Beginning where we left off in our last chapter….that rain foretold here by the (affectionately) US WRF-GOOFUS models back a few days ago for the 19-21st for us only remains a possibility if you’re Canadian:
Valid at 5 PM AST, November 19th. Rainy system strikes Cal, on doorstep to AZ. You got yer subtropical jet stream crashing into the coast over southern Cal, a nice low off SFO, and plenty of rain predicted as far south as Los Angeles.Valid at the SAME TIME as the Canadian GEM model above, 5 PM AST on the 19th of November! This is a horrible prediction by our own best model, because it robs us of our rain! For rain here in the cool season, we have to have the jet stream over or to the south of us here in Arizona, and here the jet stream is over Oregon! There is no low off Frisco, either! No “Waterworld1” here.Areas of rain predicted for the 6 h preceding 5 PM AST November 19th by the US WRF-GOOFUS model. The low pressure center, rather than off Frisco, is way up there by Annette Island! Or is maybe that one inland in B C.
So, with “model divergence” like this, what’s a poor meteorologist to do? Well, here, at least, we go with the Smokers1‘ version absolutely. Look for a chance of rain here in Catalina land on the 19th-21st window, as has been suggested here a few days ago, and for that reason alone we are “staying the course” as President’s like to say. We’re not here to give you necessarily the best forecast, but rather a consistent one. So, in conclusion, look for clouds and a chance of rain around the 20th. Furthermore, to maintain consistency and build confidence in the reader by avoiding the emotional distress caused by “fluctuating forecasts”, we might be forecasting rain right up until it doesn’t happen!
—–Temperature note, or “Egad!”———
Got an e-mail from local pal, Mark A., that the -27 F recorded in Wyoming a couple of days ago was the lowest temperature ever recorded in the State for the whole month of November! How could that be? It was only 12-13th of the month! Incredible. Weather, global warming or not, are truly amazing!
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Yesterday’s clouds
Here are a couple shots of the Cirrus clouds we had yesterday and thge day before, so the header is not accurate. Not much going on lately, but those Cirrus clouds did make the sky pretty at times before racing off toward the eastern horizon.
6:39 AM November 12th. Cirrus clouds add color to the morning sunrise.9:46 AM. But which day? This is a surprise quiz for those aspiring to cloud mavenhood.
9:16 AM. Yesterday or the day before?
The End
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1Movie buffs of course, recall the great Kevin Costner movie, “Waterworld” and know that the villainous “Smokers” in that movie were Costner’s subtle nod to Canadians who smoke a lot. Pretty funny, really. I can’t believe all the pop culture information you get here! Its pretty incredible.
1I put in a second “1” footnote in case you missed the first one.
Data, except for the past summer, are from Our Garden down there near Stallion and Columbus. That last data point is from Sutherland Heights.
The End, except for what’s below.
Fall in the Sonoran Desert (the season)
These shots below from hikes/horsey rides on Friday and yesterday, FYI. Seemed a little greener than usual for this time of year probably due to those September and early October rains. I think you should hike or ride a horse/bike out there in the Catalina Mountains before the rains hit. Yeah, that’s right; its gonna rain in November1.
The End
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1Assertion subject to error. But check THIS out, from last evening’s run at 11 PM AST which I just now saw at 7:46 AM:
Valid at 11 AM AST Thursday, November 20th! Note “storm face” complete with eyes and a frown.
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.
Finally found some rain for you. Took awhile. Came from the 11 PM AST global data from last night using the WRF-GFS model, our best. The rain falls around the 19th, “only” 11 days from now and during the “sweet spot” for southern California rain in mid-November, 10-20th, which gives it a few more percent of credibility than it otherwise would have.
BTW, there is virtually no support for this pattern from the NOAA spaghetti factory. So, all of the discussion below about an upcoming rain in Catalina might erroneous, based on a personal hunch about an outlier model run being the correct “solution”, one based on experience, and to HELL with spaghetti1, a study in forecasting subjectivity, etc.
Got that Bay Area rain timing info originally from C. Donald Ahrens, the big author of Meteorology Today and Essentials of Meteorology, both of which have about 400 editions out by now, while he and I were at San Jose State College University.
Don, a grad student then, and me, and undergrad, worked and sang together to Top 40 songs radiating from KGO-FM 2,3 in a little corrugated metal building there by the San Jose State football stadium back in the late 60s, and it was somewhere between songs that he told me about his findings.
