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


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: