Rain continues to fall in Catalina on the 13th

Today is the 9th.

Great news!  Another decent rain assured now sa the models have converged on rain here on the 12th during a nice, and very sharp cold front passage, those in which the temperature can fall from a toasty 60s to 43 F over an hour along with a withshift to the NW from gusty SW winds.   So we have quite a dramatic weather event coming up.  Here’s what the Canadians have to say about it:

Valid at 5 PM AST, December 13th.  Areas where the model has calculated precipitation during the prior 12 h, are marked, from light to heavier amounts, green to blue to yellow.  There's a little yellow in Arizona north of Catalina.
Valid at 5 PM AST, Saturday, December 13th. Areas where the model has calculated precipitation during the prior 12 h, are marked, from light to heavier amounts, green to blue to yellow. There’s a little yellow area of heavy precip over Catalina (see arrow, lower right), and that’s why I am posting this panel!

But what does it all mean, all the models predicting rain for Catalina on the 13th?   Here’s what it means:

The chance of measurable rain here on Saturday,  the 13th is now more than 100 %; its in the bag.  Count on it.  This is weather forecasting at its best.  The rain may start in the early morning hours of the 13th.

The models have varied drastically on the amounts of rain, and so there’s quite a range that could occur.  From this keyboard:

Minimum amount is 0.15 inches (10% chance of less than that)

Maximum amount, 0.80 inches (10% chance of more than that)1

Since the average of those two theoretical “extremes” dreamed up for this situation by yours truly is 0.425 inches, that’s my personal prediction for my house.   It helps, too, that I am the same person who will also measure the rain as well.

Will look, too, for a little ice in the rain toward the end of it as the temperature plummets after the cold front goes by.

So, what’s yours?  (Everyone should have a personal prediction.)

Yesterday’s clouds

Not much going on, mostly Cirrus, then Altostratus in the afternoon, that gray icy sheet that dimmed the sun so well.  However, there were a few flakes of Cirrocumulus.

7:41 AM.  Kind of a mess.  Some ancient contrail streaks, natural Cirrus, and some Cirrocumulus flakes (dark thin lines).  Because the sun is low, Cc clouds can have shading, otherwise, no.
7:41 AM. Kind of a mess. Some ancient contrail streaks (streak in center), natural Cirrus, and some Cirrocumulus flakes (dark thin lines). Because the sun is low, Cc clouds can have shading, otherwise, no.
4:19 PM.  Classic Altostratus clouds, deep icy ones with tops at CIrrus levels, typically 25-35 kft or so above sea level.  Published meteorogists, looking at satellite imagery, often call this cloud "Cirrus."  How funny is that?  They do that because they see in the satellite imagery that the tops are cold, less than -40 C and don't realize that only a patchy type of Cirrus, spissatus, can have shading!  How funny is that, again?  But, here, my reader knows better than that!
4:19 PM. Classic Altostratus clouds, deep icy ones with tops at CIrrus levels, typically 25-35 kft or so above sea level. Published meteorogists, looking at satellite imagery, often call this cloud “Cirrus.” How funny is that? They do that because they see in the satellite imagery that the tops are cold, less than -40 C and don’t realize that only a patchy type of Cirrus, spissatus, can have shading! How funny is that, again? But, here, my reader knows better than that!

Enough fun for today….

The End

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1Reluctantly, I remind the reader that the maximum rain amount seen for the last storm, 0.40 inches (10% chance of a greater amount), was laughable;  1.16 inches fell in Catalina/Sutherland Heights.  However, in formulating an excuse, CM would point out that the models didn’t see it coming either.

One thought on “Rain continues to fall in Catalina on the 13th”

  1. Hi Art….
    Don’t look often, but always enjoy it when I do. Great pics and commentary! I would think for you…..when it rains (or snows) is like Christmas every day. Have a truly joyous Christmas!

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