Beginning to wonder, with all the middle cloud thickness out there over and SW of Baja that’s headed this way if we won’t get sprinkles that produce a little measurable rain later today or overnight….
7 AM AST. Look at all those clouds over Baja and to the west of there.You can see this whole loop from the Washington Huskies here.
Models beginning to wetten things up here as well, like that Enviro Can model that sees our tropical surge high and middle clouds passing over us now, as deep enough for measurable rain later today and overnight. Huh. U of AZ mod, the best one for us, is still dry around here except on mountain tops. Our larger scale model, however, also has some very light rain in this area now, later today into tomorrow morning.
What’s intriguing is that a little jet core at 500 mb (up there at about the height of middle clouds) passes south of us as this happens, key for precip here1 in the cool season. The major jet stream is far to the north.
As you know, we have a bit of an El Niño going, both a “Classic Niño” as well as the “New Niño” going, and El Niños strengthen the southern portions of jet streams in the very way that we’re seeing in this situation.
They do that because its warmer than usual in the central and far eastern Pacific tropics due to heat in extra big Cumulus and Cumulonimbus clouds that pump away down there over that extra warm water, and that rising warmth produces a greater than usual difference in temperatures throughout the troposphere between the tropics and the mid-latitudes. Since jet streams are the products of temperature differences between warm and cold air around the globe, so unusually deep warmth in the tropical eastern Pacific gives a little strength tweak to jet streams coming into the coast2.
SInce there are two of these lower latitude “waves” traveling along in the southern branch of the jet stream, there are TWO chances for slight rains including that for later today. The next one barges in on the 6th of December. Will again be dense middle and high clouds with virga at its worst, like this one, though again a hundredth or two could happen.
Next real rain chance, and major front passage with air that’s too cold for us, will be on the 12th. Spaghetti folk, or “Spaghetti Busters”, those who can make sense of these balls of yarn, can EASILY see that trough on the 12th and a cold front with are “in the bag” even though that’s ten days away. Rain occurrence is more dubious, since the trough may land a bit too far east to produce rain, only a lowering of temperatures. Here is that plot from last evening. Enjoy.
Valid at 5 PM, December 12th. Pretty clear a nice trough will be in the area then.
Your yesterday’s clouds
11:44 AM. Up and down, up and down, those wavy air motions that produced this interesting line.3:37 PM. Classic Altostratus translucidus (sun’s position is visible).5:20 PM. Sunset Altostratus (ice clouds) and Altocumulus (droplet clouds).
BTW, for horsey people, the Cement Trough had water in it yesterday after being completely dry ten days ago:
11:44 AM. At the Cement Trough headed to South Gate.
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1See Rangno, 1973, unpublished manuscript and figures for the whole US using only the horizontal shear in jet stream at 500 mb as a definer of precip occurrences. Its really quite something, though, I guess you can’t see it.
2This was figured out by the Great Jacob Bjerknes of the Norwegian School of Meteorology while he was cruising into retirement (“Emeritus” status) at UCLA in the 1960s, though Chuck Pyke3,4, his grad student, did most of the work. Did a lotta work on the big “Classic” El Niño of 1957-58, which, per chance turned out to be an International Geophysical Year with a lot of extra observations! How lucky wazzat?
3Chuck, as you may recall was in the National Guard whilst at UCLA and was sent to Biloxi, MS, for two weeks of training and while there, was “gifted” with the passage of the eye of Hurricane Camille, one of the strongest of the century. Later the remnants of Camille, to go on and on, produced 31 inches of rain in 6 h in Virginia.
4Chuck P, who now lives in Arizona, also was very thorough in his evaluations of rainfall in his other studies concerning the seasonal timing of rainfall throughout the West. He once told me when I visited UCLA once to get Bjerknes autograph5 that he had gone to every rainfall measuring site in his study! Now some people go to every baseball park in America, but going every rain gauge site would be more interesting to cloud mavens. He further told me he found one that had not moved for 30 years, but the rainfall had been decreasing. When he went to that gauge, he found that it was being overgrown by a tree! This is why you have to check things.
