This whole situation, in spite of the inclinations seen in “spaghetti”, has gone to pot. Well, actually, to the north more than foretold days ago. No rain is now foreseen here for another week or two.
But instead of discussing in minutiae what went wrong, and why CM fell for it, that is, go through a bunch of hand-wringing about how bad our models are, even with some chaos thrown in (produces “spaghetti”), let us instead change direction for awhile, a diversion really, and consider the two forms of anarchy today: good anarchy, and bad anarchy.
We begin our discussion with an example of “good anarchy”, shown below:
Here, at an entrance to the University of Washington, conscientious citizens exhorting their fellow citizens to be as good as they can be and not break laws. While it was illegal to write on the wall, you can see that they were good-hearted people, ones that might pick up litter as well.
In contrast, below I present an egregious example of quite “bad anarchy.” Please note the clear message by the authorities on the sign at right:
This was horrific, shocking. Here people, but not me, violate a clear edict about walking past a sign with a black pole marking the point you are not supposed to go past. And the violators seem to have no remorse about they have done, but are just kind of ambling along. What has happened to us? Perhaps the woman on the left is bowing her head in shame. Maybe THAT is the only thing we can take away to boost our spirits over this sad scene of otherwise happy, non-chalant acting people in violation of the law. I will never forget this scene.
Yesterday’s clouds
We did have a nice sunset; so many here. Hope you saw it. Pretty much an all daymlollipop lentiular cloud downwind of Ms. Lemmon yesterday, too. Here’s the U of AZ time lapse for yesterday. You can really see how these clouds hover, shrink and expand, disappear, reappear, as the moisture grade changes.
6:45 PM. Altostratus with virga, lit from below due to a distant hole that allowed the fading sun to illuminate this portion of the As clouds and the light snow falling from them (virga).
7:03 AM. Ac len downstream of Lemmon.1:13 PM. Still there.4:43 PM. Some more over there, too.
Its not about hairdressing. Its about the “curl of the low” and its jet stream configuration, as shown here by here (IPS MeteoStar):
Valid for Wednesday, March 20th, 2013. Want to see if anyone reads the captions.
Oh, shoot, this is for a storm and cold blast about 13 days from now! (Secretly, with the storm tomorrow so well predicted at this point by all—might as well show you that it might not be the end of March storms.)
OK, lets try again to get a more timely forecast map:
Oh fer Pete’s Sake. This is valid for 256 h from last night, or the morning of March 18th! But we’re in the curl AGAIN!
Oh, shoot, this ones for 256 h or almost 11 days from last night! What is going on here?
One more try for something relevant, well. its all relevant (suggests we’re in the “trough bowl”:
Finally, valid for 11 AM AST tomorrow morning, this from last night’s WRF-GFS run.
Maps look kinda similar don’t they? Hence, talk about the “bowl” phenomenon where troughs “remember” where they’ve been like your horse does, and they know where they should be. There’s a long fair weather gap between the one tomorrow and the ones later; don’t get fooled by thinking winter’s over.
This last one for tomorrow suggests the rain is either here or imminent at 11 AM AST as the jet core at 500 millibars, is already deployed to the southeast of us by that time. The timing of all of what happens tomorrow is pretty good for rain amounts since with the chilling air aloft (making it easier for air to rise from near the surface), the cold front will blast across Catalina in the later afternoon. This means that the little heating that we will get tomorrow, limited by windy conditions and clouds, will work to plump up the Cumulonimbus clouds in the frontal band–oh, yeah, there should be some, and that means what?
Graupel (soft hail)! Shafts of them, here and there in the frontal band. The presence of graupel, and it’ll be bashing snowflakes and ice crystals on the way down (the latter can’t get out of the way fast enough) means the clouds will get “plugged in”, electrified, due to those collisions because they generate electricity and lightning is virtually certain in AZ tomorrow. Talk about excitement! Cbs, graupel, lightning, a strong frontal passage, strong winds, and a greater than 100-200 percent chance of measurable rain in Catalina! It doesn’t get better than that!
This pattern also favors better accumulations of precip here with the winds being more southwesterly to west at cloud levels. Amounts? Mod, the very excellent U of AZ mod run indicates Catlania-ites will get around half an inch! I am so excited since this is close to the median amount (0.60 inches) forecast from this microphone two and more days ago! Something must be wrong! Here’s the AZ cumulative precip map for Arizona. Look at all the precip in the State, about an inch and a half of liquid expected on top of Ms. Mt. Lemmon! This is going to be so good for our drought.
