812
FXAK67 PAJK 250618 AAA
AFDAJK
SOUTHEAST ALASKA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JUNEAU AK
1018 PM AKDT MON AUG 24 2026
UPDATE
FOR 06Z TAF ISSUANCE.
AVIATION
/THROUGH 06Z WEDNESDAY/
CLEARER SKIES UP NORTH HAVE ALLOWED SOME SHALLOW RADIATION FOG TO
DEVELOP IN THE VICINITY OF GUSTAVUS AS OF 10PM. A SIMILAR
SITUATION COULD PLAY OUT FOR YAKUTAT, THOUGH INCREASING CLOUD
COVER THERE IS EXPECTED TO LIMIT ITS DURATION IF IT DOES FORM.
OTHERWISE, THE NORTHERN TERMINALS ARE GENERALLY EXPECTED TO SEE
VFR CONDITIONS OVERNIGHT WITH SOME LIGHT RAIN AS THE BAND OF RAIN
STREAMING OVER THE SOUTHERN PANHANDLE WAVERS. SPEAKING OF WHICH,
THIS RAIN WILL CONTINUE TO COVER THE SOUTHERN TAF SITES FROM
KETCHIKAN NORTHWARD TO PETERSBURG THROUGH THE OVERNIGHT PERIOD,
GRADUALLY DIMINISHING FROM SOUTH TO NORTH THROUGH TUESDAY
AFTERNOON.
NO MAJOR CHANGES TO THE INHERITED AVIATION FORECAST, EXPECTING
IFR CONDITIONS TO DEVELOP FOR MANY OF THE SOUTHERN TERMINALS EARLY
TUESDAY BEFORE IMPROVING BY MID TO LATE MORNING BACK TO MVFR.
WINDS ACROSS THE PANHANDLE WILL LARGELY BE 10 KT OR LESS ACROSS
THE BOARD, WITH A DEVELOPING SEA BREEZE AT SKAGWAY BEING THE HIGH
MARK AS IS OFTEN THE CASE, WITH GUSTS UP TO 20 KT LIKELY. STILL NO
SIGNIFICANT LLWS CONCERNS THROUGH THE TAF PERIOD. WHILE NOT
EXPECTED TO DIRECTLY IMPACT ANY OF THE SOUTHERN TERMINALS, WE ARE
MONITORING A SLIGHT CHANCE OF THUNDERSTORMS TO DEVELOP IN THE
VICINITY OF HYDER AND THE MISTY FJORDS AREA TUESDAY AFTERNOON.
STAY TUNED FOR FURTHER UPDATES IN FOLLOW UP DISCUSSIONS.
PREV DISCUSSION......ISSUED AT
359 PM AKDT MON AUG 24 2026
SYNOPSIS...
KEY MESSAGES:
- RAIN RATES AND RAIN COVERAGE DECREASES ACROSS THE SOUTHERN
PANHANDLE MONDAY INTO TUESDAY.
- SLIGHT CHANCE OF THUNDERSTORMS POSSIBLE FOR THE SOUTHERN
PANHANDLE NEAR MISTY FJORDS AREA TUESDAY AFTERNOON.
- BRIEF BREAK IN RAIN EXPECTED BY TUESDAY AFTERNOON ACROSS THE
NORTHERN PANHANDLE BEFORE MORE WIDESPREAD RAIN RETURNS
WEDNESDAY MORNING.
SHORT TERM...
THE ATMOSPHERIC RIVER THAT HAS IMPACTED THE
SOUTHERN PANHANDLE HAS BEGUN TO MOVE SOUTHWARD OUT OF THE AREA AS
THE UPPER LEVEL LOW DRIFTS FURTHER EASTWARD. THIS UPPER LEVEL LOW
IS EXPECTED TO DROP DOWN FAR BELOW HAIDA GWAII, WITH A SHORTWAVE
MOVING UP FROM THE SOUTH. LEADING INTO THIS TROUGH RACING
NORTHWARD, RIDGING ALOFT WILL ASSIST IN CLEARING FOR MUCH OF THE
PANHANDLE. THIS RIDGING FOR TUESDAY LOOKS TO ALSO BRING IN WARMER
TEMPERATURES, RANGING FROM THE UPPER 60S TO THE MID 70S FROM NORTH
TO SOUTH RESPECTIVELY. AS THE AFOREMENTIONED TROUGH MOVES
NORTHWARD, IT LOOKS TO CLIP MISTY FJORDS RIGHT AS DAYTIME HEATING
IS MAXIMIZED. CAPE VALUES LOOK TO BE BETWEEN THE 400-800 J/KG
RANGE WITH LIS AROUND -2. THE LIMITING FACTOR HERE IS THE LOW CAPE
BELOW THE -20 CELSIUS HEIGHT, WHICH MAY LIMIT ANY ICE AND
LIGHTNING DEVELOPMENT IN ANY DEVELOPING STORMS. KEPT CHANCES
AROUND 20% (ISOLATED) FOR ANY THUNDERSTORM DEVELOPMENT, BUT WITH A
BULK SHEAR OF 30 KNOTS, EXPECT ANY THUNDERSTORM THAT DOES DEVELOP
TO LAST LONGER THAN USUAL.