5I failed. He was “Emeritus”; too good to be in his office that day. You see, your Catalina cloud maven was a strange person even then, wanting an autobgraph by Bjerknes rather than one by Mickey Mantle, though one by Mickey M would be worth a lot more today.
Been away from you for a couple of days, wanting to see how you do on your own, perhaps see you grow in your cloud watching obsession, namely, that you want to name everything you see, as though you were Luke Howard himself. Hope you logged all cloud genera, varieties and species, 27 all told, over the past 48 h. You can bring your photo log books to the next meeting and CM will go over them with you.
Measurable rain chance still pretty reasonable for the window of Nov. 20-21st, too, as we have purported for some time here, but it will be pretty minimal.
The weather way ahead; a promise of substantial rains
However, as often happens, on the horizon is a substantial storm for Arizona, ones that have a habit of disappearing it seems as the foretold event gets closer. Here it is depicted below in plots from our cherished NOAA spaghetti factory:
Valid at 5 pm AST, December 2nd. Pretty cool, huh?Same spaghetti plot, annotated. Recall that these plots are ones where the model input has been deliberately errorized to see how big little errors make in the outcome of the model. Why do that? Because we know at the outset that our measurements are not perfect, and have all kinds of actual little errors in them. These plots are a way of seeing how robust a predicted pattern is, and those areas where the forecast is pretty reliable, is indicated by bunched lines (key contours of the airflow at 500 millibars, or around 18,000 feet above sea level in the mid-latitudes, lower near the poles, higher near the equator. Why do we use a pressure level instead of the pressure at a height? Go here. CM would like to see as well, in the 21st century, maps of constant altitude (3 km, 5 km, etc.) with the high and low pressures on them as we have on our sea level maps! Is anybody listening? (A google search just now could not locate, constant altitude pressure maps….)
While the above forecast of contours is two weeks away, and numerical models are often unreliable at those long horizons, we see that the red lines (not to be confused with political markers) have dipped down in great bunches over the extreme eastern Pac 12 Ocean, and continue all bunched up across Baja Cal and thence into Texas. In the plot above, the red lines represent a 500 mb height of 5760 meters, one that’s on the southern periphery of the jet stream. So, when its well south of us, our chances of rain are engorged. Recall, too, that the 5640 meter contour, just that bit lower in height, is associated with leading edge of rains in the central and southern California area–remember Brier and Panofsky, Some Applications of Statistics to Meteorology? Well, in that book you will learn that contour is what the LA weather service used to use as crib for when rain would occur in southern California.
I am sure you remember two things, maybe more than two. We have an El Nino in progress, not a great one, but an OK one, AND that El Niños strengthen the southern jet stream in the eastern Pac and across the southern latitudes to the east. So, we expect to see this pattern, one of a stronger jet stream in the sub-tropics carrying stronger disturbances as a result, evolving as the winter develops, that is, more disturbances in the lower latitude band of the jet stream (sub-tropical part). The plot above is a classic one for predicting that kind of regime, maybe with a bit of a split in the J-stream with northern and southern branches being pretty vigorous at this map time, and before, for that matter.
Valid at 5 AM AST, Monday, December 1st. Colored regions are those in which the model has calculated that precipitation has fallen in the prior 12 h.
The plot above, it has laid a foundation of credibility for what is show below, from IPS Meteostar’s rendering of our WRF-GFS forecast model output based on the 5 PM AST global data. It shows 24 h of substantial Arizona rains, including here in Catalinaland, at the beginning of December. You’d be pretty cool to inform your friends about this, ones who might be heading back somewhere after a TG visit to sunland1. (Besides, they won’t remember what you said anyway by the time December gets here.)
Valid at 5 PM AST, Monday, December 1st. Colored regions are those in which the model has calculated that precipitation has fallen in the prior 12 h.
Today’s clouds
Lots of pretty Cirrus.