Valid for 3 PM AST on the 9th. Most of this falls on the 8th, but passing showers add that bit more into the 9th.
Yesterday’s clouds
They were great, such as they were, and before leaving for NM and points east. Take a look:
6:56 AM. I wanted to hug these little Cirrus uncinus clouds. So cute, just trying like anything to make a little snowstorm to water the ground. Just look at those long tails!
7:47 AM. Then you got to see a Catalina lenticular cloud. How nice was that? Note parhelia on the right.8:04 AM. A nice, patterned Altocumulus perlucidus translucidus.
All in all, I thought it was quite a good day for you. As usual, thinking about others here.
Today’s clouds
Today we’ll likely see some precursor Cirrus, maybe a flake of Cumulus here and there. I will predict more clouds, if necessary, as they occur.
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?
—————————
1Deadlines have a way of getting in the way of “truth.”
I’m not missing any of this. Its too good. Supposed to rain off and off until the frontal blast about 10 AM -Noon, then clear up for awhile, then scattered showers develop from what will be icy looking Cumulus and small Cumulonimbus clouds, kind of the usual storm chronology we have here. This sequence shown in the U of AZ model run from last night is here, and its been well-predicted by the media weather folk as well. Don’t watch TEEVEE much, but I did catch some bits and pieces by George. It was pretty comprehensive, quite good really, and then I started to feel sad. Why am I doing this, blogging about weather myself when its already out there???????????????????????? Oh, well.
It will be interesting to see if there is more than a few flakes of snow as the front goes by, the rain becomes moderate to briefly heavy, and that’s when the precip will start to have ice in it, maybe turn to snow for awhile due to a diabatic effect where the snow level comes down due to big melting snowflakes dragging it down. An early morning frontal passage would have been better for the best snow accumulation, but, oh, well.
Still looks to be an appreciable amount here, both eyeballing the situation and in the U of AZ mod run from last evening. From this keyboard yesterday, the best estimate for this storm that just kind of popped out was 0.450 inches (the median between a lower limit of 0.20 and upper one of 0.70 inches). Since “we” last wrote, the U of AZ model has increased its precip for us, as though it was affected by something I said. The green “half inch” region has crept that bit closer to Catalina in this latest run below over where it was yesterday.
Accumulated precip for the 24 h ending at midnight tonight.
And we’ll need as much rain as we can squeeze out of this one as the follow up series of storms foretold so long ago in the mods have disappeared–shown during a time when our “truth viewer”, those NOAA spaghetti plots were down for a few days, or they might have tipped us off to be more “circumspect” about a run of storms by showing that they were not reliable predictions. No further rain is forecast for the two weeks after this now! Dang!
The intermittent rain that has been falling is WAY ahead of the front, over there by Yuma as I write at 4:41 AM.
Its developing in the moist flood of air that rushed in overnight at lower levels along with a huge icy shield overhead, no doubt a thick Altostratus with virga on top of Stratocu, maybe dumping some drops into the lower cloud deck. Need more of that.
——————Learning module———————–
The effect of rain drops falling into a lower layer of Stratocu?
If you dropped a cup of water on the top of the layer yourself, the amount coming out the bottom would be more than a cup. Those fast falling drops, about 5-10 meters per second, say for regular raindrops, collide with the itty bitty cloud droplets blowing sideways in the wind. The larger cloud droplets, say bigger than 20 microns in diameter, collide and stick to the fast-falling raindrop, adding to its size. We call this accretion. That bottom kilometer of storms where otherwise “harmless”, non-precipitating Stratocu is likely to be, is critical for appreciable snow and rainfall due to this process in mountainous regions. Almost always, the impression is that its the Stratocu that’s precipitating, but usually its not. So, when you see a raindrop fall, thank a Stratocu deck for making it that bit bigger, thought in some cases to increase precip by 50% due to the effect of accretion in the bottom kilometer (3300 feet).
