897
FXAK68 PAFC 021330
AFDAFC
SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
530 AM AKDT FRI MAY 2 2025
SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 THROUGH 3)
AT 4 AM THIS MORNING, A SURFACE LOW IS SITUATED IN THE
NORTHWESTERN GULF ABOUT HALFWAY BETWEEN SEWARD AND KODIAK CITY. AN
OCCLUDED FRONT ATTACHED TO THE LOW IS SWEEPING OVER THE NORTHERN
GULF AND IS POISED TO DRIVE INLAND BY MID-MORNING. THE FIRST
UPPER-LEVEL WAVE OUT AHEAD OF THE SURFACE FRONT IS NOW TO THE WEST
OF COOK INLET WITH THE WIDESPREAD RAIN ASSOCIATED WITH IT
CONTINUING TO TRACK WEST OF ANCHORAGE AND KENAI.
WINDS ALONG THE SURFACE FRONT ARE QUICKLY PICKING UP WITH
SOUTHEASTERLY GUSTS ALONG THE IMMEDIATE SOUTHCENTRAL COAST AND
PRINCE WILLIAM SOUND. RISING PRESSURES AND AN UNSTABLE AIRMASS
BEHIND THE FRONT WILL HELP TO INCREASE THESE GUSTS AS THE FRONT
MOVES INLAND THIS MORNING. EXPECT A RAPID INCREASE IN GUSTS FOR
THE TYPICAL GAP LOCATIONS BY LATE MORNING OR EARLY AFTERNOON. THE
STRONGEST WINDS AND GUSTS WILL LIKELY BE THROUGH PASSAGE CANAL AND
AND ACROSS WHITTIER AND PORTAGE AND ALONG TURNAGAIN ARM.
WIDESPREAD SHOWERS WILL CONTINUE FOR THE COASTAL MOUNTAINS AS THE
SOUTHEASTERLY FLOW PERSISTS. SHOWERS WILL ALSO PICK UP ACROSS THE
COPPER RIVER BASIN AND NORTHERN SUSITNA VALLEY LATER THIS MORNING
AS THE UPPER-LEVEL WAVE WITH THE FRONT MOVES INTO THE INTERIOR.
FOR THE WESTERN KENAI PENINSULA NORTH INTO THE SOUTHERN MAT-SU
VALLEYS, BREAKS OF SUNSHINE WILL ALLOW FOR AN INCREASE IN DAYTIME
HEATING AND THE POTENTIAL FOR ADDED INSTABILITY. THIS, COMBINED
WITH ANOTHER WAVE PUSHING INLAND, MAY LEAD TO THE DEVELOPMENT OF A
FEW ISOLATED THUNDERSTORMS. AN ISOLATED THUNDERSTORM IS ALSO
POSSIBLE ACROSS THE NORTHERN GULF AND AROUND CORDOVA.
THE TURNAGAIN ARM WIND, ALONG WITH OTHER GAP WINDS, WILL DIMINISH
FRIDAY NIGHT AS THE LOW NEAR KODIAK DEVOLVES INTO A TROUGH AND
PUSHES EASTWARD. ALSO, PRECIPITATION CHANCES WILL SIMILARLY
DIMINISH AS THE LOW DEVOLVES, LEAVING LINGERING SHOWERS THROUGH
SATURDAY AS A WEAK RIDGE BUILDS.
SUNDAY WILL SEE A FRONT FROM A LOW OVER THE ALASKA PENINSULA SLAM
INTO THE COAST, DRIVING HEAVY PRECIPITATION AND A BARRIER JET
ALONG THE COASTLINE. INLAND AREAS WILL BE SHELTERED FROM MOST
PRECIPITATION DUE TO THE MOUNTAINS AND WILL SEE LOWER
PRECIPITATION CHANCES. ONCE AGAIN, HIGHER ELEVATIONS GENERALLY
ABOVE 2500 FT COULD SEE SNOWFALL, ESPECIALLY AT NIGHT. WINDS WILL
BE DRIVEN UP AS WELL FROM THIS FRONT. BY SUNDAY AFTERNOON GAP
WINDS WILL INCREASE TO STORM FORCE NEAR THE BARREN ISLANDS WITH
HIGH END GALE FORCE WINDS IN THE OTHER GAP REGIONS. THERE IS SOME
UNCERTAINTY WITH REGARDS TO WINDS ESPECIALLY WITH THE
AFOREMENTIONED BARRIER JET. SOME GUIDANCE HAS IT AT STORM FORCE
STRENGTH WHILE OTHERS KEEP IT AT GALE FORCE.
