Altostratus clouds – Page 10

Smoke and mirrors in the models; fire in the sky

For those of you who have forgotten that heavy metal pioneering band, Deep Purple, and their hit, “Smoke on the Water”, to which this post sort of alludes to, straining really, take this. It was kind of fun to see this “songumentary”, because it was about something that really happened. In a line out of Spinal Tap, the parody heavy metal band, one review considered Deep Purple, “the globe’s loudest band.” How funny!

Here’s the “fire in the sky” at sunrise yesterday, and in case you missed it. Fabulous blaze of fire underlighting those Altostrastus clouds with their snow virga.

Then, in the afternoon, we had these sky gems; Altocumulus clouds, mostly of the floccus and castellanus varieties, some shedding ice in what up there would have felt like snow flurries. For those three of you who follow this page, you can guess immediately how cold those ice-shedding Altocumulus clouds were: colder than -10 C, and probably colder than -15 C without even looking at a temperature sounding.

The weather ahead; discouraging.

The models have been gradually reducing the chances of rain since the last blog about rain ahead, and when they do show rain on or around February 7th, its been reduced from what was once going to be a substantial period of rain to a minor event. Hence, the models have truly come up with “smoke and mirrors”; looks real but its not.

Rain at the end of the tunnel?

Finally, the dark tunnel of pleasant, dry weather may be coming to an end, I am happy to say. The WRF-GOOFUS model longer range output has been showing RAIN in southern Arizona for two or three runs out around the 7th to 14th of February. Of course, those who follow this blog know that RAIN predicted in southern Arizona that far away is like the square root of -1. It doesn’t really exist; its imaginary. Still, it COULD happen, and you get a little more confidence when it shows up in more than one model run. The USA! WRF-GFS model is really very good out to about five-seven days, but gets “goofus” after that, you almost always can’t rely on what it says with rare exceptions. But, that having been said, remember that our models are still a lot better than economic forecasting models. Think of the unforeseen “black” stock market days that come up! Q. E. D. They don’t know what the HELL they are doing over there. Just kidding.

Below, some happy thoughts should accrue from viewing the images below if not already in place due to coffee. Think of flowers. And, if you’re like me, you’re happier overall and feel better about yourself thinking about a future rain in a desert region. Below, what the WRF-GOOFUS model thinks February 12th will look like, based on thinking done on last evening’s (5 PM AST) global data. This is so good I have reproduced TWO renderings from IPS Meteostar for that day. It can hardly get ‘”greener” (show more precip) in the entire Southwest than what this storm is supposed to do on February 12th, and we even see some dark “green” (heavier rain), turning into blue (even heavier rain) in southern Arizona in this sequence. Streams would likely run in places in southern AZ with this overall scenario. Its a great thought!

BTW, the later model run, just six hours after this one (based on 11 PM AST data, but whose awake then to take good obs and there aren’t that many anyway?) took a lot of this rain away and so I didn’t want to show it because its who I am. (hahahaha, sort of)

On a more mundane level, another fabulous AZ sunset last evening caused by…..what kind of clouds am I? Moslty Altostratus (really thick all or mostly ice clouds) and Altocumulus (mostly droplet clouds far horizon and very thin). See far below.

The End.

Pomp and circumstance, but only a hundredth

“Pomp”, in the form of some thunder and lightning, and a few hail stones between 10 and 10:30 PM AST; “circumstance” with a pretty strong trough going by. But they only delivered a hundredth of an inch of rain at the ground here in Catalina. I guess the bugs will be satisfied, but it was a tiny bit disappointing to me. Was hoping for TWO hundredths. The U of AZ computer model did a nice job foretelling a tenth or less of rain. The most rain reported around here is 0.12 inches way up in the Catalina Mountains at CDO and Coronado Camp.

In case you missed it, here’s when and where the lightning occurred from Strikestar-Astrogenic systems. The last panel, lower left, shows those surprise lightning strikes that occurred around 10:15 to 10:30 PM AST last night. BTW, these folks have the best presentation of lightning occurrences that I have been able to find, one that includes non-ground strikes.

Now its sit and wait in the sun for maybe two weeks or more for precip. The closest thing to a storm here in the next FIFTEEN days that the models (courtesy of IPS Meteostar) are showing is this very strong upper low and trough that, as shown below over the Four Corners area, passes by too far to the east of us on February 1st-2nd to be considered a threat.

