I smiled seeing the groundskeepers scurrying about, sweeping and scraping snow off the courses and environs at the Dove Mountain golf tournament yesterday. I was smiling because the golf culture here is so different from that in Seattle, Washington, much more “pampering” here. Due to frequent inclement weather in Seattle, we have to toughen our skins against weather if we want to play golf. Rain? Snow? No problem.
In Seattle, golf season begins on March 1st. That’s because in March in Seattle, its only raining (or occasionally snowing) on every other day by then, not every day, as earlier in the winter.
So we’re going golfing on March 1st, dammitall, no matter what!
So shop keepers like this one below on Aurora Avenue in the north end of Seattle, knowing that Seattle golf culture, exult with big signs like this one when March 1st arrives!
The golf weather culture in Seattle, Washington, as represented by this sign. Photo by the writer, March 1st, 1990.
Inaccuracy in media re Catalina snowfall or maybe it wasn’t: a tirade
I was thinking that maybe a tirade would be a nice change of pace for you before some cloud discussions.
First, since I heard a weather presenter report that “2 inches” of snow fell in Catalina, a visual correction to that report. There was FOUR inches on the ground after settling/melting during the day and night of the 20-21st. If there is FOUR inches the following morning, it HAD to have snowed quite a bit MORE than FOUR inches! (The total depth of snow that fell was 5.5 inches here on Wilds Road).
Here is the proof, 4 inches of depth as measured by a raingauge dip stick, one tenth inch markers are 1 inch in length–I didn’t have a regular ruler. Some of the labels indicating light amounts of rain have worn off while the stick was being used in Seattle for 32 years, so you’ll have to count down from the 1.00, 90, 80 hundredths labels, ones clearly visible. For added proof I have added a second photo, and if you call now, you’ll get a third photo free plus for $75 for handling and shipping…
7:02 AM, February 21st. A raingauge measuring stick protrudes from a FOUR-inch depth of snow on a hitching post (where some snow could have even slipped off, or blew off!)7:04 AM. A slightly higher depth on a second hitching post–oh, yeah, leading the big western life here in Arizony with a horse and hitching posts.
I felt sad, though, remembering the words of humorist Dave Barry, speaking to the National Press Club back in ’91 I think it was, when he diverged from humor into a serious note, admonishing his Press Club Audience: “Why can’t we get it right?1”
Maybe in our case of the missing snow, it was because the person that called in the report was not a Cloud Maven Junior, and did not know how to measure snow. Maybe less actually fell where that person was (unlikely). Let us not forget that the snow on a flat board in Sutherland Heights, above Catalina proper, measured at nearly the same time as this, was SIX inches!
Yesterday’s clouds, and those snow-covered mountains
While it was sad to see so much snow disappear so fast, it was, overall, another gorgeous day in a long nearly continuous series of ones since the beginning of time here in Arizona, except maybe for those days of upheavals and dinosaurs and then when it was underwater, a remnant of the latter epoch as shown here in this fossil of a hydrosaurus, a precursor to grain eating critters like the Perissodactylas we have today…(horseys and such). As you can see, the teeth here were for eating something like mueslix, not for ripping flesh. I can’t believe all the information I am providing you today!
Possible hydrosaurus fossil encountered on a hike in Catalina State Park (still checking on what it is). Finding was reported to park rangers.
Here are some shots with some notes on them or in the captions. First those MOUNTAINS!
8:21 AM, February 20th, looking east from Sutherland Heights, which had SIX INCHES of snow on the ground at this time. Stratocumulus clouds top Samaniego Ridge.9:13 AM. The snowy Tortolita Mountains with some Altocumulus perlucidus above.
2:25 PM. With most of the snow already gone around Catalina, the majestic Catalina Mountains remind us of our great February 20th snowstorm and why we live here.
2:26 PM. While it was serene-looking over the Catalinas, to the southwest the sky was filling in with Cumulus and slightly higher Stratocumulus clouds. Why don’t you see virga even though we know they are at below freezing temperatures? In unison: “NO ICE!” (Tops too warm and cloud droplets likely on the small side.) This was to change in the next couple of hours.
3:24 PM. But first, another look at the Catalinas from Shroeder Ave in Catalina because I think its worth it before continuing. Golder Ranch Drive is on the far left.
5:25 PM. Clearly there has been a change in the temperatures at the tops of these clouds, likely now colder than -10 C. A trough of colder air was approaching aloft, and that likely lifted and cooled cloud tops. The cloud layer was due mostly to the spreading out of Cumulus tops (Stratocumulus cumulogenitus). The TUS sounding indicated cloud tops were about -13 C, capped by a very strong stable layer. There was a fall of sparse drops around this time, so some of it was getting to the ground.
The weather ahead
Cold then HOT. Hot when? Heat’s on already by March 1st for sure. Look at this “signal” in our trusty NOAA “ensembles of spaghetti” from last night:
Valid for 5 PM AST, March 1st. You won’t see a signal stronger than this one for 8 days from now. Likely will reach into the 80s when this ridge of warm air is fully developed.
The End, at last. Anyone still there?
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1Deadlines have a way of getting in the way of “truth.”
…and it will seem like one. Windy today, real windy tomorrow morning before the cold front goes by in the mid-morning. Clouds is already here, rain predicted to develop SE of us in Mexico during the day. A jet max at 500 mb is already to the south of us, and that means that the door is open for a moist flow from the Pacific ahead of the main storm today, before the main blast tomorrow. So, there’s a chance of sprinkles and light showers around our area even today from thick splotches of middle and high clouds and the virga that will fall out of them.