Don had done a rain frequency study for the Bay Area for a local insurance company and it turned out that he found that it was somewhat more likely to rain in the middle of November than earlier or later in the month. That rain fell more more often than earlier was no surprise, but more often than later in the month was. Later I found that it was also true for southern California.
Sometimes oddities like these are referred to by big professors of weather, like Reid Bryson at the U of Wisconsin Badgers, as “singularities”, a weather pattern that tends to recur year after year around the same time of the year, like the so-called “January thaw” in the East which I don’t think happened last year.
So, ever since Don told me about the mid-November peak of rain in the central and southern parts of Cal, I have looked for it year after year and it seems to turn out quite often, and this November seems to be no exception, though the models were resisting this pattern for quite awhile before “giving in.”
Well, anyway where was I? It seems that the southern California rain is now being foretold for around 18th of November, and a day or so later it trudges on into Arizona. From IPS MeteoStar, a Sutron Company, whatever that is, this wonderful map:
Valid the night of November 19th-20th. Colored regions denote those areas where the model thinks it has precipitated during the PRIOR 12 h. So, storm has arrived here during the day on the 19th.
Some clouds
we have known over the past few weeks while CM was re-hydrating mentally:
Some ice for you on a warm fall day.Some ice for you on a warm fall day (virga from Altocumulus castellanus and or floccus)Pretty iridescence (or irisation) in a Cirrocumulus cloud.Pretty sunset, Altocumulus featured.
The End
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11The non-supportive spaghetti plot from the 00 Z (5 PM model run from last evening):
Valid at 5 PM AST Wednesday, November 19th. Arizona is in a low amplitude ridge, according to most of the “members” of the repeat model runs with itty-bitty errors deliberately put into them. I have rejected this plot and look for validation of this action around the 19th of November. You will not hear about it further if I am erroneous in this action!
2An odd, almost mysterious Frisco FM radio station with no commercials featuring, “Brother John.” We’d sing along to the Four Seasons, The Five Americans’, “Western Union” (about telegraph, the way people used to communicate before the Internet).
3 We both had quite a talent for falsetto it seemed at the time.
While living the big western life yesterday by riding a horse, me and my ridin’ pal, Nora B., came across some water flowing in the Sutherland Wash by the rusty gate on the east side of the wash that leads to Coronado National Forest land.
So, with with a 3-5 inch rain on the Catalinas, there WAS some water in the Sutherland here in the Catalina area. It was remarkable that there was no sign whatsoever of water having flowed at the Cottonwoods at the Baby Jesus Trail head on the north side of this flow (shown below), but water was flowing in it a few hundred yards farther downstream.
Nor was there any sign that water had flowed from our big rain in the Sutherland Wash at the back gate to Catalina State Park. In fact, we saw where this Sutherland Wash water disappeared just down from the rusty gate.
So, a lesson has been learned here about wash water flows: it can be flowing modestly between two dry points. Huh. Might not see this again for some time, and it will all be going away soon. Too bad so many of us have to pass hiking or horseback riding to these rare scenes today due to a necessary Pac 12 football TEEVEE vigil beginning just after 12 noon today and lasting through midnight I think. Kind of sad when you have to make choices between two equally worthy activities like these.
Cloudwise, I hope you logged the occurrence of distant Cumulonimbus clouds in the high country on the NW-NE horizon late yesterday afternoon.
The End.
9:18 AM. The Sutherland Wash near the rusty gate.9:54 AM. The apparent source of the water, the tributary Big Rock creek a few hundred yards south of the Baby Jesus trail head at the Cottonwoods.
The “perfect storm”? Well, maybe the perfect rain, and it kept giving fro several hours yesterday after our best model said it should end yesterday before 11 AM. And what a nice rain! 1.18 inches total here in Sutherland Heights, as measured by a CoCoRahs plastic 4 inch gauge. (You might consider getting one, btw, or one from the U of A’s rainlog.org)
Went down to the CDO and Sutherland Washes to see what was up after seeing the gargantuan 4.96 inch total on Ms. Lemmon, and the 3.62 inches at the Samaniego Peak gauge. Below is the resul for the Sutherland, both were the same, nary a drop in them:
8:15 AM. Looking upstream in the Sutherland Wash at the back gate of Catalina State Park. I could hardly believe that there was no flow with so much rain having fallen in Catalinas! But it was good in a sense; all that rain mostly soaked in.