Might look like this if you could step back to the south of the Catalinas today and draw a crummy cartoon of what was happening, but it was the best you could do at the time
From a 101 class I taught at the U of WA, with modifications to show I am in Catalina, AZ. Background: couldn’t get the real guy to teach that class that summer, and so I was enlisted to do the job at the last minute, thus lowering the accreditation rating of the University of Washington. You see, I have NO ADVANCED degree of any kind, and to have a lecturer without the big Ph. D. means you go DOWN! On the other hand, unlike most faculty at ANY university, I have been asked my opinion on something and was quoted about it in the Wall Street Journal in 2011! Oh, yeah, baby! Wanna spike a football right now! Credentialism; a bunch of hooey (sometimes).
————end of learning module and statement on credentialism aloong with a display of immaturity—————
Back to the storm…. After a couple of light and brief showers, we have amassed 0.01 inches! Only 0.44 inches to go to make a perfect prediction!
Yesterday’s clouds
Kind of a bust, really, and admitting that will make up for some exultations above. Sure, there were some Altocumulus with virga hanging down, but those virga trails needed to be about 20,000 feet longer to be anywhere near where I thought they would be. And then it cleared off almost completely during the afternoon! Oh, well. Pretty day, with lots of wind and mild temperatures. Here are a few shots:
6:55 AM. Altocumulus floccus virgae–has virga. These were up around 20,000 feet above sea level, or about 17,000 feet above ground level here in Catland. Top temperatures with all that ice falling out? About -26 C (-15 F).7:12 AM. Ditto.9:46 AM. More of the same but less.
6:25 PM. After a clear afternoon, a vast shield of Altostratus/Cirrus advances on Catalina.
…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!
“Sixteen hundredths”, originally a song by a boy group of that day so long ago, The Crests, about a light rain that fell in May in southern California, an event that is quite rare and exciting at that time of the year there. But then practical and marketing considerations caused the song to be revised to one about candles of all things. How odd. I thought you might like to know some reliable history behind that venerable song, one that made us cry, it was so sweet, and think about, as boys, how much we liked girls when WE were sixteen or so.
Yesterday, while Mr. CMP (“cloud maven person”, but using acronym in trying to be as indirect as possible here) was making some fun of students mixing up units in their calculations of pressure at various heights in the atmosphere, he himself was mixing up cloud “units”, by informing his reader that cumuliform clouds, some dropping graupel, would be seen over Catalina yesterday, not stratiform, sky-covering Altocumulus, followed by great masses of Stratocumulus underneath it, combining later with gray, dank, Altostratus, a scene that finally evolved in the mid-day hours into Nimbostratus with light rain, sometimes with light snow mixed in! Briefly, too, it was ALL “surprise” snow!
The total, 0.16 inches, was also about sixteen times more than CMP thought would fall from that perceived marginal weather producer. (Note: the U of AZ local model’s 11 PM run the night before had it predicted perfectly! However, in some kind of bloated self-evaluation of skill levels, CMP did not consult that model until it was “too late.”) Today, I am quite confident, however, that I really don’t need to look at that model…
What is going on here? Fallibility, I calls it, human fallibility. Remember that old saying about pencils with erasers at the end? So simple and yet, profound.
Oh, well. All’s well that ends well, and the “well” ending was one of a nice little rain mixed with snow (will burn your CMJ tee if you refer to rain mixed with snow as “sleet”!) and beautiful snow down on the Catalinas, so pretty yesterday evening as the clouds lifted.
Today a fine day with small Cumulus clouds, very photogenic again as this kind of wintertime day is here. The mountains should be spectacular, too, due to the cold air that remains that will allow them to be white down low for a few hours this morning.
Precip totals from the U of AZ rainlog.org network here and the national CoCoRahs org here for AZ totals. The measrements at rainlog will indicate that they are for yesterday, the 11th, while the CoCoRahs convention, to assign the rain to the date it was reported, will show the totals for our storm using today’s date, the 12th. You’ll have to wait until about 8-10 AM to get most of the loggers’ reports.
The most I saw in the Pima County gage network was 0.43 inches, an amazing amount, down in Avra Valley. Shocking, really.
BTW, the cloud regime that CMP foresaw for Catalinaland was just to the west of us, around Ajo, AZ, not that far away astronomically speaking. And at sunset yesterday, you could see those Cumulonimbus clouds on the horizon coming into view.
5:53 PM. The forecasted Cumulonimbus clouds for Catalina begin to come into view. I wish I could make this image bigger, maybe in 3-D so you could “feel” this cloud coming at you.
To cry-baby about it a bit more about a missed cloud forecast, this “visible” wavelength satellite image:
1:45 PM AST.
