Sunsets – Page 14 – Cloud-maven

Cold one on tap for Catalina; tubes in Cal

First, this is not about BEER!

Usually when you get carried away and expect something unusual to happen, it doesn’t, like that girl I thought liked me but didn’t (there have been a number of those…) Yesterday, carried-away Mr. Cloud Maven person mentioned the possibility of tubes in Cal. Here’s the report in the Big Valley near Merced, CA, from yesterday. Big hail, too. I am pumped! Spiking fubball now!

0535 PM FUNNEL CLOUD ATWATER 37.35N 120.60W
04/12/2012 MERCED CA PUBLIC

3 DIFFERENT FUNNEL CLOUDS IN THE ATWATER AREA

0605 PM HAIL ATWATER 37.35N 120.60W
04/12/2012 M1.75 INCH MERCED CA AMATEUR RADIO

Official name of tube-producing clouds? Oh, something like, “Cumulonimbus capillatus incus (has an anvil) tuba.”

Actually, its not terribly unusual to have tubes in Cal when the air is extremely cold up top over Cal in April and May, and that’s what we have now. Take a look at this nice, compact map from San Francisco State Former US Hippiedom Capital Weather Department for last evening at 5 PM AST. At San Francisco, its -29 C at 500 mb, very unusual for mid-April. (Actually, they got some real nice maps there.) Combine that with the strong sun on land surfaces, and voila, Cumulonimbus galore!

Also, if you look carefully, you will see that where there is no data, over the Pacific Ocean, the 500 millibar pressure contours are nice and smooth . But notice how “nervous” they get once crossing the coastline where there is data. I think really it has something to do with the interpolation scheme that try to place the contours exactly at the right spot between the real data; that algorithm may be a little primitive. Kind of funny in a way.

That cold core of air is heading for Arizona, and no doubt some April low temperature records will be set, such as lowest maximum, and likely a few minimum temperatures before this passes on into the Plains, with no doubt true severe weather there the result of that. And we, too, will have some Cumulonimbus clouds, lightning here and there around the State.

Below the SFO State map is the forecast from IPS Meteostar showing where this mass of cold air will be later Saturday at 5 PM AST, northern AZ. U of WA WRF-GFS mod thinks rain will be occurring here just about ALL DAY on Saturday after beginning around dawn! That would be a heckuva cold day, winter-like, with temps in the 40s-50s here at 3,000 feet and we’d have those pretty white Catalina Mountains afterwards. Sure seems like 0.20 inches is in the bag for the bottom of this rain event, with maybe 0.50 inches being at the top here in Catalina.

Yesterday’s line of enhanced virga in As deck at sunset

Now here’s an odd feature. Looked at first that it might have been due to an aircraft passage in that streak of Altostratus, but then I rejected that thought, as I can do. I came to believe somewhat confidently, odd as it is, that it was natural. Natural linear features in clouds are fairly common. Here it is, in case you missed it:

Dusty parhelia

No, that’s not a baseball player that played for the Dodgers or Giants back in the 1950s, that was Dusty Roads; though Dusty Parhelia would be a nice name for a baseball player. Yesterday, with our slightly dusty skies, and on the 22 degree halo ring, and horizontally from the sun’s position, was a couple of sun dogs (parhelia) late in the day associated with those cirriform clouds we had. You know by now that those high clouds are comprised of small ice crystals. Here’s a few shots of those clouds, which were often CIrrostratus with embedded other Cirrus cloud species like spissatus, fibratus, and uncinus.

SONY DSC — CIrrostratus fibratus with a faint 22 degree halo.

The ice crystals in those clouds are typically hexagonal (six-sided) plates, ones that fall face down. If you could be there in them, and see them falling, at eye level you would see only the sliver side of them, but if you looked down at one that went by, you would see the whole hexagonal plate. The way that they fall is why aircraft laser imagery, when the laser is oriented in the vertical, captures such beautiful, full images of plates and other flat crystals in ice clouds as the aircraft flies through them.

