607
FXAK68 PAFC 280025
AFDAFC
SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
425 PM AKDT THU MAR 27 2025
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA
(DAYS 1 THROUGH 3: THIS AFTERNOON THROUGH SUNDAY EVENING)...
A WEAK UPPER-LEVEL LOW CONTINUES TO SPIN NEAR KODIAK ISLAND THIS
AFTERNOON AND WILL EVENTUALLY MOVE SOUTH AND INTO THE NORTH
PACIFIC BY FRIDAY EVENING. IN THE MEANTIME, EXPECT CLOUDY
CONDITIONS TO PERSIST ACROSS KODIAK ISLAND THROUGH TONIGHT WITH
CHANCES OF A BRIEF SHOWER BEING SMALL. FURTHER NORTH ACROSS THE
MAINLAND COAST, GUIDANCE HAS COME INTO BETTER AGREEMENT WITH A
SOUTHEAST GULF LOW LIFTING NORTHWESTWARD TO THE WESTERN GULF BY
FRIDAY EVENING. MOST PRECIPITATION WILL BE CONFINED TO COAST WITH
THIS SYSTEM; ESPECIALLY WESTERN PRINCE SOUND AND PORTIONS OF THE
EASTERN KENAI PENINSULA. LOCATIONS SUCH AS WHITTIER AND SEWARD CAN
EXPECT LIGHT RAIN OR BRIEF RAIN/SNOW MIX GOING OVER TO ALL RAIN
FRIDAY EVENING INTO SATURDAY. AT THE SAME TIME, A SHORTWAVE
ACROSS INTERIOR ALASKA WILL DIG SOUTHWARD AND HELP TO PULL UP SOME
GULF MOISTURE OVER THE COPPER RIVER BASIN. THIS WILL RESULT IN A
PERIOD OF LIGHT SNOW ACROSS THE BASIN LATE FRIDAY NIGHT THROUGH
SATURDAY AFTERNOON BEFORE PRECIPITATION BECOMES MORE CONFINED TO
HIGHER TERRAIN OF THE WRANGLES AND CHUGACH. GAP WINDS WILL PERSIST
THROUGH PASSAGE CANAL, RESURRECTION BAY, VALDEZ NARROWS, AS WELL
AS THOMPSON PASS.
UNCERTAINTY ENSUES STARTING SATURDAY EVENING. AN INVERTED SURFACE
TROUGH IS POISED TO PIVOT WESTWARD ACROSS THE GULF THROUGH SUNDAY.
HOWEVER, THERE CURRENTLY LOW CONFIDENCE IN THE PROGRESSION/SPEED
OF THIS FEATURE. AS SUCH, STUCK WITH CHANCE POPS ACROSS THE
NORTHERN GULF COAST AND PRINCE WILLIAM SOUND COMMUNITIES SATURDAY
EVENING THROUGH SUNDAY EVENING.
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (DAYS
1 THROUGH 3: TONIGHT THROUGH SUNDAY)...
AN ALMOST COMPLETELY STEADY-STATE PATTERN IS EXPECTED TO PERSIST
INTO THE WEEKEND AS A STRONG, BLOCKING UPPER RIDGE AXIS EXPANDS
AND INTENSIFIES ACROSS THE WESTERN BERING SEA OVER THE NEXT FEW
DAYS. TO THE EAST OF THIS AREA OF HIGH PRESSURE, DRY AND COOL
NORTHERLY FLOW IS CONTINUING ACROSS SOUTHWEST, WHERE MOSTLY CLEAR
SKIES AND SEASONABLY COOL TEMPERATURES REMAIN IN PLACE. STRONG AND
GUSTY WINDS HAVE PICKED UP THROUGHOUT THE DAY ACROSS THE EASTERN
ALEUTIANS AND SOUTHERN AKPEN, SUPPORTED BY A COMBINATION OF COLD
AIR ADVECTION AND A STRONG PRESSURE GRADIENT BETWEEN THE RIDGE OUT
WEST AND A WEAK LOW IN THE GULF. GALE FORCE WINDS WITH GUSTS UP TO
STORM FORCE ALONG AND JUST SOUTH OF THE AKPEN WILL CONTINUE FOR
THE FORESEEABLE FUTURE AS THIS SUPPORTING LARGE SCALE PATTERN
REMAINS FAIRLY STAGNANT THROUGH THE WEEKEND. QUIET CONDITIONS WITH
MUCH CALMER WINDS WILL PERSIST FARTHER WEST ALONG MOST OF THE
ALEUTIAN CHAIN AND PRIBILOF ISLANDS.
