872
FXAK68 PAFC 211411
AFDAFC
SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
511 AM AKST FRI FEB 21 2025
SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 THROUGH 3)
DISCUSSION:
THE GULF WILL REMAIN ACTIVE HEADING INTO AND THROUGH THE UPCOMING
WEEKEND AS SEVERAL SYSTEMS ROTATE NORTHWARDS FROM THE NORTHERN
PACIFIC. THESE SYSTEMS WILL CONTINUE TO BRING MOSTLY RAIN TO THE
LOWER ELEVATIONS AND SNOW FOR THE HIGHER ELEVATIONS OF THE COASTAL
MOUNTAINS.
THIS MORNING'S SYSTEM IS CURRENTLY PUSHING WESTWARD ACROSS THE
KENAI PENINSULA WITH TROUGH EXTENDING EASTWARDS ALONG THE COAST AS
IT BEGINS TO MOVE INLAND AND WASH OUT. GUSTY WINDS IN PRINCE
WILLIAM SOUND OVER TO TURNAGAIN ARM WILL DECREASE LATER THIS
MORNING AS THE LOW RETROGRADES BACK TOWARDS BRISTOL BAY AND
GRADIENT RELAXES. WHILE A FEW LIGHT SHOWERS MAY MAKE IT OVER THE
MOUNTAINS, THE BULK OF THE PRECIPITATION STILL LOOKS TO FALL
ACROSS THE EASTERN KENAI AND WESTERN PRINCE WILLIAM SOUND BEFORE
SHIFTING OVER TO THE CHIGMIT MOUNTAINS AND INTO THE NORTHERN
SUSITNA VALLEY LATER THIS MORNING. A SECONDARY WAVE IS TAKING
SHAPE OVER THE NORTHERN GULF AS NOTED ON SATELLITE
IMAGERY...LIFTING NORTH INTO THE WESTERN COPPER BASIN TODAY. THIS
MAY ALLOW FOR A FEW SHOWERS TO DEVELOP THIS AFTERNOON.
ANOTHER SYSTEM WILL LIFT UP ACROSS THE WESTERN GULF SATURDAY WITH
THE SURFACE LOW STALLING AND LINGERING NEAR KODIAK ISLAND. TO ADD TO
THE FUN, ANOTHER SYSTEM WILL BE WORKING UP ALONG THE EASTERN GULF
COAST WITH A SLUG OF MOISTURE BEING TUGGED ALONG WITH THE SYSTEM. AS
HAS BEEN THE CASE THE PAST SEVERAL DAYS, THE NORTHERN GULF COAST
WILL SEE THE BULK OF PRECIPITATION FROM TOMORROW'S WESTWARD
PROPAGATING WAVE. ALTHOUGH MODELS ARE IN FAIRLY GOOD AGREEMENT
THROUGH THE FIRST HALF OF THE WEEKEND...THAT AGREEMENT QUICKLY
DISSOLVES BY SUNDAY AS EACH MODEL WANTS TO TAKE A DIFFERENT TRACK.
REGARDLESS OF WHICH TRACK ULTIMATELY PLAYS OUT, THE GULF LOOKS TO
REMAIN UNSETTLED WITH MOST INLAND AREAS OF SOUTHCENTRAL REMAINING
DRY, OR MOSTLY DRY THROUGH EARLY NEXT WEEK.
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (DAYS
1 THROUGH 3: TODAY THROUGH SUNDAY)...
VERY LITTLE REGARDING THE OVERARCHING PATTERN HAS CHANGED COMPARED
TO YESTERDAY, AND IS NOT REALLY EXPECTED TO CHANGE MUCH THROUGH
THE WEEKEND. A BROAD, DISORGANIZED UPPER LEVEL TROUGH WITH SEVERAL
EMBEDDED SMALLER FEATURES CONTINUES TO DRIFT OVER MUCH OF THE
BERING SEA AND SOUTHWEST THIS MORNING. VERY WEAK FLOW, BOTH AT
THE SURFACE AND ALOFT, IS TRANSLATING TO ONLY SLIGHT MOVEMENT OF
MULTIPLE WEAK LOWS EMBEDDED IN THE LARGE SCALE TROUGH IN PLACE.
ONE OF THESE LOWS IS STILL DRIFTING OVER THE WESTERN BERING, AND
THIS FEATURE WILL CONTINUE TO WOBBLE IN PLACE IN THE SAME VICINITY
FOR THE NEXT FEW DAYS. ANOTHER SMALL, WEAK LOW IS DRIFTING SLOWLY
NORTH NEAR KODIAK ISLAND. NORTH OF THIS LOW, A WEAK DEFORMATION
BAND OF PRECIPITATION HAS DEVELOPED FROM THE NORTHERN AKPEN OUT
TO THE DILLINGHAM AREA. THIS AREA OF RAIN AND SNOW SHOULD DIMINISH
AS THE BAND WEAKENS AND MOVES OFFSHORE LATER THIS MORNING.
