the southwest are evident soon after dawn

7:34 AM. New round of rain begins on the Catalinas. Shafting here implies mounding cumuliform turrets on top, likely glaciating. From up there they would probably look like soft Cumulonimbus capillatus clouds, ones with weak updrafts.

8:34 AM. One of the prettiest sights can be just a tiny little cloud like this when a sun glint falls upon it. It looked so CUTE! Imagine, you could be up on that little knob and run in and out of it, maybe play hide and seek with your friends, except that being a "clean" cloud, the visibility would be pretty good in it, not like the shallow, impenetrable fogs you sometimes get around Bakersfield, CA. There, you could play really great hide and seek! — 8:34 AM. One of the prettiest sights around here can be just a tiny little cloud (Stratus fractus) like this one when a glint of sun falls upon it. It looked so CUTE! Imagine, you could be up on that little knob and run in and out of it, maybe play hide and seek with your friends, except that being a “clean” cloud, the visibility would be pretty good inside it, not like the shallow, impenetrable fogs you sometimes get around Bakersfield, CA. There, in one of those, you could play really great hide and seek! I’m guessing that if you’re reading this far, you may not have a lot of friends. :}

1:23 PM. In the midst of our mid-day light rain, a clear example of Nimbostratus with underlying Stratus fractus and Stratocumulus. Remember, its not the LOW clouds that are raining, its the deep Ns layer above them. However, it is OFTEN true that the lower clouds ADD to the rain because as the rain falls from the Ns layer, those drops often collide with the floating drops in the lower clouds thus making a raindrop bigger. That's one main reason why rain and snow are so much more on the upslope side of mountains just due to that collection of non-precipitating cloud drops! Its so cool! Away from mountains, you likely won't have so many clouds on the bottom of Ns, and the rain is less. — 1:23 PM. In the midst of our mid-day light rain, a clear example of Nimbostratus with underlying Stratus fractus and Stratocumulus. Remember, its not the LOW clouds that are raining, its the deep Ns layer above them. However, it is OFTEN true that the lower clouds ADD to the rain because as the rain falls from the Ns layer, those drops often collide with the floating drops in the lower clouds thus making a raindrop bigger. That’s one main reason why rain and snow are so much more on the upslope side of mountains just due to that collection of non-precipitating cloud drops! Its so cool! Away from mountains, you likely won’t have so many low clouds at the bottom of Ns, and the rain is less.

2:50 PM. After the rain ended, suddenly this lower cloud line formed representing a wind puff from the west. It headed toward the Catalinas, but then, within a few minutes, pooped out with no precip having fallen out. It was quite a bit fatter before this photo, too. That dissipation indicated that whatever wind source had produced had died out. But anyway, when you see a cloud line like this, think “windshift.”

4:57 PM. Expansive deck of Stratocumulus with spots of very light rain in the distance promises, along with the curly air feature being so far to the west of us at that point, promises that the rain is not over. — 4:57 PM. Expansive deck of Stratocumulus with spots of very light rain in the distance promises, along with the curly air feature (an upper level vortex) being so far to the west of us at this point, promises that the rain is not over.

The weather way ahead

Dry for almost two weeks. However, a crazy NOAA spaghetti factory plot suggests rain in about two weeks, around the 23-25th, as you can plainly see here:

NOAA spaghetti factory plot (aka, "Lorenz plot", after chaos scientist, Edward N. Lorenz--he would really like this plot!) valid for 5 PM AST Oct 23rd. Rain is hinted at by loopy lines in Arizona dipping down to the south. — NOAA spaghetti factory plot (aka, “Lorenz plot”, after chaos scientist, Edward N. Lorenz–he would really like THIS plot!) valid for 5 PM AST Oct 23rd. Rain is hinted at by the loopy lines in Arizona dipping down to the south. Will keep you posted on that, but not very often.

The End. Its really amazing how much information I have passed along today! Most of it correct, too!

——————————————————————-

^cCoCoRahs gauge, not Davis tipping bucket which seems to have a problem of late.

