923
FXAK68 PAFC 230107
AFDAFC
SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
507 PM AKDT MON JUN 22 2026
SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 THROUGH 3)
A COMPLEX LOW IS MOVING THROUGH THE GULF OF ALASKA AND IS
CURRENTLY NEAR KODIAK ISLAND. RAIN IS BEING PUSHED INTO KODIAK
AND ALONG THE COAST OF SOUTHCENTRAL FROM SHORTWAVES MOVING AROUND
THE LOW. THESE SHORTWAVES NEAR THE LOW ARE ALSO CREATING A
COASTAL RIDGE OVER THE CHUGACH RANGE, ALLOWING FOR ELEVATED
SOUTHEASTERLY WINDS (10 TO 15 MPH, WITH GUSTS AROUND 25 MPH) IN
PALMER, SOUTH ANCHORAGE, AND THE COPPER RIVER BASIN THROUGH
TUESDAY. ISOLATED THUNDERSTORMS WILL HAVE A 10 TO 20% CHANCE OF
FORMING, MOSTLY OVER THE FOOTHILLS OF THE THE TALKEETNA MOUNTAINS
AND ALASKA RANGE. SOUTHEASTERLY FLOW ALONG THE COAST WILL ALLOW
FOR DOWNSLOPE DRYING ON THE LEE OF THE MOUNTAIN RANGES, BUT LIGHT
RAIN SHOWERS WILL STILL HAVE A 20 TO 30% CHANCE OF OCCURRING.
BY TUESDAY, A MORE ROBUST TROUGH FROM THE LOW WILL MOVE ACROSS
SOUTHCENTRAL FROM EAST TO WEST AND REACHING WELL INTO THE COPPER
RIVER BASIN AND SUSITNA VALLEY. THIS WAVE WILL PRODUCE STEADIER
RAINFALL, WHICH WILL CAUSE MODERATE TO HEAVY RAIN OVER THE
NORTHERN AND WESTERN SUSITNA VALLEY. UPSLOPE ENHANCEMENT WILL
PROMOTE HIGHER RAINFALL AMOUNTS FARTHER INLAND, NEAR THE TALKEETNA
MOUNTAINS AND THE ALASKA RANGE. LOWER ELEVATIONS (INCLUDING
ANCHORAGE) WILL SEE LESS RAINFALL DUE TO DOWNSLOPING, BUT THE
SHEER AMOUNT OF MOISTURE MAKING IT IN WILL ALLOW AT LEAST 0.05 TO
0.10 INCHES OF RAIN TO FALL. THE BAND OF MODERATE TO HEAVY
RAINFALL WILL LINGER OVER THE SUSITNA VALLEY THROUGH WEDNESDAY.
BETWEEN TUESDAY AND WEDNESDAY, 1 TO 2 INCHES OF RAIN WILL FALL
BETWEEN CANTWELL, THROUGH TALKEETNA AND SKWENTNA TOWARD THE WEST
ALASKA RANGE. CONFIDENCE IS HIGHER TODAY, BUT THERE IS STILL SOME
UNCERTAINTY REGARDING HOW LONG THE BAND OF RAIN LASTS OVER THE
SUSITNA VALLEY. BY WEDNESDAY EVENING, RAINFALL WILL DECREASE IN
INTENSITY AS THE LOW MOVES MORE TO THE EAST AND THE STRONG
SHORTWAVE INLAND DISSIPATES. ADDITIONAL SHORTWAVES WILL MOVE
THROUGH, BUT RAINFALL ASSOCIATED WITH THEM WILL BE LIGHTER.
THURSDAY WILL SEE MOISTURE MOVE INTO THE COPPER RIVER BASIN. THIS,
COMBINED WITH CONTINUED EASTERLY WAVES WILL ALLOW CHANCES (50 TO
60%) FOR SHOWERS.
-JAR/RUX
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (DAYS
1 THROUGH 3: TODAY THROUGH THURSDAY AFTERNOON)...
THE FORECAST REMAINS LARGELY ON TRACK, THOUGH THERE CONTINUES TO
BE LOWER CONFIDENCE WITH THE TIMING AND PLACEMENT OF
AFTERNOON/EVENING THUNDERSTORMS ACROSS SOUTHWEST ALASKA IN THE
COMING DAYS. STILL, THE EXPECTATION IS FOR THUNDERSTORM ACTIVITY
TO BE LESS VIGOROUS THAN WE'VE SEEN IN THE PAST WEEK, AS
INCREASING CLOUD COVER WILL LIKELY KEEP STORMS WEAKER. OTHERWISE,
GENERALLY EXPECT A TREND TOWARDS CLOUDIER SKIES AND BREEZIER AND
WETTER CONDITIONS AS LOWS PROGRESS INTO THE REGION AND DISPLACE
THE RIDGE OVER THE BERING SEA.
