Thursday, January 7, 2010

Winter '09 / '10 - ECHAM5

Latest hemispheric sea-level deviation forecasts from ECHAM5.

RED: negative deviations
BLUE: positive deviations



JAN:  Aleutian LOW pressure is forecast to persist as well as the current storm track into the Mediterranean Sea.  Strong HIGH pressure deviations centered over NW Russia suggesting a shift of the high-latitude block now east Greenland will continue to drift.

Pressure configuration over CONUS is suggestive of persistent +PNA flow regime...a continuation of arctic air masses sweeping through the east coast...and the potential for snow storms from 'Alberta Clipper' and Miller 'A' storms.



FEB:  HIGH pressure retrogrades to a -NAO-east position centered over Iceland.  LOW pressure deviations off the Canadian Maritime provinces supports the continued flow of arctic air masses into the eastern CONUS from the vicinity of Hudson Bay...and cold air damming.

Deviations near the Aleutian LOW weaken and split...with one action center moving to the Gulf of Alaska.



MAR:  Expansive LOW pressure deviations span much of the eastern Pacific.  HIGH pressure over eastern Alaska suggests the stream of arctic air shifts toward the western NOAM. 

JAN/s storm track through the Mediterranean is replaced by HIGH pressure deviations suggesting an end to the persistently negative Northern Annular modes of late.

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