¹This is the concept behind kooky schemes to defeat potential global warming which hasn’t happened for 18 years or so by polluting oceanic clouds, making them “brighter” on top, darker on the bottom by inserting extra aerosols into them. Ghastly thought! Haven’t we polluted enough?

²Recall that weathermen and women were WAY out in front when it came to what we now call “texting”, as in “2KOLD4me” that kind of thing.

Let me give you an example from the 50s when we were rocking around the clock: “M8BKN15OVC2R-F68/661713G24989 R-OCNLY R”, a text phrase that would take a paragraph to unravel, to paraphrase language maven, Noam C^3,4., except in those days we had our own private symbols which I can’t duplicate for “BKN” (a circle with two vertical parallel lines in it) and “OVC” (a circle with a plus sign in it). Weather typewriters and teletypes came with those private symbols!

³Wow, a footnote in a bunch of footnotes! Breaking ground again I think! What Noam C. said: “takes a phrase to tell a lie; a paragraph to unravel it.”

⁴Factoid, one not having to do with weather: Language maven, NC, really liked Pol Pot and his “restructuring” of society back then until he learned about all the millions of skulls were piling up along with that “restructuring.” You can hear about Pol Pot (and hypocrisy) here in Holiday in Cambodia, one of the defining songs of the 1980s IMO, as interpreted by The Dead Kennedys featuring lead singer, Jello Biafra. (You remember Jello don’t you? Ran for president a while back. Kind of surprised we didn’t elect him…)

Tattered “O” creeps into Arizona

Old Man O is kind of a mess now. Still hoping for half an inch here in Catalina/Sutherland Heights, but now even wonder it that will materialize as O goes by today and tonight. Darn!

But, even though O MIGHT be a rain disappointment here in Catalina, there are plenty of opportunities to get substantial rains AFTER O goes by due to lingering tropical air combined with the presence of an upper low pressure center along the Cal coast in the days ahead. Cloud Maven Person thinks (of course, as an “unofficial weather thinker”) that more rain will fall in the spotty thunderstorms here in the Catalina area in the five or so days after O than in O today. We shall see, won’t we?

However, before moving along, let us examine in the colorfully annotated map below those results produced by the truly great thinker inside the “Beowulf Cluster” at the University of Arizona’s Dept of Atmospheric Meteorology to compare the dinky amount CMP is dreading. Its only fair.

Shown below is more like a heavenly rain here, some 1-2 inches is predicted to fall over a number of hours, not in one dump. Hoping for what is shown below, but think it will be quite a bit less.

Total rain accumulation in the 24 h ending at midnight tonight, most will fall in the late morning to evening hours. This map from the model run at 11 PM AST last night, the very latest available. The reddish areas represent where the model thinks the center of O will go with its central heavier rains. Notice that it thinks some little areas of Mexico inland from the Gulf will get a mind-boggling TEN inches or more!

Besides, rather than having completely cloudy skies, as today’s sky will likely be, those heavy guys in the days ahead will be far more “photogenic” you might say with their black shafts and sparks. Rainrates will be greater, too, in those situations than from O’s clouds, which are a little too stratiformy and all mixed together for the blinding rains we see in our thunderstorm rain shafts. Also, since O’s little circulation will pass just to the east of us, the flow off the Catalinas will be a little downhill from the east, which helps to reduce what we might get here, too.

In contrast to the semi-steady rains of O later today, our summer thunderstorms can drop an inch or even two in 15 minutes (yep, its been recorded in gauges). The flooding rains we had a week ago last Monday, the rates were 1-2 inches. Makes quite a difference in erosion.