The End
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1By the way, the Great Lakes are freezing over already, a month earlier than normal due to some astounding cold back there, so TG visitors from back East, upper Midwest, may look for reasons to stay longer. Well, at least until the rain and cold hit here.
This was pretty neat, this forecast map from yesterday’s 11 AM AST WRF-“GOOFUS” (GFS) run. Look at all the rain barging into Arizona and Catalina!
Plenty of rain here in southern California AND Arizona! Valid at 11 AM November 20th.
What’s remarkable is that the ensemble runs made yesterday’s prediction of rain, one discussed here, quite the “outlier” of the rest of the “members” of the spaghetti plots, so one wouldn’t be expecting to see any rain for Catalina again!
But, here was that rain again, and this whole storm complex along the California coast falling mostly within that time period where over the decades there has been a tendency for storms to strike the more southerly locations between the 10 and 20th of November, something that was mentioned yesterday as a bit of a conundrum. Rain, though not as much, was shown again in the next run based on 5 PM AST global data, and due to that prediction of less rain, I am not showing it.
Below is a comparison of how the ensemble outputs (shown as “spaghetti” plots of a couple of key contours at 500 mb (around 18,000 feet above sea level) have changed since yesterday. To this observer, its been an unusually large change in where the grouping of those key contours are in just 24 h (they always change some, of course).
Notice how the blue (contours of flow pretty much in the heart of the jet stream) and red lines (periphery of it) have been shifted 10 degrees latitude and more southward from the first plot to the second, latest spaghetti plot, indicating that we’re going to be more in the storm track at that time, and the likelihood of a rain threat on the 19th-20th is more credible, less subjectively based as was yesterday’s take. Maybe subjectivity in forecasting isn’t that bad afterall…
Valid at 5 PM, Wednesday November 19th. Note how the red and blue lines bulge northward along the West Coast, suggesting a fair weather pattern.
Also valid at 5 PM AST, Wednesday November 19th. Blue lines (contours along which the wind blows from left to right) are now much farther south, and the red lines are now so far south they’re almost not in the map domain. Also, those red lines now do not bulge northward anymore, but rather are suggesting a broad trough along the West Coast at lower latitudes, completely different than the plots just 24 h earlier.
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 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 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 (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 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!
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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 C3,4., 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…)
Day went pretty much as planned for us by the models, with Cumulonimbus (“Cbs”, in texting form) clouds arising early and often, moving in from the SW, more of a fall pattern (which is approaching too fast for this Cb-manic person). If anything, those clouds arose earlier than expected with dramatic morning results;
But those storms that got here divided as they approached The Heights yesterday; cell cores went right and left with places like Black Horse Ranch down by Golder Drive getting 0.53 inches, and a place in Saddlebrooke, 0.94 inches yesterday, while we only received 0.23 inches.
Seeing this happen in real life was tough. Still, there was a last rain burst after only 0.14 had fallen that was really great as the sky began to break open and the sun was almost out when it happened. That last parting shower dropped a final 0.09 inches in just a few minutes. So, maybe we were a little lucky.
BTW, you can get area rainfall from the Pima County ALERT gauges here for the past 24 h. And, also, from the U of AZ rainlog network here. USGS. Coco. NWS climate reports. (Editorial aside: (earlier cuss word, “dammitall”, has been removed)—WHY don’t they gather all the rain reports into one comprehensive site???!!!)
7:04 AM. Soft top Cumulonimbus protrudes high above other clouds producing a long shadow on a lower Altocumulus perlucidus layer.7:04 AM. “Soft-serve” Cumulonimbus calvus top emerges above lower Cu and Altocumulus clouds. This kind of top goes with weaker updrafts, likely less than 10 mph.