6:37 AM. A photo of drizzle falling from Stratocumulus clouds. Hope you got out and jumped around in our rare drizzle occurrence. Big hat, no bicycle, works in drizzle, too, the tiny drops won’t get on your glasses. Note how uniform the fuzziness is toward Catalina/Oro Valley, only gradually thickens to the left. Took about 2 h to get a hundredth when this was going on.
7:23 AM. Drizzle drops as seen by your car’s windshield after about 1 sec at 1 mph. Note how close together they are. The tiny drops and how close together they are is what differentiates true drizzle from the phony labeling of spares large drops as “drizzle” we sometimes get from our TEEVEEs by semi-pro meteorologists. Sorry to bang on them again, but REALLY, folks, they should know better. Sure, I’m a drizzle-head, but it really does matter since its a whole different process that produces drizzle compared to sparse large drops. Sorry, too, for another mini-harangue on this, but REALLY folks, we should know the difference! Feeling better now, got that out.
8:02 AM. Heading down to the Sutherland Wash on Golder Ranch Drive with temperatures and dewpoints in the mid-60s, there really was a feel for being on the wet side of the Hawaiian Islands, maybe above Hilo, HI, at 3,000 feet elevation, except for the dead grasses.10:20 AM. One of the many dramatic scenes yestserday, this one looking toward the Charouleau Gap NE of Catalina.10:19 AM. While it was nice to see all the water glinting off the rocks on the side of Samaniego Ridge, a deeply troubling aspect was the amount of aerosol that had moved in suddenly it seemed, evident in the crespuscular rays. How could it be this dirty so soon? Seems like a weather oxymoron after such a long period of rain. Also, one wondered if this aerosol loading would stop the warm rain process by providing too many, and smaller droplets in our clouds. Fortunately, that did not happen, and what appeared to be warm rain events, or ice formation at relatively high temperatures in our clouds, also requiring extra large cloud droplets, for the most part, continued intermittently into mid-afternoon.
10:32 AM. Close up of aerosols and sun glints on wet rocks.
12:23 PM. Glimpse of ice-forming top (smooth region above crinkly top). Types of crystals visible here? Needles and hollow sheaths because the top temperature was likely equal to or warmer than -10 C (14 F) and cooler than -4 C, and that is the temperature range that those crystals form under when there is water saturation, as there is in a Cumulus turret before it glaciates. OK, a lot of hand waving, but that’s what I think and I am here mainly to tell you what to think, too.
5:36 PM. The day ended quietly with a little, but pretty scruff of orographic Stratocumulus castellanus on Sam Ridge, the clouds mashed down by the subsiding air at the rear of our little trough that went by yesterday afternoon.
The weather WAY ahead, too far ahead to even speculate about:
NOAA spaghetti plots still suggesting a pretty good chance of rain here around the 23-25th of this month. Nothing before then.
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…)
The obvious often makes a good headline: “National debt HUGE; more on way!”
With Simon’s decrepit, but juicy remnants on the way, and swept in our direction due to a little upper trough of the southern Cal and Baja coasts, significant rain is likely here. The heaviest reported amounts from the USGS and the Pima County ALERT sites (as of 4 AM) are already a little over an inch in the Green Valley area and near Bisbee. Likely more has fallen in the data sparse SW part of AZ. Will have to depend of radar-derived amounts there, but some of those will surely be over an inch as well.
Oddly, the Yuma radar doesn’t see much to the east of them, which is quite incorrect, but the PHX radar does see something akin to what was predicted the evening before last; a narrow band of heavy rain starting near the border near the Organ Pipe Cactus NM.
Overdoing the radar discussion but continuing anyway, the PHX radar is too far away to really see what fell at the ground down there by the SW border, but it did have that band of heavier rain shown in their storm total loop near Organ Pipe.
Our own TUS radar is also too far away to catch what’s going on that far to the west of us. However, it does show several hot rain accumulation spots already over an inch at of 4 AM AST to the SE-SW of us, validated by those larger totals around Bisbee and Green Valley mentioned above.
Radar-derived rain totals through 4 AM AST October 8th. Yellow areas denote those where the radar believes more than an inch has already fallen.