AS ALREADY MENTIONED, LITTLE CHANGE IN THE PATTERN IS ANTICIPATED
FOR THE NEXT SEVERAL DAYS AS LIGHT STEERING FLOW AND WEAK, SLOW-
MOVING FEATURES REMAIN THE DOMINANT THEME. THE LOW IN THE WESTERN
BERING WILL SLOWLY DRIFT SOUTH, THEN EAST ALONG AND NORTH OF THE
CENTRAL/WESTERN ALEUTIAN CHAIN BETWEEN SATURDAY AND SUNDAY AS IT
HELPS TO KICK OFF SCATTERED SNOW SHOWERS. WINDS WILL GENERALLY
STAY QUITE WEAK AS THE LOW MOVES PAST, GENERALLY UNDER SMALL CRAFT
RANGE. MEANWHILE, AN INVERTED TROUGH AXIS WILL CROSS OVER THE
ALASKA/ALEUTIAN RANGE FROM THE EAST LATER TODAY INTO TONIGHT,
SUPPORTING ANOTHER ROUND OF LIGHT RAIN/SNOW FOCUSED PRIMARILY OVER
CENTRAL AND NORTHERN PORTIONS OF BRISTOL BAY. A COMPACT UPPER
LEVEL LOW WILL ALSO DRIFT UP FROM THE EASTERN ALEUTIANS INTO
SOUTHWEST FROM SATURDAY INTO SUNDAY, PROLONGING POTENTIAL FOR
AREAS OF LIGHT SNOW AND RAIN. TEMPERATURES REGION-WIDE WILL STAY
MOSTLY IN THE 20S AND 30S THROUGH THE WEEKEND, WITH A SLIGHT TREND
TOWARDS COOLER TEMPERATURES ACROSS SOUTHWEST BY SUNDAY.
-AS
.LONG TERM FORECAST (DAYS 4 THROUGH 7) MONDAY THROUGH THURSDAY.
A BROAD UPPER LEVEL TROUGH EXTENDS FROM A SIBERIAN LOW CENTER
ACROSS THE BERING AND INTO THE GULF OF ALASKA THROUGH THE FORECAST
PERIOD. A SECOND LOW CENTER IN THE NORTH PACIFIC WORKS ITS WAY
INTO THE GULF BEFORE DISSIPATING BY MIDWEEK. THE FLOW PATTERN
STARTS OFF CHAOTIC WITH NUMEROUS SHORTWAVES ROTATING THROUGHOUT
THE SYSTEM, BUT BECOMES SMOOTHER AND A BIT MORE ORGANIZED THROUGH
THURSDAY. A COUPLE OF LOW CENTERS SLIP ACROSS THE NORTH PACIFIC TO
THE SOUTH OF THE ALEUTIANS AND ALASKA PENINSULA WITH LITTLE
EFFECT OVER ALASKAN WATERS. A UPPER LEVEL RIDGE OUT OF WESTERN
CANADA BUILDS OVER INTERIOR ALASKA THROUGH THE WEEK.
A DECAYING FRONT ALONG THE SOUTHCENTRAL COAST SPREADS AREAS OF
RAIN, RAIN AND SNOW MIXED OR SNOW FROM KODIAK ISLAND TO THE
CANADIAN BORDER MONDAY. RIGHT ON ITS HEELS IS A SECOND LOW AND
FRONT THAT CONTINUES MORE ACTIVE WEATHER OVER THE SOUTHCENTRAL
COASTAL ZONES, AND EXTENDS THE PRECIPITATION AREAS INTO THE AKPEN
AND SOUTHWEST ALASKA THROUGH THROUGH THURSDAY. IN THE WEST, A
SERIES OF WEAKENING LOWS BRINGS MOSTLY RAIN ACROSS THE ALEUTIANS
AND BERING THROUGH THE WEEK. A WELL DEVELOPED NORTH PACIFIC LOW
AND FRONT APPROACHES THE ALEUTIANS FOR THURSDAY, AND OPENS WITH
SNOW CHANGING TO RAIN BEYOND THE END OF THIS FORECAST PERIOD.
- KUTZ
AVIATION
PANC...VFR CONDITIONS AND LIGHT NORTHERLY WINDS WILL PERSIST.
CEILINGS COULD DROP BELOW 5000 FT ON SATURDAY MORNING AS A GULF
LOW APPROACHES SOUTHCENTRAL, THOUGH CONFIDENCE IS HIGH THAT
CEILINGS WILL REMAIN VFR.
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