Small Craft Advisory 952, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
401 PM AKST SUN NOV 29 2015

.ANALYSIS AND UPPER LEVELS...
A BROAD UPPER LEVEL TROUGH ENCOMPASSES MUCH OF THE BERING RIGHT
NOW...WITH ONE EMBEDDED LOW CENTERED NEAR KAMCHATKA PENINSULA AND
A SECOND LOW OVER THE EASTERN ALEUTIANS. TO THE EAST...A BROAD
RIDGE STRETCHES ACROSS BRITISH COLUMBIA INTO MAINLAND ALASKA. A
WEAK UPPER LEVEL WAVE IS TRAVERSING ACROSS SOUTHCENTRAL AND
SUPPORTING ISOLATED SHOWERS ACROSS THE KENAI PENINSULA...SUSITNA
VALLEY...AND ANCHORAGE BOWL. AT THE SURFACE...A LOW IS CENTERED
OVER THE EASTERN ALEUTIANS WITH AN ASSOCIATED FRONT THAT STRETCHES
FROM THE PRIBILOFS TO THE ALASKA PENINSULA. MEANWHILE...COLD AIR
CONTINUES TO BE BOTTLED IN THE WESTERN BERING WHERE COLD AIR
ADVECTION IS SUPPORTING WIDESPREAD SHOWERS.

&&

.MODEL DISCUSSION...
MODELS REMAIN IN GREAT AGREEMENT TODAY WITH GENERALLY MINOR DIFFERENCES
IN THE INTENSITY AND TIMING OF THE FRONT AS IT PROGRESSES FROM THE
AKPEN TO THE NORTHERN GULF OF ALASKA COAST. AS A RESULT A BLEND
OF MODELS WAS PREFERRED...WITH THE GFS FAVORED OUT WEST...AND THE
NAM FAVORED IN THE EAST FOR CAPTURING LOCAL AFFECTS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
AS THE LOW NEAR THE EASTERN ALEUTIANS CONTINUES ITS TRACK TO THE
EAST ITS FRONT WILL PUSH NORTH THROUGH THE GULF AND MAKE IT TO THE
NORTH GULF COAST MONDAY NIGHT. THIS WILL BRING MORE RAIN AND SNOW
TO AREAS ALONG THE COAST. THE LOW WILL ALSO ALLOW FOR CONTINUED
SOUTH TO SOUTHEAST FLOW FOR SOUTHCENTRAL INTO WEDNESDAY WHICH
WILL CONTINUE THE FLOW OF WARMER AIR MAINTAINING ABOVE AVERAGE
TEMPERATURES. ADDITIONALLY...THE SOUTH TO SOUTHEAST FLOW WILL BE
STRONG ENOUGH TO DOWNSLOPE INLAND AREAS AND KEEP THE MAJORITY OF
THE PRECIPITATION ALONG THE GULF COAST.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
THE SURFACE LOW NEAR THE EASTERN ALEUTIANS PUSHES THE FRONT FROM
THE ALASKA PENINSULA INTO BRISTOL BAY TONIGHT. GUSTY EAST WINDS
ARE EXPECTED TO INCREASE TONIGHT ACROSS THE ALASKA PENINSULA AND
BRISTOL BAY...WITH THE STRONGEST WINDS ACROSS THE COASTAL AREAS OF
BRISTOL BAY AND ALONG THE ALEUTIAN RANGE. A MIX OF SNOW AND RAIN
WILL ACCOMPANY THIS FRONT AS TEMPERATURES HOVER IN THE 30S...EXCEPT
FOR SNOW ACROSS THE KUSKOKWIM DELTA WHERE TEMPERATURES REMAIN BELOW
FREEZING. ACCUMULATIONS WILL BE LIGHT AS THE LOW CENTER BECOMES
DISORGANIZED SOUTH OF THE ALASKA PENINSULA.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE OCCLUDED SURFACE LOW ACROSS THE EASTERN ALEUTIANS MOVES SOUTH
OF THE ALASKA PENINSULA TONIGHT. WARM PACIFIC MOISTURE WILL CONTINUE
TO STREAM INTO THE EASTERN BERING BRINGING A MIX OF RAIN AND SNOW
AS FAR NORTH AS THE PRIBILOF ISLANDS AND THEN CHANGE TO ALL SNOW
FURTHER NORTH. NORTH TO WESTERLY FLOW RETURNS ACROSS THE BERING
THROUGH MONDAY. GUSTY WINDS ARE EXPECTED TO INCREASE ACROSS THE
SOUTHERN BERING AND ALEUTIANS MONDAY NIGHT AS THE PRESSURE GRADIENT
INCREASES DUE TO A PATTERN SHIFT. THE UPPER LOW OVER THE KAMCHATKA
PENINSULA KICKS A SURFACE LOW EAST WHICH PUSHES AN AMPLIFYING
SURFACE RIDGE TO THE WESTERN BERING. THE PRESSURE GRADIENT
TIGHTENS ACROSS THE EASTERN CHAIN AS THE LOW NEAR THE PENINSULA
REMAINS STATIONARY THROUGH TUESDAY.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
BEGINNING THE EXTENDED PERIOD ON WEDNESDAY...A BROAD UPPER LEVEL
TROUGH WILL BE IN PLACE ACROSS SOUTHERN ALASKA AND THE NORTHEAST
PACIFIC...WITH ANOTHER GALE TO NEAR STORM FORCE BERING LOW
DEVELOPING OVER THE WESTERN ALEUTIANS. WITH THE MAIN PACIFIC JET
AND STORM TRACK SHUNTED WELL SOUTH OF THE REGION...SOUTHERN ALASKA
WILL BE UNDER A RATHER WEAK FLOW REGIME WITH COASTAL SHOWERS AND
CONTINUED CLOUDINESS INLAND. A SERIES OF WEAK UPPER TROUGHS WILL
SUPPORT SOME INLAND SNOW SHOWERS WEDNESDAY NIGHT AND THURSDAY...MAINLY
ACROSS SOUTHCENTRAL...BEFORE DRYING OUT FRIDAY INTO THE WEEKEND.
WITH AN ARCTIC SURFACE HIGH IN THE VICINITY OF THE NORTH SLOPE...WEAK
OUTFLOW WINDS IN THE LOW LEVELS WILL ALLOW TEMPS TO CONTINUE
MODERATING BACK TOWARD NORMAL THROUGH THE WEEKEND. OTHERWISE...THE
PACIFIC JET WILL REMAIN QUITE ACTIVE...WITH THE STORM TRACK REMAINING
AROUND 40-45N. THIS WILL KEEP INTERIOR SOUTHERN ALASKA FREE OF ANY
SIGNIFICANT STORMS THROUGH NEXT WEEKEND. NO SIGNIFICANT COLD AIR
OUTBREAKS ARE EXPECTED EITHER AS THE MAIN BELT OF COLD AIR REMAINS
ACROSS THE WESTERN AND CENTRAL BERING SEA.

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING 130 131 132 138 150 155 160 165 170 171 172
                      173 174 175 176 180.

&&

SYNOPSIS AND MODEL DISCUSSION...EN
SOUTHCENTRAL ALASKA...DK
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...KH
LONG TERM...JA