Here are the surprising totals from the Pima County Alert gauges. Mt. Lemmon received 0.31 inches from last night’s little rain! And most gauges, except the ones in Catalina, got measurable rain. Very nice NWS radar-derived rain graphic here (and below), something that shows we probably got a sprinkle here in Catalina. (Trace detector was not parked outside last night, a huge oversight caused by too much football on TEEVEE.)
Rain totals from 6 PM to just after 4 AM AST last night. Note how rain streamer just missed us to the east.
Some residual clouds are around and likely will provide some nice sunrise shots, but the rain possibility is over for now.
2:27 PM. Altocumulus perlucidus3:49 PM. Altocumulus, getting fatter here, tending toward castellanus and floccus (tiny Cumulus clouds)5:41 PM. Altocumulus castellanus clouds getting bigger yet, pretending not to be doing anything. No virga showing here, but some was beginning to show up on the extreme SW horizon at dark, as clouds began to fill in toward the S through SW. The appearance of virga would mean that the cloud tops were higher and colder than are seen here.
Next chance for rain is late tomorrow afternoon through overnight tomorrow as clouds fill in late in the day. US mods have backed off rain here, while our Canadian friends with their mod still have some (shown here) as they have calculated a deeper trough; more strength and amplitude (more of an extension to the south of us). However, its a marginal situation and the most that can fall here in Catalina in “Rain 2” would be less than a tenth of an inch.
Way ahead….
Some mod runs still have decent storms affecting Arizona in the 9 to 13 day period, 12th and 17th of November, to be specific, from last evening’s 11 PM run. Not good to be too specific at that forecast range as you know.
That’s it. Its a kind of news release, best released on the 1st. Its news, of course, you won’t find on other weather sites because maybe they’re chicken, or prudent. Check back on November 30th, and if its rainless again, there will be no mention of this forecast.
But, after the rainless October (we average about an inch here in Catalina), you probably won’t believe me. Check this out from the NOAA spaghetti factory. I got pretty excited when I saw it. I think, you will, too, maybe mention it to your neighbors over coffee this morning, having been pretty convinced yourself after seeing this that storms are a brewin’ for Catalina and vicinity (all of Arizona) in November:
Valid for November 10th at 5 PM AST. Originates with global data obs made at 5 PM AST last evening, and represents a few key 500 millibar height contours after DELIBERATE little errors have been put in and the computer model rerun with them in it.
Thank E. N. Lorenz, a meteorologist for Chaos Theory and maps like the above that show how little tweaks in the original data can change stuff a lot if things are fragile, but not so much if the signal is robust, and things not so fragile. Here a deep trough along and off off the West Coast on November 10th is virtually guaranteed by the blue and red lines that plunge so far to the south off the West Coast. A trough out there, as you know, gives us the best chance for rain as it progresses to the east. The bunching of lines indicates where the forecast, with baby errors, is strongest, like off Asia, and hereabouts, off Baja. Those red lines are pretty much where the south edge of the jet stream will be at this time of year. As you know, we have to be on the north side of the jet during the winter here in old Arizony to get precip, so it looks good for that to happen as we move forward in the month.
BTW, here’s your official forecast for the whole month of November from the Climate Prediction Center (CPC). As you can see, this November is a tough month for them, no real signals showing up for the month as a whole as indicated by the HUGE areas of “EC”, i.e., “equal chances” of above or below normal precip. We’re kind of on the edge of “we don’t know what’s going to happen” (in the popular lexicon, “clueless”) which is good. The signal for continued drought here is not so strong, though it is there. Poor New Mexico, though.
November precip forecast for North America made on Halloween by the CPC.
Cloud photo op coming up
A weak trough ejects from the Pacific and over us beginning tomorrow, and it should bring some great photogenic Cirrus and Altocumulus clouds tomorrow afternoon and evening, likely some “castellanus” if you care. Likely to be some virga (snow falling from the Ac) too, so could be a great sunset shot coming up. With the virga, always a slight chance of a sprinkle-its-not drizzle.
One of the best, really, never mind all that wind yesterday. No rain, of course, in our future, not even fantasy rain these days.
See usual rehash of yesterday’s clouds, the 60s, in case you forgot, below:
8:49 AM. This Altocumulus perlucidus cloud behaved like a lenticular, holding in place for at least 2 h, but did not have the classic pancake or sliver look of lenticularis clouds. Air likely too unstable (temperature dropped with height rapidly) and allowed tiny cumuliform elements to form. Only on the very right edge where it first formed, did this cloud appear “lenticular” in any way with its smoothness
10:15 AM. More classic looking, sliver Altocumulus lenticularis beyond the Catalinas. Cloud forms on the right edge, dissipates on the left as the air rises and falls slightly.
