Gale Warning 1040, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKST THU DEC 9 2010

.MODEL DISCUSSION...SYNOPTIC INITIALIZATIONS ARE REASONABLE AS WILL
AS SYNOPTIC TRENDS. BIGGEST DIFFERENCE IS IN THE TIMING OF
PRECIPITATION INTO MOVING INTO PRINCE WILLIAM AND ITS WESTERN EDGE
OVER SOUTHCENTRAL. AT 12Z THE GFS SEEMED TO BE A LITTLE FASTER THAN
THE EC AND MUCH (4-6 HRS) FASTER ON PRECIPITATION PUSH INTO THE
SOUND. THE 18Z NAM RUN NOW IS CLOSER TO THE GFS AND APPEARS TO AGREE
WITH CURRENT RADAR IMAGERY. ANOTHER ISSUE IS THE WESTERN EXTENT OF
PRECIPITATION INTO THE ANCHORAGE BOWL AND MAT VALLEY. THE GFS TENDS
TO KEEP THE PRECIPITATION ALONG THE CHUGACH FRI WHEREAS THE
EC/NAM/WRF BRING THE PRECIPITATION BAND MUCH FURTHER WEST. WOULD TEND
TO LEAN TOWARD THE NAM IN THIS RESPECT WITH WEAK OVERRUNNING SE FLOW.

.SHORT TERM FORECAST...

.UPPER LEVELS...STRONG RIDGE CONTINUES OVER THE BERING SEA THROUGH
THROUGH SUN. A TROUGH MOVING EAST ACROSS THE ARCTIC OCEAN CONTINUES
TO DIG SOUTH ACROSS THE INTERIOR THROUGH TONIGHT. A SECONDARY LOW
CENTER FORMED OVER THE NW GULF OVERNIGHT AND IS EVIDENT ON CURRENT
SAT IMAGERY. AS UPPER TROUGH CONTINUES TO DIG SOUTH THE FLOW BECOMES
MORE SOUTHERLY OVER THE GULF AND CONTINUES THROUGH FRI NIGHT. FLOW
THEN SHIFTS TO E OR NE SUN AFTERNOON AS RIDGE BUILDS IN FROM WEST AND
CUTOFF LOW FORMS OVER THE NE PACIFIC.

.SURFACE...
SOUTHCENTRAL...
PRESSURE GRADIENT RELAXED SOME ACROSS THE NORTHERN GULF
OVERNIGHT...HOWEVER STRONG TEMPERATURE GRADIENTS REMAIN IN PLACE AND
SOME LOCALLY BRISK WINDS WERE STILL EVIDENT ACROSS THE
REGION...ESPECIALLY ACROSS THE GULF THIS MORNING. PRESSURE GRADIENTS
ACROSS THE GULF WILL INTENSIFY A LITTLE TONIGHT AS THE SURFACE LOW
WHICH FORMED SOUTH OF THE KENAI PEN OVERNIGHT INTENSIFIES. THIS
SURFACE LOW WILL DRIFT TOWARD SEWARD TONIGHT...THEN STALL AND
DISSIPATE SAT. EXPECT OVERRUNNING SNOW TO SPREAD INTO PRINCE WILLIAM
SOUND TONIGHT AND INTO INTERIOR SOUTHCENTRAL FRI. BLIZZARD POTENTIAL
IS LOOKING MORE FAVORABLE FOR THE THOMPSON PASS/KEYSTONE CANYON AREAS
LATE TONIGHT THRU FRI EVENING AS MODELS ARE STARTING TO ZERO IN ON A
COMMON SOLUTION. GENERALLY SE FLOW OVER THE GULF SAT WILL KEEP THE
POPS RELATIVELY HIGH ALONG THE COAST AND TO A LESSER EXTENT INLAND.
WARM ADVECTION ACCOMPANYING THIS LOW CLOUD BRING MIXED PRECIPITATION
TO GULF REGIONS SAT.

SOUTHWEST MAINLAND AND BERING SEA....
A FAIRLY STATIC PATTERN REMAINS IN PLACE FOR THE SHORT TERM. A STRONG
NORTHERLY JET CONTINUING FROM THE WESTERN COAST TO ACROSS THE AKPEN
WILL KEEP STRONG WINDS IN PLACE WITH COLD TEMPERATURES...MAKING WIND
CHILLS A FACTOR AS THEY APPROACH THE -10 TO -30 RANGE IN A LOT OF
PLACES ACROSS THE SOUTHWEST MAINLAND. IN ADDITION...WINDS BLOWING
THROUGH GAPS IN THE ALEUTIAN RANGE ON THE AKPEN WILL OCCASIONALLY
HELP PRODUCE WINDS NEARING HURRICANE FORCE AT TIMES. FARTHER WEST IN
THE CENTRAL AND WESTERN BERING SEA...FAIRLY CALM WINDS UNDER HIGH
PRESSURE AND PERIODS OF FOG WILL BE COMMON THROUGH THE WEEKEND. A
DISTURBANCE MAY APPROACH FROM THE WESTERN ALEUTIANS SUNDAY AS THE
HIGH BEGINS TO POSSIBLY BREAK DOWN.

.LONG TERM FORECAST...
MODELS STILL SUGGEST THAT THE LONG WAVE ATMOSPHERIC PATTERN WILL
REMAIN SIMILAR THROUGH THE NEXT 7 TO 8 DAYS. THIS WOULD SUGGEST
TEMPERATURES NEXT WEEK WILL REMAIN NEAR TO BELOW NORMAL...WITH
PRECIPITATION BELOW NORMAL EXCEPT TOWARDS THE GULF COAST...WHERE IT
WILL LIKELY REMAIN NEAR TO BELOW NORMAL.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WATCH...131
MARINE...GALES...121 127 130 155 160 165 170 171
         STORMS...150
FIRE WEATHER...NONE.

RMC DEC 10