ALASKA EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
221 PM EDT TUE MAY 21 2013

VALID 12Z SAT MAY 25 2013 - 12Z WED MAY 29 2013

UPPER PATTERN OVER ALASKA IS FORECAST TO TRANSITION TO FROM A
RATHER AMPLIFIED PATTERN TO ONE LIKE A STACK OF PANCAKES... WITH
RELATIVELY WEAK TROUGHS ATOP RIDGES /ATOP TROUGHS... ETC/ FROM THE
NORTH POLE SOUTHWARD TOWARD HAWAII. THIS SHOULD RESULT IN A
QUICKER AND STRUNG OUT PATTERN OF SYSTEMS THAT SLIDE EASTWARD
ALONG 50N ONCE THE PATTERN SETTLES AFTER SAT/D4. RIDGING FROM
NORTHERN CANADA SHOULD RETROGRADE WESTWARD INTO THE INTERIOR EARLY
NEXT WEEK LEADING TO THE ZONAL PATTERN ESPECIALLY SOUTH OF 50N.
THE MODELS HAVE TROUBLE IN QUICK FLOW SO CAPITALIZED ON THE
AGREEMENT BETWEEN THE GEFS MEAN AND ECENS MEAN FOR THE FORECAST.
HOWEVER... INCORPORATED BOTH THE 12Z GFS AND 00Z ECMWF EARLY IN
THE PERIOD BEFORE THE 00Z ECMWF APPEARED TOO FAR REMOVED FROM ITS
MEAN WITH A DEEP SYSTEM SOUTH OF THE GULF NEXT WEEK... BUT
OTHERWISE REASONABLE. PRECIP SHOULD FOCUS ON THE ALEUTIANS AND SW
ALASKA WHILE THE EASTERN/INTERIOR/PANHANDLE REGIONS STAY DRY UNDER
RIDGING UNTIL ENERGY MOVES EASTWARD TOWARD THE SOUTHERN PANHANDLE
NEXT WEEK. TEMPERATURES SHOULD REBOUND NICELY TO ABOVE NORMAL
UNDER HIGH PRESSURE.


FRACASSO