This system been showing up on the models for days and days, sometimes as one that can bring rain here, but it hasn’t been shown that way lately in the models. The fact that it has been persistent as a feature that affects the Southwest is a good sign that something major will pass by us in early February, and at the least will bring quite a chill whether we get precip or not.

In the meantime, we will have to be content with a long, long stretch of a sunny weather malaise, where almost everyday is perfect for a winter day.

Clouds?

Here are some from yesterday, and again, a great, late-blooming sunset. Almost gave up on it happening. First, the nice strand of Cirrus yesterday morning that heralded the thicker layers behind it and shots of those multi-layered clouds consisting of Altocumulus, Altostratus (the smooth one), and then the sunset “bloom.”

The End.

“And I think its going to rain today”

Well, how can we forget that mournful Leonard Cohen song? And the sweet rendition of that tune by Judy Collins? It was played a lot in Seattle, of course, where I’m from. But, it also looks like it might be apt for late today right here in Catalina. Check out this “incoming” here from the U of AZ Weather Department’s model output here. This loop of rain areas will show you how the precip creeps toward us during the day, eventually overrunning almost the whole State of AZ. “Oh happy day”, to quote another song title. Just hope we get more than the tenth of an inch the model projects, all of which falls overnight tonight after midnight. (Hmmmm. Seems a little slow to me.)

Here’s a loop of satellite imagery and the surface pressure maps for the past 24 h from the University of Washington. The interesting thing about these maps, is how one hurricane-like center with lots of isobars off the Pacific NW coast crashes into British Columbia while a new low develops off the California coast and is now pummeling central and southern California while heading to the southeast and toward us. Reminds me of someone getting a “spare” in bowling by knocking two widely separated pins to the left and right to get it.

Why would storms divide in their paths like that? You have to look aloft at the steering by the jet stream. Low centers separating like that always means there is a split, a dividing point in the flow. Higher level pressure maps from the UW shows that. Below is a 300 millibar pressure map (about 9 km above sea level or around 30,000 feet), a level where the jet stream is just about the best developed. Notice how part of the flow whirls around the big vortex in the northern Gulf of Alaska and toward BC, while a more powerful branch dips toward California. Its that trough, that bend in the winds just now off California, that will come barreling through here tonight bringing that surface low center now near SFO with it–well, what’s left of it after it gets wrecked by mountains. The next chance for rain/snow is in early February.

Nice clouds again yesterday. Here are a few shots, including another nice sunset. The haze you saw was dust, leftover from the strong winds of the previous day in western AZ. The first, Cirrus over dust. The second, some Altocumulus with Cirrus, and finally, Altostratus with some under lit Altocumulus in the distance.

Twice as nice; 0.53 inches in Catalina (0.58 inches as of 6:39 AM AST)

What a superb rain that was last night. It just kept coming until finally we piled up an astounding-to-me 0.53 inches by 4 AM this morning. The regional rain reports from around Tucson can be found here. As you will see, the upper regions of the Catalina Mountains got around an inch (1.22 inches at CDO wash at Coronado Camp now). Mt. Lemmon probably got a little more, but the record says “0.00” due to snow at that elevation. This is a substantial boost for our emerging spring desert vegetation after our four week drought. This is so much better than that near rainless January of last year! Looking at some of the statewide precip reports, it looks like the Catalina area and the Cat Mountains got more than anywhere else. Lucky us.

If you would like to relive yesterday, at least in clouds, go here to the U of AZ time lapse. One of the things you will see later in the day are Altocumulus lenticularis clouds over the Catalinas. You will see their upwind edges spurt upwind (seem to go the “wrong way”, against the wind) as the lifted air got more moist, one of the tricks that these clouds can pull. You will see quite a panoply of clouds in this movie, from Stratocumulus, Altocumulus, Altostratus (dead gray and smooth higher layer), Nimbostratus (when the rains come) along with some mammatus formations. Hmmmph. There’s that “m-word” again, the one I used so many times yesterday. Wonder what’s going on?

“But wait, there’s more!”