11:58 AM. Cirrocumulus (delicate granulation) on the fringes of Altocumulus (larger elements on the right). 12:01 PM. These clouds change by the second as the degree of moisture in the air jetting along up there ebbs and wanes. Look how much larger that fine granulation on the left got in just a couple of minutes. 2:09 PM. One of the many examples of iridescence seen yesterday in those Cirrocumulus clouds, or on the very thin upwind edge of Altocumulus lenticularis clouds. Its due to the formation of extremely tiny droplets, a few microns in diameter, that cause diffraction in the sun’s rays (see link for a more complete explanation and nice examples). Do you remember that white light has the wavelengths of all the colors in it? Here you can see some of them, and photograph them by performing a replication of the Black Power salute of Tommy Smith and John Carlos from my alma mater, San Jose State, one that beat the Wyoming Cowboys recently in fubball. I added a link in case you forgot and wanted to get worked up again. Yes I was at SJS when that happened down Mexico way, minding my own business doing weather forecasts with a political slant (left, of course, because that’s what made you popular during the rad lib days) for the college paper. Suddenly, I feel like going to San Francisco, putting some flowers in my hair.…
2:19 PM. Cirrocumulus and Ac lenticularis in the same layer. Recall Cc can’t have shading, not that it matters that much.
4:39 PM. This dramatic scene amid the dust and wind. This would be an Altocumulus lenticularis, one that devolves into Altocumulus perlucidus (honeycomb pattern seen downwind from the distant leading edge).
I was driving down in Tucson yesterday, kind of moping around about all the blogs I had done with little or no interest. You may recall from a blog I did a few months ago I reported to my reader that a business site had evaluated the worth of my blog, and due to the amount of traffic it brought, it was found to be worth $25.
But then as I rounded Campbell and headed northbound from Fort Lowell, I saw this sign exhorting fellow Tucsonians to watch clouds! My mood brightened. Maybe there were a few out there that I had affected after all; a whole cloud watching movement had started! I did see, however, that since the sign maker was wondering whether there were clouds in the sky or not, and there was a lot of Cirrus overhead, I saw that I had more work to do.
This sign seen near Campbell and just north of Fort Lowell yesterday afternoon.
Yesterday’s clouds
9:03 AM. Cirrus fibratus in rolls, undulations, due to waves in the atmosphere associated with the strong jet stream above us.
In case you were asleep, watching Monday night fubball, and NOT watching clouds, here is yesterday’s magnificent sunset as the sun underlit those dense Altostratus clouds that developed from thinner Cirrus ones during the afternoon and evening.
5:44 PM.
Today, more mid-level clouds and with strong winds aloft, we should see some lenticular clouds in the lee of the Catalinas. Videoing them would be a good thing for you to do because you would, in fast playback, be able to see how they keep forming on the upwind side and disappearing on the downwind side while holding their overall position. If the moisture increases, they expand, and if it decreases, they shrink and dry up, something likely to happen later in the day.
While that’s going on, there’ll likely be some Cumulus and Stratocumulus off to the north, and since the air is going to be much colder aloft to the north today, some ice is likely to form in them late in the day in those northern clouds, leading to some virga. Those lower clouds, according to our models, should begin appearing around here, too, in the late afternoon and evening. Alas, measurable rain is very unlikely, and with this, last little threat, October 2013 will go out rainless here in Catalinaland.
Farther ahead…..
More middle and high clouds and great sunrises and sunsets are likely on November 3rd and 4th as a little upper level trough creeps in from the lower latitudes of the Pacific off Mexico. It was once projected by the models to bring rain to here, but now it seems only a sprinkle is possible; most of the tropical moisture shunted to the south and over northern Mexico.
In the longer term, while all “fantasy rain” has disappeared for AZ based on last evening’s 11 PM AST model run, stronger than normal storms are showing up for California later in the first week of November, and with that, we’ll always have the hope that this time, the “fantasy” in that model calculations is no rain shown for here.
My fantasy rain team (I call, “WURF-GOOFUS“) already has FIVE inches of fantasy rain in Arizona for November, and here’s more from last night’s 00 Z model run! In case you went to school lately and have trouble finding where you are, I have added an arrow on the map so that you’ll know where SE AZ is (“hey”, we’ve read those stories about HS students not being able to name states….)
Valid for Wednesday, November 6th at 5 PM.
And its not only this map, but a few after this as well. Here’s 24 h later and its STILL raining in SE AZ, with a rain center right on my house!
Valid for Thursday, November 7th at 5 PM AST. How great is this fantasy rain?
I’m thinking now that my fantasy rain team from WURF-GOOFUS has six or seven inches predicted for just November! OF COURSE, its not real rain, its fantasy rain, but, there it is again.
Losing control, the rainless October, the mostly clear skies day after day getting to brain functions, hallucinating again over model outputs of clouds and rain…. Must seek treatment.
