“Volcano” erupts north of the Tucson Mountains; California Niño, too, along the Cal coast

The documentary photos, below, of  a modest-looking Cumulus congestus cloud yesterday afternoon that lept up to the stratosphere in the 20 minutes that cloud maven person wasn’t watching.  Yours truly, while videoing it from start to finish, only got two still shots in those 20 min due to a distraction1; was not taking photos of every cloud every three minutes as the “compulsar”,  CMP likes to do:

1:51 PM.  zzzzzzzzzzz.  Not much likely to happen. Cloud is isolated over a flat area all by itself, no pals to group along with, so its certainly going to fade away after the itty-bitty amount ice on the right said produces maybe a sprinkle.
1:51 PM. zzzzzzzzzzz. Not much likely to happen. Cloud is isolated over a flat area all by itself, no pals to group along with, so its certainly going to fade away after the itty-bitty amount ice on the right (frizzy part)  produces, oh, maybe a sprinkle or slight rain shaft.  Maybe I’ll take a nap while things are calm.

20 minutes later….something unbelievable has happened:  a “volcano” of sorts erupted from this moderate, isolated cloud.  I have never been so embarrassed in all my life not to have seen this coming.  But it was also so wondrous at the same time.

2:11 PM.  Wha?  Can it possibly be the same cloud?
2:11 PM. Wha? Can it possibly be the same cloud?  It was.  LOOK at that rain shaft!  Also, in the middle,about halfway up, that dark thing almost looks like vortex.  Kinda reminded me of the Mt. St. Helens eruption.

Also seen was the rarely seen Cumulus congestus pileus tops here and there indicating strong uprushing currents pushing into the air above the top, and rushing up so fast, the air above the top is pushed up and starts to condense into a cloud before the actual cloud top reaches it.  See below:

2:18 PM. Pileus cap cloud tops Cumulus congestus turret.  If you're in an airplane with instrumentation, you really want to penetrate this one to get high measurements of liquid water, maybe two or three grams or so.
2:18 PM. Pileus cap cloud tops a rapidly rising Cumulus congestus turret over the Catalina Mountains. If you’re in an airplane with cloud instrumentation, you really want to penetrate this one right hear the top to get high measurements of liquid water, maybe two or three grams or so.
5:14 PM. This thunderstorm was almost in the same exact area as the "volcano."
5:14 PM. This thunderstorm was almost in the same exact area as the “volcano.”
5:14 PM.  It looked like a promising sitiuation was propagating down from N of Charouleau Gap, but the new bases ahead of outflow winds crept closer to the mountains instead of extending out over the lower terrain and Oro Valley.  This led to a dramatic rainshaft scene that CMP missed because he didn't bail on a dinner situation at a restaurant.  I guess it was quite a show when it cut loose a few minutes later, with a great rainbow, I hear.
5:14 PM. It looked like a promising situation was propagating down from N of Charouleau Gap, but the new bases ahead of outflow winds crept closer to the mountains instead of extending out over the lower terrain and Oro Valley. This led to a dramatic rainshaft scene that CMP missed because he didn’t bail on a dinner situation at a restaurant. I guess it was quite a show when it cut loose a few minutes later, with a great rainbow, I hear.
7:06 PM.  Did catch the lastbit of the show in these Cumulonimbus mamma clouds.  So, something to show for having a good time with friends at a local Goose Plaza restaurant.
7:06 PM. Did catch the lastbit of the show in these Cumulonimbus mamma clouds. So, something to show for having a good time with friends at a local Goose Plaza restaurant.

For the full day yesterday, see the U of AZ time lapse. Its a rolling archive and so it will gone if you read this after today.

Time of the hurricane, and of the California Niño

Those model generated ones, that is, that are shown to come close to Arizona; “close” being within 500 miles or so, which, astronomically speaking, is incredibly close.

This time of year, we look forward to the possibilities that one of the many hurricanes that affect the Mexican Pacific will rush up Baja coast, angle northeastward and cross the border into Arizona.  Remember that one in 1976 that hit Yuma with 76 mph winds?  Yeah, like that one.  Go here to read about it if you don’t believe me that Yuma experienced hurricane force winds from a hurricane.  Mt. San Jacinto in southern Cal got over 14 inches of rain, too.