-TM/JAR
.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 THROUGH 3: TODAY
THROUGH SUNDAY NIGHT)...
A LOW IN THE GULF OF ALASKA SENDS A FRONT WESTWARD INTO SOUTHWEST
ALASKA TODAY, BRINGING LIGHT RAIN TO INTERIOR BRISTOL BAY AND THE
LOWER KUSKOKWIM VALLEY. MUCH OF THE KUSKOKWIM DELTA AND BRISTOL
BAY COAST REMAIN DRY, WITH DILLINGHAM AND VICINITY LIKELY
EXCEEDING 50 DEGREES TODAY WITH NORTHWESTERLY DOWNSLOPE FLOW. IF
SKIES REMAIN CLEAR, WHICH IS BY NO MEANS CERTAIN, TEMPERATURES
COULD REACH INTO THE MID 50S. BEHIND THE FRONT, RELATIVELY CLEAR
SKIES WILL COMBINE WITH COLD AIR ALOFT TO PRODUCE SOME LIMITED
INSTABILITY THAT WILL SUPPORT SHOWER DEVELOPMENT FOR PORTIONS OF
THE WESTERN ALASKA RANGE. THERE IS A SLIGHT CHANCE THAT ONE OR TWO
OF THESE STORMS IS STRONG ENOUGH TO PRODUCE A FEW LIGHTNING
STRIKES THIS AFTERNOON/EVENING. THE FRONT WEAKENS OVER SOUTHWEST
ALASKA TONIGHT, WITH PRECIPITATION TURNING SHOWERY AND LARGELY
CLEARING OUT FOR SATURDAY. HOWEVER, A SHORTWAVE NUDGING IN FROM
INTERIOR ALASKA COULD LEAD TO CONTINUED RAINFALL FOR PORTIONS OF
THE LOWER KUSKOKWIM VALLEY. DURING THE OVERNIGHT HOURS, THERE IS
POTENTIAL FOR SOME LIGHT, NON-ACCUMULATING SNOW.
SATURDAY NIGHT, A NORTH PACIFIC LOW TRACKS TOWARD THE GULF AND
PUSHES A FRONT INTO SOUTHWEST ALASKA. THE MAIN IMPACT FROM THIS
WILL BE GUSTY EASTERLY WINDS THROUGH KAMISHAK GAP INTO BRISTOL
BAY, WITH LIGHT PRECIPITATION LIMITED TO PORTIONS OF BRISTOL BAY.
THIS GENERAL PATTERN CONTINUES AS THE LOW LINGERS NEAR KODIAK
ISLAND THROUGH AT LEAST SUNDAY NIGHT.
.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 THROUGH 3:
TODAY THROUGH SUNDAY NIGHT)...
A GALE FORCE NORTH PACIFIC LOW TRACKS ALONG AND SOUTH OF THE
ALEUTIANS THROUGH THIS WEEKEND. ITS FRONT PUSHES THROUGH THE
CENTRAL ALEUTIANS TODAY, BEGINNING INITIALLY AS RAIN BUT WITH SNOW
MIXING IN AS COOLER AIR FILTERS IN FROM THE NORTH, ESPECIALLY BY
TONIGHT, AT WHICH POINT PRECIPITATION LIKELY TRANSITIONS OVER TO
SNOW SHOWERS. ACCUMULATION IS EXPECTED TO BE LITTLE TO NONE. A
SIMILAR STORY IS EXPECTED AS THE FRONT REACHES THE EASTERN
ALEUTIANS TONIGHT, WITH INITIAL STEADY RAIN OR A RAIN/SNOW MIX
SLOWLY TRANSITIONING OVER TO SNOW SHOWERS BY SATURDAY NIGHT.