But tomorrow; that will fab. Bruising cold front, gusty puffs of wind to 40 mph or more here in Catalina, especially likely on the higher ground, before it hits, followed by our “usual” huge temperature drop of 15-20 degrees in 1-2 h around mid-day, lets say about 10 AM-noon tomorrow, Wednesday (U of AZ mod run from last night sez it passes between 8-9 am AST, FYI, sometimes its a little fast). There ought to be light to moderate rain, briefly even heavy rain as it passes, maybe with some ice in the bigger raindrops.
What exactly is moderate rain you ask?
0.10 to 0.30 inches per hour, water is running off stuff pretty good. Its pretty common in most of our frontal bands. Heavy rain, which I think we will see, is just more than 0.30 inches per hour; drops are bouncing off the pavement an inch or two in height, and there are a lot of them. Now, it may not LAST an hour, this is just what you would call it if that intensity is reached. As a respectable CMJ, you’ll want to keep these numbers in mind, in case your friends ask you about something like this, “You just said ‘moderate rain’, what izzat, anyway?”
What the chance of measurable rain in Catalina and environs between now and Thursday morning?
About 200-300 percent, maybe 1000 percent on top of Mt. Sara Lemmon or even on Samaniego Ridge with this Big Boy blaster tomorrow. (We’re breaking new forecast ground here….you won’t hear the NWS telling you that the chance of rain is 200 percent!) ((Tell your friends.))
Amounts of rain here in Catalinaland?
Mods have juiced things up a bit, but a friend reported that yesterday the WRF-GFS had “as much as 0.25 inches” here. Friends, I pooh-poohed that forecast yesterday because it was TOO DAMN LOW for what we have coming. Besides, we need more than that, and this storm will deliver.
From this weather bully pulpit, the minimum amount, surely to be exceeded here, is 0.20 inches, the top I think now is more like 0.70 inches, that is, its not likely to exceed that amount. The median amount, the one most likely, the average of these two extremes, is 0.45 inches, a really good, and very needed rain. Its great to be able to say things like this, make people happy, except maybe snowbirders. Look, too, for happy Catalina Mountains with a LOT of snow on them. Get cameras ready for extra nice shots Colorado-ee shots on Thursday!
Hah, just looked at the U of AZ mod for the first time, and it is predicting that Catalina is in the 0.25 to 0.50 amount category, and Mt Sara Lemmon gets 1.5 inches! Yay! This will be so great if it happens, for our water situation. You can see that output here.
Saturday’s violent clouds
Never seen anything like them, those strange, and to me, violent looking high clouds, seemingly with tiny rope vortices in them; I swear I could see rotation. Here are a couple of shots. They seemed to pop out of blue sky for a few minutes, then disappear, then pop out again downstream some (toward the east).
12:24 PM, Saturday, Feb. 16th. There is no name that I know of that fits these clouds.12:38 PM. The one on the left just shot up in a minute or two; the one on the right MAY have a rope vortex in the middle.
12:45 PM, Saturday, Feb. 16th.
I didn’t remember to check PIREPS until long after the event. But, got help from NOAA’s David Bright who sent me a list of ones for Saturday morning throughout the West. Only one was intriguing in that list; “urgent, mod-sev turb….FL 310” (moderate to severe turbulence, flight level 31000 feet). But when I plotted the coordinates of that (9 AM AST PIREP, it was just about over San Diego, CA, and it was at 16 Z. There was nothing reported near us at the time of these photos, taken between noon and 1 PM (19-20 Z). But could that turbulent air, as represented by these clouds at Cirrus level, have gotten here from San DIego?
Below is the back trajectories starting at 9 km and 10 km ASL (30,000 to 33000 feet above sea level). Seems to lend credibility that our strange clouds MIGHT be the associated with the same region of turbulence reported by that pilot.
6 h ack trajectory for air arriving north of Catalina at 30 Kft and 33 KFt on Saturday, Feb. 16th at 2 PM.
Adding more mystery is the truncated TUS sounding, also attached, and the wild wind shifts. Did they lose the balloon? Maybe the balloon couldn’t take it, gave up as it got close to the turbulent layer above 22 KFT. Note how wild the wind direction got above about 16 KFT, or about 550 millibars. Normally these plots extend to the top of the diagram, 100 mb, but not on the afternoon of the 16th. Hmmmmmm.
The Tucson sounding, launched around 3:30 to 4 PM AST for Saturday afternoon, Feb. 16th. It will be known, in Z, or CUT time as the sounding for 00Z, Feb. 17th.
BTW, I have done a lot of work here for you on this strange case.
Yesterday’s beautiful uncinus, and another great sunset
Yes, mare’s tails on display yesterday. They make hygrometers out of of horse tail hair… Did you know that? Yep, its true. Horse tail hair responds to changes in humidity really well. You wonder who and how that was discovered? “Wow, look at how fat and short my horse’s tail is! Must be really humid today! I think I will grab a hair and make some kind of humidity sensor out of it, one that has linkages that trace the humidity on this little drum that goes around. I’ve always wanted to make something out of my horse’s tail.” (That venerable instrument? The horse hair hygrometer. Used for decades.)
9:38 AM. Does it get prettier than this? I don’t think so.6:19 PM. Patch of Altocumulus undulatus (has ripples), center, along with patches of Cirrus spissatus (thick Cirrus) and maybe some lenticulars on the right. It was a complex scene!
I wonder if you noticed the blackish smog layer to the south and southwest of Catalina yesterday? Usually it stays down that way, flowing peacefully toward the northwest from Tucson across Marana and Avra Valley, an area where a close meteorologist friend and his wife just bought a house even though they knew this happens in winter and not one in Catalina where we normally escape this characteristic Tucson smog plume. They must like winter smog overhead, but then as the sun heats the ground, it comes down to you. Go figure.
