786
FXAK68 PAFC 241353
AFDAFC
SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
553 AM AKDT MON AUG 24 2026
SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 THROUGH 3)
DISCUSSION:
CLOUDS ARE BEGINNING TO SPILL OVER THE RIDGE INTO SOUTHCENTRAL THIS
MORNING AND SHOULD HELP TO MITIGATE FOG POTENTIAL FOR MANY AREAS
FROM KODIAK ISLAND NORTH TO THE ALASKA RANGE. THE COPPER RIVER
VALLEY, WHERE THIS UPPER LEVEL CLOUD COVER HAS NOT QUITE REACHED
YET, COULD STILL SEE SOME AREAS OF FOG BEFORE THE CLOUD COVER
INCREASES. AREAS ACROSS THE LOWER MATSU VALLEY AND NORTHERN PORTIONS
OF THE ANCHORAGE BOWL HAVE ALSO SEEN A 3500-5000 FT CLOUD DECK
DEVELOP HELPING TO KEEP THEIR OVERNIGHT TEMPERATURES IN THE LOWER
50S. ELSEWHERE, LIMITED CLOUD COVER FOR THE FIRST HALF OF THE NIGHT
AND CALM WINDS ALLOWED TEMPERATURES TO QUICKLY DROP INTO THE 40S FOR
MANY AREAS.
TODAY THE RIDGE SW TO NE ORIENTED RIDGE AXIS WILL SLOWLY SHIFT
EASTWARDS AS A SYSTEM LIFTS UP ACROSS THE BERING STRAIT. ITS FRONT
AND SOUTHWESTERLY FLOW ALOFT WILL BRING A GOOD FETCH OF MOISTURE
INTO SOUTHWEST ALASKA AND THE BRISTOL BAY REGION. THIS INITIAL FRONT
WILL FALL APART AS IT PUSHES EAST TODAY AND MAY PROVIDE ENOUGH
FORCING FOR RAIN TO SPREAD INTO THE WESTERN SUSITNA VALLEY LATE THIS
MORNING INTO EARLY AFTERNOON. ANOTHER SYSTEM WILL RAPIDLY MOVE
ACROSS THE NORTHERN BERING AND INTO WESTERN ALASKA BY TUESDAY
MORNING. A STOUT JET STREAK WILL MOVE OVER SOUTHWEST ALASKA WITH AN
ACCOMPANYING FETCH OF PACIFIC MOISTURE. RAIN WILL QUICKLY SPREAD
INLAND, FROM WEST TO EAST ACROSS SOUTHCENTRAL, AND EXITING THE
COPPER BASIN BY WEDNESDAY AFTERNOON. THE HIGHEST RAINFALL AMOUNTS
ONCE AGAIN LOOK TO FALL OVER THE NORTHERN AND EASTERN PORTIONS OF
THE SUSITNA VALLEY, WHERE UPSLOPE FLOW ALONG THE HIGHER TERRAIN WILL
HELP TO MAXIMIZE RAINFALL AMOUNTS. WILL LIKELY SEE RAINFALL AMOUNTS
OF AN INCH OR MORE FOR THESE AREAS WITH RISES ALONG AREA CREEKS AND
RIVERS.
IN ADDITION TO WIDESPREAD RAINFALL, THIS SYSTEM WILL ALSO ALLOW FOR
A STRONG SOUTH-NORTH PRESSURE GRADIENT TO DEVELOP ACROSS
SOUTHCENTRAL, RESULTING IN STRONG AND GUSTY GAP WINDS OUT OF THE
COPPER RIVER VALLEY, KNIK VALLEY AND TURNAGAIN ARM FOR MUCH OF THE
DAY ON TUESDAY. GUSTY GAP WINDS WILL SUBSIDE BY LATE TUESDAY NIGHT
AS THE SYSTEM DEPARTS AND THE GRADIENT SLACKENS.