10:04 AM. Showers and heavy Cumulus (Cumulus congestus) continued to range along the Catalina Mountains toward Oracle. These were nice clouds.10:14 AM. Looking in the upwind direction from Catalina, not much going on though storms are raging in the Catalina Mountains. That farthest line of bases, with that fat one out there toward I-10, though, drew your attention yesterday, I am sure, given the explosive conditions we had for storms.10:36 AM. OK, this is looking potent. Finally, tops have reached the ice-forming level and precip is beginning to eject out the bottom of the one on the right. So big, high, top visible, which was of concern, thinking it might only be a light rainshower. Generally, the higher the tops, the more that falls out the bottom1. 10:57 AM. A two part panorama of the incoming, broken line of storms. Part A above, looking SSW with Pusch Ridge on the far left.
10:57 AM. Part B of panorama, looking at this exciting line of showers and thunderstorms toward Twin Peaks, Marana, and Oro Vall
11:07 AM. A strong shaft has developed, indicating much higher tops than in the earlier scene above at 10:57 AM. 11:07 AM. Close up for instructional purposes. Let’s say you’re hang gliding and want to go up into the clouds. That lower extension next to the rain shaft is where the strongest updrafts would be, and, on top of it, the fastest rising top. Have a nice ride!
11:14 AM. Hole in rain aiming for house! This could be bad! Will cloud roll ahead of rain areas, buoyed my outflowing winds ahead of them develop new rain shafts?
12:23 PM. By this time it was all over, the 0.23 inches had fallen, leaving some evidence of flooding. In a change of pace, I wanted to get that evidence in combined with a sky photo so that you could see that there were still clouds around. Cloud has some ice in it, too.
3:53 PM. A final threat of rain appeared as the winds turned briskly from the north and new turrets formed above it and, for a time, headed toward Catalina. It was a dramatic scene, to be sure, but one that disappointed. The clouds forming about the outrushing wind from heavy rain to the north, diminished in size as they approached, no longer reaching high enough to form precip. Partly this is because of our lower temperatures yesterday afternoon, and because when the air goes southbound from areas to the north, its always moving a little downhill and that works against new clouds, too.
3:59 PM. While the dissipation of those clouds to the north was disappointing and not unexpected, to be honest, still it was good to be out and see how green the desert has gotten since the end of July.
The End
Oops today is supposed to be drier witih isolated Cbs, more tomorrow as moisture from TS Lowell leaks into AZ.
The extremely strong hurricane that forms after TS Lowell is sometimes, in the mods, seen to go into southern or central Cal (!) as a weak remnant circulation or stay well offshore, as in the latest 11 PM AST run from last night.So, lots of uncertainty there. Check out the spaghetti below for the bad news:
Valid in ten days, Aug. 19th, 5 PM AST. Those blue circles WSW of San Diego represent a clustering of the most likely position of that hurricane then. And, that cluster is too far to the west to us, or maybe even southern Cal any “good.”
—————————–Historic footnote—————————— 1“TIme to be distracted from the task at hand…. “Generally”, of course, is a fudge word. For example, in the tropics, it was learned back in the 1960s that rain fell as hard as it could about the time the tops reached the freezing level, and before ice had formed. Didn’t rain any harder even if the tops went to 30 or 40 thousand feet! These results were confirmed in aircraft measurements in the Marshall Islands, oh, back in ’99 (Rangno and Hobbs 2005, Quart. J. Roy. Meteor. Soc.).