This is definitely not the same title as was a few days ago for a similar map, one also valid for Nov 3rd-4th. That title was quite different: “Not likely, but a wonderful map.” The rainy Arizona map back then from our best model showed a tropical storm and moist plume being drawn northward into AZ.
Almost the exact map as that one a few days ago has shown up again out of the blue, if you can say that when you’re talking about clouds and precipitation. There’s been nothing like that former map since that first time it showed up, and, in view of how odd it was, you tend to write it off as something you’ll not see again. But there it was again, now only 10 days out.
Below, the happy, rainy AZ map churned out by last night’s model run based on global data taken around 5 PM AST yesterday ( from IPS MeteoStar):
Model output valid for 5 PM AST, Monday, November 4th. Shows tropical storm remnant being sucked up toward Arizona with lots of rain already here. Green blobs denote where the model thinks rain has fallen in the prior 12 h, which here is the entire State of AZy!
Below is the pattern aloft that steers (hahaha) all that moisture into our water-challenged State, one that has a lot of steers.
HOWEVER, this rainy situation requires a lucky conjunction of a Pacific trough coming in out of the Pacific onto the southern California coastline, while a tropical storm/former hurricane is off Mazatlån at that same moment. If these two features of interest are just about anywhere else than is shown here in these model projections, forget it.
The flow pattern in the middle of the troposphere, around 15,000 to 20,000 feet above sea level. Yep, that’s right, half the air is gone by the time you get to only about 17,500 feet!
The first time this rainy map was shown for Nov. 3-4th, back about five days ago, the chances of it actually happening were probably somewhere around 0.2 percent. Just too much had to fall into place. Coming up twice, however, jacks the lucky numbers up to, oh, maybe to an 8 percent chance of actually happening as a wild guess. Not a great chance, but one that’s trending upward. You know, after the rainless October that’s about to finish up, we really deserve this storm in early November. The NOAA spaghetti factory has good support for a trough along the California coast at this time, so its likely THAT ingredient will likely be in place on November 3rd-4th.
Yesterday’s clouds; yes, there were a couple, some patchy Cirrus and a little band of Altocumulus, some of the latter trending toward lenticularis-ee ones. later on. Here they are.
2:37 PM. Patches of Cirrus drift across the southeastern sky.3:51 PM. Lines of Ac perlucidus streaked across the sky in the afternoon, soon to disappear.4:52 PM. Ac len below a patch of Ac perlucidus.
Last evening’s model1 run based on global data from 5 PM AST yesterday, gave us this, the remnant of a tropical storm barging into Arizona on November 3rd, just after our rainless October closes out:
Valid at 5 PM AST, November 3rd two weeks from today.
As an expert “spaghetti” decipherer, you can easily see from the map below that there’s not much chance of this happening though its not completely impossible. Too much “noise” in the pattern around here (lines aren’t bunched like they are off Japan and in the western Pacific). I just posted the map above because its the first one in SO LONG that had any Arizona rain on it, that green and blue stuff on the map above.
Valid at 5 PM November 2nd, the day before the map above, but close enough.
Who knows, maybe there’ll be a cloud over us one day again, too.
Of note… unusually cold air for October is poised to rush into the eastern and central US in several waves during the next two weeks; those events have a much higher probability of occurring according our venerable NOAA plots of spaghetti like the one above. Likely will see cold air refugees beginning to bail to Arizona in their droves from eastern units of the country as October low temperature records fall.
Its great to be where other people want to be.
The End.
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1Namely, the Global Forecast System-Weather Research and Forecasting (GFS-WRF) model, pretty much our best.
Some rare drizzle precip1 fell yesterday. Suggests clouds were pretty “clean”, that is, didn’t have much aerosol loading and the concentrations of droplets in them was low (likely less than 100 cm-3) Also likely, in view of the recent strong winds, some of the aerosols in those clouds might have been large dust particles2 rather than those due to just “smog” and other tiny natural aerosols. Large dust particles can not only influence the development of ice at higher temperatures than normal (above -10 C), but is also known to aid the formation of rain due to cloud drops bumping into each other and sticking together; collisions and coalescence because large dust particles can accelerate this process by forming large initial drops at the bottom of the cloud where drops first condense. Here, drops are nearly always too small to bump together and join up unless clouds are deep, like our summer ones, and ice is going to form anyway.
So, yesterday, was a bit of a novelty. Some photos and story telling:
1:34 PM. Drizzling from Stratocumulus!
