A Thanksgiving Fantasy

November 25, 2009

Happy Thanksgiving! 

To celebrate the big day I found this map in tonight’s 00z GFS model run.  Click on it to see a much better view.  It’s the 324 hour forecast;  that’s ONLY two weeks from tonight!  The image includes surface pressure, rainfall, and 500-1000mb thickness.  It shows a cold arctic high dropping into Montana and southern British Columbia/Alberta.  At the same time warm and very wet Pacific flow is surging in from the southwest.  This is a great setup for an ice storm  in the Gorge and probably into the Metro Area as well.  One can only dream eh?  Well, something to dream about while enjoying the turkey.  Two other things quite obvious on recent maps; we are in ridging or split flow along the West Coast through the next 7-14 days.  There were hints on the ECMWF and a bit here on the 00z GFS that some slight retrogression may occur beyond 5 days.  That allows cooler air (probably not arctic) to come south for gusty east wind and sunshine Tuesday and beyond next week.    Other than that it’s dry, dry dry.    The 2nd regime I notice is an active southern jet stream.  Several systems move from Texas east through Florida during the next 10 days.  Possibly (as indicated on this map) California starts to get wet at some point too.  Of course all of this is classic El Nino weather.  But just as we can’t attribute any one weather event to Global Warming, we can’t just take the first week or two of this pattern and say “El Nino is here!”.  Now if this pattern recurs several times between now and early February?  That’s a different story and something we might expect with an ongoing El Nino episode.

I’ll be back at work Saturday, but no blog updates between now and then.  Enjoy the holiday.

Chief Meteorologist Mark Nelsen