Friday Am:

NMC/HPC Update Shows up to 4 inches of new snow over the crest with 1 to 2 in town by Saturday AM….with heaviest rain throughout San Diego County south. Coastal Sections of LA and Orange County under 1/2 inch.

Just a brief update.

Closed upper low is moving SE off shore and will effect mainly coastal section of Ca and especially Extreme Southern Ca. However, it is questionable how far inland the precip will get. Expect anywhere from 4 inches over the Crest to an inch or two in town Mammoth.

Next week looks pretty dry through mid week with near seasonal temps.

More importantly, using the MJO phase space and the GSDM model/GWO, it is evident that the far west will become increasingly under the gun for major storminess beginning about next weekend and may continue into the Holiday. 

The GWO “The Global Wind Oscillation” is expected to shift into Phase 1 by the next weekend.

From Global Weather Systems.com

Stage 1 (La-Nina like) – the global relative AAM anomaly is negative. The negative anomaly is primarily due to easterly upper level wind anomalies that extend from the Eastern Hemisphere tropics to the Western Hemisphere mid-latitudes. A retracted Pacific Ocean jet stream is a key feature in the total field.  Troughs are probable across the “western USA” with a ridge over the southeast.  High impact weather is favored across the Plains. The Signature is the reverse phase of the PNA teleconnection. So the odds are tilted toward a cold and stormy pattern for the Sierra with a Western Trof/Southeastern states ridge. And…..if there is an Arctic cold air source, Cold dry powder for the Sierra is possible.

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml

http://www.esrl.noaa.gov/psd/map/images/gcm/gwo_40d.gif

PS. The ECMWF is picking up on the change nicely…….

Remember…according to Ed Berry, the long range global models do not incorporate the effects of tropical forcing beyond 5 to 7 days.

ECMWF:  http://www.ecmwf.int/products/forecasts/d/charts/medium/eps/ensm/essential%21Geopotential%2520at%2520500hPa%21North%2520America%2124%21pop%21od%21enfo%21plot_ensm_essential%212010052412%21%21/

 

PS. For those of you that really want to get into the lastest cutting edge longer range forecasting that will improve your odds during week 2 and beyond, go to the following link:  http://www.globalweathersystems.com/Climatology/GWO.htm

 

Understanding the two systems, the MJO and the GSDM, and how they excite each other, is key to better week two and three sub-seasonal forecasting.

 

More Later……………………………..:-=)

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Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.