—-rambling aside below—-

Its interesting to me, stepping aside from direct weather commentary into a more philosophical one, how the story of O resembles life in general as happens to all of us growing up. All of the promise that O had for producing heavy, but mostly beneficial, rains here in Arizona, has been reduced, like that of a youngster growing up that gets straight A’s in the 7th grade, 8th grade, but then loses all of his focus when puberty hits and notices all those wonderful, endlessly intriguing, fascinating, “can’t take my eyes off of you”, creatures around you that seemed so boring and non-existent just a few years earlier. But now they have become the greatest conundrum in all of life! Instead studying, you, as I did, began making jokes in class as a way of getting the opposite sex (!) to notice you because you didn’t have any other social skills to interact with “girls” with. And, like me, you started getting kicked out of class and sent to the principal’s office for causing distractions. THESE humiliations after all those straight A’s and accolades we got from teachers just a year or two earlier. All of our promise, like O’s, dissipated: you’ve discovered that you’re a Saffir-Simpson Category 5 heterosexual, to continue a tropical theme here.

The life of O has been just like that; the once proud storm, so organized, so full of rain potential for Catalina, became “distracted”, disorganized, and torn apart by mountains, vagaries in the topography and lack of warm water to feed on. O’s life reflecting our own lives when hormones hit, blind siding us, deflecting us from the productive lives we thought were ahead but instead into poor grades and lack of self-control, which meant we had to go to a community college instead of real college. And even then, when you find you have a Spanish class there with Miss Wisconsin of 1961, the distractions and poor grades continue… You can’t even get into UCLA after seven years of JC!

Yes, O’s story IS the story of every man. Believe me, I understand what you went through and how hard it was to dissipate so much promise early in life, as tropical O has likely done for us here in Catalina.

—–end of RA—-

Here is a nice, but sad loop of radar and satellite imagery of O during the last 12 h or so from IPS MeteoStar, one that documents O’s decline.

Yesterday’s clouds

One size fits all it seemed yestserday, but I am giving you three anyway, so here they are, your cloud day.

8:03 AM. Light rain falls on the Catalinas and on Catalina, producing about a tenth of an inch here. The lack of variation in the rain intensity (“shafting” as we say here) along the mountains reflects small variations in the height of cloud tops; rain from stratiform clouds. The cloud? Nimbostratus.

1:56 PM. Those deep Altostratus/Nimbostratus clouds, typically with tops at CIrrus levels (30 kft or more), moved off after the rain ended, leaving Altocumulus opacus droplet clouds to continue the gray day.

4:41 PM. A few drops were falling off toward Tucson from this mostly ice Altostratus layer; some Altocumulus in the upper left corner, and in the distance.

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.

Better late than never; night storms dump 1.42 inches on Sam Ridge!

If you were awakened last night by thunder, as I was, but then that bit disappointed that not a lot of rain fell, well it did, just not here. In three hours, in the epicenter of those storms, Samaniego Peak got a whopping 1.42 inches, by far the most around, bringing the 24 h total there to a magnificent 1.93 inches. Here in “The Heights”, we only got a tenth last night, with the 24 h total ending at 7 AM, of just 0.19 inches, thanks to about a tenth yesterday morning. You can see more precip data here from the Pima County ALERT gages, along with the other sites such as Rainlog.org and CoCoRahs.

The “tropical river” of moisture from the Tropics is shifting east, and soon we’ll be in the “dry wash” of the westerly flow from the Pacific, too soon really, with a very small chance of storms. Today is the last day of the larger ones, ones with a greater chance of landing on Catalina. After today, we’ll likely just see them off in the distance.

There were some fabulous scenes yesterday, even in the overcast morning rains, followed by those low Stratocumulus and Stratus fractus clouds lining the Catalinas. Here are a few, well, too many again:

7:56 AM. You may wonder why I am posting this shot. Well, its a sky we don't see often here, that dark, rainy look, Stratus fractus creeping along the Catalina Mountains. I thought it was pretty neat. Wouldn't if I still lived in SEA; would be same old same old as they say. But here! Fabulous. — 7:56 AM. You may wonder why I am posting this shot. Well, its a sky we don’t see often here, that dark, rainy look associated with Nimbostratus (the amorphous cloud above the darker ragged Altocumulus.Stratocumulus clouds in the center). Stratus fractus is creeping along the Catalina Mountains. I thought it was pretty neat scene. Wouldn’t if I still lived in SEA; would be same old same old as they say. But here in Catalina? Fabulous.

