981
FXAK68 PAFC 101313
AFDAFC
SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
513 AM AKDT THU JUL 10 2025
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA
(DAYS 1 THROUGH 3: THURSDAY THROUGH SATURDAY EVENING)...
AN UPPER-LEVEL RIDGE CONTINUES TO EXIT THE REGION TO THE NORTHEAST
THIS MORNING AS AN UPPER-LEVEL TROUGH OVER THE AKPEN SLIDES EAST
INTO THE WESTERN GULF. AT THE SURFACE, AN AREA OF LOW PRESSURE
WEST OF SITKINAK ISLAND IS PUSHING AN OCCLUDED FRONT INTO
THE SOUTHWESTERN GULF AND ACROSS KODIAK ISLAND THIS MORNING. THIS
IS A RATHER POTENT STORM SYSTEM WITH WIDESPREAD EASTERLY GALES
DEVELOPING ALONG AND AHEAD OF THE FRONT. OUT AHEAD OF THE FRONT, A
WEAKER SURFACE TROUGH IS PUSHING INTO PRINCE WILLIAM SOUND, WITH
BANDS OF SHOWERS MOVING FROM AROUND MIDDLETON ISLAND NORTHWEST
TOWARD WHITTIER. THE COASTAL RIDGE IS ALSO STILL IN PLACE,
ALLOWING FOR BOTH A TIGHT PRESSURE GRADIENT AND SOUTHEASTERLY GAP
WINDS TO PERSIST OVERNIGHT AND INTO THE EARLY MORNING HOURS.
THE AFOREMENTIONED FRONTAL SYSTEM WILL CONTINUE TO DRIVE NORTH
TODAY AS A NEW, TRIPLE-POINT LOW SPINS UP SOUTHEAST OF KODIAK
ISLAND. THIS NEW FEATURE WILL HELP TO BRING A MORE NORTHEAST-
SOUTHWEST ORIENTATION TO THE SURFACE FRONT AS IT ARRIVES ALONG THE
SOUTHCENTRAL COAST. THIS ORIENTATION SHOULD ALLOW FOR
SOUTHEASTERLY GAP WINDS ACROSS THE COPPER RIVER BASIN TO QUICKLY
TAPER OFF FROM EAST TO WEST THROUGH THE AFTERNOON. SOUTHEASTERLY,
TURNAGAIN ARM AND KNIK RIVER VALLEY WINDS SHOULD REDEVELOP,
HOWEVER, AS THERE STILL REMAINS A THERMAL TROUGH NORTH OF THE
ALASKA RANGE. THESE WINDS MAY ONLY PERSIST FOR A FEW HOURS,
THOUGH, AS THE GRADIENT EVENTUALLY PULLS ANY GAP WINDS BACK DOWN
COOK INLET BY EVENING.
RAIN WITH THIS SYSTEM WILL BE RATHER WIDESPREAD ALONG THE COAST,
AS THE EAST-SOUTHEASTERLY FLOW ALOFT DRIVES MOISTURE INTO THE
COASTAL MOUNTAINS. INLAND, A FEW WEAK UPPER-LEVEL WAVES MOVING
INLAND BY AFTERNOON MAY ALLOW FOR A FEW SCATTERED SHOWERS FROM
WESTERN COPPER RIVER BASIN INTO THE SUSITNA VALLEY.
WINDS ALONG THE COAST AND THE INNER WATERS DIMINISH ON FRIDAY AS
THE LOW AND FRONT WEAKEN WITH MOST OF THE ENERGY HEADING TO
SOUTHEAST ALASKA. PRECIPITATION ALSO TAPERS OFF FROM THE COAST
FRIDAY. HOWEVER, AN EASTERLY WAVE FROM YUKON, CANADA WILL MOVE
WEST ACROSS THE COPPER RIVER BASIN FRIDAY THROUGH FRIDAY EVENING.
WIDESPREAD SHOWERS ARE LIKELY FROM MCCARTHY TO NABESNA AND
NORTHWESTWARD TO PAXSON. ISOLATED THUNDERSTORMS ARE POSSIBLE WITH
THIS ACTIVITY ALONG THE NORTH SIDE OF THE WRANGELL MOUNTAINS,
EASTERN ALASKA RANGE, THE TALKEETNA MOUNTAINS. MOST OF THE AREA
LOOKS DRY FOR SATURDAY, EXCEPT SOME SCATTERED SHOWERS DEVELOPING
ALONG THE TERRAIN AND MOUNTAIN RANGES SATURDAY AFTERNOON.
-TM/DAN
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS
(DAYS 1 THROUGH 3: TODAY THROUGH FRIDAY)...
A LOW PRESSURE SYSTEM ON THE SOUTHERN SIDE OF THE ALASKA
PENINSULA CONTINUES TO BRING LIGHT RAIN AND GUSTY, OFFSHORE WINDS
TO THE REGION AS WELL AS THE BRISTOL BAY AREA. THE PRESENCE OF THE
LOW HAS SPREAD MUCH CLOUD COVER OVER THE AREA, INHIBITING THE
DEVELOPMENT OF AFTERNOON CONVECTIVE SYSTEMS AND THUNDERSTORMS FOR
INTERIOR SOUTHWEST ALASKA. THE KUSKOKWIM DELTA WILL NOT SEE AS
MUCH INFLUENCE FROM THE SOUTHERN LOW PRESSURE SYSTEM, HOWEVER WILL
HAVE THE POTENTIAL FOR LIGHT STRATIFORM RAINFALL TO DEVELOP
THROUGH THE NEXT FEW DAYS.