Here is yesterday’s Tucson smog plume exiting Tucson:
8:47 AM. Smog plume exiting Tucson, moving left to right over Twin Peaks area. This was one of the densest, most awful ones I’ve seen from Catalina.
But then, in the later morning hours, a southerly wind brought that smog bank to our normally clear air oasis of Catalina, infecting the shallow Cu fractus clouds that formed as the sun heated the ground. This was a real disappointment since probably most of us were expecting the kind of pristine view of the Catalinas yesterday morning.
10:09 AM. Smoke-filled Cumulus fractus clouds. The smog looks white here instead of dark because of “forward scattering”; the white light of the sun is being scattered in the viewer’s direction by the smoke particles. (In the first photo, there was no forward scattering and so you can see the actual dark hydrocarbony smoke particles for what they are, dark and sooty.
Fortunately the smog was dispersed as the day wore on. As the layer in which it is contained gets deeper, and without more smog being added to it, the amount of smog, say, per cubic mile diminishes and pretty soon it gets so thin you can’t detect it with your eyes. Still, exactly the same amount might be in the column of air between you and the higher cloud bottoms. Here’s what it looked like in the later afternoon:
BTW, while its easy to see that the Cumulus fractus clouds in the second photo are very low, in the 3rd photo above it’s much harder to detect how high these small Cumulus are. The TUS sounding indicated that they topped out at 9,000 feet, or only about the same height as Ms. Mt. Lemmon! Top temperatures in these smoke-filled clouds were no colder than about -8 C (about 20 F), too warm for ice to form in them, especially when the cloud droplets are reduced in size by smog. The larger the cloud droplets, the higher the temperature at which ice begins to form in them, and so smog generally reduces the chance of rain in shallower clouds.
This is why oceanic clouds in pristine regions lacking smog, even shallow ones, rain or drizzle so easily. The cloud droplets are much larger in those clouds right from the get go than those in smoggy regions. So oceanic clouds can rain either because those larger cloud drops reach sizes where they can collide and stick together, forming larger drops that can fall out (“warm rain process”) or form ice at the highest temperatures known for ice formation, -4 to -5 C (23-25 F). Usually both processes are work in those ocean clouds that rain so efficiently. They’re pretty great, really, such little clouds that rain.
Vacation in Hawaii if you’d like to see some up close (though not downwind of the Kilauea volcano plume and in the lee of the Big Island of Hawaii since that volcanic plume can smoke up the clouds real bad there and they stop being so darn efficient as rain producers. Recall that the biggest drop in the world was measured in clouds in Hawaii (1 cm in diameter, Beard, private communication, received AFTER Peter Hobbs and me got the Guinness record for the biggest drop ever measured, 8.6 mm in diameter–got a lotta publicity around the world, too, calls came from everywhere!).
You see, Beard didn’t publish anything about HIS BIG DROP; we published ours in a refereed journal. “Neeny, neeny, neeny”, I think is what you conclude here. Immaturity: sometimes I think its not valued enough in life.
That’s what its like in academia; you publish or die! Die that slow death as an “Assistant Associate” professor of something, never reaching the exalted “Professor” status.
The “combo” ice seen yesterday morning
We had two forms of ice yesterday morning that you may have noticed, say, on your car if it was parked outside overnight. There were originally rain drops left from the storm that froze in place during the cold night (was 30 F here yesterday morning), and then the deposited ice from water vapor on top of the drops.
The deposition process, as we call it, leads to hoar frost ice crystals growing in time as the molecules of water vapor add to it during the night. This combo ice led to an unusual site on the car before the sun did away with it. Here are a couple of shots of this unusual sight:
9:57 AM. “Strange brew.”
9:58 AM.
The weather ahead
After the “sunny malaise” for 5-6 days, with Arizonans statewide out doing things, its back to the Bowl, the trough bowl. The period we’re in now might be called, “a sucker ridge”, a high pressure ridge that is. You might well think, “Well, that’s it for winter in Arizona!” after a few days of the “sunny malaise”, but you’d be WRONG. I can’t emphasize the word, “wrong” enough. The Bowl comes back with a vengeance, too, when it reforms here in the Southwest; there will be one storm and cold blast after another. If you’re a snowbird, you might start to cry, and wonder why you didn’t go to Costa Rica for the winter.
Well, I am looking forward to storms and seeing more scenes of white mountains deep in snow, and green vegetation shooting skyward. That’s the promise of the “Bowl” ahead, where storms collect, in the weeks ahead right into March.
Taking a few days off now, likely without pay, to replenish mind, get out and do things like the rest of Arizonans will. Will give you time to ruminate on all that’s been said here over the past year or so, correct and incorrect, mature and immature…
Its not about car racing…. though that might be more exciting than what I am going to write about. This is a discussion about 500 millibar maps and what you can get out of them.
Here’s this morning’s 5 AM AST 500 millibar pressure map below. Knowing that sea level pressure averages 1013.6 millibars, then 500 millibars, around 18,000 feet or so, is about halfway through, in pressure anyway, ALL the air above us that we have on this planet. Thins out, of course, as you go higher; 10 millibars, for example, is around 120, 000 feet above sea level. You don’t want to be there. Thought I would check around for that height of the 10 millibar level, and here’s what I came across
At this link on the web, however, it is calculated that the 10 millibar level is reached at “5.48 miles” above sea level, and at 4 miles above the sea level, about 21,000 feet, the pressure is but “13.44 mb”! I started laughing because you’d need a space suit to be at the top of our Mt. Lemmon with a vertical pressure distribution like theirs. Yikes! No wonder our math and science scores are behind those in the developed countries!
