November to close out/December to begin on wet notes

Kind of tired off entering zeroes for precipitation every day in CoCoRahs and the U of AZ’s rain log. org, as you are, too.

So, what the HECK, am going to end the boredom to assert that November will close out,  and December will begin with storms and significant  rain here in Catalinaland.   Our November average rainfall is just under an inch, less than October or December’s normal.  Hence, if anyone uses that word anymore, its not unusual for a dry November, as this one has been so far., completely so.

This outlandish, even outlaw forecast is based on many “signs”; the ensembles  (aka, spaghetti plots) are trending toward a stagnant trough along the West Coast with the jet flow way down into Baja California with the southern edge of the jet stream clustering around Cabo1 (!),  combined (ingredient 2) with computer models that now and then show strong storms invading southern California and the interior of the SW recently (again showing strong storms in the latest model runs,  combined (ingredient 3) with the rapidly developing Niño conditions in the central and eastern Pacific2 , combined (ingredient 4) with a strong gut feeling that the usual fantasy storms being predicted in the model for us beyond 10 days from now are real–well, they ARE real in the model, just not generally in real life.

I think they’re real this time.  End of story.

Here are some of the usual plots to feast your eyes on, if anyone is out there, after the long hiatus here.  While its not likely that a particular upper level configuration will verify exactly as  shown below, a map for two weeks from now showing a colossal trough affecting the SW, it does nevertheless appear as though similarly strong troughs will be affecting AZ as the month closes continuing into early December.

Before those major troughs threaten appreciable rain, some weak upper air disturbances will bring lots of cirri form and middle clouds (Altocumulus and Altostratus) prior to the onset of the major troughs. One of those preceding  weaker ones might produce a sprinkle Monday night into Tuesday.

I hope you’re happy now.  As the Beatles once sang (before they sadly changed the lyrics to something about guns) ,   “Happiness… is a big rain, mama, yes it is….”

The End

1In case you don’t believe me, here’s a typical spaghetti plot from last evening’s global model run at 5 PM AST with directions on it:

Valid on Thursday, 5 PM, November 29th. Illustrative diagram showing stuff.
Valid December 1st, 11 AM AST. An example of a humongous storm that’s shown up on the computer models. A couple of storms for AZ precede this one. If this exactly verified, there’d be cloud bursts, hail. maybe a waterspout or two in southern Cal.

2In case you don’t believe me that there’s a significant Niño developing, here is a link to the Climate Prediction Center where you can read so that you can see that I am not lying about it:

CPC Niño discussion (80% chance of coming through)

Historically, the SW does great under Niño conditions except during that “Godzilla” Niño of a couple of years ago.  We’ll forget about that “Godzilla” bust in ’15-’16; it kind of materialized the following winter (’16-’17) when there was no warm water in the east Pac at all!   Yes, that’s right, Virginia, weather often breaks your heart,, but then surprises you with the unexpected to make you happy again.

But, not this time, I venture, will there be a “bust.”  In fact, I would buy some Niño merchandise right now, maybe a Tee, proclaiming in a big font,

“Niño 2018-19!  Oh, yeah,  baby.                                                                 Weather and water is on the way! ”

Maybe that’s too much, but, that’s what we’re about here, too much of almost everything, including footnotes.

Categorized as Definitions

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.