Some of the biggest rain drops ever measured (5-10 mm in diameter!) were in clouds in the Hawaiian Islands whose tops that had not reached the freezing level–see Bob Rauber’s 1992 paper in J. Atmos. Sci., with Ken Beard, the latter who tried to get rid of intercollegiate athletics at UCLA when he was there in the turbulent late ’60s, as did the present writer at San Jose State (a story for another day). But then, BOTH me and Ken went on to become science weathermen, not the radical kind of Weatherman, i. e., those under Bernadine and Bill, because we left our radical roots and reggae back behind in the ‘1960s, 70s, and/or 80s (well, maybe not reggae…)
A rare day for Catalinians: five thundering cells drifted off Ms. Mt. Lemmon and its environs and over Catalina and Oro Valley yesterday providing lots of local excitement. The Sutherland Heights district got 0.46 inches, and early on, was leading Mt. Lemmon and the Samaniego Peak gauges because the cells did not drop their loads until over the foothills and the Valley. Below, the exciting day reprised:
12:52. Cloud street drifts off the Catalinas over Catalina. Because the Cumulus clouds didn’t seem to be going anywhere, were so modest in the afternoon, rather than thundering before noon, I was kind of sad, disappointed.1:46 PM. But, then when suddenly those clouds began erupting upward, reaching the ice-forming level, and rain falling out, I was so happy. Started raining on me a few minutes after this shot. You can see the slight initial rainshaft to the right of center on the foothills of the Catalina Mountains. 1:51 PM. Rain approaches Sutherland Heights/Catalina from the east. The little guys up there began to thunder as well. Several cloud to ground strikes in that area you see in the photo! Amazing how small a lightning producing cloud can be here sometimes. However, “thunder1” only dropped 0.06 inches here; more fell a little south. Still, it was so great to see measurable rain fall!
2:11 PM. Remarkably, and hopefully, after thunder1 went by, it looked like another cell might drift off the Catalinas into Catalina soon afterward!
2:25 PM. Thunder2 underway on Sam Ridge. Samaniego Peak recorded 0.94 inches yesterday. More cloud to ground strikes here, some rather distant, a mile or two, from this shaft, so watch it when you’re watching it. (Professional viewer; do not attempt.)
3:58 PM. Thunder3 rolls off the Catalinas! This was much larger than Thunder1 and 21, and drenched the south side of Catalina, and into Oro Valley with rains of around half an inch. The lightning was awesome.4:02 PM, just FOUR minutes later! Thunder3 in full dump mode, lightning galore!4:14 PM. Small crowd of local lightning viewers. On the left, a viewer is using the “cushion technique” to block lightning. It is NOT effective; this is an urban legend. This cannot be emphasized enough.
5:10 PM. A remarkable Thunder4 formed on the Catalinas and headed toward Catalina! I could not believe it!
6:07 PM. If there was a downside to the rain, it was that dusty floodwaters (another great name for a western singer) began to impact dirt roads. Note sign at right…
7:29 PM. The day ended with a great rosy glow (another great name for a singer!) on the northwestern horizon, but it wasn’t the end of the thundering herd, was it? Nope. FQT LTG was only an hour or so away. Now that was really was amazing, that Thunder5, developing near and rolling off the Cat Mountains early last evening. What a great day it was after appearing to be a disappointing one during the late morning and early afternoon. To reprise the whole day: see movie.
Well, C-M person has told enough stories about past weather for today, so shutting down here at 4:42 AM. Dewpoints are still very high, mods expecting more thundering herds in the Catalina/Oro Valley area today.
Have camera ready for some great shaft shots, those black, straight sided ones that go all the way to the ground. If you can, try to get the shot just before the bottom drops out; the two make a great, dramatic couplet for friends and family to enjoy I find.
Farther ahead…..
A disturbing, possibly week long dry spell has been showing up in the models, beginning the 17th, lasting through the 25th or so. Has to do with a giant summertime upper level trough set to bring those record low temps to the upper Midwest beginning in the next few days. The NW flow on the backside of this trough is foretold to extend into Arizona, thus, drying things out and pushing the tropical air southward. May see some hot days and only small Cu and maybe very isolated, distant Cumulonimbus clouds during that time. Ugh.
On the bright side, spaghetti says, and with a lot of confidence, that the dry spell will be eroded and the normal wetness will return after the 25th or so. I think you can see that here, now that you’re an expert spaghetti consumer:
NOAA “spaghetti” plot, valid for 1700 AST, July 26th. Looks great for storms!
Forgetting about yesterday’s unforecast subdued afternoon convection hereabouts after about 1 PM), lets talk about the misery of others; the little crybabies that leave Arizona in the summertime, decimating its economy, so that they can be cooler and “happy” in northern climes (while dodging hail and tornadoes, we might add).