The pressure at 4 miles above sea level (at 21,000 feet) averages about FOUR HUNDRED FIFTY millibars, not “13”, fer Pete’s Sake, and its still about 320 millibars at the top of Mt. Everest, about 5.5 miles above sea level. I guess these folks don’t do any hiking above about 1,000 feet above sea level. Might be too dangerous without an oxygen bottle in the atmosphere they’re making calculations for. (Looks like someone mixed units; English and metric in their calcs.)1
Now, where was I?
Oh, yeah, this morning’s 500 millibar map… Note where the wind maximum is around a cold trough that is about to pass over us, the one that extends across Utah to Vegas. The peak wind is just about over us, and as the day goes by, it drifts farther south. So what, you say?
Check below where the moisture is at mountain top level, or around 700 millibars, 3 km or about 10,000 feet above sea level.
Valid for 5 AM AST today.Temperatures and moisture at 700 mb, about 10,000 feet above sea level, also for this morning at 5 AM AST. See how the moist air at mountain top level is contained within the wind maximum at 500 millibars. Its just how it is here in the interior of the SW–doesn’t work so well along the coast or north of Salt Lake CIty, UT, or much east of Denver in the wintertime, but it is a pretty solid relationship for hereabouts.
Later today, that green area will be over us and there’ll be some scattered showers. Cloud bases will be high, higher than Mt. Lemmon, and so the precip is going to be pretty marginal. Will be very happy if even a few hundredths of an inch falls in Catalina this afternoon or evening. BTW, with the freezing level so low again this afternoon, soft hail (graupel, tiny snowballs) falling from these clouds is a certainty this afternoon or early this evening. (I’ve repeated some of this in the caption below…. Hmmm. Mind going.)
Here is the latest surface map of obs and infrared satellite imagery on top of the obs from the U of AZ. And, if you look out the window now, adding this at 6:45 AM, you’ll see the first clouds with this trough, likely good enough for a bit of sunrise color here in Catalina.
5 AM AST this morning. Good thing this trough and its minimal amount of moisture is swinging over us in the afternoon since a nightime passage would not have the scattered glaciating Cu and small Cbs we’re going to see later today. And, by the way, the skies should be real pretty, too; big long shafts of virga falling from high based convective clouds. And, as you can see, some jet stream layer clouds–Cirrus, high Altocumulus in advance (near tip of arrow at bottom. Likley another day for lenticular clouds before the cold core gets here. Lots to look forward to today!
What’s ahead? Storms
Storm world, that’s what’s ahead because we’re in the bowl now, the trough bowl, resulting intermittent periods of storminess, broken by deceptively nice weather for several days; the latter, times of some trough fakery, one that make you think the “bowl” is gone. But then its BACK! So, don’t be afraid when the weather turns nice again after today.
Here is a sequence of maps from IPS MeteoStar ones that document what I am trying so poorly to explain, the overall spell of storms that we’re in, where one cold trough after another is drawn to Arizona like metal filings to a magnet. First the “interruptus”, now on deck, a map for about five days from now. For some reason, I put all of what it means in the caption.
Valid Saturday, February 16th at 11 AM AST. No trough nowhere near Arizona. In fact, it looks like the trough bowl might be relocating to the Ohio Valley down to Natchez, MS. This is pure trough “trickeration”, the latter a term used in football for trick plays where somebody looks like they’re going to do one thing and then they do something entirely different. So at this time here in Arizona, you’re thinking, “la-dee-dah, no more storms, just nice weather now for quite a while”, and at the same time reading about bad storms and cold in the eastern US. But you’d be so WRONG, as we like say around here. Look at that trough coming into the Pac NW. Guess where its headed? By the time that one gets here, you’ll realize that you went for the “fake”, and that all is not well weatherwise in Arizona, and more troughs after that one piles on top Arizona, bringing bountiful late winter rains, one after another. Finally, you go back to Michigan, you can’t take it any more, because you only came here for the good weather, not to stay and be one of us for the whole year….Valid for 5 PM AST, the 20th of February. Now look who’s bowlling! Its Arizona! Lot of great rain foretold with this one.Valid for 5 AM AST, Sunday, February 24th. More rain on the doorstep.Valid for 5 PM AST, Tuesday, February 26th. The grandaddy, the Big Bopper, a crescendo of troughy-ness occurs.
In conclusion, and remembering that these exact depictions above are not going to be realized as such, they will vary in intensities and positioning; nevertheless, the prediction from this keyboard is that February 2013 will have ABOVE NORMAL precip in just about all of Arizona due to storms that occur in the last 15 days. I am really happy for you, and its always great to conclude things like this, conclusions that bring so much happiness to others.
The End
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Mr. CMP, in a twinge of conscience, realizes that the error he goes on about today is one that he himself would like have made during his struggles in math and physics in HS and college.
It seems we’re heading into another “trough bowl”, a persistent collection area for cold air in the upper levels over us during the next couple of weeks. In the meantime, something about today’s great weather, if you like a little drama.
Underview
The wind starts blowing pretty hard later on this morning or certainly by mid-afternoon. As it gets gusty and dramatic, its only natural for our heads to start swiveling around, looking skyward, knowing something ominous is happening; something’s changing drastically, like the barometer. That gut reaction comes not from the gut, as popular lore would have it, but from the deep responses to fear located in the amygdala, that ancient piece of brain that knows scary things1. And it would be right.
Here is the scary stuff that going to happen, first from the NWS, as told in their latest (as of 4:30 AM) very “Special Weather Statement“, FYI. Have goose bumps now!