DIVING INTO THE DETAILS... ROBUST UPPER LEVEL LOWS APPROACHING
THE WESTERN ALEUTIANS/BERING AND MOVING IN THE GULF OF ALASKA (AS
WELL AS THEIR ATTENDANT SURFACE LOWS) WILL BRING A TREND TOWARDS
GLOOMIER CONDITIONS. THESE UPPER LOWS WILL ALSO BE A MAJOR SOURCE
OF FORECAST UNCERTAINTY IN THE COMING DAYS, AS GUIDANCE IS SHOWING
POOR CONSISTENCY AND POOR AGREEMENT REGARDING HOW THESE LOWS
INTERACT WITH EMBEDDED SHORTWAVES AND OTHER WAVES MOVING THROUGH
THE UPPER LEVEL FLOW. THE BIGGEST IMPACT OF THIS UNCERTAINTY WILL
BE ON THE CONVECTIVE/THUNDERSTORM FORECAST, ESPECIALLY AS UPPER
LEVEL ENERGY WILL PLAY A LARGER ROLE IN THUNDERSTORM DEVELOPMENT
GIVEN CLOUDIER SKIES AND LIMITED SURFACE HEATING. THE OTHER MAJOR
AREA OF IMPACT WILL BE RAIN AMOUNTS ALONG THE WESTERN ALASKA RANGE
AS A PARTICULARLY ROBUST AND WET TROUGH MOVES EASTWARD THROUGH
THE INTERIOR. RIGHT NOW, THE AREA FROM LIME VILLAGE TO ILIAMNA HAS
A 40% CHANCE OF SEEING 0.5 INCHES OF RAIN OR GREATER FROM TUESDAY
EVENING THROUGH WEDNESDAY AFTERNOON, WITH NEAR-CERTAIN LIKELIHOOD
OVER THE ALASKA RANGE. STILL, MODELS CONTINUE TO SHOW SHIFTS IN
THE PLACEMENT AND TIMING OF THIS FEATURE, WHICH WILL AFFECT
OVERALL RAIN AMOUNTS.
FOR SOUTHWEST ALASKA AND THE BERING SEA, LOW CLOUDS AND FOG LINGER
FOR ANOTHER NIGHT, BUT SHOULD GRADUALLY RETREAT AS TWO SURFACE
LOWS APPROACH THROUGH TOMORROW. GENERALLY EXPECT STEADY RAIN ALONG
THE ALEUTIANS LATE TUESDAY AND WEDNESDAY, WITH SUSTAINED WINDS
AS HIGH AS 20-35 KT. HOW THESE TWO SURFACE LOWS INTERACT AND MERGE
WILL AFFECT THE TIMING, DURATION, AND INTENSITY OF WINDS AND
RAIN ALONG THE FRONT. FORTUNATELY, THIS LOW COMPLEX LOOKS FAIRLY
MIDDLING IN TERMS OF STRENGTH, SO IT'LL BE MORE LIKELY TO BE A
NUISANCE STORM THAN AN OVERLY IMPACTFUL ONE.
-KC
LONG TERM FORECAST (DAYS 4 THROUGH 7: FRIDAY THROUGH MONDAY)
THE LONG-TERM PATTERN CONTINUES TO FEATURE AN UNSETTLED PATTERN
ACROSS THE SOUTHERN MAINLAND. A LOW PRESSURE SYSTEM IN THE BERING
SEA WILL CONTINUE TO BRING SHOWERY CONDITIONS ACROSS THE CENTRAL
ALEUTIANS, EASTERN ALEUTIANS, AND PRIBILOF ISLANDS FRIDAY AND
SATURDAY BEFORE THE RAIN MOVES TO THE SOUTHERN ALASKA PENINSULA
(AKPEN) FOR SUNDAY. A RIDGE BUILDS IN BEHIND THIS SYSTEM WITH
LIKELY LOW STRATUS AND MISTY CONDITIONS FILLING IN ACROSS THE
CENTRAL BERING SEA AND CENTRAL ALEUTIANS SATURDAY EVENING INTO
SUNDAY. THIS RIDGE AND THE ASSOCIATED LOW STRATUS WILL MOVE
EASTWARD THROUGH MONDAY ACROSS THE REST OF THE ALEUTIANS AND
SOUTHERN AKPEN WHILE THE WESTERN ALEUTIANS AND WESTERN BERING WILL
CONTEND WITH NORTH PACIFIC FRONTS.