EXPECTING LITTLE TO NO SNOW ACCUMULATION WITH TEMPERATURES
REMAINING ABOVE FREEZING AT SEA LEVEL, THOUGH HIGHER ELEVATIONS OF
THE ISLANDS MAY SEE SEVERAL INCHES OF SNOW.
THERE ARE SOME GALES IN THE FORECAST MAINLY SOUTH OF THE CENTRAL
ALEUTIANS. AS THE LOW STRENGTHENS SOUTH OF THE ALASKA PENINSULA
ON SUNDAY, GALE FORCE WINDS SPREAD ACROSS THE EASTERN ALEUTIANS
AND ALASKA PENINSULA. LIGHT RAIN AND SNOW SHOWERS CONTINUE TO FALL
ON THE BACK SIDE OF THE LOW HEADING INTO EARLY NEXT WEEK.
LONG TERM FORECAST (DAYS 4 THROUGH 7/MONDAY THROUGH THURSDAY)
A WELL DEVELOPED UPPER LEVEL LOW WEAKENS AS IT MEANDERS BETWEEN
THE WESTERN GULF OF ALASKA AND THE EASTERN NORTH PACIFIC THROUGH
THE WEEK. WITH THIS LOW TO THE EAST OF KODIAK ISLAND, CONSIDERABLE
ENERGY DRIVES INTO SOUTHCENTRAL ALASKA FROM KODIAK ISLAND TO THE
CANADIAN BORDER. THIS LOW OPENS UP TO A BROAD TROUGH OVER MAINLAND
ALASKA AND THE GULF BY THURSDAY. A HIGHER AMPLITUDE RIDGE PUSHES
ACROSS THE BERING AND FLATTENS OUT OVER THE ALASKA PENINSULA FOR
MIDWEEK. A CLOSED HIGH SETS UP OVER THE RUSSIAN FAR EAST. A MODEL
BLEND OF ECMWF AND GFS CARRIES THE MAIN FEATURES THROUGH THE
PERIOD, AS THE CANADIAN MODEL TENDS TO RUN MORE SLOWLY. GREATEST
UNCERTAINTY REMAINS WITH THE SMALLER DETAILS.
A STRONG SURFACE LOW SOUTH OF CENTRAL AKPEN AND ITS FRONT
EXTENDING ACROSS THE NORTHERN GULF OF ALASKA PUSHES HEAVY RAIN
OVER KODIAK ISLAND AND THE KENAI PENINSULA MONDAY AND TUESDAY
BEFORE SPREAD ALONG THE REST OF SOUTHCENTRAL ALASKA BY WEDNESDAY.
A STRONG BARRIER JET SETS UP ACROSS THE NORTHERN GULF WITH GALE
FORCE WINDS AND STORM FORCE GUSTS, DIMINISHING TUESDAY. HIGHER
ELEVATIONS WILL GET SNOW ACROSS SOUTHCENTRAL ALASKA THROUGH
THURSDAY. A LARGE AREA OF GUSTY WINDS MOVES OVER THE EASTERN
BERING AND AKPEN INTO THE NORTH PACIFIC, DIMINISHING TUESDAY. A
STRONG NORTH PACIFIC LOW AND FRONT BRINGS HEAVY RAIN INTO THE
WESTERN ALEUTIANS AND BERING MONDAY, SPREADING TO THE EASTERN
ALEUTIANS AND BERING BY WEDNESDAY BEFORE CURVING INTO THE NORTH
PACIFIC FOR THURSDAY.
- KUTZ
AVIATION
PANC...VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE TAF
PERIOD. LIGHT RAIN SHOWERS THIS MORNING WILL CONTINUE TO TAPER OFF
BY MID TO LATE MORNING AS SOUTHEAST FLOW ALOFT STRENGTHENS. THUS,
ANY CEILINGS AROUND 5000 FT SHOULD ALSO LIFT. LIGHT NORTHERLY
WINDS THIS MORNING WILL BECOME SOUTHEAST THIS AFTERNOON WITH GUSTS
AROUND 25 TO 30 KTS AT TIMES. WHILE GUSTS TAPER OFF DURING THE
EVENING, WINDS CONTINUE TO REMAIN OUT OF THE SOUTH TO SOUTHEAST
INTO SATURDAY MORNING.
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