9:25 AM. While the little rain storm had ended, those low Stratocumulus (too bumpy to be Stratus) were a delight to see up against the mountains with the light playing on them as holes in the higher Altocumulus deck went by,

10:25 AM. Springtime for fungi. Our recent rains have triggered unusual life forms. Here, a large white disk has emerged from the soil just off ET *Equestrian Trail), encountered while walking the dog. — 10:25 AM. Springtime for fungi. Our recent rains have triggered unusual life forms, probably from Seattle. Here, a large white disk has emerged from the soil just off ET *Equestrian Trail), encountered while walking the dog (Laurie Anderson).

11:40 AM. Wasn't long before a bit of heating launched giant Cumulonimbus, though soft ones, not real powerful ones. Still, a gorgeous sight. — 11:40 AM. Wasn’t long before a bit of heating launched giant Cumulonimbus, though soft ones, not real powerful ones with a lot of lightning. Still, a gorgeous sight. Looking northwest, beyond Saddlebrooke.

12:10 PM. Windshift line marked by a line of Stratocumulus approaches Catalina. This did not seem good. There was no real response to it, just shallow clouds, and the clouds behind it seemed suppressed, suggesting drier air was going to move in. I wonder if you saw this line of clouds? — 12:10 PM. Windshift line marked by a line of Stratocumulus/Cumulus congestus (right) approaches Catalina. This did not seem good. There was no real response to it, just shallow clouds, and the clouds behind it seemed suppressed, suggesting drier air was going to move in. I wonder if you saw this line of clouds? Any cloud line like this should be viewed as one likely associated with a wind shift. It was also approaching pretty fast.

3:10 PM. After being in the gym for awhile, came out to see that drier air had indeed moved in, and these great looking Cumulus congestus clouds were going nowhere. From the "Not taken while driving" collection. I really like not taking pictures while driving. That would crazy to do. — 3:10 PM. After being in the gym for awhile, came out to see that drier air had indeed moved in, and these great looking Cumulus congestus clouds were going nowhere. From the “Not taken while driving” collection. I really like not taking pictures while driving. That would be a crazy thing to do.

4:09 PM. The Cumulus over the Cat Mountains continued to wither under the influence of drier air. Was getting pretty discouraged since little of the daytime rain predicted had occurred by this time.

In fact, the only precipitation I had seen since about 9 AM in the morning was by this cow. "Precipitating Cow", yours for $2,000. — In fact, the only precipitation I had seen since about 9 AM in the morning was by this cow (look closely). “Precipitating Cow”, yours for $2,000.

5:31 PM. Cute little cloud tries to grow up like his surrounding brother and sister clouds. What an effort! (Demonstrates the instability of the layer in which the Cumulus formed.)

6:30 PM. But hope arose again as a line of Cumulonimbus appeared on the horizon before sunset, and grew closer. Because there were several, you could tell it was something organized was yet to come; it was not just an isolated one or two. Note the pileus cap on the highest turret (between the lines) indicating a strong updraft.

6:54 PM. Unzoomed view of the approaching group of Cumulonimbus, our nighttime storms. The shadow radiating from the setting sun was due to a Cumulonimbus top not visible on the horizon at right. Indicative, too, of organization, something that might make it into the night, not just die away, were all the towering Cumulus lined up on the horizon to the left of the big cell in the center. Pretty darn spectacular scene I thought.

Precipitating cow

Wall of Voodoo

Cold slam arrives but with little rain; 0. 03 inches

7:34 AM. Coming at you! A line of Cumulus congestus bases briefly passed over Catalina, but only an isolated drop fell out of them before they fell apart. But, for this moment, it was a time to be excited.

Once in the “behemoth-of-the-month” club some 10-12 days ago in the models as a major rain producer this month, and even its timing on the 28th was WELL-predicted as far back as that, yesterday’s storm and powerful trough aloft was ultimately a disappointment, producing only 3 hundredths here. That tiny amount of rain was phenomenally well predicted in the SHORT term, however, with no model thinking it would be anything more than that in Catalina a couple of days away. Still, with SO MUCH bluster aloft, it was disappointing.