While the computer models have a tough time generating hurricanes in their right places too far in advance, they are remarkable in how many they generate, considering that those hurricanes pop up out of loose-looking cloudy masses, with weak areas of low pressure associated with equally, loosely-organized upper level features.  To have a tropical storm leap out of that cloud mass,  the upper air pattern has to spread the air aloft over those clouds so that more air can come into the developing storm at the bottom.  And, as more thunderheads (though they don’t usually thunder much) pile upward, more warming aloft occurs, and that helps the air spread away even faster.

Today, we have a coupla interesting predictions, one by our Canadian friends, showing a tropical storm roaring up the coast of Baja just next Thursday.  This from their 5 PM AST model run yesterday.   The remnant of that TS goes into southern California!  This is just 5-6 days away, which,  in model time, is not that far off and usually is fairly reliable.

But, USA model (WRF-GFS) from 5 PM AST last evening,  has no such feature!  See below.   Boo-hoo.

Still, something interesting has shown up in our own USA model about two weeks out that seems to be due to  something unusual that’s happening off the West Coast.  A new phenomenon, reported in Nature (!) and akin to the “The New Niño” (the one in Pacific Ocean Region 3.4) and the “Classic NIño” (the one we heard about as kids where the water off Peru gets real warm), has recently been dubbed, the California Niño.

This is an oscillation caused by the slackening of the onshore winds along the Cal coast.  Those winds, when as strong as they usually are, cause really cold water to boil up to the surface;  when those winds become slackers, the water warms tremendously.

This year the water temperatures offshore of the Cal coastline,  are way warmer than usual.  No wetsuits needed off Monterey this year (a friend says)!  These warmer waters will help tropical storms stay together a little longer when they are directed north and northeastward toward southern California and Arizona.  Yay!

This may explain why a hurricane/strong tropical storm is shown drifting to the NW only a few hundred miles SW of San Diego, as shown below, in about two weeks.  The eye-popping stat in that model projection, is that the low pressure in the center is still as low as 982 millibars when its fairly close to San DIego!  This shows that the models knows about the water temperatures out there (that kind of data is always being fed into them), and it thinks that a pretty good sized tropical low can exist that far close to San Diego with water temperatures as warm as they are.

All we have to do now is wait for the right upper air “steering” pattern, to keep the western motif here, so that those stronger storms are directed thisaway, to continue yet again with the western theme.

The prediction shows that the model thinks that conditions are warm enough to support such a storm relatively close to southern California.   What grabs your attention is the 982 mb central pressure in the eye of that predicted storm two weeks from now.  Let us not forget the near hurricane that blasted southern California in September 1939, likely having occurred during “Cal Nino” conditions.

Check these predictions out, first from Canada, where a magnifiying glass will be required to view details:

Valid Thursday morning, Aug. 21st at 5 AM AST.
Valid Thursday morning, Aug. 21st at 5 AM AST.  The storm is moving N.

 

Valid for the afternoon of August 29th.
Valid for the afternoon of August 29th.  This one is moving NW.

 

The reason for the excitement is that troughs and jet streams are beginning to creep farther south and when they do that, sometimes they can “steer”, to use a western term again here, a storm toward the north and northeast.  In June, July, and into much of August, the many hurricanes that form off Mexico and central America drift west and west-northwest only to die over the cooler waters north of the Equator.

More showers and thunderstorms are buiilding on the Catalinas!  And late afternoon or evening rains are foretold here.

The End.

 

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1Ironically, the distraction was having his computer almost stop working because he had filled up the “C” hard drive with too many photos and almost nothing worked any more!  Note:  Put photos on a different HD.  Leave at least 10 percent of the C hard drive “file-less”, so’s it can work properly.

By Art Rangno

Retiree from a group specializing in airborne measurements of clouds and aerosols at the University of Washington (Cloud and Aerosol Research Group). The projects in which I participated were in many countries; from the Arctic to Brazil, from the Marshall Islands to South Africa.