Also shown at that link is a “Special Statement” from the Albuquerque office of the NWS, one in that I particularly liked because of their use in their own Special Statement of the word, “potent” to describe this incoming storm. Its a great word to employ, and apt in this case; and its a word that conveys power. A “potent” this or that is something tremendous! “Po-tent”; fun word to say, too. Think, too, of the devastation when just two little letters are prefixed to that word.
Today is the precursor day for our “potent” storm, a day with potent winds, likely reaching 40 mph in momentary “puff gusts” (lasting just a second or two) here in Catalina, especially in the hills overlooking our little berg. The air gets squeezed against the Catalinas today as it races northward into a large Great Basin low center. Should be gusty here right up to when the potent cold front hits tomorrow morning. When that front hits, we should see light to moderate rain for a couple of hours, along with our usual temperature drop of about 15-20 degrees in an hour, too. And, as it always does, the wind will drop off dramatically, turning to the northwest for awhile before returning from the southwest.
BTW, since we haven’t had strong winds in so long a time, there will likely be more dust raised today and tonight than would normally be the case. Also, you tend to see more branches break off trees after a long non-windy period such as we have had.
All the mod outputs I’ve seen from overnight (3, USA, Canadian, and the downscaled U of AZ one) have rain here tomorrow morning followed by the chance of a passing, brief shower in the afternoon. Those passing shower clouds would be Cumulus congestus converting to small Cumulonimbus clouds. Very pretty to see in the winter.
The chance of measurable rain here in Catalina tomorrow?
Oh, 100%. We don’t mess around here; but then we don’t have any particular responsibility to anyone either.
Amounts?
U of AZ mod has us on the edge of the 0.25 inches region, slightly less than was forecast yesterday at this time. SOP from this keyboard: minimum 0.08 inches, maximum 0.38 inches, middle ground, 0.23 inches, same forecast as yesterday. However, as a person who suffers from a desert version of precipophilia, I love it when its MORE than I think it could possibly be. (Didn’t really have this syndrome in Seattle…)
Rain chance here HAS to be near 100% due to our position near the Catalinas, and how those frontal band clouds will be fattening up as they approach them, especially to the point tops are fattened up to BEGIN raining in the trailing part of the frontal band (requires the formation of ice up there, as you know). The trailing parts of storm bands is where we in Catalina Census Designated Place pick up an additional amount of rain over outlying areas in fronts like the one coming tomorrow.
So, in sum, tomorrow will be a fun day and a dramatic one with rain pounding down in the early morning, and, with the snow level plummeting to below 3500 feet during the rainy part of the storm, and a scenic one when the leftover, non-raining Stratocumulus clouds begin to break open, build into scattered Cumulus and small Cumulonimbus clouds. Those snow covered mountains will come fully into view. So, a VERY photogenic day ahead tomorrow, particularly in the afternoon. Charging camera batteries now.
Today’s clouds
First, as we saw at sunset yesterday, Cirrus clouds, lots of different varieties/species today, probably including the patchy thick versions with shading called Cirrus spissatus. Most likely these clouds will thicken enough in coverage to be termed, Altostratus, widespread gray looking ice clouds. Below those, maybe a brief Cirrocumulus or maybe an Altocumulus lenticularis–again, look to the northeast of the Catalinas for that. These latter clouds can have the best, really delicate patterns embedded in them on days like this. But, they may only last minutes if they form.
Our high cloud spawning grounds have been doing their work overnight, as you will see in this infrared satellite loop from the University of Arizona. You will see that high clouds have spawned from clear air in the lee of both the mountains of southern California and those in northern Baja California. Those cloud spawning zones have quit for the most part now as the air dries out aloft over them, but the shield of clouds they launched now extends over the middle of Arizona, some are over us now, too, so a good chance of some sun rise color. That nice plume of ice clouds launched by those mountains is wrapping around our coming upper level low center as it marches down the California coast.
As you know, those high clouds are “decorations” in a sense because they will have nothing to do with the surge of lower clouds and rain that blasts into Catalina tomorrow morning. But they do present us with the chance of great sunrise and sunset color. Just now I saw that the U of A model foretells drying at Cirrus levels over us near sunset today, meaning that the huge clear slot that (oddly) precedes storms so many times, may arrive just as those Cirrus/Altostratus clouds depart around sunset. Hope so.
The weather ahead and far ahead (beyond 10 days)
This is great news and not so great news (if you’re snowbirding in Arizona); the coming rejuvenation of winter. The mod output from last night’s 5 PM AST global data crunch (can be seen here) has a series of troughs of cold air dropping southward from the Pac NW into the Southwest US, meaning multiple chances for rain, but even if no precip, lower than normal temperatures. In other words, it appears that we are entering another spell where we are in a trough bowl, a nesting place of sorts for cold air aloft and the storms that come with them.
Below, from our TUS NWS, is an example of what it means to be a thermometer going in and out of “trough bowls”, that region where one or more upper level troughs find us for a couple of days or more, this graph for January. You can see that if you were a thermometer, it would be like being in the ocean with big swells driving you up and down, up and down. That’s what’s ahead now, that same temperature roller coaster we saw in January appears to be ahead for us through the remainder of February.
Temperature roller coaster due to sporadic positioning of “trough bowls” in the SW US.
But, with troughs come chances to joyfully fill our February rain gauges and see our desert vegetation spring to life. So, really, snowbirds aside, its all good.
Would refer you to our venerable error-filled NOAA ensembles of spaghetti plots to support or weaken these longer term conclusions, but I haven’t been able to get in, seems site must be down.
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1May be some kind of “first” here, seeing the word amygdala in a weather briefing. Tell your friends.
