593
FXAK68 PAFC 210141
AFDAFC
SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
441 PM AKST THU FEB 20 2025
SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 THROUGH 3)
A WEST-TO-EAST ORIENTED TROUGH IN THE WESTERN GULF OF ALASKA WILL
CONTINUE TO LIFT NORTH AND ROTATE INTO THE NORTHERN GULF COAST
THIS AFTERNOON THROUGH FRIDAY, CONTINUING THE ACTIVE WEATHER
PATTERN FOR COASTAL AREAS AND WARM TEMPERATURES ACROSS
SOUTHCENTRAL. AS THE TROUGH CONTINUES NORTHWESTWARD INTO SOUTHWEST
ALASKA, THE HIGHEST PRECIPITATION ACCUMULATIONS ARE EXPECTED TO
REMAIN OVER THE EASTERN KENAI PENINSULA AND TURNAGAIN ARM. LOWER
ELEVATIONS CONTINUE TO SEE MOSTLY RAIN WITH ELEVATIONS 500-1000
FEET SEEING A CHANGEOVER TO SNOW THROUGH TONIGHT BEFORE THE
TRANSITION ZONE RISES TO ABOVE 1000 FEET AS WARM SOUTHERLY FLOW
BEHIND THE FRONT PUSHES INLAND. THE TIGHTENING PRESSURE GRADIENT
AS THE FONT APPROACHES WILL ALLOW FOR WINDS OVER THE WESTERN
CHUGACH AND KENAI MOUNTAINS TO PICK UP TONIGHT AND REMAIN ELEVATED
THROUGH TOMORROW AFTERNOON. WHILE THE BULK OF THE PRECIPITATION
WILL REMAIN ON THE GULF SIDE, WILL LIKELY SEE SOME LIGHT
PRECIPITATION SPILL INTO THE COPPER BASIN OVERNIGHT TONIGHT AND
FRIDAY. BY TOMORROW MORNING, UPSLOPE FLOW ALONG THE ALASKA RANGE
WILL INCREASE PRECIPITATION CHANCES ACROSS THE WESTERN AND
NORTHERN SUSITNA VALLEY THROUGH SATURDAY MORNING.
A BREAK BETWEEN SYSTEMS ALONG THE GULF COAST WILL BE SHORT-LIVED
AS ANOTHER SYSTEM TRACKS NORTH ACROSS THE EASTERN GULF,
REINFORCING LIFT AND CONTINUED UNSETTLED WEATHER ALONG THE COAST.
WHILE MODEL AGREEMENT REMAINS LOW ON THE EXACT TRACK AND EVOLUTION
OF THE LOW AS IT TRAVERSES NORTH THROUGH THE GULF, ANOTHER ROUND
OF PRECIPITATION FOR COASTAL AREAS LOOKS LIKELY BEGINNING BY
SATURDAY AFTERNOON THROUGH THE REMAINDER OF THE WEEKEND AS MOIST
SOUTHERLY FLOW OVER THE GULF PERSISTS INTO THE EARLY PART OF NEXT
WEEK.
-JH
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (DAYS
1 THROUGH 3: TODAY THROUGH SUNDAY MORNING)...
BROAD UPPER LEVEL LOW PRESSURE IN THE BERING SEA WILL BRING A
CHANCE OF SNOW SHOWERS TO THE WESTERN ALEUTIANS, INCLUDING ADAK
FROM THIS AFTERNOON THROUGH THE WEEKEND. A SURFACE LOW MOVING WEST
OF THE PRIBILOF ISLANDS HAS ALREADY BEGUN ENTRAINING COLDER AIR
AT THE 850 MB LEVEL, SIGNIFICANTLY DROPPING TEMPERATURES OVER THE
WESTERN AND CENTRAL BERING. WEAK UPPER LEVEL FEATURES WILL PROVIDE
SUPPORT TO LOCALLY ENHANCE SHOWERS AS THEY MOVE THROUGH THE FLOW.
SOUTHWEST ALASKA WILL CONTINUE TO SEE PERIODS OF SHOWERY
PRECIPITATION AND EASTERLY TO NORTHEASTERLY FLOW AS ANOTHER NORTH
PACIFIC LOW CROSSES THE ALASKA PENINSULA AND INTO BRISTOL BAY ON
SATURDAY, AND AS THE HEIGHT OF THE FREEZING LAYER CONTINUES TO
LOWER, BRISTOL BAY AND THE ALASKA PENINSULA WILL SEE RAIN AND
RAIN/SNOW MIX CHANGE TO ALL SNOW BY SATURDAY. SURFACE
TEMPERATURES FROM THE PRIBILOF ISLANDS TO THE ALASKA PENINSULA AND
BRISTOL BAY WILL HOVER IN THE MID TO LOW THIRTIES, EXCEPT FOR THE
LOWER KUSKOKWIM VALLEY AND KUSKOKWIM DELTA, WHERE TEMPERATURES
WILL ONLY REACH THE TEENS TO MID-TWENTIES. THE POTENTIAL FOR LIGHT
PRECIPITATION WILL PERSIST FOR BRISTOL BAY AND ALASKA PENINSULA
UNTIL SUNDAY MORNING.
.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. A FEW
WEAK EASTERLY WAVES ARE STILL EXPECTED TO WILL MOVE ACROSS THE
TERMINAL WITH A FRONT MOVING INTO SOUTHCENTRAL BY FRIDAY, BUT
PRECIPITATION AND SIGNIFICANTLY LOWER CEILINGS LOOK UNLIKELY WITH
ANY OF THESE FEATURES.
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