SOUTHCENTRAL AND SOUTHWEST ALASKA WILL ALSO REMAIN UNSETTLED AS A
SERIES OF EASTERLY WAVES MOVES ACROSS THE SOUTHERN MAINLAND FROM
YUKON, CANADA AND SHORTWAVES LIFT FROM THE NORTH PACIFIC, THE THE
GULF OF ALASKA, AND OVER SOUTHCENTRAL ALASKA. MOST STEADY
PRECIPITATION WITH THESE DISTURBANCES BETWEEN FRIDAY AND MONDAY
WILL LOOK TO FALL ACROSS INTERIOR PORTIONS OF THE SOUTHWEST ALASKA
WITH SCATTERED RAIN SHOWERS ACROSS SOUTHCENTRAL ALASKA. THE ONE
CHALLENGE WITH THE LONG-TERM FORECAST, WITH REGARDS TO THE
INTERIOR LOCATIONS, WILL BE ASSESSING HOW MUCH INSTABILITY WILL BE
AVAILABLE. THIS WILL DETERMINE HOW MUCH OF A THREAT LIGHTNING
STRIKES COULD BECOME. RIGHT NOW, FRIDAY AFTERNOON LOOKS TO BE THE
MOST UNSTABLE DAY ACROSS SOUTHWEST ALASKA WITH SUNDAY AFTERNOON
ACROSS THE COPPER RIVER BASIN OF SOUTHCENTRAL ALASKA.
AVIATION
PANC...VFR CONDITIONS ARE EXPECTED TO PERSIST. A SOUTHEASTERLY TURNAGAIN
ARM WIND WILL STRENGTHEN THIS AFTERNOON/EVENING AND HAS A CHANCE
OF PRODUCING GUSTS UP TO 25 KTS BEFORE DIMINISHING BY AROUND 09Z
TUESDAY MORNING.
FIRE WEATHER
KEY MESSAGE:
WETTING RAIN CHANCES INCREASE FOR TUESDAY AND WEDNESDAY ACROSS
INTERIOR SOUTHCENTRAL ALASKA AND INTERIOR SOUTHWEST ALASKA.
DISCUSSION:
A STRONG EASTERLY TO SOUTHEASTERLY SHORTWAVE WILL LIFT ACROSS THE
GULF OF ALASKA THROUGH MONDAY NIGHT AND SPREAD WETTING RAINS
BEGINNING TUESDAY MORNING ACROSS THE COPPER RIVER BASIN. THE
AIRMASS THIS UPPER-LEVEL DISTURBANCE IS MOVING OVER WILL BE
STABLE, SO LIGHTNING SHOULD BE LITTLE THREAT. STEADY WETTING RAINS
WILL MOVE TO THE SUSITNA VALLEY BY LATE TUESDAY MORNING. WETTING
RAINS THEN SHIFT TO INTERIOR OF SOUTHWEST ALASKA BY TUESDAY
AFTERNOON TO TUESDAY EVENING WITH AREAS ALONG THE WESTERN ALASKA
RANGE AS WELL AS PORT ALSWORTH AND NORTHWARD SEEING STEADY RAIN.
THIS STEADY RAIN WILL LAST ACROSS INTERIOR SOUTHWEST ALASKA WILL
LAST THROUGH WEDNESDAY MORNING BEFORE TAPERING OFF. SOUTHEAST FLOW
BEHIND THE UPPER-LEVEL DISTURBANCE, NOW OVER SOUTHWEST ALASKA BY
WEDNESDAY AFTERNOON, WILL ALLOW FOR MORE MOISTURE TO WRING OUT
ACROSS THE WESTERN SUSITNA VALLEY ALONG THE ALASKA RANGE THROUGH
WEDNESDAY EVENING WHICH WILL RESULT IN MORE WETTING RAIN FOR THAT
AREA.
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