But first, continuing from yesterday: “…and a few small to moderate sized Cumulus (humilis and mediocris) clouds as well to go with the high and middle clouds.”
Sorry I took so long to finish that up, but it was worth the effort because it was pretty darn accurate.
The storm on the doorstep
Here is your very excellent Catalina forecast as of now (4:50 AM) from the computers at the NWS. There is a statement on the exciting New Mexico weather, posted by the Tucson NWS here. You can feel the excitement in NM in this message they consider quite special, labeling it a “Special Statement.” Hope our Arizona guys and gals get on board with the NWS in ABQ and issue something special soon! Being weathercentric, of course, I am at one with the ABQ office even now.
Here’s a depiction of the incoming storm from our best model, that at the U of AZ, one that downsizes the “WRF-GFS” model to smaller scales so we can see what happens in our local mountains and valleys as it barges across California and then into Arizona on Saturday. Precip is shown to begin on the Catalinas before dawn on Saturday, but probably won’t reach here for a few hours after that. The model onset time here in Catalina is 8 AM AST on Saturday. However, this model tends to run a bit fast in these situations, so it may be mid-morning before those cold, cold raindrops start falling. But, 8 AM vs maybe 11 AM AST? Amazingly close no matter how you put it. It just shows how good our modeling systems have gotten over the years.
The amounts? Seems measurable rain is certain here in Catalina–the flow pattern jetting against this side of the Catalina Mountains favors us here. The finest scale model at the U of AZ, the first place to look, is showing a range of values between 0.25 and 0.50 inches, oddly corresponding with a ludicrous guess made too far in advance here a few days ago. Hmmm. The Catalinas are shown to get more than an inch and that calls for a celebration.
Here is the scoop from the 11 PM AST U of AZ model run for total precip (snow on the Catalinas again, the best kind of precip because it just sits there and soaks in when melting):
Valid at 2 AM AST Sunday the 10th, the storm is long gone from Catalina at this time but still adding some in the mountains up to about here.
Out of character a bit, but also since we’re on the edge of the predicted range of amounts, I think the bottom is closer to 0.08 and the top likely amount is 0.38 inches, with a “median”, most likely amount of about 0.23 inches, to be a little silly here.
Clouds today?
Probably (and this time I will examine the TUS sounding more carefully than yesterday), just a few isolated Cumulus clouds again, likely dissipating during the afternoon, and a couple of Cirrus clouds.
The clouds tomorrow (more interesting)
One of the interesting cloud formation zones for Arizona is over and downwind of the mountains in northern Baja (Sierra de Baja California). Gigantic plumes of Cirrus/Altostratus ice clouds often form in these situations as moisture at high levels from the Pacific Ocean (located west of Baja, California) travels over those mountains. Those clouds would be something akin to standing wave clouds, lenticulars, but because the air is pretty moist (“ice saturated”) wrapping around this powerful low, they don’t evaporate downstream once having formed but end up as a huge, icy plume across central and southern Arizona. I think we’ll can see that start to happen today, first in the lee of the Sierras of California, as the jet stream works it way down the West Coast toward us.
Eventually, the higher level moisture dries out over those Baja mountains, as it will later tomorrow, and the icy plumage source ends, and many times we see the end of that plume from those Baja mountains (Cirrus/Altostratus clouds) as a huge clearing that, oddly, preceeds the real storm; the surge of lower level clouds that carry the precip. And with that clearing as well, the passage of the core of the jet stream (in the middle levels) above us.
I know many of you have seen this sequence over and over again, the clearing of a high dense layer of clouds from the actual storm that’s on its heels.
Such a separation in those two clouds systems, the high and the low, can lead to spectacular Catalina sunsets. Tomorrow, out on a limb here, is the kind of day where that could happen–the sun sets in the distant clearing to the west as the shield of icy plumage overhead passes.
Yesterday’s clouds
Yesterday was another one of those especially gorgeous days here in the wintertime. Delicate patterns in Cirrus, as well as the dense patches. Then, a few lower Altocumulus clouds above scattered small to medium Cumulus clouds against a vivid blue sky and limitless horizontal visibility. Here are some examples:
7:47 AM. Old Cirrus (foggy stuff above palm tree) below in altitude newly formed Cirrus (flocculent specks to left and right).
10:31 AM. Only the exceptional cloud maven junior would have noticed this rogue Altocumulus castellanus masquerading as a Cumulus. Its betrayed by those specks of Ac floccus around it. Also, if there was a true Cu fractus nearby, you would have noticed a tremendous difference in the relative movement of the much higher Ac cloud and the real Cu.
12:02 PM. Last of the high clouds (Cirrus spissatus) approach Catalina with Cumulus fractus and humilis starting to form.
2:36 PM. One of the best shots of the day; small Cumulus with a trace of Altocumulus perlucidus above.
5:51 PM. Though it was clear to the west, we still had our sunset color on the Catalinas, and an orange reflection on the bases of the last clouds hanging on above them.
Kind of rushing around today, hope this is intelligible….
You will soon notice a nice sunrise with a sky full of clouds, Cirrus-ee ones, Altostratus, some Altocumulus tending toward lenticulars (red denotes cloud forms added after the sun came up and I saw them.)
I am late today, not because I overslept some, but also because I wanted to post a great sunrise photo for you.
You know, its all about YOU again, isn’t it? Maybe you should step back and think about that for a second…ask yourself just where your life is going? Thanks in advance for doing that!
Here is this morning’s nice sunrise, Altostratus clouds with virga:
7:07 AM today.
When you see this morning’s clouds, and the great sunrise, no doubt you will be thinking along the lines of a great sunset today as well.