If you call now (well, actually if you continue reading) you’ll find that a few more hundredths of rain are possible this morning before about 8 AM AST, AND, (We interrupt this blog for an important message: “hey”, just started raining again now at 5:03 AM! Yay!)

all of the model runs are indicating rain again on the 22-23rd timeframe; even the “pernicious” 00 Z run from the 5 PM AST global data. (I have questioned that output of late, rationally or irrationally, because it kept drying the State of Arizona out whilst the model runs before and after that time, foresaw precip in spades in the State.

Here is a sample of the IPS Meteostar renderings of what happens in our rain window of the 22-23rd according to our latest model run, one from 11 PM AST data. Note green areas of precip in the 6 h ending at 5 AM AST, Jan 23rd. This is pretty satisfying since another good rain will keep us on track for a great spring bloom.

On other fronts…

While I could go on to talk about all sorts of things due to the ambiguity of the subtitle phrasing above, I will actually only talk about weather fronts, not this or that.

The coming floods in northern Cal-Oregon still on track. Storms break through from the Pacific “under” the Bering Sea “blocking” high, one that diverts the potent Asian jet stream that comes into the Pacific into two branches, one of which is forced southeastward in the central Pacific where water temperatures are warm. (Just heard some rain on the roof again. What a nice sound that is!) The other branch goes deep into the Arctic and merges with the southern branch in the eastern Pacific after it turns southward over AK.

Those warmer storms, heavy with semi-tropical rain clouds, race to the West Coast once the southern jet breaks through the weakening southern part of the blocking high. And once that jet stream has broken through, its days before things change, so the duration of rain adds to the colossal totals certain to occur now. In a ten day span, beginning tomorrow, the peak totals in this event will likely exceed 30 inches of rain.

Here is the current weather map (5 AM AST today) from the University of Washington that illustrates the odd flow pattern developing now from the central Pacific to the western US. The block is developing from a ridge in the eastern Pacific now (evidenced by the lack of green contours in it) that extends from the tropics all the way to the Bering Sea! It will fracture in its southern portion tomorrow. It has overextended its “reach”, in a manner of speaking, at this point, and will fail just like a dam break and all those clouds to the west of it will flood eastward. Its a pretty exciting thing for us precipophiles.

Canadian behemoth

One particularly bruising storm, one the size of Asia practically, with “tentacles” from the Aleutian Islands to Minnesota, was shown to develop in this series of storms battering the West Coast in the European model run by Environment Canada based on last night’s data.

I show this output below because you RARELY see a low whose circulation is this big, at least one of the biggest I have ever seen, portrayed on a weather map (upper right panel). The map below showing this colossal low is valid for the evening of Jan. 21st. The entire West Coast would be battered by this bruiser.

The End.

Pretty and eerie skies yesterday; let the rain begin today

Here are some examples from yesterday’s pretty, then toward evening, eerie skies with sprinkles, the latter due to backlit Altostratus opacus mammatus, to go the whole nine yards, an icy cloud with downward hanging protuberances that resemble something. I’ve reduced the size of that image accordingly. Below, in sequence, 1) Cirrus, 2) Altocumulus, 3) the incoming bank of Altocumulus with Altostratus clouds on the horizon late yesterday afternoon, ones with virga and mammatus; 4) the mix of Altostratus with virga and mammatus with Altocumulus after it got here, and finally, 5) that eerie scene last evening of what I would surmise was a sunset colored layer of Cirrus above the Altostratus clouds with mammatus that gave the Altostratus an orangish tint. I seem to be thinking a lot about mammatus formations today. Hmmmmm. Oh, well the CLOUDS were nice, and I guess you might say, our official cloud names a little suggestive. For the full fascinating day, go here to our great U of A time lapse movie for yesterday.

All of these clouds are emanating out of and around a low that a week ago, in the models, was supposed to have already gone by. Well, what’s left of it finally goes over us today, kicked out of place by a quite rudely interjecting jet around a cold trough in the NE Pacific and over the Pacific Northwest.

Here is a satellite loop from the University of Washington showing those clouds that went across yesterday and those similar versions that will be crossing our Catalina skies today, ones that are coming deep out of the tropics. You’ll want to crank up the speed button to really see what’s going, at the upper left of this loop. The mods have been seeing a bit more moisture with this upper level low (doesn’t show up on the surface maps at all) as time has passed and so maybe we can wring as much as a quarter inch out of it. Here’s what the U of A Beowulf Cluster has to say about the incoming rain amounts. These amounts, up to an inch in the mountains, would be fantastic and very satisfying considering the long dry spell. The best chance of rain is overnight, so we’ll have lots of pretty clouds, probably a lot like yesterday, during the day before the really thick stuff moves in.

