Keeps getting better..the storm on the doorstep, that is

“Better” means wetter, of course.  You don’t read this blog to read about DROUGHT!  You read it to read about rain and moistness; clouds, too.  Let’s leave drought for the other guys…

Here is the latest model permutation from the Canadians, one that successively, and successfully, I might add, jacks up the amount of rain for AZ as the real deal gets closer on the November 21-23rd.  Take a lot at these two depictions from Canada  for the 22-23rd (sorry about the small size; the Canadians are shy about their model outputs and don’t like to post large gifs or jpegs; also remote areas of Canada mostly have dial up so big files are a problem I’m guessing):

Valid at 5 AM 23 November 00_054_G1_north@america@zoomout_I_4PAN_CLASSIC@012_132
Valid at 5 AM Saturday, November 23rd.  Note streamer of heaviest rain in central AZ,  The colored regions are for those areas in which rain is forecast by the model for the prior 12 h.
Valid at 5 PM November 22nd.  Very heavy rain indicated for central AZ mountains 00_054_G1_north@america@zoomout_I_4PAN_CLASSIC@012_120
Valid at 5 PM, Friday, 22 November. Note streamer of heaviest rain in eastern AZ, and over our area with lots more ahead!

The colored regions are for those areas in which rain is forecast by the model for the prior 12 h.

Note round low near San Diego in the first panel, upper left:

“Round lows out of the flow; no one knows where they want to go.”

This old weather forecasting limerick I just now made up sums this situation well. Round lows sit, spin, wobble and jerk around for awhile, and so they shovel rain and clouds over the same areas for one or two days, sometimes longer.

So, instead of a nice sharp frontal band passing by within a few hours and then its over, as happens most of the time here, bands rev up and keep spinning around the wobbling low, often hitting the same areas and the rain/snow keeps piling up. Remember the giant cutoff low in December 1967, and the MOUNTAINS of snow it produced back then in northern and central Arizona, stranding hundreds? Well, this ones not THAT big, but its big deal anyway with lots of water in it, and not so cold as the one in 1967 when “album rock” was emerging.

So, this could put a real dent in our October-November rainfall deficit throughout Arizona, a real “worth billions of dollars storm” to agriculture!  I am pumped, as are you!

Great storm, too,  if you’re planning on getting those spring wildflower seeds in the ground; do it just before the storm arrives and you’ll likely get a colorful return in the spring this year.

What are the chances of measurable rain here in Catalina? Oh, right now, I’d say anywhere between 100 and 200 percent. Now the NWS is NOT going to give you those kinds of percentages I might add. You only get them here.

Amounts?

Let’s go for it. I say the minimum (10% chance of LESS) is 0.40 inches, maximum (10% or less chance of more), is 1.50 inches (big top side due to stationary aspects of storm, likely thunderstorms in area). Median of these, which might be the best estimate for Catlanders (those domiciled in Catalina): 0.95 inches, all falling between the morning of the 22nd through the morning of the 24th, likely in pulses.  Goodbye dust!

But in those central AZ mountains, with flow more or less perpendicular to them from the south, their best rain producing wind direction, 1-4 inches is very likely. Yay for rain and snow, maybe some TSTMS, too, comin’ right up.

Didn’t mention the US mods but they are “on board” for a major rain event in AZ.  Canadian one saw it happening first, so am sticking with it.

Still another pretty good rain chance as the month closes, but a far colder situation than the one coming up.

Yesterday’s clouds

Small ones, Cumulus humilis, no ice, but pretty anyway.  Also, a little smidgeon of Cirrocumulus late, with Cirrus, too, invading from the SW, and a pleasant sunset.

5:11 PM.  Cirrocumulus blossomed overhead as a moist layer way up top encroached.  No ice indicated.
5:11 PM. Cirrocumulus blossomed overhead as a moist layer way up top encroached. No ice indicated.
DSCN6228
2:46 PM. Cumulus humilis dot afternoon skies. No ice indicated.
DSCN6234
5:32 PM. Cirrus clouds provide target for fading sunlight.

 

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.