But you’d be so WRONG!
Using a technique developed here, you can foretell where the back side of today’s band of high and, later, middle clouds will be quite accurately. You won’t need the Titan supercomputer to do it, though it would be nice if you had one. Will reprise that methodology for you:
1. First go to, say, a web site having infrared image loops, such as here in purple and gold Huskyland up there in the wet Pac NW
2. Select a loop that you like that shows the clouds to the west of us, such as the one I have selected for you.
3. Stop the loop at a time period not less than 4 h from the current time (probably best not to exceed 12 h).
4. Get out a Hollerith card (computer punch card), and carefully mark the position of the backside of the cloud band of interest that is upwind of your location, pressing the card hard against your computer montior.
5. Proceed in stepwise fashion to the current time in that satellite loop and mark on the same punch card, the location of the backside of the cloud band. You will now have two “tick” marks denoting the movement of the backside of the clouds over the time period you chose.
6. Now, move the first “tick” mark to the current backside, carefully moving the card along the direction of movement of the band, and pressing it against the computer monitor.
7. The second tick mark you made will now be ahead of the band at a future position and time, based on the time increment you have used.
8. Determine from that future position whether local sunset will occur to the west of the backside while it is still OVERHEAD. If the answer is “yes”, then a tremendous, memorable sunset is likely.
Illustrative example, using an 11 h time increment to enhance difficulty:
Satellite image 1
6 PM yesterday. Cloud band backside is over central California.
Satellite image 2
6 AM this morning. Backside approaching Colo River Valley. But is it moving slow enough to be overhead at 5-6 PM with the big clearing to the west?
Preparation of the Hollerith card; no “hanging chads” here–some people disperse incense now:
Results
The back edge of our cloud band is too far east for a good sunset tonight. New clouds would have to form on the backside for a good sunset. Yes, that COULD happen, and it sometimes does in certain situations, but it probably won’t today. Be thankful for a nice sunrise.
The weather ahead? The cold slam?
Well, every weather presenter is on top of that big time, and so why blather about it here? Of course, tomorrow….”tomorrow is another day” to quote a quote. And after I see how this mostly clear sky sunset prediction turns out.
Let’s look at February’s climo for Catalina, now that the month is practically half over (hahahah, sort of):
Oh, my, such a sad chart so far….What the experts at NOAA’s Climate Prediction Center are thinking–a smudge of higher precipitation for Arizona, thought the chances, they feel, aren’t great, 30-40 % is all. Still, its something. This would be a pattern of precip that goes with our upcoming storm, one that will be much more of a dumpster in the northern half of the State than here. With the spaghetti plots having already indicated a high probability of a big trough in the SW US a week ago, this forecast may be based only on that one pretty sure thing which would give a monthly prediction of above normal in the Four Corners area and northern Arizona a leg up, so to speak. I mean, you wouldn’t want to forecast below normal precip in a region for a whole month if you knew there was going to be a flood in the first two days of that month! Hope this forecast is due to more than our Cold Slam, coming up!
BTW, yesterday I discovered at first sunlight that a trace of rain HAD fallen the previous night by finding raindrop images in the dust on my “trace detector” instrument (a car parked outside under the open sky). Hope you found drop images somewhere, too, and properly reported or at least, logged, your trace of rain.
Here’s a radar depiction of those areas of sprinkles from WSI Intellicast, amounts ending at 5 AM AST yesterday. If you are in one of the faintly blue areas shown below, and DID NOT report a trace, we will have to consider confiscating your Cloud Maven Junior tee….and you should consider whether being a CMJ is really for you. Its OK if its too much…
Here the rain forecast from the WRF-GFS model, our best, as rendered by IPS MeteoStar:
Valid for 11 AM February 10th. This is the first WRF-GFS run with rain here in it. Only the Canadian model had rain here before this one.
Here’s a nice little example of how the weather computing models start to go awry fast when a little flummoxed when little DELIBERATE errors are input into them as they start their northern hemisphere data crunch (below, from the global data ingested at 5 PM AST yesterday). Us folks here in Arizona and those in the Southwest US comprise one of two “centers” of the greatest uncertainty in all of the Northern Hemisphere, as shown below in the red and blue lines (selected height contours at 500 mb).
Model outputs and what they are predicting will go to HELL faster due to our “zone of uncertainty”. Chaos in action. Wiggle something here, and it falls apart over there and all over. This example is the contour forecasts for 5 PM tomorrow.
Valid for 5 PM AST Monday, February 4th.
Does this epicenter of uncertainty hereabouts mean we have a chance to get some real rain in the next 36 h?
No, but its great that you know about this uncertaity and how it plays out in the NOAA “ensembles of spaghetti”; useless-in-some-ways-knowledge, absorbed just for the sake of knowledge.
The uncertainty illustrated above is associated with a upper level wiggle in the winds and exactly how that will play out as that wiggle moves toward us from the NW today. Its a little baby trough in the upper air flow that the model is uncertain about but it is too weak to have much affect on the big cloud mass that will be drifting over us today, that cloud mass originally from a location about halfway between the Galapagos and Hawaiian Islands. These are real tropical clouds over us today, and they’ll be piled in layers (Altostratus, Altocumulus, Cirrus, Cirrostratus) over us to more than 350,000 feet!
Range of amounts here in Catalina: ZERO on the bottom to 0.10 inches, tops.
Below is an example (full set here) of what the Beowulf Cluster from the U of AZ sees in the moisture overhead at 3 PM local time (in other words, during the 84th hour of the Superbowl pre-game show). I realize that many of you will not be able to go outside and look at the sky at any time today due to this historical sports emergency, and so I will tell you something now about what you likely would have seen had you gone outside, perhaps even missing an equally historic commercial break of some kind:
Forecast sounding for 3 PM AST today, an hour before Superbowl kick-off.