The sun’s white light is separated into its colored components in these hexagonal crystals (but only at certain specific angles) and for this reason, the bright spots are at the same locations relative to the sun. Since I am not an atmo optician, I am relying on the links above to provide more complete, comprehensible explanations.

Note: Caption function stopped working again in WP for the fourth photo, and after half a dozen tries, will write it here:

Photo 4 caption: An especially vivid parhelia can be seen just above the horizon at lower left. The brightest ones like this are usually associated with aircraft contrails since those have high concentrations of pristine crystals. A flying saucer, or a bird with its wings closed at the instant the photo was taken, is also visible.

Continuing….

Sat image loop from the U of WA weatherfolk show lots more cirriform clouds in route to AZ next few days with occasional breaks. So, keep your camera ready for optics and sunrise/sunset color.

The weather ahead? Dusty cold snap.

“Dusty” is kind of the word of the day today.

Long foretold big Cal storm on the 12th-13th affects southeast AZ mostly with wind and dust on the 13-14th followed by unusually cool weather for mid-April. A hint of rain excitement for Catalinians has begun to show up in model runs, such as this one from the U of WA for early Saturday morning on the 14th. Yay.

The End

Cirrus, maybe some lenticulars, and dust ahead

In case you missed it, the thin layers of Altocumulus clouds provided a bit of a sunset “bloom” around 6:30 PM AST yesterday. Here’s what yesterday looked like, and I am doing this because I have a strong feeling some of you like to live in the past, like I do when I think about my best sports days in high school and JC R’s bat, and maybe a coupla others after that, so that’s why I am reprising yesterday below):

Here’s what we are looking at, in order of their appearance: 1) encroaching Cirrus (its not a cloud name, its what it was doing), 2) later, the Cirrus thickening (usually downward) into a nice example of Altostratus, a cloud normally composed of only ice crystals and snowflakcs, 3) Altocumulus perlucidus translucidus (honey-comb pattern, quite thin), with traces of ice falling out if you look VERY carefully, and 4) and 5), the Altocumulus as it was briefly (you only had a few minutes) underlit by the distant setting sun (its 93, 000, 000 miles away).

Moving on to the future, such as the rest of today

Its great, weather people can really do that, look to the future and say things that will actually happen with a great degree of confidence, like for the rest of today. (HELL, an economist can’t even predict what will happen in the next few hours!)

What will happen in the hours ahead? Cirrus clouds, patchy ones here and there, and a good chance of some Altocumulus or Cirrocumulus lenticular clouds as the jet stream powers its way down here, shooting from the southwest over us by late in the day. Sometimes, and I have predicted this before without a lot of success, you get these tremendously fine grained clouds (Cirrocumulus) that suddenly pop out of the blue overhead. There’s an awfully good chance of seeing those today, too, with the strengthening winds aloft. Of course, I’ll be watching for you if you miss them, and will replay anything “exciting” tomorrow.

Also, as the low in southern Nevada strengthens tremendously during the day, the winds will pick up as you all likely know by now, and the blue sky will start to wash out in a brownish dust haze. Twin Peaks may not be visible from Catalina late in the afternoon due to dust. You can track the development of that low here, from the University of Washington. Right this moment, 5:50 AM, there is not much there, so a lot of the development excitement in southern Nevada is ahead. The NWS, Tucson is quite excited about all the things that might happen, as you will see here!

Enjoy and interesting day!

The End

Plethora of storms ahead; Catalina snow day still being foretold for Feb. 25th which is only nine days away now!

To help understand that odd word, “plethora” in the title in case you are befuddled by it, I have added a YouTube teaching module to help you out: “What is a ‘plethora’?”

Well, one of the great model runs of our time has come out once again last night after yesterday’s great model run of our time based on the that morning’s data. SEVERAL rain days foretold in the next couple of weeks! One of these is actually a snow day, Feb, 25th, first predicted by the models about a week ago. This would be the “real deal” here in Catalina, not some “diabatic” (a weather term opposite of “adiabatic”) fluke as was our inch or so of snow two days ago, one that happened due to extremely heavy precip in the clouds above us, thus drawing the freezing level downward.