For 5 PM AST, yesterday, this 500 millibar map showing the huge system that passed over us yesterday and last night. — For 5 PM AST, yesterday, this 500 millibar map showing the huge system that passed over us yesterday and last night (from the Huskies, purple and gold).

Early yesterday morning, and against the model predictions, as the Cumulus congestus piled up over the Catalinas and to the west through northwest, visions of squall lines danced in my head; surely an arcus cloud with a wall of precip would roll through Oro Valley/Cataina later in the morning or early afternoon with a substantial, if short-lived rain. Maybe we’d get 0.25 inches, not less than a tenth.

Cumulus congestus powered higher into Cumulonimbus clouds for a time to the northwest, giving momentary support to that thought of a rip roaring squall line, maybe some lightning with it.

But no.

They soon moved away and the sky began to change into more stratiform (flat) looking clouds, no congestus to be seen anymore by about 9 AM. The disappointment was huge, kind of like that girl you thought was flirting with you, but then you find out you were deluded, had completely misread the situation. Yeah, it was that painful when the congestus were gone.

Here are a few early shots, ones that created so much early excitement, so much portent, those early bulging Cumulus congestus clouds. Still kind of pretty to look at, like that girl I was thinking of, but I wasn’t good enough for her (actually, that should be plural); maybe they didn’t like all the weather talk, who knows?

8:02 AM. Nice looking Cumulus congestus to the N.

8:05 AM. Line of Cumulus congestus to the NW. Congestus everywhere! Nice Cirrus, too.

8:45 AM. Cumulus congestus turning into Cumulonimbus capillatus! Look at all that ice up there on the right. "Here comes that squall line, maybe with a nice arcus cloud", I thought. — 8:45 AM. Cumulus congestus turning into Cumulonimbus capillatus! Look at all that ice up there on the right. “Here comes that squall line, maybe with a nice arcus cloud”, I thought.

9:22 AM. Same view. Need I say anything? Light, Seattle-like rain had begun to fall. — 9:22 AM. Same view as above 47 minutes later. Need I say anything? Light, Seattle-like rain had just begun to fall, from stratiform clouds, of course. It was a sad moment. Reality was setting in; there would be no squall line, a relationship was not going to be torrid, but platonic, if at all¹.

10:59 AM. So Seattle! "Platonic" Nimbostratus, but if you really like someone, I mean rain, its OK, its something. This was the emotionless heart of our storm. Stuck on a theme here... — 10:59 AM. So Seattle! “Platonic” Nimbostratus, but if you really like someone, oops, I mean “rain”, platonic Nimbostratus is OK; its something. This was the emotionless heart of our storm yesterday. Stuck on a theme here…

2:47 PM. Hope began to increase that we might STILL get a good shower. But no rain fell on us from this promising scene. Why? No ice in those clouds overhead/upstream. — 2:47 PM. Hope began to increase that we might STILL get a good shower.
But no rain fell on us from this promising scene. Why? No ice in those clouds overhead/upstream.

5:39 PM. While the cloud tops were not cold enough overhead, it was nice to see a long period of light snow falling on the Catalinas where the cloud tops were lifted and did get to ice-forming temperatures.

5:40 PM. The sunset turned out to be a muted one in terms of color, but still interesting. The sky full of clouds, continued to give promise of rain or snow overnight as new showers developed in western Arizona. They went south of us this morning. — 5:40 PM. The sunset turned out to be a muted one in terms of color, but still interesting. Crepuscular rays are seen in the distance. The sky, full of clouds, continued to give promise of rain or snow overnight as new showers developed in western Arizona. They went south of us this morning.

What’s ahead?

This:

You got yer moderately high probability of a low center WAY down off’n Baja, kind of meandering around down there, not sure what to do, in the last night’s spag plots. That low is located just about where our great rains of last Saturday came from. Remember, like your horse, weather has a memory, knows the “trails” you’ve forgotten, and so its not too surprising to see a weather pattern replicate itself in a future forecast map. Gives it a little credibility.

Valid for 5 PM AST, February 3rd. Looks pretty good, eh?

