Cold slam3, the sequel; arrives in air around theatres February 9th

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.
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 mid-day Altostratus opacus virgae with virga.
12:50 PM. Your heavy mid-day Altostratus opacus virgae with virga.
3:13 PM. Undercutting layer of Altocumulus overspread sky rapidly from the west. Starting looking for strange cloud bases here.
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.
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.
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.
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

Sat 9 Feb 2013 00_054_G1_north@america@zoomout_I_4PAN_CLASSIC@012_132
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!
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!

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.