WEDNESDAY SEES THE NEXT SHORTWAVE TROUGH MOVE IN, ORIGINATING
FROM THE BERING SEA. THIS TROUGH IS RELATIVELY QUICK MOVING AND
DOES NOT LOOK TO BE MODIFIED BY THE WARMER WATERS OF THE GULF OF
ALASKA. AS SUCH, NOT EXPECTING MUCH MOISTURE TO BE ATTACHED TO
THIS SYSTEM, AND THEREFORE, RAIN RATES ARE EXPECTED TO BE LIGHT AT
BEST, JUST CLOUDS AT WORST. THIS SYSTEM LOOKS TO DIG SOUTH ALONG
THE COAST WEDNESDAY INTO THURSDAY BEFORE CLEARING OUT AGAIN.
FURTHER DETAILS IN THE LONG TERM SECTION.
LONG TERM.../THURSDAY THROUGH SUNDAY/...
A WEAK SHORTWAVE TROUGH IS EXPECTED TO BRING A FRONT ACROSS THE
REGION WEDNESDAY MORNING THROUGH THURSDAY MORNING, CAUSING RAIN
SHOWERS TO MOVE FROM THE NORTHWEST TO THE SOUTHEAST. THIS INITIAL
SYSTEM IS EXPECTED TO BE RELATIVELY LIGHT, WITH HIGHER CONFIDENCE
IN 24-HOUR PRECIPITATION TOTALS ALONG THE COAST RANGING FROM 0.25
TO 0.5 INCHES. AMPLIFICATION BY OROGRAPHIC LIFTING COULD CAUSE
WINDWARD AREAS TO SEE TOTALS ON THE HIGHER END OF THIS RANGE.
PRECIPITATION WILL TAPER OFF THURSDAY NIGHT INTO FRIDAY MORNING AS
HIGH PRESSURE BRIEFLY BUILDS ALOFT AND HELPS TO CLEAR SKIES.
CONDITIONS ARE EXPECTED TO DETERIORATE AGAIN FRIDAY NIGHT, AS A
STRONGER FRONT APPROACHES FROM A LOW MOVING INTO THE NORTH-CENTRAL
GULF. THIS SYSTEM WILL BRING MORE SIGNIFICANT PRECIPITATION TO
THE GULF COAST, SPREADING ACROSS THE ENTIRE PANHANDLE THROUGH THE
WEEKEND. WHILE GUIDANCE ON THE LOW'S PROGRESSION VARIES, HIGH
CONFIDENCE EXISTS FOR 24-HOUR TOTALS OF 0.5 TO 0.75 INCHES, WITH
POTENTIAL FOR 1.25 TO 1.75 INCHES IN SOME MODELS. THE HEAVIEST
IMPACTS ARE ANTICIPATED ALONG THE COAST FROM YAKUTAT TO SITKA,
WITH SIGNIFICANT OROGRAPHIC ENHANCEMENT EXPECTED IN THE
FAIRWEATHER, CHILKAT, AND COAST RANGES, LIKELY INCREASING TOTALS
IN INLAND AREAS SUCH AS JUNEAU, PETERSBURG, AND KETCHIKAN.
ADDITIONALLY, AS THE FRONT PUSHES INLAND SATURDAY, THE INCREASED
PRESSURE GRADIENT WILL STRENGTHEN WINDS, SPECIFICALLY IN LYNN
CANAL AND BETWEEN CAPE SUCKLING AND CAPE FAIRWEATHER, WHERE A WEAK
BARRIER JET MAY FORM AS THE LOW MOVES FURTHER EAST.
TEMPERATURES THROUGH THIS PERIOD WILL PERSIST IN THE UPPER 50S
AND 60S, WITH POTENTIAL TO SEE UPPER 60S FURTHER INLAND ON FRIDAY,
GIVEN AMPLE CLEARING.