The actual model runs, at times, have had a lot of rain as this system, after fiddling around down there off Baja like the last one, suddenly ejects northeastward across Baja into Arizona on the 4th-5th as the higher latitude westerlies give it a shove. An example, from IPS, and from one of the wettest model runs, naturally, is shown below, the one from last night’s 11 PM AST global data. Presently, the main conundrum is whether part of this meandering, sub-tropical low center will come out on the 4th-5th, before another part combines with a strong Pacific trough on the 7th, kind of a “two for one” situation.

Can’t tell now, of course, which of these scenarios will verifiy, but there WILL be a low in place off Baja soon that, as we like to say, will be “filled with rainy portent” for Arizona again.

The End.

————-
Did you know that psychologists have a lab standard called, the Passionate Love Scale?
Stage 1 is marked by “obsessive-delusional thinking” (this so funny!), and “euphoria” when things seem to be going right, as in some weather maps I’ve seen.

“Sprinkle rain”, thought to be only capable of a trace, piles up 0.06 inches in Catalina

Yesterday’s news, of course, and a surprising development “locally” where measurable rain during the day seemed remote, at least at 6 AM yesterday. But, a blob of rain moved in around noon and gave out 0.06 inches. We’ll take it.

And as you all know, much more rain from our tropical system off Baja is just ahead, U of AZ mod says beginning late tonight and continuing into most of tomorrow morning as you can see here. If you want to see the forecast rain/snow in all of Arizona pile up over time, go here (from the U of AZ). The model is thinking between 0.25 and 0.50 inches here, an inch or so on top of Ms Mt Lemmon. Gut feeling is that we’ll see more than half an inch here from this, with a good chance that it will go beyond noon tomorrow when the mod thinks its all over. Hoping, anyway.

Below, amounts forecast by the U of AZ model ending at noon tomorrow. The model was run on data from last night at 11 PM AST.

Also yesterday, we had a very brief but fabulous sunrise “bloom” illuminating the bottoms of the thick Altocumulus clouds overhead. It looked something like this¹: Hoping for same today.

7:23 AM. Year different from 2013 because Mr. Cloud-maven person did not have a memory card in his camera.... — 7:23 AM. Year different from 2013.

In case you missed it, here’s what gray skies and light rain look like, falling of course, from that great steady rainmaker, Nimbostratus.

12:31 PM. "Riders were approaching (under Nimbostratus), the wind began to howl...." That Dylan line would been that bit better with "Nimbostratus" in it.(From "All along the Watchtower") — 12:31 PM. “Two riders were approaching (under Nimbostratus), and the wind began to howl…”² Well, OK, one rider. Note rain haze against Pusch Ridge and smoothness of sky due to precipitation fallout that obscures cloud detail. When you saw that smooth sky approaching from the SW, that was the time to turn your horse around and head for the barn, as here.

The rest of yesterday? Blasé. Steady diet of overcast Stratocumulus/Altocumulus clouds sometimes with splotches of virga, and a sprinkle here and there. Here’s pretty much what the rest of the day looked like:

SONY DSC — 2:01 PM. Two layers of Altocumulus are visible, the lower one on the S horizon beyond Pusch Ridge. Cloud detail (rumples and such) shows that there was no precipitation falling from these clouds. If someone asked you why, you’d say that the layer was not cold enough to produce ice crystals-snowflakes, things that would grow and drop out the bottom. The cloud droplets in these clouds are too small to fall, and even if they did float down and out, they’d be gone in a few seconds because they are so small.

4:46 PM. Creamy-looking Stratocumulus. Sometimes cloud bottoms look this way because of a moist layer overrunning dry and stable air, air that raggifies the cloud bottoms. — 4:46 PM. Creamy-looking Stratocumulus. Sometimes cloud bottoms look this way because of a moist layer overrunning dry and stable air, air that “raggifies” cloud bottoms and wind shear at cloud bottom can produce concave (inverted bowl-looking bases). TUS sounding at 5 PM shows air speed sped up a little at cloud base over wind just below them and wind direction turned about 10 deg from that just below cloud base. Was it enough? I guess so, but not really sure except by sky.