Some un-Cumulus scenes from yesterday:
10:30 AM. Altocumulus perlucidus undulatus and Stratocumulus begin overspreading the sky.11:41 AM. Dark bases of Stratocumulus-Cumulus line up with the wind and head toward Catalina. Virga spews in the distance on the right. Above these clouds was an icy layer of Altostratus.11:58 PM. Mounding tops of Stratocumulus or embedded Cumulus become infected with ice and spew forth virga. Now under this guy, there may well have been a couple of graupel. Above these clouds was an icy layer of Altostratus that helped impregnate the lower Stratocu and Cu with ice, kind of like seeding them.1:17 PM. The lumpy and dark looking bases had disappeared in the virga and snow falling from the thickening Altostratus layer as it became, Nimbostratus. What you’re looking at here is a classic example of snow melting into rain that appears to be the base of the cloud, but its really a transition zone that reveals the snow level.3:14 PM. Snowing hard in Catalina for a few minutes. Here’s what it looks like, coming down at you. Some aggregates of snowflakes were more than an inch across.5:42 PM. The result of our little storm on the Catalina Mountains, Samaniego Ridge.
The weather ahead into March
Gotta ride the storms, ones already predicted as of yesterday here over the latter half of this month. Never good to “yo-yo” on a forecast, as forecasters will tell you.
However, not getting help again in this longer range musing from the NOAA ensembles of spaghetti; site is still down, so riding bareback here so-to-speak, using a western idiom (or is it “idiot”?) In sum, Arizona to end up with above normal precip when whole state considered. This due to being in the bowl, the trough bowl, though breaks in storms, and nice weather, sometimes for several days at a time, will try to fool you into thinking you’re not.
Going farther out on a limb, twig, really, looks like the active storminess will continue well into March. We seem now to have a wet pattern going, though in a desert, its not THAT wet compared to Washington State or elsewhere. Stand by for occasional updates. Am excited for wildflowers now; there may be some!
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….
CS3 preview: its got rain in it, likely also our first real good windy day in awhile. In sum, a real action packed, thriller of a day coming. Don’t miss it!
1. We didn’t get the odd cloud bases yesterday. That lower undercutting layer of…..Altocumulus clouds (of course, you knew what they were) below the icy Altostratus clouds was too thin, not embedded in much wind shear, so the hoped for weird cloud bottoms didn’t materialize though there were hints of those concave bases off to the north late in the afternoon.
2. Since I was disappointed that really weird cloud bases didn’t show up yesterday afternoon, instead of showing the clouds that did show up right away, I thought I would annoy you first with a public service message:
“Arizona reminds drivers that when you see a sign informing you that you are on a DIRT road, that the speed limit is often no more than 15 mph.”
Sign near Red Rock.
Yesterday’s clouds
Here are the clouds that did show up yesterday, pretty much as the U of AZ model predicted:
12:50 PM. Your heavy mid-day Altostratus opacus virgae with virga.3:13 PM. An undercutting layer of Altocumulus clouds overspread sky rapidly from the west. Starting looking for strange cloud bases here.4:24 PM. Altocumulus undulatus. Actually there are two layers of Ac, and a full sky description would add the word “duplicatus”, used when more than one layer is present. I am not kidding.Ocean swells coming ashore near Monterrey, CA, in case you have never seen the ocean, breaking waves and swells. These are unusually large and were due to a giant low center off the Ca coast. Cirrostratus and Altostratus clouds, with flakes of Altocumulus droplet clouds, are present.6:09 PM. With the Altostratus now gone, a hole in the clouds allowed this brief rosy “bloom” in the remaining Altocumulus clouds. The higher layer sported some virga, and some remnant virga can be seen in the center of the photo.
Since there were sprinkles around Catalina last night, you’ll want to check your “trace detector”–a car parked outside overnight with a coating of dust on it–for drop images in that dust. I hope you didn’t forget to keep your car outside last night, as good CMJs do in possible sprinkle situations that you might otherwise miss. Happy to report a sprinkle here last night.
Today’s clouds?
Residual Cumulus and Altostratus, some Altocumulus (now that I can see them) patchy Cirrus, clearing out later in the day.
Cold slam3, the sequel
Valid for February 9th, 5 am AST. Precip is shown in the lower right panel by green coloration, and its over us, which you can see if you take out your microscope.
