Area Forecast Discussion - SouthCentral and SouthWest


FXAK68 PAFC 181327
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
527 AM AKDT FRI APR 18 2014
.ANALYSIS AND UPPER LEVELS...
A BROAD LONGWAVE TROUGH ENCOMPASSES ALASKA AND ITS SURROUNDING
WATERS. WATER VAPOR IMAGERY EARLY THIS MORNING SHOWS A CLOSED LOW 
CENTER SPINNING ALONG THE WESTERN ALASKA PENINSULA. MULTIPLE
SHORTWAVES ARE EMBEDDED THROUGH THE FLOW AROUND THE LOW CENTER. A
WEAK SHORTWAVE IS MOVING INTO THE NORTHERN GULF OF ALASKA THIS
MORNING...BUT LACKS ANY DISTINCT SURFACE FEATURE. RAIN SHOWERS ARE
DEVELOPING ALONG THE WAVE IN THE NORTHERN GULF WITH A FEW SHOWERS
MAKING IT INLAND. TO THE WEST...PATCHY FOG WITH SCATTERED RAIN AND
SNOW SHOWERS SPAN ACROSS THE BERING. THE NEXT SYSTEM THAT WILL
MOVE INTO THE SOUTHERN GULF LATER TONIGHT IS A STACKED LOW PRESSURE
SYSTEM SOUTH OF 50N AND ALONG 150W.

&&
.MODEL DISCUSSION...
MODELS CONTINUE IN GOOD AGREEMENT WITH THE OVERALL SYNOPTIC
PATTERN THROUGH SUNDAY NIGHT. RAIN AND SNOW ACTIVITY ASSOCIATED
WITH THE SHORTWAVE IN THE NORTHERN GULF WILL SPREAD INLAND TODAY
AND THEN DIMINISH AS THE WAVE MOVES NORTH. LOW PRESSURE IN THE EASTERN
BERING WILL BECOME STATIONARY AS IT IS SQUEEZED BETWEEN HIGH
PRESSURE BUILDING INTO EASTERN ALASKA AND THE WESTERN BERING. THE
RIDGE BUILDING INTO THE MAINLAND WILL ALSO SHUNT THE NORTHWARD
PROGRESSION OF THE NORTH PACIFIC LOW THAT IS CURRENTLY MOVING
TOWARD THE GULF. THE ECMWF AND GFS WERE THE FAVORED MODELS FOR
UPDATES TO THE FORECAST PACKAGE AS THEY HAD THE BEST MODEL RUN
CONSISTENCY.

&&
.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...
RAIN AND SNOW ALONG THE NORTHERN GULF WILL SPREAD INLAND TODAY AS
THE SHORTWAVE MOVES NORTH. THE GULF WILL SEE PERIODS OF RAIN
THROUGH THE WEEKEND AS LOW PRESSURE FROM THE NORTH PACIFIC
MEANDERS ACROSS THE SOUTHERN GULF. THIS LOW WILL BRING AN OCCLUDED
FRONT INTO THE SOUTHERN GULF TONIGHT. RAIN DEVELOPING ALONG THE
FRONT WILL BRING MODERATE TO HEAVY RAIN AT TIMES FOR KODIAK ISLAND
THROUGH SATURDAY WITH SNOW ALONG THE HIGHER ELEVATIONS INLAND.
SCATTERED SHOWERS WILL SPREAD NORTH FROM THE LOW CENTER MAKING IT
TO COASTAL LOCATIONS AND THEN DIMINISH WITH THE PREVAILING HIGH
OVER THE MAINLAND. 

SOUTHWEST ALASKA...
THE UPPER LEVEL TROUGH WILL STALL OUT OVER THE EASTERN BERING SEA
THIS EVENING BEFORE DISSIPATING EARLY SATURDAY MORNING. THIS WILL
KEEP SKIES CLOUDY WITH PERIODS OF RAIN FOR BRISTOL BAY
TODAY...WITH MORE SHOWERY ACTIVITY EXPECTED FURTHER NORTH AND
WEST. ANOTHER BAND OF RAIN WILL PUSH INTO COASTAL BRISTOL BAY
EARLY SATURDAY MORNING AS A GULF LOW APPROACHES BEFORE THE ENTIRE
AREA WILL BEGIN TO CLEAR OUT LATE SATURDAY INTO SUNDAY. THE ONE
EXCEPTION TO THIS TREND WILL BE WITH A SLIGHT CHANCE OF SHOWERS
FOR THE KUSKOKWIM DELTA ON SUNDAY AS A SHARP ARCTIC TROUGH CLIPS
THE AREA.

BERING SEA/ALEUTIANS...
THE MAJORITY OF THE ACTIVE WEATHER WILL REMAIN FROM THE PRIBILOF
ISLANDS EASTWARD INTO THIS WEEKEND. SCATTERED TO NUMEROUS RAIN AND
SNOW SHOWERS WILL MIGRATE THROUGHOUT THE EASTERN BERING THROUGH
SATURDAY. FURTHER WEST...RIDGING WILL SLOWLY BEGIN TO BUILD INTO
THE WESTERN ALEUTIANS LATER TODAY...WHICH WILL BRING CLEARING
SKIES AND OTHERWISE BENIGN WEATHER THROUGH SATURDAY. MORE ACTIVE
WEATHER WILL ONCE AGAIN RETURN TO THE WESTERN ALEUTIANS SUNDAY AS
THE NEXT ALEUTIAN LOW DRAWS NEAR.

&&
.LONG TERM FORECAST...
LONG TERM FORECAST CONFIDENCE IS GAINING AS LITTLE CHANGE HAS
OCCURRED IN THE FORECAST IN THE LAST 24 HOURS. THE MODELS REMAIN
IN GOOD AGREEMENT THAT HIGH PRESSURE THAT WILL BUILD OVER MAINLAND
ALASKA EARLY NEXT WEEK WILL KEEP A MAJORITY OF THE ACTIVE WEATHER
CONFINED TO THE BERING SEA AND ALEUTIANS. THIS WILL BRING A RETURN
TO MOSTLY CLEAR SKIES AND SPRING LIKE TEMPERATURES TO MUCH THE
MAINLAND THAT WILL CONTINUE INTO THE MIDDLE OF NEXT WEEK.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALES 131 132 138 351 352.
FIRE WEATHER...NONE. 

&&

$$

KH/DEK APR 14