High Wind in Alaska, May 25, 2005

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM ADT WED MAY 25 2005

.DISCUSSION...

THE NORTHERN HEMISPHERE 500 MB PATTERN IS ESSENTIALLY STABLE.
MAJORITY OF COLD CENTERS REMAIN IN THE EASTERN HEMISPHERE...WITH
WEAKER SYSTEMS SCATTERED ACROSS THE MIDLATITUDES OF THE WEST. DEEP
LOWS OF INTEREST ARE IN THE WESTERN BERING AND OVER THE ARCTIC COAST
OF ASIA. THE LATTER IS THE CENTER OF THE COLDEST AIR AND IS ACTING AS
THE NORTHERN HEMISPHERE ANCHOR. A WEAKER CENTER IS IN THE NORTHEAST
PACIFIC AND SOUTHERN GULF OF ALASKA. OVER THE NEXT 48 HOURS THE LOW
IN THE WESTERN BERING WILL SLIDE SOUTHEAST. MODELS DIFFER ON THE
SPEED...BUT THE ETA40 AND THE ECMWF AGREE CLOSELY WHILE THE GFS AND
UKMET ARE OUTLIERS. LATTER TWO MODELS MOVE THE LOW ACROSS THE CENTRAL
ALEUTIANS FASTER THAN THE FORMER TWO. LOW IN THE GULF IS A DIFFERENT
STORY...WITH ETA40 THE OUTLIER AND THE OTHER THREE IN RELATIVELY
CLOSE AGREEMENT. LOOKING AT ALL FOUR TOGETHER INDICATES GFS190 IS
CLOSEST TO THE MEAN SOLUTION.

ON THE SURFACE...MAIN POINT OF DISAGREEMENT IS WITH LOW IN THE
WESTERN BERING. ALL FOUR MODELS INITIALIZE WELL...BUT BY 26/18Z
DIFFERENCES BEGIN TO EMERGE. SOURCE OF THE DIFFICULTY APPEARS TO BE
DEVELOPMENT OF A SECONDARY LOW SOUTH OF THE ALASKA PENINSULA. GFS AND
UKMET QUICKLY MAKE THE SECONDARY THE DOMINANT LOW...ALTHOUGH THEY
DIFFER ON MOVEMENT AND CENTRAL PRESSURE OF THE SYSTEM. ETA40 AND
ECMWF KEEP THE PRIMARY AS THE DOMINANT LOW...AND ARE IN SOMEWHAT
CLOSER AGREEMENT ON THE CENTRAL PRESSURES AND MOVEMENTS OF BOTH THE
PRIMARY AND SECONDARY CENTERS. FOR THIS REASON...AS WELL AS
SIMILARITIES NOTED AT 500 MB...THE ETA40 SEEMS LIKE THE BETTER CHOICE
FOR NOW.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.

STKM MAY 05