- PP
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (DAYS
1 THROUGH 3: TODAY THROUGH THURSDAY)...
AS OF THIS MORNING, AN OCCLUDED ~985 MB LOW LOCATED NEAR THE
BERING STRAIT HAS ITS FRONT DRAPED SOUTH AND EASTWARD JUST
OFFSHORE OF SOUTHWEST ALASKA. RADAR RETURNS SHOW A SWATH OF
RAINFALL MOVING ACROSS INTERIOR SOUTHWEST ALASKA AND PUSHING INTO
THE EASTERN KUSKOKWIM VALLEY. RAIN SHOWERS EXTEND WESTWARD ALONG
THE FRONT FROM THE EASTERN BERING TO THE PRIBILOF ISLANDS. ALOFT,
A POSITIVELY TILTED AND DIGGING SHORTWAVE TROUGH IS PROGGED TO
MOVE OVER THE BERING AND EVENTUALLY OVER SOUTHWEST ALASKA THROUGH
TUESDAY MORNING, ENHANCING RAINFALL ASSOCIATED WITH THE FRONT. TO
THE SOUTH OF THE ALEUTIAN CHAIN, WITH HIGH PRESSURE SITUATED
ACROSS THE NORTH PACIFIC, REINFORCED SOUTHWESTERLY SMALL CRAFT
WINDS ARE LOCATED ALONG A CORRIDOR BETWEEN THE PRIBILOF ISLANDS
AND THE EASTERN ALEUTIANS. AS THE PARENT AREA OF LOW PRESSURE
PULLS FARTHER AWAY AND LOSES INFLUENCE OVER THE BERING AND
ALEUTIANS, THESE SOUTHWESTERLY WINDS WILL TREND DOWN THROUGH
TUESDAY MORNING AS THE PRESSURE GRADIENT WEAKENS.
IN THE WAKE OF THE LOW PRESSURE SYSTEM WEDNESDAY MORNING,
SYNOPTIC WINDS SWITCH AROUND TO NORTHWESTERLY, WHICH WILL CAUSE
SOMEWHAT ELEVATED GAP WINDS THROUGH FAVORED BAYS AND PASSES ALONG
THE ALASKA PENINSULA. NEGATIVE (OR ANTI-CYCLONIC) VORTICITY
ADVECTION UPSTREAM OF THE PASSING SHORTWAVE WILL GIVE SOUTHWEST
ALASKA A BREAK IN RAINFALL FOR WEDNESDAY AS UPPER LEVEL HIGH
PRESSURE MOVES OVERHEAD. MOS GUIDANCE DOES SHOW HINTS OF FOG OR
LOW STRATUS DEVELOPING WEDNESDAY MORNING UNDERNEATH THE RIDGE FOR
MUCH OF THE BERING AND THE KUSKOKWIM DELTA FOR AREAS LIKE BETHEL
GIVEN SUBSIDENCE WITH THE ADDITION OF RESIDUAL MOISTURE FROM
RECENT RAINFALL.
LOOKING WESTWARD, MODELS HAVE TRENDED FASTER AND A BIT STRONGER
WITH A KAMCHATKA LOW APPROACHING THE WESTERN ALEUTIANS WEDNESDAY
MORNING. AGAIN, WITH THE RIDGE STILL ANCHORED ACROSS THE NORTH
PACIFIC, THE LOW PRESSURE SYSTEM WILL WORK IN TANDEM WITH THE HIGH
TO YIELD ANOTHER ROUND OF SOUTHERLY WINDS. WITH SOLID GALES
SHOWING UP IN THE BOUNDARY LAYER, HAVE INCREASED SYNOPTIC WINDS TO
LOW END GALE FORCE WITH THE FRONT BY WEDNESDAY AFTERNOON FOR THE
WESTERN AND CENTRAL ALEUTIANS WITH THIS FORECAST PACKAGE. AS THE
LOW MOVES NORTHEASTWARD ACROSS THE WESTERN BERING, THE ATTENDANT
FRONT TRAVERSES THE BERING WITH HIGH END SMALL CRAFT WINDS AND
GALES THROUGH THURSDAY AFTERNOON.