The first rain day is today, likely beginning after 5 PM AST, and then continuing into tomorrow for a second day. Here are some rainy/snowy snapshots from our friends in Canada at the EnviroCan weather service where they use a modified version of the ECMWF (European) forecast model here. The first panel is valid for 5 PM today just before the rain is supposed to begin. (If you don’t click on the panels below, you’ll need binoculars to see what I am talking about.)

Does this pattern look familiar in that first panel?

Yep. “SOSO” as we have been seeing all winter when storms strike. In the lower left panel you will see all that moisture streaming (colored regions) into our today’s cut off vortex from the south from the Mexican Pacific and linking up with a moist plume from the Gulf. Interesting to see that. Also, as it gets cut off, and great for us, it begins to dawdle while edging eastward along the US-Mexican Border, allowing those moist plumes to “filler up”, just like at a gas station. So, the rainy areas with this low should be expanding/appearing as clouds are enhanced; deepen up and begin to precip. Very exciting.

What’s been great is seeing the amount of precip predicted in Catalina from this low increase gradually over time as the models were seeing that it was not going as far south as they thought earlier. Here is another panel for this storm, valid for tomorrow afternoon at 5 PM AST. While the low has gone by to the south during the day tomorrow, this model suggests that it likely will have rained on and off during the day. This is because so much moisture arrived in this low that it has developed a “wrap around” band of rain to its north and west, good for us, kind of like a sucker punch. You should be able to see that happening today and tonight in this great IPS sat and radar link, as well as clouds “appearing” over the deserts to the west and south of us, and then developing echoes as they deepen.

Our local U of AZ Wildcat Weather Department has this great depiction of this “wrap around” development from their own model run here. Nice!

Here are the additional days ahead with more rain, and also, low snow levels. Mt Lemmoner’s rejoice! Below, the next panel, Sunday afternoon into Monday morning, this next trough.

Brrrrr, another cold blustery day Sunday, but notice this one is NOT a cut off and so will move through rapidly. Then, 4th panel, a dollop on Tuesday, just a minor trough passes by, and then, after a break, the Arctic iceberg on the 25th. Check this trough out in the last panel. Awesomely cold!

With luck, and a little verification of these predictions, maybe the washes will run later this spring!

The Cloud Report part of blog

Had some complicated, but nicely detailed Cirrus clouds float over in the early afternoon, a part of our invading storm’s circulation. This was followed by a large clearing and then encroaching Altocumulus patches trailing virga (ice crystals) in gorgeous, fine strands that wiggled this way and that in the setting sun’s light as that falling snow responded to slight changes in the wind below those little flakes of Altocumulus cloud. Enjoy.

The End.

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.

“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.

Near miss on rain; pretty clouds and a nice sunset

Here are a couple of scenes from pretty yesterday, a day that the phony numerical models had rain predicted for us one to two weeks in advance, and then dried that system out as far as we here in Catalina are concerned as the days got closer. This happens all the time in the models, so you would think I would develop a tough skin to these repeated disappointments, but I haven’t. Oh, photos. Here they are-the middle panel having a nice pancake-like stack of Altocumulus lenticularis clouds northeast of Charouleau Gap:

So what was the missing ingredient? Well, the core of the jet stream at around 18,000 feet above sea level, what we call the 500 millibar pressure level as well, stayed just to the north of us. If you have read this blog, you know that the core at 500 mb has to be over or to the south of us and that didn’t happen. Its a necessary condition in the cool season here, but not always sufficient. Shown below is last evening’s 500 mb map, courtesy of the University of Washington with station plots and infrared satellite imagery. Those two flags and a wind barb for our Flagstaff balloon site (“rawinsonde” site) shows that the core of the jet stream was just about right over Flagstaff at that time, and the wind was over 120 mph (105 knots)! Note that the wind at the same pressure height on this map is “only” 65 knots over Tucson. By this morning, that core had settled a little more southward to between Albuquerquequeque and El Paso, and along with that the precip shifted a bit south as well. Darn, had this happened 12 h earlier we likely would have gotten a small amount of rain.