OVER THE WEEKEND ACROSS SOUTHWEST, CLOUD COVER WILL BEGIN TO
INCREASE AS MOISTURE WRAPS EAST AROUND THE CREST OF THE RIDGE
FROM A FRONTAL SYSTEM MOVING ACROSS THE NORTHERN BERING SEA. THERE
WILL BE SOME CHANCE FOR AREAS OF LIGHT PRECIPITATION TO FILL IN
ACROSS PARTS OF THE KUSKOKWIM DELTA AS THIS MOISTURE AXIS STREAMS
INTO PLACE BETWEEN SATURDAY AND SUNDAY, BUT ANYTHING THAT DOES
REACH THE GROUND WILL LIKELY REMAIN VERY LIGHT. THERE IS A SMALL
CHANCE FOR SOME OF THIS TO FALL AS A MIX OF SNOW, FREEZING RAIN
AND SLEET. THIS POTENTIAL IS DUE TO THE COMBINATION OF A STRONG
WARM NOSE PRODUCED BY SUBSIDENCE WARMING UNDER THE RIDGE AND
SURFACE TEMPERATURES THAT COULD HOVER AT OR JUST BELOW FREEZING
THROUGH SUNDAY. AGAIN, ANY MIXED PRECIPITATION THAT DOES DEVELOP
IS EXPECTED TO REMAIN LIGHT.
-AS
LONG TERM FORECAST (DAYS 4 THROUGH 7: MONDAY TO THURSDAY)
THE STEADY CHANGES IN THE OVERALL PATTERN CONTINUE THROUGH THE
FORECAST PERIOD. THE UPPER LEVEL BERING RIDGE FLATTENS OUT, BUT
REMAINS QUITE BROAD THROUGH THE WEEK. A COUPLE OF UPPER TROUGHS
MOVE OVER THE RIDGE IN THE ARCTIC. AN UPPER TROUGH EXTENDING FROM
A LOW IN THE CANADIAN ARCTIC CURVES BACK INTO THE EASTERN GULF OF
ALASKA THROUGH MIDWEEK. A GFS / ECMWF / CANADIAN MODEL BLEND
CONTINUES GOOD CONTINUITY WITH THE DETAILS THROUGH MOST OF THE
FORECAST, AND SWITCHES TO AN ENSEMBLE BLEND FOR THE END OF THE
WEEK TO KEEP HOLD OF THE FORECAST FEATURES.
AREAS OF LOCALLY MODERATE SNOW MOVE OVER INTERIOR ALASKA AND
EXITS THE EASTERN BORDER THROUGH TUESDAY. A NEW FRONT INTRODUCES
MORE SNOW AND GUSTY WINDS ALONG THE WEST COAST LATE TUESDAY,
SPREADING TO THE INTERIOR AND ALASKA PENINSULA THROUGH THURSDAY.
SNOW CHANGES TO RAIN AROUND THE WESTERN YUKON AND KUSKOKWIM
VALLEYS COASTAL AREAS BEFORE DISSIPATING EARLY WEDNESDAY. A WELL
DEVELOPED CENTRAL KAMCHATKA LOW AND FRONT BRINGS LOCALLY MODERATE
SNOW CHANGING TO RAIN AND GUSTY WINDS INTO THE WESTERN ALEUTIANS
AND BERING TUESDAY, DIMINISHING WEDNESDAY OVER THE BERING.
- KUTZ
.AVIATION...
PANC...VFR CONDITIONS AND NORTHERLY WINDS PERSIST THROUGH FRIDAY
AFTERNOON.
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