The ominous aspect, though VERY exciting to us stormophiles, is, when you review that satellite loop from the Washington Huskies Weather Department, is the accumulation of clouds and storms in a long belt just north of the Hawaiian Islands. Take a look! In just a couple of days, those clouds and storms will begin streaming toward the West Coast like a dam breaking, impacting most heavily, northern California and Oregon with tremendous rains. You will certainly read about those rains! From experience, I can tell you that the most favorable mountain sites for rain will likely receive 20-30 inches of rain in just a few days as this pattern develops and matures with one strong low center after another racing across the lower latitudes of the Pacific under the soft underbelly of a blocking high in the Bering Sea.

Man, I want to be in the King Range/Shelter Cove area so bad! Let’s see, fly to SFO now, rent four wheel drive vehicle for forest back roads in the King Range, bring rain gauge, sleeping bag, tent for camping out and listening to 1 inch per hour rain intensity on tent roof. Hmmm….. Its doable. Maybe all of us should go there today, get set up, and then wait for those pounding rains with 50 mph plus winds. That would be great!

And the ocean waves will be something to see, too, along the Oregon and northern California coasts, thundering surf really. Been there, seen it. And believe or not, there are surfers who come to the West Coast for just these situations, the long tropical fetch that generates huge waves. And there is even a small cadre of folks who race to the coast just to see that thunderous surf. All very exciting. Well, kind of getting distracted here, and a little nostalgic. Those big rollers would look something like this.

Also, since I have doubtlessly piqued your curiosity about Shelter Cove and the King Range, below a shot of the King Range from Shelter Cove, a shot in the King Range, looking toward the highest peaks, and finally, an example of the people of Shelter Cove.

Now, where was I concerning Catalina? Oh, yeah, mods have more rain ahead, though we’re only sideswiped by the powerful storms affecting Shelter Cove. Best chance for the next rain is on the 21-22nd.

In sum, today’s focus, or more accurately, preoccupations? Mammatus and Shelter Cove, CA.

The End.

Models warming up to rain; some cloud shots from yesterday

Been kind of sitting around waiting for the billions/trillions of numerical model calculations to get it “right”, that is, to come back with some decent rain SOMEWHERE in Arizona after some pretty sad dry model results over the past couple of days.

Today, the great USA WRF-GFS model (rendered by IPS Meteostar) finally got it “right” by showing rain over Arizona on at least three days during the next 15 when it examined global data from this morning balloon, satellite, surface, aircraft, personal weather stations, rumors, TEEVEE weather presenters’ data, etc. Here are the days on which rain is shown in our great state, a state that ranks 21st in objective measures of subjective happiness by US State. The first rain is just this Sunday afternoon and evening, the 15th. Be ready. This is from the cutoff that got lost off the coast of Baja, one that was a week ago the models foretold that it was supposed to be over Catalina today! Unbelievable. It was only off by a 1000 miles.

The second AZ rain day is Saturday night into Sunday, the 21st-22nd. This rain is only supposed to stay north of about Phoenix. That’s OK. That’s followed by a much heavier burst of precip on the night of the 23-24th, again mostly north of us (3rd panel). That’s OK#2. We benefit when the rain and snow falls in the north, too.

Lots to look forward to!

BTW, when that Pac jet slams the West Coast from the central Pacific, starting next Tuesday afternoon, it will cause a lot of excitement for weatherfolk and plain folk as floods develop over the following few days in northern California and Oregon. In some places in northern California it has been as dry as the Great Drought of 1976-77, which was dang dry along the whole Pac coast. They’ll soon be “exulting-complaining” about all the rain filling up the reservoirs and washing things away, respectively. Watch your local newspapers.

Yesterday’s clouds (see below)

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What a great, if a cool day it was, to watch Altocumulus and Altostratus pass by. There were a number of places where it looked like an aircraft may have created some virga in supercooled Altocumulus clouds, but lots of natural mammatus type virga, too. You can see the whole day go by from the U of A campus time lapse camera, pointed at the Catalina Mountains, here. That small hole in the middle shot was likely caused by an aircraft, the ice from that passage, long gone. And, of course, there was the superb sunset! How nice it is to be here.