Rain still foretold for Sunday night into Monday morning, followed by a cold blast, but amounts have been on the decline. Could be just a few hundredths to a quarter inch is about all this one can produce.

Clouds today

More interesting scenes today of “multiple layers” as we would call them, and not as widespread as yesterday overall; Altocumulus (and with the wind picking up aloft, a lenticular here and there–look to the NE of Ms. Mt. Lemmon) Altostratus, Cirrus. And, with luck, a great sunset.

Way ahead…….

In the usual model vagaries, absent rain in them after this Monday for awhile, rain has shown up, beginning on the 4th of February. This is a new development in the models for that period. The NOAA spaghetti plots give this system pretty good support–that is, something is likely to approach the central and southern California coast a day or two before our possible “storm” on the 5th. but thereafter, not much confidence for a storm here. So, likely to be on the doorstep for us on Feb 3rd or so as it. Interestingly, it rains for two days off and on here, Feb. 4th and 5th, and the rain follows a trajectory from the Pacific much like we have today, which is always a good sign since the atmosphere likes to repeat itself. You can see the full sequence here.

——————————-

¹A replica of yesterday’s sunrise since Mr. Cloud-maven person’s camera failed to ingest a memory card prior to a dozen or so snappages. Camera acted like there was nothing wrong!

²That Dylan line would been that bit better, more dramatic, with “Nimbostratus” in it.
(From Dylan’s, “All along the Watchtower”, the best version, it goes without saying, performed by Seattle’s own Jimi Hendrix.)

Arizona: the Emerald State

Now THAT was a monsoon-like day yesterday, one right out of the western state of Kerala, India; the thick rain of mid-morning, seemingly thicker than most here, the clothes-gripping humidity outside, the strip of fog on the side of the western Ghats, oops, Catalina Mountains, the relatively gentle breezes in the rain, the subdued green hues under the overcast of light rain at the end of the unusual morning drencher, aspects that, en toto, made the morining seem so India-like to me (and I’ve been there in those Kerala rains). Take a look at our green state and State.

INDIA009_i — In the Ghats, India, 1975, in case you didn’t believe that I have been in ACTUAL monsoon rains.

And while the rest of the day was sunny, humid and cool for us, the rain wasn’t over with another thunderbludgeoning last night after 9 PM that brought 0.25 inches and the day’s Catalina rain total to 1.02 inches. Drink up, desert!

Here are the rain reports from around Pima County. Looks like the “Catalina” foothills has the 24 h total winner at 1.38 inches. Here are other rain reports from around the State from the USGS. One of these stations, Chrysotile, NE of Globe, had 4.21 inches in the 24 h ending yesterday afternoon, also a total that is VERY Indian monsoon-like.

We also had a nice Altocumulus lenticularis at sunset, suggesting some wind aloft. Seemed almost fall-like seeing this because they are more common with our winter troughs.

Another Big Day ahead

2012082312_AZmap — 3 AM, Arizona obs. Several stations have dewpoints in the low 70s, with TUS reporting, along with light rain, a shockingly high dewpoint of 72 F, really extraordinary.

Get ready! A disturbance over southern California will help organize our storms into ones like those that occur in central Florida today, grouping them into large clusters, with some eye-popping rain amounts likely somewhere in the State (“eye-popping”, 3 plus inches). Don’t be too surprised if you hear about a “tube” somewhere as well. Tubes happen in conditions like these.

After today, its “mostly” dry through the end of September, with the best chance of rain on the 27th-28th.

The End.