Well, how about them birdies being really COLD before very long, due to record breaking low July temperatures? Yes, that’s right, what’s left of the “polar vortex” will once again, due to global warming, of course, spin out of control and down into the northern US in just about 5-7 days. And with it, long term July low temperature records will fall in the eastern US. Count on it.
So, once again, as some scientists alleged last winter, global warming will actually cause cooling. (Almost everything that happens is due to GW these days, as we know. (“GW”, BTW, now repackaged in the catch all, temperature-neutral phrase, “Climate Change”, during the past few years because, globally, it stopped getting warmer way back in ’98, and when the years began to pile up without global warming, scientists had to find another phrase to hang their mistaken hats on. (Where was the usual scientific “caution” back then?)
HOWEVER, continuing on with this harangue, and being a “lukewarmer”, we must watch out that the coming big El Nino doesn’t release a spring-loaded, pent up release of global heat. Might well happen, so don’t give up on “GW” quite yet; hold some cards on that question for another few years.
And, of course, if there is a step jump up in global temperatures just ahead, the phrase, “climate change” will be dumped by scientists and media for “global warming” again. Count on it, #2.
But, I digress, mightily, mainly due to yesterday’s cloud disappointments.
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Not in a great mood after yesterday’s bust, as you can tell, except for that strong thunderstorm that pummeled the north side of the Catalinas beginning about 11:30 AM, that was pretty cool; had continuous thunder for about an hour and a half, too. Dan Saddle up on Oracle Ridge got 0.63 inches, but you can bet 1-2 inches fell somewhere up there.
I was so happy then.
I thought the “Great Ones” would arise upwind of us in the direction of Pusch Ridge, but no. Those clouds got SMALLER as the afternoon wore on, it was incredible, and by sunset they were gone with only trashy debris clouds of Altocumulus and Altostratus cumulonimbogenitus from great storms in Mexico drifting over our sky. Even the sunset was disappointing.
Well, that 3:15 am to 3:30 am little shower this morning than dropped 0.15 inches here in the Heights, and 0.24 inches down there at the Bridge by Lago del Oro gave a psych boost1 that got me here on the keyboard.
10:55 AM. Nearly invisible veil of ice crystals begin to fall from an older Cumulus congestus turret. This was about an hour and a half ealier than the prior day, indicating that the Cu tops were reaching that level sooner than the prior day, suggesting bigger things (I thought). When you see this happening this early, you also look for an “explosion” some massive turret to suddenly blast out of these developing clouds, and that did happen within about half an hour after this.
10:55 AM. Close up, in case you don’t believe me.
11:04 AM.
7:33 PM. Your sunset.
Today? Check here. Once again, mod expects early Cumulonimbus on The Lemmon, then groups of thunderstorms move in during the evening (as was more or less predicted yesterday, but didn’t happen.) Will go with mod again, though, because I would like that to happen.
The weather way ahead
We’ve talked about cold air, now to balance things off, how about a discussion of the warm air ahead? Real hot air.
Was blown away by the spaghetti outputs from last night for the period of about two weeks from now. You can see the whole package from the NOAA spaghetti factory here. Below, our weather in 12-15 days, usually beyond confident predictions, but not here:
Valid at 5 PM AST July 22nd. Massive blob of really hot air settles in over the western half of the US. In this map, the most reliable long term predictions are over the western half of the US and over the Saharan Desert (indicated by the lack of lines in those two areas. A lot of lines means the weather pattern is pretty unpredictable.)
Valid at 5 PM July 25th. Massive upper level blob of really hot air continues to dominate the western half of the US.
&
So
The hot blob of air should lead to record HIGH temperatures all over the place in those days beginning around the 20-25th of July. Rainfall here? Indeterminant. If the high center sits over us, it might just be hot, real hot, but dry.
But, if the configuration aloft is as shown in the second plot, it could be very wet as tropical disturbances shift northwestward from Mexico into Arizona.
Sorry, can’t do much with precip from these, I don’t think.