While waiting for a “better” numerical model output….

As we say, “if you don’t like the model run now, wait 6 h and get a new one with different results.”

Last night’s model run based on global data taken at 5 PM Arizona time, was truly mediocre in rain in Arizona in the week to two weeks ahead. Sure, great storms bash northern California, where they need rain desperately this year, and Washington and Oregon as well, ones that are likely to make the news, the jet stream was again retracted to the north in that run. Take a look at this, courtesy of IPS Meteostar for Sunday, January 22nd and notice where the reddish area is compared to the output I showed yesterday (below). The impacting jet stream is now centered over Portland, Oregon, fer Pete’s Sake! Its outrageous. No rain is imminent here with a map like that! We’re on the wrong side of the jet stream as anyone can see. Just yesterday, we had the kind of output from global observations that showed the Pacific jet stream (JS), this on model calculations from only six hours earlier than the output shown in the first panel. As you can see, in that slightly earlier run, the JS is shown bursting into California at almost the exact same time on January 22nd instead of into Oregon. That second panel was loaded with rainy portent for Arizona (see last panel)! So, its worth checking into IPS Meteostar, a weather provider I favor for their nice imageries, later today to see what the 5 AM AZ Time global obs say.

Why do these fluctuations occur that prevent confidence in weather predictions more than a few days out? Well, we have a reason: “bad balloon.” (Or “missing balloon.”)

While small changes in initial conditions in themselves can cause vast changes in model outputs many days ahead, sometimes these problems are caused by errors in measurements and probably more often, missing measurements in the global network. The models then have to guess what is happening in the missing data regions, usually with the help of satellite measurements, and/or use the prior model run’s prediction of what was supposed to be in the missing region.

I am getting the impression that the quality of the 00 Z runs are not as high in reliability 1-2 weeks in advance as those at 12 Z.

In the meantime, while waiting for a new more better model run, a word about today’s clouds…

Right now (8:44 AM AST) we have an overcast layer of Altocumulus (Ac) with patches of Altostratus (As) clouds. The former are mostly composed of droplets while the latter are ice clouds. The TUS sounding indicates that the Ac layer is based at -20 C (-4 F). Those Ac clouds are ultraripe for aircraft produced ice, and right this minute, I would say that much of the virga around is due to aircraft on those “supercooled” clouds. This is particularly evident if you see straight lines of virga, or a hole with ice in it. Here’s a line of virga (those downward hanging protuberances called “mammatus”, to the SW of Catalina right now that looks suspiciously like it may have been produced by the passage of an aircraft through some Ac. That passage would cause tremendous numbers of ice crystals to form, and then fall out as fine snow we call virga.

Grandson of “Frankenstorm” knocking on Heaven’s door (Catalina, Arizona)

Well, I think Catalina, AZ, being next to the Catalinas, is “Heaven’s door”. I think, too, to have a second consecutive thought, that we’ll get more than an inch out of this Big Boy which is rare here in Catalina for a storm in the wintertime. Not close in areal extent to the original “Frankenstorm” that struck the West Coast in January 2010 with record setting low pressure, but a potent one anyway. In the January 2010 storm we received 1.41 inches the first day and 1.18 inches the second to “ice” a fabulous wildflower bloom that year. We sure seem headed to a fabulous bloom season this year, too.

BTW, there has been a lot of rain in droughty Texas. We are brothers/sisters in drought relief it seems these days. How nice; adds to the holiday cheer. Maybe the price of hay will go down.. It seemed interesting to throw something about Texas in there. Here is a map showing that great TX rain of yesterday from WSI Intellicast¹. These radar-derived amounts precipitation are pretty much spot on–I’ve checked ground gages a number of times. We should be seeing “green”, 1-2 inches) over much of AZ in the next couple of days, too. So, the map below is like a preview for AZ.