Today
Now here’s the excitement plan for today: Check this out from OUR very own University of Washington Huskies’ Weather Department, one of the highest ranked publicly-funded universities, not at all like Stanford U. which gets huge amounts of funding from big billionaires:
A forecast of the locations of curly air (red areas) at 5 PM AST today. The model run was based on global data taken at 5 PM AST last evening.
Red curly air, always in low pressure troughs, can organize storms. Looking at this, one would expect that as the red curly air moves toward Arizona in the trough that was off southern Cal but passes over us tonight, that storms will get organized and move through our area later today as it approaches! Because they’re organized, one tends to think, if its me, that there will be a nice line of thunder rain, and the rain duration would be several hours, heaviest at first, then tapering off to steady rain that gradually decreases, much like in our winter cold fronts.
The use of “curly” here, BTW, means those locations aloft where the air has relatively high vorticity, or rotation, as in around a center, as in the inside of a low; check out the “red curly air” in that low south of the Aleutians on this map). The approach and passage of “red curly air” (as it is shown in this color scheme) over you is associated with upgliding air motions that assist in the formation of large cloud shields; helps organize rainbands. So, a depiction like this, showing that southern Cal trough passing over us, combined with all the tropical air that has come into the State ahead of it during the past 24, portends some heavy rains in the State today with the cores of the heaviest cells. That’s, of course, what the models are anticipating, too, though going “blind” at this point, haven’t checked ’em, which is kind of silly. OK, checking now as a rational weatherperson would do…. OK, here goes:
Accumulated rain between now and 4 PM AST tomorrow afternoon from the 11 PM AST U of AZ Beowulf Cluster model run by the U of AZ. Now this is pretty exciting since it shows that twixt later today and tomorrow that something around an inch will fall here, and an inch and a half to two in the Catalina Mountains!
Yesterday’s clouds
Not a really exciting day, though a great sunrise due to Altocumulus, just more Altostratus and Altocumulus clouds as we had the day before. By mid-afternoon, some exciting towering Cu began to appear over the Rincon Mountains and to over the Santa Rita Mountains indicating the lower level moistening of the air approaching us.
6:15 AM. Under lit Altocumulus with a higher vale of Cirrostratus above. TUS sounding suggests the Ac was about 19,000 feet above the ground as seen from Catalina. BTW, during our (U of WA) research, we found that Altocumulus clouds, via pilot reports obtained directly from the local ATC Center1 and in our own flights were often higher than usually thought of as “middle level” clouds).
7:49 AM. Band of Altocumulus with Cs above. No virga here.11:40 AM. Virga to the west from an Altocumulus castellanus buildup, but in this case some of the virga was reaching the ground as a sprinkle-not-drizzle, a great sight because that showed how moist the air was all the way to the ground.4:36 PM. Dense Altocumulus clouds with considerable virga spread over the sky late yesterday. By this time, sounding data indicated that they had lowered from 19,000 feet above the ground to 13,000 feet.
Hoping to report at least half an inch by this time tomorrow morning.
The End.
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1 In those days of the 1980s and 1990s, it was possible to call the ATC Center in Auburn, WA, and ask if they had an aircraft taking off from or landing at Sea-Tac, and get the height of an Altocumulus layer when it was intercepted by that aircraft! Imagine, being able to call some guy working the planes and getting that info (for our research on aircraft-produced ice)? It seems totally amazing now.
While waiting for the remnants of former H. Simon to pass over us during the next couple of days, bringing some rain, starting overnight, got distracted while looking to see how many rainfall measuring stations they have in Baja Cal, and found this about the Great O from NASA. Its a pretty fascinating read I thought, which you will also find fascinating. Sure, intense hurricane O’s floody remnants missed us here in Catalina/Tucson, but it did produce some prodigious rainfall on its path across Baja and points northeast from there into NM. NASA’s Tropical Rainfall Measuring Mission (TRMM) radar estimates that over the ocean off southwest Mexico that about 33 inches fell over a ten day period while O was meandering around down there with some other disturbances, probably raising sea level that bit. And up to 5 inches per hour was falling in rainbands as it entered Mexico from the Gulf of Cal! O was deemed the strongest hurricane (tied with 1967’s Olivia) to ever hit southern Baja since sat images became available.
You will also see reprised in the “Diary of O” the huge rainfall totals that were expected in the TUS area but rains that missed us, the sad part of the story for some folks, who we will not mention. But, as Carlos Santana said, “Those who do not know history, are doomed to repeat it.”