The End, and covering all the possibilities, CM
==================================== 1Paraphrasing, the song for weathermen, those speaking to clouds; “Rain on me, when I’m downhearted….”
What a day, Mr. and Mrs. Catalina, except for that last second “header”:
7:57 AM. Cirrocumulus with exceptionally fine granulation (left center). You might feel a little chop if you were flying in it, but it would be hardly anything. More chop, lower right, where you have something akin to ocean waves rolling along from left to right.
8:04 AM. Pretty Cirrus fibratus (strands are pretty straight in Ci fib).4:47 PM. Pretty Cu humilis and fractus scene near the S-Brooke population complex.5:05 PM. Cu hum and fractus over the Catalinas, Nice shadow bounds the mountains I thought.
The weather way ahead, 10 days and beyond; dreaming green pixels
Rain showing up around these parts beginning overnight on July 3rd-4th, kind of a normal time for a summer rain season onset. This from last evening’s global model crunch. Prior model runs have been dry, so it could be bogus, of course. But, its a hopeful sign. Rains every day after that in this run. Below, the titillating start as rendered by IPS MeteoStar:
Valid at 5 AM AST July 4th. Green areas show those ones where the model has calculated some rain in the prior 12 h.Valid at 5 PM AST July 8th. Raining all over Arizona by this time. How great would that be? Com’on model! Don’t let me down! A feel a really old song coming on about being let down.
Let’s look at some spaghetti and see if the “solution” above has any credibility at all:
Valid at 5 PM July 4th. Note gaps in red lines in Arizona and NM. Errorful mod runs (deliberately so, recall) are therefore pretty confident the necessary ridge of high pressure aloft WILL be centered just to the north of us at this time, extruding all the way from the central Atlantic. So, there is a fair amount of confidence from spaghetti that the summer rain season will start pretty much on time. What’s also supportive is the bulge in the jet stream to the north in southern Canada, as indicated by the bunching of those bluish lines. Pac NW looks cool and rainy with this pattern, BTW. You can enjoy more spaghetti here.
So, right or wrong, you heard it here first because I got up early; summer rain season looks to start on time.
Well, its not windy1 yet, but it will be, and everyone knows it. The infamous “Tonopah Low”, as the ancient weathermen called it, is now in formation over Tonopah, Nevada, as a big bad trough roars into California, over the Sierras, and into the Great Basin today and tomorrow. We should have noticeable winds by mid-day, a dramatic accompaniment to some pretty Cirrus clouds, ones that will be chugging along up there at 100 mph or so. The U of AZ mod also suggests a few mid-level clouds, ones likely to be brief Cirrocumulus patches (those clouds having tiny granulations that make them look higher than they really are) or Ac lenticulars NE of Ms. Lemmon; also off to the north of Catalina, as the moistness aloft increases later in the day. Cirrus likely to devolve into thicker Altostratus. Watch for a great sunset today, since holes far to the west of us in these higher clouds are possible that would allow the fading sun to light up the bottoms of the high and middle clouds after it sets. Hope so, anyway.
I am really happy for you today since this will be the really first interesting cloud day in awhile. You might consider leaving work around lunchtime so you don’t miss anything, like some iridescence around the Cc.
Of course, the late April cold air blast, mentioned here so long ago in a blog that I might get a forecasting award of some kind2, will hit tomorrow as the cold front (sudden drop in temperature, barometer rises instantly, and wind shifts) hits later tomorrow morning. Have jacket ready.
Looks like this cold front, with the jet stream sagging over us or slightly to the south, will be enough for a little rain now, a tenth of an inch likely the most that can fall. Still, it will be something to break up the monotonous string of zero precip days.
Now I will look at the AZ mod precip output and see if there is any credibility to that rain amount mentioned just above. (Oh, fer Pete’s Sake, accum precip run ends at 1 AM today here a few minutes before 5 AM AST.)
Well, the WRF GOOFUS model run, based on global data taken at 5 PM AST yesterday, did have some rain here tomorrow morning. Rain for Catalina and environs has been coming and going in various outputs for days on end.