AVIATION.../THROUGH 00Z WEDNESDAY/
MVFR TO VFR FLIGHT CONDITIONS ACROSS THE PANHANDLE THIS AFTERNOON
AS A LOW IN THE N PACIFIC SPLITS THE PANHANDLE VERTICALLY, WITH A
PERSISTENT BAND OF RAIN INTO THE S PANHANDLE TERMINALS WITH
CLEARING ACROSS THE NORTH. RAIN WILL CONTINUE INTO MONDAY EVENING,
PRIMARILY FOR TERMINALS FROM PETERSBURG TO KAKE AND SOUTHWARD
BEFORE GRADUALLY DIMINISHING MOVING INTO LATE MONDAY NIGHT WITH A
GENERAL WIDESPREAD DRYING TREND INTO TUESDAY MORNING. BY TUESDAY
MORNING, PREDOMINATE MVFR TO VFR FLIGHT CONDITIONS FOR THE
NORTHERN TERMINAL TAF SITES, ALONG AND NORTH OF THE ICY STRAIT
CORRIDOR. FURTHER SOUTH, THINKING FLIGHT CONDITIONS WILL BE A BIT
LOWER FOR TUESDAY MORNING WITH PREDOMINATE MVFR CEILINGS, HIGHER
CONFIDENCE OF IFR DEVELOPMENT BY 12Z, AND BRIEF PERIODS OF LIFR
POSSIBLE THROUGH 16Z.
SUSTAINED WINDS ACROSS THE PANHANDLE WILL REMAIN AROUND 10KTS OR
LESS THROUGH WEDNESDAY MORNING ACROSS THE SEAK TERMINALS WITH SOME
ISOLATED GUSTS UP TO 20KTS THROUGH THIS AFTERNOON. NO SIGNIFICANT
LLWS CONCERNS THROUGH THE TAF PERIOD.
MARINE...
OUTER WATERS: THE LOW IN THE GULF IS MOVING SOUTHWARD, BRINGING
CALMING CONDITIONS IN ITS WAKE AS HIGH PRESSURE TAKES ITS PLACE.
THE REST OF MONDAY AND TUESDAY, WINDS ARE EXPECTED TO BE LIGHT
AND VARIABLE, NO MORE THAN 10-15KTS. SIGNIFICANT WAVE HEIGHTS ARE
NOT EXPECTED TO EXCEED 5FT THROUGH TUESDAY. EARLY WEDNESDAY
MORNING, ANOTHER LOW PRESSURE SYSTEM MOVES INTO THE GULF, BRINGING
ANOTHER ROUND OF WIND AND WAVES. CURRENT THINKING IS THAT WINDS
ARE NOT LIKELY TO EXCEED 20KTS IN THE GULF, BUT COULD BE GUSTY AS
THE FRONT MOVES ACROSS THE AREA. NW WINDS ALONG THE COAST COULD
ALSO FUNNEL WINDS AROUND PROMINENT CAPES LATE IN THE DAY TUESDAY
AND THROUGH THE NIGHT AS THE LOW PRESSURE CENTER CREATES SOMEWHAT
OF A RIDGE BETWEEN ITSELF AND THE COAST.
INNER CHANNELS: HIGH PRESSURE LOOKS TO BUILD OVER THE PANHANDLE
MONDAY NIGHT AS THE LOW PRESSURE CENTER MOVES SOUTH OF THE AREA.
THIS IS LIKELY TO BRING LIGHT AND VARIABLE WINDS OVERNIGHT AND
THROUGH THE MORNING ON TUESDAY. CLEARING ACROSS THE NORTHERN
PANHANDLE ON TUESDAY ILL ALLOW SEA BREEZES TO PREVAIL WITH LYNN
CANAL EXPECTED TO REACH 15KT SE. A LOW PRESSURE CENTER IS
EXPECTED TO MOVE INTO THE GULF ON WEDNESDAY, BRINGING A FRONT THAT
IS LIKELY TO BRING GUSTY WINDS, ESPECIALLY IN THE NORTHERN
PANHANDLE. WIND ARE EXPECTED TO BE RELATIVELY MORE ELEVATED IN
THE NORTHERN PANHANDLE, AROUND 15KTS, AS THE FRONT WILL BREAK
APART ACROSS THE TERRAIN AS IS MOVES SOUTH.
AJK WATCHES/WARNINGS/ADVISORIES
PUBLIC...NONE.
MARINE...NONE.
UPDATE...STJ
SHORT TERM...NC
LONG TERM...BAS
AVIATION...NM
MARINE...AGP
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