For that reason, in view of the prodigious rains predicted in southern AZ again, but to the west of us, I thought we should be prepared for disappointment by recalling O’s “terrible” miss for TUS.
Here are some graphics from our very fine U of AZ Weather Department’s Beowulf Cluster computer outputs from just last evening at 11 PM AST, ones that can be found here, in case you don’t believe me again, a seeming theme around here. First, when the computer model thinks it will start raining, Figure 1, and in Figure 2, the expected gigantic totals expected along and near the US border where we really shouldn’t go unless you 1) go in an armored vehicle of some kind, 2) make prior arrangements with the appropriate ruling Mexican drug cartel for that part of the US that you just want to visit some rain, nothing more:
Figure 1. Valid for 2 AM AST tonight. The leading edge of the rain has reached Catalina. You might want to stay up for that. That wet desert aroma as rain begins is so awesome!Figure 2. Valid for 3 PM tomorrow afternoon. One small, mountainous area around Organ Pipe Cactus National Monument is forecast have more than TEN inches by then, likely slowing the amount of incoming drugs. Organ Pipe Cactus NM is a US national park that you are warned not to visit, or if you do, you might be shot or have some other untoward happenstance if you go hiking. So you probably shouldn’t drive down there to see this once in a century rain. How sad is THAT?
Right now, as of 4 AM AST on Thursday, this model thinks Catalina and vicinity will get less than half an inch. Be prepared for more, though, rather than less. Note the streamer of heavy precip associated with Simon in Figure 2. Well, recall that O’s heavy precip streamer was going to be right over us, but then shifted eastward in the models and in real life at the last minute. The above prediction would only have a bit of a “westward bias” (the real streamer is EAST of where its shown now) to give TUS and vicinity a memorable, drenching October rain. This is what occurred with O’s streamer of torrential rain which was expected to pass over TUS, but ended up a little east of us. So, anyway, given all the little uncertainties in model predictions at this point, the watchword here is “watch out” which is actually two words. The view from here, incorporating a positive rain bias as you know, is somewhere around an inch for Catalina. The grassy green is gone, most annuals in serious wilt or crispy now, but could an inch bring some green back? Clueless on that score.
Yesterday’s Clouds
6:06 AM. Nice Cirrus sunrise, maybe some Cirrocumulus at far right, and off on the left horizon.
5:05 PM. Altostratus translucidus with an Altocumulus layer on the horizon.
5:07 PM. A “classic” view of Altostratus translucidus (sun’s position can be discerned through it), and here, an all ice path to the sun. Liquid cloud elements would appear as dark flakes, or would obscure the sun’s position. Sounding indicated that this layer was 26 kft above the ground in Catalina!
Remember last October we didn’t get nothing, we got a trace instead, which is almost nothing. This October, with a juicy tropical storm remnant headed our way, I predict something more than nothing which is quite something. Remember it was foretold here just a month ago that rain would fall in September in Catalina…
TS Simon, about to be a remnant low by tomorrow, the NOAA hurricane folks say, is beginning to send in the clouds to Arizona with promises of rain, “real” rain, at least a tenth of an inch. Here’s Simon as seen by NOAA’s NexSat just a few minutes ago, and do we really need all that lighting?:
Satellite image of Simon as of 6 AM this morning.
Today
Overcast to broken Cirrus is all most of the day, likely thickening into Altostratus at times, thinning at other times–you can see that sequence approaching us in the sat image above.
As you cloud folk know, Altostratus is a Cirrus-like cloud that’s much deeper with tops at Cirrus levels as a rule, but bottoms in the middle levels, between roughly about 8,000 and 22, 000 feet above the ground. Altostratus, a layer cloud that covers much or all of the sky, has gray shading which Cirrus can’t have (with the exception of one patchy variety, Cirrus spissatus). Like Cirrus, As clouds are usually all ice. Maybe some Ac later, too. So, not a REAL interesting cloud day for you.
The Catalina Water Year Record Updated through 2013-14
This is probably the only worthwhile part of this blog. Actually our total, from a Davis Vantage Pro Mark IV Extra Deluxe Personal Weather Station “tipping bucket” gauge located here is probably a little low. A chincy CoCoRahs gauge always had more, including 4.63 inches on the Sept 8 true monsoon day, whereas the tipsy bucket couldn’t apparently keep up, reporting “only” 4.18 inches. The actual water year total is likely just over 15 inches.