The Cirrus will be gone tomorrow, but with lots on interesting lower clouds, some having ice in them, will produce nice picaresque views of the Catalinas as clouds and shadows of clouds roll across them after the front goes by and the clearing takes place.
The Weather WAY ahead:
Very “troughulent”, in a word.
A lower latitude trough will be affecting this area not too long after this current big boy passes starting a few days into May. With those lower latitude troughs usually comes just high and middle clouds with their spectacular sunrises and sunsets, and their presence keeps the temperature from spiking to astrological levels due to those clouds, but also because the air aloft is a little cooler in a trough than when an upper level high pressure area (a region of deep warm air) is squatting on top of us. So, really ovenly weather will be MOSTLY held at bay as we roll into May. Yay.
Once in a while, one of those persistent troughs, too, can scoop up some real moisture from the tropics and bring some rain here, so there’s even a chance of May rain as this situations develops. This troughy situation begins to develop about 8 days out now, around May 4th, but persists beyond the 10th.
Check out the spaghetti for the morning of May 10th to see what I am talkin’ about:
See arrow that points to the general area in which you live. Note, too, where all the red lines are, big gap over the West until the blueish lines, indicating a pretty darn reliable forecast even this far out.
The End
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1TItle is a pathetic reference to a popular but crappy IMO song from the 60s.
2Actually, I didn’t think it up by myself, that forecast of cold air late in April, but relied on the NOAA spaghetti factory to give me a heads up, so that if I was to get an award, I would have to acknowledge and thank the NOAA folks who produce spaghetti for their work in supporting my efforts, and I couldn’t have done it without them.
Today we celebrate the model in techno-pop song, and not only the human ones, but also the ones that give us hope (or not) for rain in Arizona. (Advisory: If you listen to the Kraftwerk 1980s tune above, you won’t be able to get rid of that melody all day!) Speaking of today, see farther below after lesson in reading spaghetti.
Below, two model outputs for the almost the exact same time separated by only 6 h of obs as input for the late afternoon and evening of Wednesday, April 23rd.
One outputm the first one, suggests we’re in for another, unseasonal, blazing heat wave like the current one for Arizona. while the other a wet, cold blast into the Great Basin, with windy conditions here and a major cool down just ahead; the latter leads to sequence of troughs that leads to rain here, with eventually exceptionally COLD weather, and considerable snow in the mountains!
Repeated-annotated for emphasis
In the East, the first one above suggests that winter will seem likes its continuing into summer with a super cold wave for late April, while the model output below shows nothing special going on at all.
Sadly, the one above with the oven lit here (big ridge in the West and the amazing vortex in the Midwest_, is the one that was computed on data 6 h LATER than the one below, the one that looks pretty exciting for us, even if its just a cool down with a bunch of wind. “Later”, as you imagine, usually implies more accuracy.
Who you gonna call to see which of these astoundingly different model outputs has the most credibility, which one is the most likely model ghost buster? The NOAA spaghetti factory! See below:
On the map above, the deep vortex in the Midwest has almost no support at all (you would have to see a LOT of blue lines in the US and not in Canada for that support), while the West Coast has a lot of support for a big trough to blast in (lots of blue lines along the West Coast).
In sum, it would appear that the chance for rain late in the month is not completely bogus, but a very a big heat wave is. Rather, keep coats handy for later in the month. See rain in AZ below associated with the more credible output (from IPS MeteoStar’s rendering):
Valid Saturday morning, April 26th. Wouldn’t this be great!
Clouds….
About like yesterday. But there’s a real “storm” up there of sorts. If you were on Mt Everest and Mt Everest was here where Ms. Mt. Lemmon is, there would be a real blizzard up there at the top; 50 kt winds, light, dust-like snow off and on all day. In normal speak, there will be lots of Cirrus, Altostratus (huge gray areas), those former clouds composed of ice crystals, some Altocu (droplet clouds) mixed in.