-AM
LONG TERM FORECAST (DAYS 4 THROUGH 7: THURSDAY THROUGH SUNDAY)
THE LONG-TERM PATTERN WILL REMAIN ACTIVE ACROSS THE BERING SEA AS
PROGRESSIVE WEST-TO-EAST FLOW CONTINUES. CONFIDENCE REMAINS HIGH
THAT A STRONG SYSTEM OFF OF THE KAMCHATKA COAST THURSDAY WILL MOVE
TO NEAR SAINT LAWRENCE ISLAND BY FRIDAY. STRONG SOUTHERLY TO
SOUTHWESTERLY WINDS, SMALL-CRAFT TO GALE-FORCE WILL MOVE FROM THE
BERING TO THE KUSKOKWIM DELTA COAST BY THURSDAY AFTERNOON, ALONG
WITH MODERATE TO HEAVY RAIN WITH AN ATMOSPHERIC RIVER ACCOMPANYING
THIS SYSTEM. MODERATE TO HEAVY RAIN ALONG THE PRIBILOF ISLANDS
AND PORTIONS OF THE WESTERN AND CENTRAL ALEUTIANS WILL MOVE TO
INLAND PORTIONS OF SOUTHWEST ALASKA THROUGH THURSDAY NIGHT AND
FRIDAY MORNING. LIGHT TO MODERATE RAIN WILL ALSO MOVE ACROSS THE
EASTERN ALEUTIANS AND ALASKA PENINSULA THROUGH FRIDAY.
SOUTHCENTRAL ALASKA WILL EVENTUALLY GET IN ON THE RAIN BY FRIDAY.
PRIOR TO THIS RAIN, SOUTHCENTRAL WILL HAVE EXPERIENCED A
RELATIVELY NICE AND QUIET THURSDAY. FOR NOW, IT LOOKS LIKE THE
HEAVIEST OF THE RAIN WILL FALL ACROSS SOUTHWEST WITH THIS SYSTEM
WITH LIGHT TO MODERATE RAIN ACROSS SOUTHCENTRAL. POCKETS OF
HEAVIER RAIN ALONG THE NORTHERN GULF COAST ARE POSSIBLE FRIDAY
NIGHT INTO SATURDAY. RIVER LEVELS ACROSS THE SUSITNA VALLEY, SUCH
AS THE YENTNA RIVER AT LAKE CREEK WILL HAVE TO BE MONITORED
CLOSELY WITH THIS SYSTEM FOR POTENTIAL FLOODING CONCERNS.
STEADY RAIN ACROSS SOUTHWEST WILL TAPER TO SHOWERS FROM WEST TO
EAST THROUGH THE DAY ON SATURDAY AS THE LOW TRACKS INTO WESTERN
ALASKA FROM NORTON SOUND. STEADY RAIN ACROSS SOUTHCENTRAL WILL
MOVE EAST TO THE PANHANDLE THROUGH SATURDAY AS A LOW IN THE GULF
ALSO MOVES EAST. MOISTURE WRAPPING AROUND THIS LOW WILL ALLOW RAIN
TO LINGER ALONG THE NORTHERN GULF COAST INTO SUNDAY WITH
SCATTERED SHOWERS ACROSS THE REST OF SOUTHCENTRAL. SHOWERS
CONTINUE ALONG THE MOUNTAIN RANGES ACROSS SOUTHWEST FOR SUNDAY.
ANOTHER SYSTEM, WEAKER THAN THE FRIDAY SYSTEM, MOVES INTO THE
WESTERN BERING BY SATURDAY AND SPREADS RAIN ACROSS THE WESTERN AND
CENTRAL ALEUTIANS THROUGH SUNDAY MORNING. RAIN ALSO MAKES IT TO
THE PRIBILOF ISLANDS SUNDAY MORNING AS WELL. WINDS WITH THIS
SYSTEM, AS OF NOW, ARE TRENDING TO BE SMALL-CRAFT OR LESS.
AVIATION
PANC... VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE PERIOD
AS MID-LEVEL CLOUD COVER IS EXPECTED TO MITIGATE FOG POTENTIAL
MONDAY MORNING. HIGH CLOUDS WILL GRADUALLY LOWER THROUGH THE
PERIOD WITH RAIN SHOWERS EXPECTED TO HOLD OFF UNTIL LATE MONDAY
AFTERNOON THROUGH EVENING. LIGHT AND VARIABLE WINDS WILL BECOME
MORE SOUTHEASTERLY MONDAY NIGHT AS THE TURNAGAIN ARM WINDS BEGIN
TO INCREASE.
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