Gale Warning 363, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 PM AKDT SAT APR 13 2013

.ANALYSIS AND UPPER LEVELS...

A STRONG HIGH PRESSURE RIDGE ALOFT IS CENTERED OVER DUTCH HARBOR THIS
AFTERNOON...WITH SOUTHERLY FLOW OVER THE WESTERN ALEUTIANS AND BERING
SEA AND NORTHWESTERLY FLOW OVER THE SOUTHERN MAINLAND OF ALASKA. IN
THIS NORTHWESTERLY FLOW...A SHORTWAVE RIDGE RESIDES OVER INTERIOR
SOUTHCENTRAL ALASKA OUT AHEAD OF A WELL-DEFINED ARCTIC LOW SITUATED
OVER FAR NORTHWESTERN ALASKA.

.MODEL DISCUSSION...

MODELS ARE IN GREAT AGREEMENT IN THE SHORT TERM. ALL MODELS MOVE THE
ARCTIC LOW SOUTH AND EAST TO SOUTHCENTRAL ALASKA BY MONDAY...THEN
STALLS IT OVER THE AREA THROUGH NEXT WEEK WHILE IT SLOWLY WEAKENS.
THE RIDGE NEAR DUTCH HARBOR STRENGTHENS AND EXPANDS NORTH AND WEST
TOWARDS FAR NORTHEASTERN RUSSIA AND THE BERING STRAIT REGION BY
TUESDAY.

.SHORT TERM FORECAST...

SOUTHCENTRAL...

EMBEDDED SHORTWAVE DISTURBANCES WILL MOVE NORTHWEST TO SOUTHEAST
ACROSS THE REGION THROUGH SUNDAY. AS EACH ONE PASSES...OUTFLOW WINDS
ARE LIKELY TO KICK UP ESPECIALLY THROUGH GAPS OUT INTO PRINCE WILLIAM
SOUND AND THE GULF. OTHERWISE...THE NEXT SNOW CONCERN COMES FROM THE
ARCTIC LOW APPROACHING FROM THE NORTHWEST. SNOW SHOWERS ARE EXPECTED
MAINLY ALONG THE ALASKA RANGE SUNDAY AFTERNOON AND SUNDAY NIGHT...BUT
THEN AS THE LOW SETTLES OVERHEAD THE ENTIRE REGION WILL BECOME
SUSCEPTIBLE TO PICKING UP SOME DIURNAL SNOW SHOWER ACTIVITY. THIS LOW
WILL BE QUITE DEEP AND STRONG...BUT NOT NEARLY AS STRONG AS THE LOW
LAST WEEKEND THAT PRODUCED OCCASIONALLY WIDESPREAD HEAVY SNOW SHOWERS
OVER THE REGION.

SOUTHWEST...

SHORTWAVE DISTURBANCES WILL CONTINUE TO CLIP THE NORTHERN PARTS OF
THE REGION...ESPECIALLY TOWARD INLAND SECTIONS OF THE KUSKOKWIM
DELTA. MOST OF THE SNOW THAT DOES OCCUR WILL GET WRUNG OUT BY THE
HIGHER TERRAIN...SO SKIES SHOULD REMAIN NO WORSE THAN PARTLY CLOUDY
FOR DILLINGHAM TO KING SALMON. TEMPERATURES WILL CONTINUE MUCH BELOW
NORMAL WITH A SLIGHT MODERATING TREND THROUGH EARLY SUNDAY BEFORE A
REINFORCING SHOT OF COLD AIR MOVES SOUTH ON THE BACK SIDE OF THE
ARCTIC LOW...CENTERING OVER THE KUSKOKWIM VALLEY REGION ESPECIALLY.

BERING SEA/ALEUTIANS...

TRANQUIL WEATHER UNDERNEATH HIGH PRESSURE OVER THE CENTRAL AND
EASTERN BERING SEA WILL NUDGE NORTH TOWARDS THE FAR NORTHERN BERING
SEA AS A SERIES OF FRONTS BEGIN TO EDGE NORTH TO THE SOUTH OF THE
ALEUTIANS. BY LATE SUNDAY THROUGH TUESDAY...THESE SYSTEMS WILL GRAZE
THE AKPEN AND ALEUTIANS WHILE GRADUALLY ALLOWING FOR AN INCREASE IN
EASTERLY WINDS ACROSS THE SOUTHERN BERING SEA REGION.

.LONG TERM FORECAST...

MOST OF THE NEXT WEEK INTO NEXT WEEKEND WILL SEE THE ARCTIC LOW
POSITIONED OVER SOUTHCENTRAL ALASKA NEAR ANCHORAGE. THIS WILL BRING A
FAIRLY DIURNAL PATTERN OF AFTERNOON SNOW SHOWER ACTIVITY TO THE
SOUTHERN ALASKA MAINLAND WITH MOSTLY CLEAR AND CHILLY NIGHTS. SOME
MODELS SUGGEST THAT THE LOW COULD PICK UP SOME MOISTURE IN THE
PACIFIC AND MOVE IT NORTH TO PRINCE WILLIAM SOUND BY MIDWEEK...BUT
CONFIDENCE IS LOW AT THIS TIME. OVERALL...TEMPERATURES SHOULD REMAIN
MUCH BELOW NORMAL FOR MID APRIL.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES...176
         HVY FRZG SPRY...121 126 127
FIRE WEATHER...NONE.

29/CC APR 13