Atmospheric River has shifted into the Pacific North West while Central and Southern CA are under a Subtropical Ridge…..Expect Warmer, then cloudy weather the next four days and Windy Weather Wednesday and Thursday……Unsetteled Weather is expected Saturday Night into Sunday AM…..Next Major Storm expected by middle of next week….
Tuesday February 11, 2014
Posted at 10:07 am by Howard
While the Pacific NW gets the Hose……The Southern Half of the West Coast gets Clouds, wind and Sun. The latest guidance shows a subtropical ridge building into California thorough Midweek and holding through Friday. The strong warm air advection pattern to our north will begin to sag south this weekend effecting Mammoth by Late Saturday night. Freezing levels will begin high, about 10,000 feet late Saturday night, then come down late Sunday Morning to 6500. The QPF is about .65 for the Mammoth Crest. So once again, it will be snow over the higher elevations above 8500-9000K from about midnight Saturday night then some very light accumulations possible in town Sunday Mid Morning. The snow level is expected to lowers to 6500 by 10:00AM Sunday at the end of system. Early estimates of 3 to 6 inches are possible up on Mammoth Mtn by Noon Sunday and about an inch or two in town at 8K.
Between now and then we’ll have warmer days and cloudier days as well. It looks especially windy Wednesday through Thursday with the Front Rt Exit region to the north, forcing NW Flow with 30 to 35 Knots at 700mb, which I double for Mammoth Mountain over the crest for forecasting purposes. High temps in Mammoth will be in the 40s one more day today, then into the 50s Wednesday into Friday. Again….Warm air advection precipitation will begin to make its way into the Mammoth Crest late Saturday night and be pretty much be over by 12:00 noon Sunday.
The period Monday night through Thursday of next week looks stormy. I like the fact that all the popular global models including the GFS, GEM and ECMWF are singing the same tune. While there are timing differences, and the GEM is not nearly as deep with the Trof coming in, as compared to the EC and the GFS. It still all looks good for a winter storm. I primarily used the ensembles of all three models this far out in time as their deterministic runs would not be as accurate. I did note that the timing is earlier with the latest deterministic Tuesday 12Z GFS run. I think that that makes sense, as the corresponding western pacific surface cyclogenesis bombs out early, and crosses 140E early as well. So do not be surprised if the zone forecasts introduce snow as early as Monday night next week for Mammoth.
All in all this looks like the potential to be a major storm in the high country with much lower snow levels and a good couple of feet of snow. And the town too should participate with moderate amounts of snowfall.
I had a peak at the CFS (Climate Forecast System) for the next 45 days. It looks pretty promising for some 6 to 7 feet of snow, now through the end of March. That is based upon its QPF of 6 to 7 inches at 10:1 ratio. Correction…..Aprox 5 to 6 feet at 10:1.
Dr Howard and the Dweebs………………………………….:-)