Small Craft Advisory 941, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
550 AM AKST TUE NOV 26 2013

.MODEL DISCUSSION...
THE MODELS ARE DECENT AGREEMENT EXCEPT FOR SOME UNCERTAINTY WITH THE
WEAK LOW PLACEMENT THAT WILL TRACK NEAR CAPE HINCHINBROOK THIS
MORNING. THIS LOW WILL MOVE TO THE NORTHERN PORTIONS OF PRINCE
WILLIAM SOUND BY TUE AFTERNOON BEFORE DISSIPATING EARLY WEDNESDAY
MORNING. THIS WILL BRING LIGHT SNOW FOR ANCHORAGE BOWL EXTENDING UP
INTO THE MATANUSKA-SUSITNA VALLEY DUE TO THE SYSTEM LOOSING SUPPORT
ALOFT. ALONG THE COAST THE PRECIPITATION WILL MAINLY BE IN THE FORM
OF LIGHT RAIN WITH SOME AREAS OF MIXED RAIN/SNOW. BY THURSDAY THERE
WILL BE ANOTHER WEAK LOW PRESSURE SYSTEM FORMING IN THE NORTHERN GULF
NEAR THE PRINCE WILLIAM SOUND ENTRANCE. THE BERING SIDE HAS A WEAK
LOW JUST NORTHEAST OF PRIBILOF ISLANDS THAT WILL DRIFT SOME BEFORE
DISSIPATING BY WEDNESDAY MORNING. THERE WILL BE A HIGH PRESSURE RIDGE
BUILDING INTO THE WESTERN BERING SEA THIS MORNING BEFORE BEING A 1032
MB POSITIONED WEST OF PRIBILOF ISLANDS BY THURSDAY EVENING. THIS WILL
BRING WIDESPREAD STRATUS WITH PATCHY FOG. THE FORECAST CONFIDENCE
REMAINS HIGH HEADING INTO THE MIDDLE OF THE WEEK.

.ANALYSIS AND UPPER LEVELS...
A WEAK SURFACE LOW IS LOCATED AT THE ENTRANCE OF PRINCE WILLIAM SOUND
THIS MORNING WITH A WEAK 80 KNOT MERIDONAL JET STREAK WITH A NEGATIVE
TILTED TROUGH WEST OF KODIAK. THERE IS A WEAK TROUGH FROM THE BARREN
ISLANDS EXTENDING TOWARDS CAPE CLEARE WITH THE SATELLITE IMAGERY
SHOWING A SWATH OF MOISTURE IN SOUTHCENTRAL ALASKA. THE SURFACE
OBSERVATIONS ARE REFLECTING BROKEN TO OVERCAST SKY CONDITIONS WITH
LIGHT WINDS. THERE IS A NEGATIVE TILTED RIDGE OVER THE COPPER RIVER
BASIN EXTENDING NORTHWEST INTO FAIRBANKS. THE BERING SEA HAS A WEAK
LOW NORTHEAST OF THE PRIBILOF ISLANDS WITH A SWATH OF MOISTURE ALONG
THE SOUTHWEST ALASKA COASTLINE FORM DILLINGHAM NORTH TO HOOPER BAY.
THERE IS A POSITIVE TILTED RIDGE MOVING INTO THE WESTERN BERING SEA
WITH THE SATELLITE IMAGERY REFLECTING A LARGE AREA OF STRATUS/FOG
ASSOCIATED WITH THE BUILDING RIDGE OF HIGH PRESSURE.

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...
THERE WILL BE A SHORTWAVE TROUGH PUSHING UP THROUGH THE KENAI WITH A
SURFACE LOW ENTERING THE PRINCE WILLIAM SOUND THIS MORNING. THIS WILL
PROVIDE MOISTURE WITH A LIFTING MECHANISM TO AIDE IN PRODUCING SNOW.
THERE IS A BAND OF SNOW SHOWERS STRETCHING FROM HOMER TO KENAI MOVING
NORTHWARD. LOOK FOR SNOWFALL ACCUMULATIONS OF 1 TO 3 INCHES TODAY
NORTH OF MOOSE PASS THROUGH PORTAGE EXTENDING INTO THE TURNAGAIN PASS
TOWARDS GIRDWOOD. FOR THE ANCHORAGE BOWL EXTENDING INTO THE
MATANUSKA-SUSITNA VALLEY THERE WILL BE SNOW BY LATE MORNING GOING
INTO THE AFTERNOON BEFORE TAPERING OFF TO SCATTERED SNOW SHOWERS BY
MIDNIGHT TONIGHT WITH SNOWFALL ACCUMULATIONS UP TO 1 INCH. THE
EASTERN KENAI STRETCHING TO CORDOVA WILL SEE RAIN DUE TO SURFACE
TEMPERATURES IN THE UPPER 30S TO LOWER 40S WITH CONTINUED WARM
TEMPERATURES DUE TO THE WARM AIR ADVECTION THROUGHOUT THE DAY.

SOUTHWEST ALASKA...NOW THAT THE WIDESPREAD PRECIP OF THE LAST FEW
DAYS HAS ENDED...MOST OF THE SOUTHWEST MAINLAND WILL EXPERIENCE ONE
LAST ROUND OF RAIN AND SNOW SHOWERS AS THE EASTERN BERING LOW
CONTINUES TO DISSIPATE. AREAS OF PATCHY RADIATIONAL FOG HAS DEVELOPED
IN BRISTOL BAY EARLY THIS MORNING...AND ARE EXPECTED TO FORM AGAIN
OVERNIGHT TONIGHT DUE THE RECENT PRECIPITATION AND WARM TEMPERATURES
MOISTENING THE BOUNDARY LAYER. EXPECT CLEARING SKIES AND FALLING
TEMPERATURES STARTING WEDNESDAY TO CONTINUE FOR THE REST OF THE WEEK
AS A RIDGE MOVES IN FROM THE CENTRAL BERING BY FRIDAY.

THE BERING SEA AND ALEUTIAN CHAIN...THE CONVECTIVE RAIN AND SNOW
SHOWERS OVER THE BERING SEA AND ALEUTIANS WILL ALSO BEGIN TO DIMINISH
TODAY AS THE BERING LOW WEAKENS AND TEMPERATURES ALOFT BEGIN TO WARM.
A GALE FORCE LOW WILL THEN CLIP THE CENTRAL AND EASTERN ALEUTIANS
WEDNESDAY BEFORE THE BUILDING RIDGE ENCOMPASSES MOST OF THE REGION BY
THURSDAY...USHERING IN COOLER AND QUIETER WEATHER.

.LONG TERM FORECAST...THERE CONTINUES TO BE GAINING CONFIDENCE THAT
THE BLOCKING PATTERN THAT DEVELOPS ON FRIDAY WILL BE SIGNIFICANT
ENOUGH TO KEEP ANY SYNOPTIC SCALE LOWS WELL AWAY FROM MAINLAND ALASKA
INTO THE MIDDLE OF NEXT WEEK. THIS SETUP WILL ONCE AGAIN KEEP
MAINLAND IN A PROLONGED COLD AND DRY PATTERN...WITH STORMS CONFINED
TO THE BERING SEA REGION.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING...130 174 176
FIRE WEATHER...NONE.

DEK/PLD NOV 13