Speaking of green, look at the “green-for-rain” in AZ in the lower right hand panel of this forecast for this afternoon ending at 5 PM MST. During the prior 12 h, beginning at 5 AM MST, the entire State of AZ is virtually covered. I am just beside myself when I see a map like this! And look how far to the south of Baja California the circulation of the storm extends. Its gorgeous to see this. I guess there could be some flooding here and there, and some “snow birds” might complain about the “crummy AZ weather”, but….you can find people who will complain about anything. See the whole wonderful model sequence of rain and mayhem in AZ here, and in much more detail from the U of A weather department, here.

Look, too, at how excited the National Weather Service, Tucson is! They must have 50 bulletins out–be sure to keep reading them. They are really having a lot of “fun” down there, too.

Late breaking storm bulletin: We have sprinkles in the area (0425 LST). Check this radar-cloud map out from IPS Meteostar. What a great day this is going to be! Enjoy. Good chance we’ll see water in the CDO and Sutherland Washes, and maybe some snow mixed in with the rain as the storm closes out Tuesday evening now.

But is this storm the end of our “fun” weather? Oh, no, my friend. Another cut off low develops in our area after speeding down as a trough out of the NW in five days. Another round of significant rain is likely, though not as much as this one.

Some cloud notes from yesterday, including some chat about the unusual streaks.

In that warm afternoon yesterday, it was so great seeing sheets of Cirrus and Altostratus (ice clouds, Altostratus with heavy shading) massing on the horizon, knowing that this time it was NOT just going to be a sky decoration for a nice sunset, but were clouds filled with stormy portent. You probably noticed the lack of sunset color due to the extensive coverage of those clouds upwind. No break allowed the sun to under light them, a sign of extensive clouds upwind to the southwest.

Also, unless you were blind you saw some unusual events in the thin Altocumulus (translucidus) layer yesterday: ice canals and splotches of ice produced by aircraft that flew in them. When so many happen as did yesterday mid-day, its a good bet those Altocumulus clouds, though comprised of liquid droplets, are terribly cold. While the TUS morning sounding did not pick up this mid-day layer, one can be confident that it was likely colder than -20 C or -4 F.

What you also saw was examples of how the presence of ice within a droplet cloud, causes the droplets to evaporate, and the ice crystals to grow and fallout, something that happens on our rain days. However, because there were so many ice cyrstals produced by these aircraft (almost certainly all jets) they compete for the tiny amount of water available at -20 C and form small crystals with little fall velocity.

So the trails of precipitation are very fine and don’t go very far. Here are some examples of that rare phenomenon, rare because for us to see it, takes a thin, cold water droplet cloud, and it has to be high enough so that aircraft are frequently penetrating it. One wonders why, in some of these cases, the trails yesterday were so long with an aircraft probably could have climbed or descended a couple of hundred feet to avoid flying in a light icing producing cloud (the Altocumulus layer composed of supercooled droplets)? Note “ice optics” in ice canal in the first photo, a weak sun dog so I didn’t just make it up that the canal was ice. I you wanna know more about this phenomenon, go here and/or here.

A pleasant 0.03 inches

Not sure even the dust noticed, but we had a brief shower around 8:30 PM that actually measured with 0.03 inches! After the spectacular sunset, indicating a large clearing to the WSW, it seemed doubtful we would even get that. But, what do I know after these past few days?

Below, an example of a nice sunset due to Altostratus clouds (overhead); “file footage” really, since I had a rare missed shot of that one last evening).

With rain still out to the west and north of us right now (go here to see this 12 h loop of clouds and radar echoes from IPS Meteostar) there is still a chance of more measurable rain later today or overnight. Still, the configuration aloft will not be favorable for anything of consequence; likely we’ll just a few more hundredths. But, what do I know#2?

Also, you will see something dreadful regarding that possibility of rain. A blast of clouds riding on a high level north wind coming out of Nevada and Utah, heading straight for our little system around northern Baja, that will try to keep any rain to the south of us. The models, such as this one from the University of Washington, have us just on the north edge of any precip.

As so often happens, our models seem to always see another rain in the future, rains that so often fail to materialize. This time the rain “mirage” is for Sunday, November 20th. Oh, well, something to think about.

Have some climo data for Catalina, about 35 years worth and will be posting that in the next day or two. Past records help you dream about what could be in a winter or summer. Can you imagine that little ol’ Catalina has had almost 30 inches of rain in a year a couple of times? Imagine how the washes ran!

The End.