Gale Warning 37, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTH CENTRAL AND SOUTHWEST ALASKA
306 PM AKST MON JAN 4 2010

.ANALYSIS AND UPPER LEVELS...A LONG WAVE RIDGE CONTINUES TO BUILD
ACROSS THE ALASKA MAINLAND WITH A RIDGE AXIS NEGATIVELY TILTED FROM
THE GULF OF ALASKA TO THE BERING SEA. A LONG WAVE TROUGH STRETCHES
ACROSS MUCH OF THE NORTH PACIFIC WITH AN EMBEDDED LOW SOUTH OF THE
CENTRAL ALEUTIANS AN ASSOCIATED BARBELL LOW TO THE SOUTH. AT THE
SURFACE...A 967 MB STACKED LOW IS 180 MILES SOUTHEAST OF ATKA WITH AN
ASSOCIATED WARM FRONT THAT STRETCHES ACROSS THE BERING INTO KUSKOKWIM
DELTA. MEANWHILE HIGH PRESSURE IS SPREAD ACROSS WESTERN CANADA INTO
NORTHEASTERN ALASKA.

.MODEL DISCUSSION...MODELS ARE IN GENERALLY GOOD AGREEMENT ON THE
GRADUAL DISSIPATION OF THE ATKA LOW AND THE PROGRESSION OF THE
ASSOCIATED WARM FRONT ACROSS THE NORTHWESTERN BERING AND INTO
NORTHERN ALASKA BY WEDNESDAY. MODELS ARE ALSO IN AGREEMENT OF THE
SLOW NORTHEASTERN PROGRESSION OF A NORTH PACIFIC LOW TOWARDS THE
CENTRAL ALEUTIAN ISLANDS BY TUESDAY EVENING.  MODELS ARE IN BROAD
AGREEMENT ON THE PROGRESSION OF AN ASSOCIATED SHORTWAVE AND FRONT
ACROSS THE SOUTHCENTRAL AND ALASKA PENINSULA WEDNESDAY. MODELS BEGIN
TO DIVERGE BY THURSDAY AND THE GFS WAS THE MOST CONSISTENT SOLUTION
FOR THE LONG TERM.

.SHORT TERM FORECAST...
.SOUTHCENTRAL...
SNOW WILL CONTINUE TO TAPER OFF IN THE UPSLOPE REGIONS OF SUSITNA
VALLEY AS A SHORTWAVE PROGRESS ACROSS THE AREA TODAY. TEMPERATURES
WILL REMAIN ABOVE NORMAL AS BROAD SOUTHERLY AND SOUTHEASTERLY FLOW
CONTINUES FOR THE NEXT SEVERAL DAYS. ONSHORE FLOW WILL RESULT IN THE
CHANCE FOR RAIN AND SNOW SHOWERS ALONG COASTAL AREAS

.SOUTHWEST/BRISTOL BAY...A WARM FRONT MOVING ACROSS THE KUSKOKWIM
DELTA AND LOWER VALLEY IS BRINGING SNOW AND FREEZING DRIZZLE TO MUCH
OF THE REGION TODAY. WHILE A DEEP REGION OF ABOVE FREEZING
TEMPERATURES EXISTS ABOVE THE SURFACE...NORTHEASTERLY FLOW MAINTAINS
COOLER TEMPERATURES AT THE SURFACE. THEREFORE...FREEZING
PRECIPITATION IS A POSSIBILITY ACROSS THE KUSKOKWIM DELTA THROUGH THE
NIGHT.

.ALEUTIANS...GALE FORCE WINDS WILL OCCUR ACROSS THE ALEUTIAN ISLANDS
TODAY. A STRONG PRESSURE GRADIENT BETWEEN HIGH PRESSURE OVER THE
NORTHWEST BERING AND A LOW APPROACHING THE CENTRAL ALEUTIANS WILL
SUPPORT STRONG WINDS IN THE WEST AND CENTRAL ALEUTIANS. A STRONG
PRESSURE GRADIENT OVER THE EASTERN ALEUTIANS ALSO EXISTS BETWEEN THE
MAINLAND HIGH AND CENTRAL ALEUTIAN LOW. WINDS WILL SLOWLY WEAKEN BY
TOMORROW AS THE CENTRAL ALEUTIAN LOW BEGINS TO DIMINISH AND MOVE
WEST. SHOWERS ACROSS THE REGION WILL ALSO DIMINISH WITH THE WEAKENING
OF THIS LOW.

.LONG TERM FORECAST...LONG TERM FORECAST IS UNCERTAIN AS ALWAYS BUT
AT THIS POINT LOOKS TO REMAIN STORMY.  A NEW LOW IS FORECAST TO MOVE
INTO THE ALEUTIANS ON THURSDAY BRINGING MORE WINDS AND MOST LIKELY
RAIN TO THE WESTERN ZONES WITH THE WARM TEMPERATURES ALOFT.
IN THE EAST...MORE DOWNSLOPING CAN BE EXPECTED ON THE WEST SIDES OF
THE MOUNTAINS WITH MIXED PRECIPITATION OR EVEN RAIN ALONG THE GULF
COAST.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING...120 130 132 138 140 150 155 160 165 170 175
176 180 185.
HEAVY FREEZING SPRAY...185
FIRE WEATHER...NONE

ELN/EZ JAN 10