851
FXAK67 PAJK 201416
AFDAJK
SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
516 AM AKST FRI DEC 20 2024
SHORT TERM.../THROUGH FRIDAY/
THE ACTIVE PATTERN CONTINUES, ALTHOUGH A BRIEF LULL IN THE
PRECIPITATION WILL MOVE FROM S TO N THROUGH THE DAY ON FRIDAY
AHEAD OF ANOTHER SYSTEM WHICH WILL ADVANCE N INTO THE SOUTHERN
PANHANDLE BY FRIDAY AFTERNOON.
THE MOST RECENT SYSTEM HAS LARGELY FALLEN APART AS IT ADVANCES
NORTH ACROSS THE PANHANDLE. THE FRONTAL BAND'S DISTANCE FROM THE
LOW, ALONG WITH LINGERING COLD AIR OUTFLOW IN THE INNER CHANNELS,
MEANT THAT THE SYSTEM HAS ALL BUT DISINTEGRATED AS IT MOVES INTO
DRIER AIR ACROSS THE CENTRAL AND NORTHERN PANHANDLE. ONE RESULT OF
THIS HAS BEEN THAT COOLER TEMPERATURES HAVE LINGERED NEAR THE
SURFACE ACROSS MUCH OF THE AREA. THIS HAS RESULTED IN PERIODS OF
FREEZING RAIN ACROSS PARTS OF THE ICY STRAIT CORRIDOR AND
PETERSBURG AS THE DECAYING SYSTEM'S WARM FRONT (AND CORRESPONDING
WARM AIR ADVECTION) HAS LARGELY PUSHED OVER THE COOLER AIR NEAR
THE SURFACE, RATHER THAN DISPLACING IT ENTIRELY. WINTER WEATHER
ADVISORIES ARE OUT FOR PARTS OF THE AREA THROUGH THE MORNING HOURS
ON FRIDAY AS A RESULT, THOUGH ONLY EXPECT MINOR ICE
ACCUMULATIONS.
IN THE WAKE OF THE SYSTEM, A BRIEF LULL IN THE PATTERN WILL EMERGE
LATER IN THE DAY ON FRIDAY, WITH STRONGER NORTHERLY OUTFLOW RE-
ESTABLISHING ITSELF. ANOTHER SYSTEM ARRIVING FRIDAY AFTERNOON INTO
FRIDAY NIGHT WILL SEE WINDS BRIEFLY FLIP OUT OF THE S ACROSS MOST
OF THE AREA BARRING THE NORTHERN PANHANDLE, ALONGSIDE A WAVE OF
RAIN AND WIND WHICH WILL RACE NORTHWARD, THOUGH THESE WILL BE
STRONGEST IN THE SOUTHERN PANHANDLE. BY LATE FRIDAY NIGHT, WINDS
ACROSS THE CENTRAL INNER CHANNELS WILL ONCE MORE BE STARTING TO
FLIP BACK OUT OF THE N AS SAID FRONTAL BAND'S IMPACT FADES, AND N
OUTFLOW TRIES TO RE-ESTABLISH ITSELF ONCE MORE.
TEMPERATURES WILL FINALLY START TO WARM ACROSS THE CENTRAL AND
NORTHERN PANHANDLE FRIDAY AFTERNOON, THOUGH THE FAR NORTHERN
PANHANDLE WILL LIKELY HOLD ON TO COOLER TEMPERATURES LONGER.
PRIMARY FORECAST CHANGES WERE TO EMPHASIZE WIND SHIFTS IN THE
INNER CHANNELS, AS WELL AS INCREASING WIND SPEEDS - ESPECIALLY
ACROSS THE OUTER COASTAL WATERS AND ACROSS LAND-BASED LOCATIONS IN
THE SOUTHERN HALF OF THE AREA. ALSO ADDED THE POSSIBILITY OF A
FREEZING RAIN RAIN/SNOW MIX IN FOR JUNEAU, GUSTAVUS, AND
PETERSBURG THROUGH PARTS OF THE MORNING ON FRIDAY. DELAYED THE
TIMELINE FOR WARMING TEMPERATURES ACROSS THE CENTRAL AND NORTHERN
PANHANDLE ON FRIDAY, ALTHOUGH DO STILL EXPECT THE WARMUP TO HAPPEN
- JUST A LITTLE SLOWER THAN PREVIOUSLY PROGGED.
LONG TERM.../SATURDAY THROUGH THURSDAY/
OVERVIEW: SE AK WILL BE IMPACTED BY A SERIES OF STRONG LOWS
MOVING INTO THE AK GULF FROM THE SOUTH THEN TRACKING WEST. THESE
SYSTEMS WILL BRING IN WARM TEMPERATURES, MODERATE TO HEAVY RAIN
FALL, AND STRONG WINDS. GULF WINDS WILL BE A GALE TO STORM FORCE
WITH SMALL CRAFT TO GALE FORCE WINDS OVER THE INNER CHANNELS AT
LEAST. OVERLAND WINDS GUSTS ALONG THE SOUTHERN AND COASTAL AREAS
OF 40 TO 50 MPH AT LEAST EXPECTED TEMPERATURES MAY NEAR RECORD
VALUES FOR THIS TIME OF YEAR WHICH WILL KEEP PRECIP AS RAIN WITH
THE EXCEPTION OF THE HAINES AND KLONDIKE HIGHWAY BORDERS WHERE AT
LEAST A FEW INCHES OF SNOW ACCUMULATION ARE PROBABLE.