1:35 PM. Drizzling here. Hope you noticed and wrote it down. I remember how excited I was in 1986 when I was in Jerusalem and it drizzled! I did not expect to see drizzle there, and I remember how I screamed out, “DRIZZLE?” after putting my hand out the window of the modest hotel I was in. In those days, the cloud drops were reported to be too small by researchers there to form drizzle in them. Yes, Mr. Cloud Maven person was the first person in the world to report in a journal article3 that it DRIZZLED in Israel! One of the great things about blogging is that you can write ALL of the things that you like to read about yourself, and this one is no exception. I am really enjoying today, reliving past efforts and accomplishments since there don’t seem to be too many ahead….The late Jack Russell, flight engineer, listening to Art tell another cloud investigation story.
2:43 PM. Cumulus humilis field over Saddlebrooke.3:06 PM. Drizzle precip just a memory. These clouds too shallow to rain via collisions, and too warm to form ice.
Looking ahead….
Mods paint dry weather for the next 15 days, and so yesterday’s disappointing “trace” (don’t recall here that Mr. Cloud Maven person had predicted at least 0.02 inches!) may be it for October. Phooey.
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1Drizzle: Fine (size range, 200-500 microns in diameter drops) close together, that nearly float in the air. Very difficult to bicycle in drizzle even with a cap or big hat. Fallspeeds, just a few mph. Smaller sizes can’t make it out of the cloud, or evaporate within a few feet almost if they do. Even true drizzle occurrences, you can’t be too far below the base of the clouds or those tiny drops won’t make it down to you.
2What is a “large” dust particle in a cloud? Oh, 1-10 microns in diameter, real rocks compared with the other stuff normally in them. So’s you get a drop that’s already pretty large as soon as condensation takes places. And, if the updrafts are weak at the bottom, then only them big ones might be activated, keeping the whole cloud’s droplet concentrations low! Happens even in places in the middle of huge land masses where in Riyadh, Saudi Arabia, we saw this happen on a dusty, moist day in shallow Stratocumulus clouds. They developed some drizzle drops. I was with the National Center for Atmos. Research on a field project then.
31988: Rain from Clouds with Tops Warmer than -10 C in Israel (Quart. J. Roy. Meteor. Soc.)
Hot off the Canadian presses from last evening’s global data from 5 PM yesterday, this exciting depiction (from Enviro Can) for Friday afternoon, the 10th. Note green and yellow regions in all of the SW, lower right panel! Note big upper trough over Vegas, upper left panel. Its all good, and, this being the 5th, its only a few days away!
Valid Friday afternoon at 5 PM AST. Note “tropical river” emanating from a tropical storm or depression off the tip of Baja (colored regions in lower left panel). No reason to be depressed if this happens.
But let’s look deeper….deep into the heart of the US WRF-GFS model for the exact same moment in time, shown below:
Also valid at 5 PM AST on October 10th from IPS MeteoStar. Perhaps the US model is sequestering rain for Arizona…. NONE, as in nil, is indicated from a model run generated at the same time as the Canadian one above! As you can see from the arrow, there is NO RAIN indicated for most of Arizona as a very strong upper level trough goes by. How bizarre is that? Something’s goofy here and its not just me.
What caused this model bifurcation?
For one thing, the US mod sees no tropical depression off Baja, and our hurricane center is very skeptical that any tropical development will take place south of Baja, one that would move NW or N and send a moist plume up into a trough positioning itself over southern Cal on the 9th. US mod has NO tropical moist stream coming out of the eastern Pac ahead of a trough over southern Cal at all, whether there is a low down there or not. Boohoo.
So, any rain here in Catalina would be with the usual passage of the jet core and in the cold Pacific air behind the cold blast headed our way on the 10th-11th. And that rain would be very light, likely less than a tenth of an inch.
The Canadian model, sadly, has to be considered a little goofy right now with its copious SE AZ rains, and widespread rain/snow over the rest of AZ, too. It would be good to inform your neighbors that you are thinking the same thing about the Canadian model, i.e. that its a bit looney as well in case they saw it and are touting a lot of rain on the way without really looking into things. Embedded editorial note: A lot of people vote like that, too, I think; also read health claims in magazines without looking at the peer-reviewed literature, taling with their doctor, examine the results of double blind, randomized trials, that kind of thing on which we base the whole edifice of medicine on. No, they’d rather read on the side of a health pill food, “these claims have not been evaluated by the FDA” and then take the stuff anyway and enjoy the effects of a placebo, which, if you believe in it, can be pretty good.
No doubt the reports of low temperatures in Arizona with this coming big upper trough on the 10th-11th, and snow in the high mountains, will spur a flock of snowbirds to migrate south. It’ll be windy and dusty, too, as it usually gets ahead of the passage of the cold front with these big troughs. That will be interesting, as well as all the cloud forms that start to show up with it.
Note: I’d show you some NOAA spaghetti so that we could get a little more on this model discrepancy, but its been sequestered from me, as you will see here. In the meantime, will hope for Canadian vindication in the days ahead.