IN THE BERING, IN THE WESTERN WAKE OF THE EXITING LOW PRESSURE
SYSTEM, A COL HAS DEVELOPED CENTERED OVER ABOUT THE PRIBILOF
ISLANDS. THIS FEATURE WILL MAINTAIN THE UNSETTLED PATTERN OVER THE
AREA THROUGH THE NEXT FEW DAYS, WITH PERSISTENT LOW STRATUS CLOUDS
COVERING MUCH OF THE AREA. A WEAK LOW PRESSURE SYSTEM DEVELOPING
IN THE NORTHWESTERN BERING SEA WILL STEADILY SHIFT SOUTHEASTWARD
TOWARD THE CENTRAL ALEUTIANS BY FRIDAY AFTERNOON/EVENING. HOWEVER,
THIS SYSTEM APPEARS TO LOSE MUCH OF ITS ORGANIZATION AND STRENGTH
BY THE TIME IT ARRIVES, BRINGING A SHOWERY LIGHT RAINFALL AND
WEAK WINDS TO THE AREA BY THE END OF THE WORKWEEK.
OVERNIGHT AND MORNING FOG IS EXPECTED TO CONTINUE FOR AREAS ALONG
THE COAST INCLUDING THE PRIBILOF ISLANDS THROUGH THE END OF THIS
WEEK. NORTHERLY WINDS THROUGH THE ALEUTIAN GAPS AND PASSES ARE
EXPECTED AS THE LOW EXITS, THOUGH AS A WEAK RIDGE BUILDS BEHIND
IT, STRONG WINDS ARE NOT EXPECTED. ADDITIONALLY, RELATIVELY GUSTY
WINDS OVER THE MARINE AREA OF BRISTOL BAY WILL BE PRESENT THIS
AFTERNOON AND EVENING, WINDS NOT EXPECTED TO EXCEED 25 MPH.
-CL
.LONG TERM FORECAST (DAYS 4 THROUGH 7: SATURDAY THROUGH
TUESDAY)...
LITTLE CHANGE FROM PREVIOUS DISCUSSION. THE LONG TERM BEGINS WITH
A BROAD LONGWAVE TROUGH OVER THE BERING AND GULF WITH SEVERAL
SHORTWAVES EMBEDDED WITHIN IT. OVER THE MAINLAND, A STRONG RIDGE
EXTENDS FROM THE CHUKCHI SEA SOUTHEAST INTO SOUTHCENTRAL. THROUGH
TUESDAY THE TROUGH WILL SHIFT EAST OVER THE WESTERN HALF OF THE
STATE AND THE ALASKA PENINSULA WHILE A STRONG RIDGE DEVELOPS OVER
THE ALCAN, YUKON TERRITORY AND BC. THE TRANSITION OF THE PATTERN
FROM SATURDAY TO TUESDAY IS MESSY, PARTICULARLY WITH HOW THE
TROUGHS WILL INTERACT WITH THE INTERIOR RIDGING. OVER THE WEEKEND
WE'RE LOOKING AT A SHOWERY PATTERN OVER SOUTHWEST AND OVER THE
MOUNTAINS OF SOUTHCENTRAL. MOVING INTO THE START OF THE WORK WEEK
NEXT WEEK MODELS INDICATE A POTENTIALLY WET SYSTEM DEVELOPING IN
THE NORTH PACIFIC AND MOVING INTO THE SOUTHERN MAINLAND. WITH THE
AMPLIFICATION OF THE PATTERN, THERE WILL BE A TROPICAL TAP TO THE
MOISTURE MOVING NORTH, SO SOME AREAS WILL RECEIVE SOME MODERATE
RAIN. RIGHT NOW THERE IS A LARGE MERIDIONAL SPREAD IN THE STORM
TRACK WITH VARIED IMPACTS THROUGHOUT THE REGION. ADDITIONALLY,
THERE IS A SIGNAL FOR A BROAD SOUTHWESTERLY FLOW TO SET UP IN THE
BERING, WHICH MAY BRING CONCERNS TO THE SOUTHWEST COAST. WE WILL
CONTINUE TO MONITOR THIS.
CJ/DD
AVIATION
PANC...VFR CONDITIONS TO PERSIST THROUGH THE PERIOD. GUSTY
SOUTHEAST WINDS MAY BRIEFLY DIMINISH DURING THE MORNING HOURS BUT
WILL QUICKLY RESUME THIS AFTERNOON. OVERALL CONDITIONS RELAX LATER
THIS EVENING CLOSER TO 06Z AS A BROAD AREA OF LOW PRESSURE LIFTS
INTO THE GULF. THIS SHOULD REVERSE THE PRESSURE GRADIENT,
RESULTING IN LIGHT AND VARIABLE WINDS TONIGHT.
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