If you look at a loop of the radar echoes during the late afternoon and overnight from IPS Meteostar, you will see that the precip is confined to near that jet stream location and northward.

Shown on the Washington Huskies loop is another powerful storm about to strike the West Coast. THIS one WILL bring the jet stream core south of us as it passes over on Monday night-Tuesday morning, the 23rd-24th, and circumscribed inside that jet stream core will be moisture and clouds low enough to produce at least scattered showers, and may a nice rain band of a few hours duration. So, maybe the rest of January won’t end up as rainless after all.

The best thing about this next trough is that it gets stuck as a cut off over west Texas and causes quite a bit of rain there in that drought stricken region for a couple of days. Might have to drive over there and see how happy the people of west and central Texas are when the rains begin.

Don’t want to end this session without a long distance model teaser, “big storm” from IPS METEOSTAR as shown here valid on February 3rd at 5 PM AST. Note how it resembles once again our early winter pattern of the isolated cut off upper low. Hmmmm. Maybe there will be something to this one because of this winter’s theme song of cut offs.

The End.

A Stratocumulus Monday

Yesterday gave us “Catalonians” the perfect example of Stratocumulus clouds. But why didn’t it rain from those dark clouds, save a few drops, maybe even a brief drizzle episode that mostly moved across Saddlebrooke around 9 AM?

Those Stratocumulus clouds were GENERALLY not cold enough at cloud top to have ice crystals form in them. There were some very light showers, mostly east of us during the day, and THOSE clouds got cold enough at cloud top to have ice form in them.

How cold does a cloud top need to be in Arizona for ice to form in it?

Around 15 F (-10 C).

Here’s the TUS 5 AM AST sounding for yesterday from the Weather Cowboys at the University of Wyoming showing the tops are right around that (normal) ice-forming limit. Where the lines split apart is close to where the cloud tops are, and the temperature lines slant downward to the left.

You may have also noticed that the clouds got markedly shallower here after about 3 PM, noticeable in the U of A movie after 3:30 PM AST. That was also close to the time an upper level trough and the accompanying slight wind shift occurred. To the rear of the trough, there is always a piston of downward moving, drier air that’s going to squash cloud tops. By the evening TUS sounding, cloud tops were barely below freezing.

Some cloud shots from yesterday’s overcast:

The weather ahead

Still looking for rain here on the 22-23rd, HOWEVER, the last two model runs confined the rain to N of us! Not good.

Nor Cal rains/flooding episode begins overnight as a series of semi-tropical storms strike the coast.

Wish I could be there for surf and on the turf there, but I have my blog audience to think about. I don’t want to let both of them down by being gone for the 10 days of this great storm series, exploring the rain intensities in the coastal ranges of Cal. Oh, well.

Still think total rains in the best coastal mountain spots over the next ten days will be 30 inches or more, actually not terribly unusual in the King Range and similarly exposed sites.

Weather 10 days from now remains uncertain

Hahahahah. That is the funniest thing I have thought of in a long time, and its not that funny. Take a look at this “spaghetti” plot for 10 days from now based on last night’s global data. The map is for 500 mb, about 15,000 to 20, ooo feet above sea level.

“High predictability”, even as far as 1o days out, is indicated by those areas where the bluegreen and red lines are all close together. For example, in the upper left hand corner, or in eastern Asia and the extreme western Pacific Ocean if you can make those areas out through all the lines. Also, both the red and bluegreen lines themselves are pretty close together there, and that says the jet stream is extremely strong there, normal for that region in wintertime. That jet stream is geographically anchored in that region and so not much changes there, even from winter to winter.

