Big weather change coming about November 10th

The evidence is clear, see below:

Ensemble plot produced by the National Center for Environmental Prediction based on global data taken at 5 PM AST last evening.  Arizona, I think,  is shown by an arrow.  (Actually this was a faulty run having too many contours; still there is something for us to glean here.)

Or, maybe should it be, “clear?” Or, “Huh?”

Of course, the two people who read this blog know that I am a big fan of these spaghetti plots, as they are known by in the business, in elucidating the likelihood of coming weather events shown on the progs.

Today’s prog has a huge trough barging into the West at this time and again a couple of days later.

Valid Saturday morning, football day, November 10th. Produced by last evening’s global data taken at 5 PM AST.

But previously, these same models had a gigantic hot air containing ridge building over us between the 10th and 15th (see it here: 15 day forecast Nov 15)! Now that same model has a couple of big troughs coming through the West at that time. So which ouput is likely to be right?

By examining the spaghetti plot, it’s PLAIN to see that its the trough of cold air that is very likely, and NOT an upper level, desiccating ridge of hot air sitting over us on November 10th.   Notice that there are a lot of lines swirling southward and then curling back to the north over the West Coast (look just to the “left” of where Arizona is).  Well, take my word for it as a meteorologist.  Hmmm.  I guess that’s not the most reliable person you would want to take his word from when it comes to weather 10 days out…

Instead of hot air over us in two weeks, an invasion of uncomfortably cold air marked by the passage a sharp cold front is almost in the bag on the 10th-11th.   There is a slight chance of rain, too.  Rain, what’s that?  Well, it falls from “clouds” and there should be some sun-blocking “clouds” with that cold front.

Get your sweaters ready.

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.