A MID LEVEL LOW IS THE MAIN STEERING FORCE FOR THE MID RANGE THAT
KEEPS THESE SURFACE LOW PRESSURE SYSTEMS ENTERING THE AREA. WHILE
THE MID LEVEL LOW VARIES AS SMALLER WAVES ROTATE AROUND IT NOT
SEEING ANY MOVEMENT FROM THE AREA UNTIL LATE NEXT WEEK. EXTREME
FORECAST INDEX HAS BEEN CONSISTENT THE PAST FEW RUNS DEPICTING
THE WARM SWATH OF AIR MOVING IN INTO NEXT WEEK. HIGH TEMPS IN THE
LOW TO MID 40S WITH POSSIBLE 50S, IF THE 90TH PERCENTILE IS
ACCURATE. CURRENT RECORD HIGHS FOR THIS TIME OF YEAR ARE MOSTLY IN
THE UPPER 40S TO MID 50S. EFI HAS THE STRONGER WINDS ALONG THE
SOUTHERN AND COASTAL AREAS FOR SUNDAY THEN AGAIN WEDNESDAY. GUSTS
OF 40 TO 50 MPH LIKELY BUT AS MOST OF THE FRONTS AS ASSOCIATED
WITH LOWS PULLING BACK TO THE WEST HAVE LOWER CONFIDENCE IN GUSTS
OF 60 MPH OR HIGHER.
ENSEMBLES DEPICTING CONSISTENT FEATURES WITH THE OPERATIONAL
INDICATING SOME DIFFERENCES EARLY ON. GFS HAS BEEN CONSISTENTLY
ON THE HIGH SIDE FOR WINDS BUT STARTED TO SEE NAM AND CANADIAN
FALL IN LINE WITH HIGHER GULF WINDS SUNDAY.
AVIATION
FLYING CONDITIONS THIS MORNING CONTINUES TO BE VERY
MUCH LOCATION DEPENDENT. FOR THE FAR NORTHERN PANHANDLE AND NE
GULF COAST, VFR CONDITIONS CONTINUE TO BE PERSISTENT WITH SOME
MVFR DEVELOPING. FARTHER SOUTH, CONDITIONS BECOME LESS FAVORABLE
WITH MVFR CIGS AND AN AREA OF FREEZING RAIN CURRENTLY ACROSS THE
PAGS TO PAJN AREA AT THE TIME OF WRITING. THIS AREA OF FREEZING
RAIN IS CURRENTLY EXPECTED TO PERSIST THROUGH THE MORNING BEFORE
WARMING TEMPERATURES AND DIMINISHING PRECIP CUT OFF PRECIP. FROM
SUMNER STRAIT SOUTHWARD, IFR TO VFR CIGS THIS MORNING AND ARE
SPREADING NORTHWARD SLOWLY AHEAD OF THE NEXT FRONT. WITH THE NEXT
FRONT MOVING IN, CIGS AND VIS ARE EXPECTED TO REMAIN IN THE IFR TO
MVFR RANGE FOR THE SOUTHERN PANHANDLE. LLWS IS EXPECTED TO SPREAD
ACROSS THE PANHANDLE WITH THIS FRONT AND IS EXPECTED TO MAKE IT
AS FAR NORTH AS THE ICY STRAIT CORRIDOR INCLUDING PAJN. AAWU
FORECASTS FOR THE PANHANDLE SHOW THAT TURBULENCE AND ICING WILL
ALSO BECOME MORE OF AN ISSUE AS THE FRONT MOVES FROM NORTH TO
SOUTH DURING THE TAF PERIOD.
MARINE
ELEVATED WINDS CONTINUE ACROSS THE MARITIME AREAS, WITH
GALE FORCE WINDS ACROSS THE OUTER COASTAL WATERS AND SMALL CRAFT
CONDITIONS AT TIMES ACROSS THE INNER CHANNELS EXPECTED TO LAST
THROUGH THE WEEKEND.
AJK WATCHES/WARNINGS/ADVISORIES
PUBLIC...WINTER WEATHER ADVISORY UNTIL 9 AM AKST THIS MORNING FOR AKZ320-
325.
STRONG WIND THIS EVENING FOR AKZ323.
WINTER WEATHER ADVISORY UNTIL 6 AM AKST EARLY THIS MORNING FOR
AKZ326.
STRONG WIND FROM NOON AKST TODAY THROUGH THIS AFTERNOON FOR
AKZ328.
STRONG WIND FROM 3 PM AKST THIS AFTERNOON THROUGH THIS EVENING
FOR AKZ330-332.
MARINE...GALE WARNING FOR PKZ641>644-652-661>664-671-672.
SMALL CRAFT ADVISORY FOR PKZ012-013-021-022-031-033>036-053-651.
SHORT TERM...GFS
LONG TERM....PRB
AVIATION...SF
MARINE...GFS
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