Saturday, February 9th. Precip looks substantial, likely MORE than half an inch here in Catalina should Canadian GEM model, shown below, verify.
Rather unsettling is that the USA! WRF-GFS, our best model, has virtually NO precip with this cold blast. When two numerical model outputs are so different the term thrown around is, “model divergence”. However, since “wetter is better”, a kind of non-viable theme here, I am now going on record as foretelling at LEAST 0.15 inches, top amount 0.60 inches, beginning on February 9th. This is the sports-like part of weather forecasting, riding the models, seeing how they change in the days ahead, and whether you get the amount you foresee, around a third of an inch median amount.
What is ASSURED for us here in Catalina is the cold blast, with or without liquid refreshments. Check this NOAA plot below out:
Valid for Saturday, February 9th. A cold spell is ASSURED! Check out that HUGE cold bowl over the Southwest US. No confusion here!
The End, unless I think of a correction or addendum, which seems to happen every day!
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).
First rain drops here at 3:30 AM. Checked sat images and they’re looking about as good as they could for us, clouds to the southwest of us, curling around that little upper level low center like a boa constrictor, buckling, and dragging all that tropical air toward us. You can see that here in a loop of the satellite imagery from the U of AZ. and take a look just off Baja and in the Gulf of California.
4:10 AM AST, the latest I got while doing this blog–I can’t keep updating it or I’ll never finish. Updating is up to you now. Thanks.
Cloud bands curling around the center and the center heading this way? Its as good as it can get for us, and means the rain bands should be pretty potent. Some Cumulonimbus clouds can be seen in the sat imagery, too, in the main rain band. Looks like it will take about 8 h for the main part of this to go through, too, with passing light showers into the afternoon and evening. So, light to moderate rain for maybe 8 h should lead to around half inch to an inch. Yay!
Paulden, near Prescott, has, as of 4 AM AST, received the greatest amount, already recording 0.95 inches. You can see the statewide totals at the US Geological Survey network here. The Pima County ALERT gage data are here, with the first measurable rain being reported at 4 AM AST. With southerly flow at mountain top level, the south sides of the Catalinas will likely get the most from this storm compared to Catalina townlet, Census Designated Place, proper. Hoping for some lightning, too, today, as there are some Cumulonimbus clouds in the main band here and there.
The best part of this situation is that most of Arizona gets drought-reprieving rains over the next 72 h, counting today, with the models thinking that all of this may amount to several inches of water in the mountains of central Arizona where its so badly needed. And with just this ONE storm sequence, January will come out looking like a decent rain/snow month in the record books.
Model musing….
In the model prediction business, today’s rain was not even seen at first while rain on the 28th has been there for at least 10 days! Then, rain began to show up today, Saturday, about 5-6 days out, but it was hardly anything at all–wasn’t even mentioned here the first time it did because it seemed so tenuous.
But look how reality has turned out! This little circulation from the sub-tropics is certain to dump more precip than the storm on the 28th, the one so long foretold. I guess this is why we weatherman like weather. The unknowns, the surprises, are still pretty great.
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4:30 AM. First hundredth of an inch, off to slow start, but like that legendary horse of old, Silky Sullivan1, should end in a hurry.
Yesterday’s clouds
7:24 AM. Rising sun illuminates the bottom of an Altostratus mammatus layer.
11:16 AM. Thickening and thinning skies all day until late, brought sunny spells as here with thin Altocumulus perlucidus.
4:18 PM. An unusual site. See note messing up photo. I worked pretty hard on it, though an english language-maven might find fault in it.
5:16 PM. Close to sunset, and almost an exact replica of the day before at this time with an overcast of Altocumulus opacus clouds. No sunset “bloom” seen, but a brief hole allowed a golden illumination of the Catalinas for just a minute or two–next photo.
5:40 PM. Charoleau Gap orangified by setting sun peaking through….through…a hole in what? Ans: Altocumulus opacus, in this case droplet clouds with little or no ice whatsoever. You didn’t see any virga did you? (“Gritty AND pretty”, $1,025)
Quitting here–haven’t even looked at models (oops, except Canadian–just remembered that; just eye-balling stuff, but this piece, long enough!
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1Hardly a person alive then in the late 1950s did not know of THAT horse, yes, just a horse! Check the video for something truly amazing! Silky Sullivan gave hope to all those that fall behind. His reputation lives on.