What does this mean?
Weird clouds, most likely. Scoop clouds, concave (downward) looking cloud bottoms. Some areas of the sky might look like ocean waves upside down, “undulatus” clouds (we had a short-lived Ac undulatus yesterday to the NW of Catalina). Clouds with waves on the bottom. The bases of our tropical clouds are likely going to be in a “stable layer”, one where the temperature remains the same as you go up. It would be located just above the top of Ms. Mt. Lemon. Along with that stable layer, and is always a part of them, is wind shear; the wind turning in direction and speed as you go upward from just below this stable layer to above it.
Stable layers and wind shear produce waves, not ones always seen since the air is often too dry for clouds, but in this case, they should be visible. Could make for some interesting cloud shots this afternoon and evening. Here’s a risky example of what I think is likely, though with too much virga falling from above, they won’t happen, hence, the risk in a cloud detailed forecast:
An educated guess about how this afternoon’s cloud bases will look. There’s likely to be much more cloud cover, however, than is shown here.
Yesterday’s clouds
Lots of contrails overhead yesterday, an unusual number. Really, we are SO LUCKY not to have many days like this, kind of a sky pollution, though at present, an unavoidable one. Just be glad we don’t live right under a main, well-traveled airway (though, with predictions of a doubling of air traffic by 2020, we are likely doomed to more days like yesterday when Cirriform clouds are present).
Yesterday’s news, of course, and a surprising development “locally” where measurable rain during the day seemed remote, at least at 6 AM yesterday. But, a blob of rain moved in around noon and gave out 0.06 inches. We’ll take it.
And as you all know, much more rain from our tropical system off Baja is just ahead, U of AZ mod says beginning late tonight and continuing into most of tomorrow morning as you can see here. If you want to see the forecast rain/snow in all of Arizona pile up over time, go here (from the U of AZ). The model is thinking between 0.25 and 0.50 inches here, an inch or so on top of Ms Mt Lemmon. Gut feeling is that we’ll see more than half an inch here from this, with a good chance that it will go beyond noon tomorrow when the mod thinks its all over. Hoping, anyway.
Below, amounts forecast by the U of AZ model ending at noon tomorrow. The model was run on data from last night at 11 PM AST.
Also yesterday, we had a very brief but fabulous sunrise “bloom” illuminating the bottoms of the thick Altocumulus clouds overhead. It looked something like this1: Hoping for same today.
7:23 AM. Year different from 2013.
In case you missed it, here’s what gray skies and light rain look like, falling of course, from that great steady rainmaker, Nimbostratus.
12:31 PM. “Two riders were approaching (under Nimbostratus), and the wind began to howl…”2 Well, OK, one rider. Note rain haze against Pusch Ridge and smoothness of sky due to precipitation fallout that obscures cloud detail. When you saw that smooth sky approaching from the SW, that was the time to turn your horse around and head for the barn, as here.
The rest of yesterday? Blasé. Steady diet of overcast Stratocumulus/Altocumulus clouds sometimes with splotches of virga, and a sprinkle here and there. Here’s pretty much what the rest of the day looked like:
2:01 PM. Two layers of Altocumulus are visible, the lower one on the S horizon beyond Pusch Ridge. Cloud detail (rumples and such) shows that there was no precipitation falling from these clouds. If someone asked you why, you’d say that the layer was not cold enough to produce ice crystals-snowflakes, things that would grow and drop out the bottom. The cloud droplets in these clouds are too small to fall, and even if they did float down and out, they’d be gone in a few seconds because they are so small.
4:46 PM. Creamy-looking Stratocumulus. Sometimes cloud bottoms look this way because of a moist layer overrunning dry and stable air, air that “raggifies” cloud bottoms and wind shear at cloud bottom can produce concave (inverted bowl-looking bases). TUS sounding at 5 PM shows air speed sped up a little at cloud base over wind just below them and wind direction turned about 10 deg from that just below cloud base. Was it enough? I guess so, but not really sure except by sky.
Rain still foretold for Sunday night into Monday morning, followed by a cold blast, but amounts have been on the decline. Could be just a few hundredths to a quarter inch is about all this one can produce.
Clouds today
More interesting scenes today of “multiple layers” as we would call them, and not as widespread as yesterday overall; Altocumulus (and with the wind picking up aloft, a lenticular here and there–look to the NE of Ms. Mt. Lemmon) Altostratus, Cirrus. And, with luck, a great sunset.
Way ahead…….
In the usual model vagaries, absent rain in them after this Monday for awhile, rain has shown up, beginning on the 4th of February. This is a new development in the models for that period. The NOAA spaghetti plots give this system pretty good support–that is, something is likely to approach the central and southern California coast a day or two before our possible “storm” on the 5th. but thereafter, not much confidence for a storm here. So, likely to be on the doorstep for us on Feb 3rd or so as it. Interestingly, it rains for two days off and on here, Feb. 4th and 5th, and the rain follows a trajectory from the Pacific much like we have today, which is always a good sign since the atmosphere likes to repeat itself. You can see the full sequence here.
TE
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1A replica of yesterday’s sunrise since Mr. Cloud-maven person’s camera failed to ingest a memory card prior to a dozen or so snappages. Camera acted like there was nothing wrong!
2That Dylan line would been that bit better, more dramatic, with “Nimbostratus” in it.
(From Dylan’s, “All along the Watchtower”, the best version, it goes without saying, performed by Seattle’s own Jimi Hendrix.)