But then look what happens to that compact jet stream as it approaches the middle of the Pacific! It comes apart, line a twisted speaker wire that’s been untwisted. The bluegreen lines, representing a colder portion of the jet stream, mostly head off to the NE, while the red lines, indicating a warmer portion of the jet stream, split off and continue more or less toward the east across the Pacific and into the Southwest. However, the details of both flows, the northern one and the southern warmer one, are pretty unknown, as evidenced by all the “scatter” in the lines, the “bowl of rubber bands” you see in the east half of the Pacific and into North America (and elsewhere). Note that the lines are tending to group that bit more over the eastern US, suggesting higher predictability, and the presence of an upper level trough (and cold in the East).

For the sake of contrast, here is the same kind of plot for just 48 h from now, showing high predictability. Of course, things always go to HELL in the longer term, but today’s 10 day vagaries are more than usual.

So, what seems to be ahead for sure is a split in the jet stream in the eastern Pacific with one of the branches coming toward us. That is the good part since that branch can be pretty wet if it is strong. But, as you can see, exactly where it is, and that’s crucial, is really anyone’s guess at this point. That warmer jet has to be south of us to have any rain with the disturbances that are shuttling along in it. And if you look over AZ, the red lines of the warmer jet are all over the map, literally.

Hence, to use an old word there, particularly uncertain times ahead. In fact the only thing that is certain, is with the southern branch of the jet in this area, there will at least be passing regions of clouds as upper air troughs go by. Will they, like yesterday, only be Cirrus? Or rainy Nimbostratus?

The second shot shows a nice “parhelia” or “sun dog” at the far right, caused by plate-like ice crystals falling face down, the normal mode. The final shot has some the rarely seen Cirrus castellanus, Cirrus clouds with little turrets or humps at the top.

Low spin cycle continuing off Baja; water being added

That enfante terrible now dawdles over the coastal waters of California and northern Baja today, adding some water to its central system as seen here from IPS Meteostar. Note, too, a scruff of Stratocumulus clouds racing northwestward in the Gulf of Baja abouit the latitude of the border between north and south Baja. This is good. Still, this is a marginal storm as it trucks through on Sunday evening and I will be happy if we get a quarter of an inch. Mods don’t think rain will get here until the upper center is upon us later Sunday. Here is the whole map forecast sequence showing temperatures and winds aloft at 500 mb from the U of Washington unranked Huskies who play #12 Baylor in the Alamo Bowl –what a horrible bowl game that is for Baylor–on Dec 29th. Still, as a spin off myself here into the SW like all of our lows this year, but from the U of WA, I will be rooting, of course, for the “company team” along with my friends and former grad students with whom I worked. BTW, these are pretty maps with lots of color as you will see.

You will also notice in this 4 day series of forecast maps for 500 mb that yet ANOTHER low drops into the Yuma area replacing the current one that begins to move toward us later today. That new low develops via the back door from Colorado and nests over Yuma as a cut off at the end of the forecast cycle above. That ‘s an unusual trajectory for a low! However, mods think its too dry to produce any rain as you might imagine. But with another low center aloft ending up in the SW, it demonstrates again our characteristic pattern for this early half of the winter, having become something of a low magnet. It certainly has been strange to see so many cut off lows.

BTW, the longer term picture after our little rain is a dry one for the next two weeks; it may well mark the end of our cut off low fantasia. Hope not.

Today’s clouds…

The marginal amount of moisture circulating around the periphery of this Baja low, I think will spin out some spectacular middle and high cloud streaks and patches over us such as Cirrus, Cirrocumulus with its tiny granulations, and Altocumulus lenticularis here and there, ones that often break up into small and interesting cloudlets downstream. Get yer cameras ready! Some of this began to happen yesterday afternoon. Sometimes you see the most amazing tiny delicate patterns, very photogenic.

Here are a few shots from yesterday, beginning with that sunrise patch of Altocumulus and ending with a sunset shot.