Drought staggering after heavy rain/snow punch, may go down someday; more blows ahead

Any winter storm that drenches the Catalina area, including Saddlebrookians, Oro Valleyians, with more than an inch of rain in 24 h has to be one of the greatest. Haven’t seen this much winter rain in since the so-called “Frankenstorm” of January 2010 when we got over 2 inches of rain in two days. Here are the gaudy 24 h totals from the Pima County Flood Control District, ending at 3:34 AM this morning, about 24 h after the rain started Pima rain. Other interesting rain totals can be found in the network established by the rainlog folks at the U of AZ here. These totals are a bit smaller than those I culled from the Pima folks since the ob time for the rainlog network is at 7 AM LST, and here, 0.41 inches had fallen in the first few hours yesterday, and then 0.99 inches for the rest of the storm (0.01 inches just now!), for a total of 1.40 inches here in Catalina. So, the storm totals at rainlog are broken up into two days (the rain pretty much fell in the 18 h from 3 AM yesterday to about 9 Pm last night). BTW, a nice way to look at the comings and goings of the local rain is via the Weather Underground’s maps with animations of the TUS radar superimposed on a regional map showing our many “personal” weather stations (e. g., here). Its interesting that many of you do not have a personal weather station. Well, the holiday season is here, and the economy can always use some impulsive buying and so maybe now is the time to pick one up before more storms hit. And they will, as our models continue to show. BTW2, a rainbow landing on a personal weather station. Think about it.

In just 36 h from now another low center barges into Arizona from the NW. Due to its long overland trajectory, it’s going to be a lot drier than “Frankenstorm Junior”, once again, as another in a winter long series, stagnates in our area as a “cut off” low spinning around flinging rain around its margins for a couple of days (Friday and Saturday mostly). So with luck, we might pick up another quarter of an inch or so. Here is a quick look at that whole sequence, and one of the panels below, valid for Friday afternoon at 5 PM LST, for your viewing pleasure.I like this format with the four panels since you got yer upper map in the upper left hand panel showing yer cut off, and you got yer precip in the lower right hand panel, all in one jpeg; more cumbersome in the US model presentations I’ve found to have this much info in one jpeg.

So, what about our drought status after all this early winter rain (see below)?

Well, as I have learned from the State Climo office in 2010, not much changes due to a couple of months of wet conditions here, such as we had in 2010 when water was flowing everywhere in southern Arizona later that winter. Seems for those folks that designate whether an area is in drought, there have to be almost years of wet conditions for the designation of droughty conditions to be removed from their maps. Its pretty discouraging. Perhaps it takes wide tree rings to indicate the drought is over (hahahaha, sort of) ((just kidding!)) (((Really))) ((((Not being sarcastic at all))))

Below is the latest drought map from the Drought Monitors at the University of Nebraska-Lincoln as of December 6th, when they last released a map, we here in southern Arizona were still in an “extreme drought” in spite of all the rain in November and early December. It will be interesting to see how this map changes after our “Frankenstorm Junior” of the past two days, and with all that rain that has, and will be occurring in the droughty areas of NM and TX. The longer term model forecasts punish (delight?) those areas with widespread heavy rains over the next two weeks. Will it remove any of the “extreme” and “exceptional” drought designations for them? Stay tuned.

At LEAST we have avoided the Climate Prediction Center’s fall forecast of intensifying drought here in AZ over the period of November-January. Seven weeks into that forecast, we have dispelled that notion, anyway. It ain’t happening. It would be hard to take another NDJ like that of 2010-2011 when only December had any rain at all!

Well, Mr. Cloud Maven person had better post some CLOUD photos if he is to remain that and stop squawking about drought…

Here are a couple from the
storm. The Catalina Mountains are so wonderful when draped in precip and snow! I would like to report that I am very happy living here full time in Catalina.

The End, though the image organization will be a mess for awhile, will “publish” now anyway.

“Stuck Inside of Tucson with the Seattle Blues Again”

Paraphrasing Bob Dylan’s song title, one that had the line, “Stuck inside of Mobile with the Memphis blues again”, that great, driving song he did in the 1960s. See photos of Seattle-like conditions of low-based Nimbostratus below with a temperature of only 37 F (!) right now in Catalina! Egad. As you can also see, after 0.39 inches of rain up until about 11:30 AM this morning, there is also some flooding going on.

(Of course, me and most Arizonans really LOVE rain; it’s to be treasured at all times! In Seattle, where I just spent three weeks, not so much.)

Local weather for Catalina here.