900
FXAK67 PAJK 171419
AFDAJK
SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
519 AM AKST TUE DEC 17 2024
SHORT TERM
COLD TEMPERATURES AND EITHER CLEAR SKIES OR HIGH
CLOUDS CONTINUE THIS MORNING. TEMPERATURES REMAIN COLD BUT SOME
LOCATIONS ACROSS THE SOUTHERN PANHANDLE HAVE BEEN WARMING DURING
THE OVERNIGHT HOURS. OUR NEXT SYSTEM IS EXPECTED TO APPROACH FROM
THE SOUTH TODAY BRINGING GALE FORCE WINDS TO THE OUTER COAST
WATERS AS WELL AS PRECIPITATION TO THE SOUTHERN PANHANDLE. MODELS
HAVE TRENDED DRIER WITH MOISTURE AS THE LOW MOVES OVER HAIDA GWAII
AND INTO BC FASTER WHICH DID BRING SNOW AMOUNTS DOWN.
FOR THE CENTRAL PANHANDLE NORTHWARD, OUTFLOW CONDITIONS ARE
EXPECTED TO CONTINUE WITH WINDS INCREASING AS THE LOW MOVES CLOSER
TO THE AREA. THE STRONGEST WINDS FOR NON-MARINE AREAS LOOKS TO BE
SKAGWAY AS WELL AS DOWNTOWN JUNEAU. AREAS AT ELEVATION THAT ARE
EXPOSED TO THE WIND WILL SEE DROPPING WIND CHILLS. WIND CHILL
VALUES LOOK TO BE AS LOW AS -20 TO -30. OUTFLOW CONDITIONS ARE
EXPECTED TO CONTINUE AS THE LOW MOVING THROUGH THE SOUTHERN
PANHANDLE EXITS THE AREA AND DISSIPATES.
LONG TERM.../THURSDAY THROUGH TUESDAY NIGHT/
MAIN STORY FOR
THE MID AND LONG RANGE FORECAST PERIOD REMAINS AN ACTIVE PATTERN
DRIVEN BY A LARGE SCALE LOW ENTRENCHED OVER THE NORTH PACIFIC,
BERING SEA, AND WESTERN GULF OF ALASKA BY MIDWEEK. MULTIPLE
SMALLER CIRCULATIONS WILL BE SPINNING ABOUT THIS LARGE SCALE
FEATURE THROUGHOUT THE WEEK. AFTER THE FIRST FIRST SYSTEM IMPACTS
THE PANHANDLE IN THE SHORT RANGE, ANOTHER FRONTAL BAND FEATURING
GALE FORCE WINDS WILL PUSH NORTHWARD AND APPROACH THE PANHANDLE
LATE WEDNESDAY INTO THURSDAY. THE SOUTHERN PANHANDLE WILL HAVE
LIKELY CHANGED TO ALL RAIN BY THE TIME OF THIS FRONTAL BAND
BRINGING A FRESH INFLUX OF MOISTURE, THOUGH SOME MIXED
PRECIPITATION ISN'T OUT OF THE QUESTION RIGHT AT ONSET OR DURING
ANY HEAVIER SHOWERS. WITH COLDER AIR STILL IN PLACE OVER THE
CENTRAL AND NORTHERN PANHANDLE, AND PERSISTENT NORTHERLY OUTFLOW,
SOME ACCUMULATING SNOW IS EXPECTED FROM WRANGELL NORTHWARD, WITH
24 HR TOTALS RANGING FROM 1 - 3 INCHES. AS OF THIS FORECAST
ISSUANCE, THE CENTRAL PANHANDLE UP TO FREDERICK SOUND IS EXPECTED
TO SEE A TRANSITION TO PRIMARILY RAIN BY LATE THURSDAY NIGHT, WITH
ANY PRECIPITATION REACHING FURTHER NORTH STILL FALLING AS EITHER
A SNOW/RAIN MIX OR ALL SNOW. DEPENDING ON THE INNER CHANNEL WINDS
AND MOMENTUM OF THIS FRONTAL FEATURE, OVERRUNNING COULD OCCUR
WHICH MAY LEAD TO HIGHER SNOW TOTALS AND A SLOWER TRANSITION TO
MIX OR RAIN SNOW FOR THE CENTRAL PANHANDLE.
WITH HIGHER PRESSURE OVER THE INTERIOR AND A MERRY GO ROUND OF
SYSTEMS MAKING THEIR WAY THROUGH THE GULF, INNER CHANNEL WINDS
WILL REMAIN RATHER STOUT THROUGH THE MID RANGE PERIOD. THE GULF
WILL ALSO BE TURBULENT WITH SEAS OF 20+ FT DUE TO AN ONGOING SSE
SWELL AND THE WINDS ASSOCIATED WITH EACH SYSTEM ROTATING THROUGH.
THIS ACTIVE WEATHER WILL CONTINUE THROUGH THE WEEKEND AND INTO
NEXT WEEK, SO NO REST FOR THE WEARY.
FOR THE LATTER HALF OF NEXT WEEKEND AND INTO EARLY NEXT WEEK THE
TREND CONTINUES TO BE WARM AND WET WITH SEVERAL POTENTIALLY GALE
FORCE FRONTS/LOWS WORKING THEIR WAY INTO THE GULF OF ALASKA FROM
THE S. THE DOMINATE FLOW PATTERN IS SOUTHERLY OVER THE AREA
BRINGING IN 850 MB TEMPS AROUND FREEZING SO SEA LEVEL TEMPERATURES
ABOVE FREEZING FOR A WIDE AREA OF THE PANHANDLE ARE LIKELY. RAIN
WILL ALSO LIKELY BE THE DOMINATE PTYPE WITH SNOW LEVELS AROUND
1500 TO 2500 FT OVER MOST OF THE PANHANDLE DURING THAT TIME.
MARINE CONDITIONS WILL BE ROUGH WITH PERIODS OF GALE FORCE WINDS
LIKELY FOR THE GULF WATERS AND PERIODS OF 25 TO 30 KT FOR VARIOUS
INNER CHANNEL AREAS AS WELL THROUGH EARLY NEXT WEEK.
AVIATION
STRONG OUTFLOW WINDS OVER THE FAR NORTHERN INNER
CHANNELS AND WIND SHEAR OVER THE SOUTHERN ZONES AS WELL AS IN THE
VICINITY OF THE JUNEAU ICE FIELD MAKE UP THE VAST MAJORITY OF THE
THE AVIATION IMPACTS FOR THE 24 HOURS. SOME AVIATION MODEL
GUIDANCE IS DEPICTING THE POSSIBILITY OF FREEZING RAIN OVER THE
FAR SOUTHERN PANHANDLE, BUT THE LATEST UPPER AIR SOUNDING FROM
ANNETTE ISLAND DOES NOT SUPPORT THIS, AS THE SATURATED LAYER IS
WAY UP AT 9000 FT. THERE WILL BE SNOW OVER THE SOUTHERN PANHANDLE
HOWEVER, AND SNOW RATES MAY CAUSE IMPACTFUL REDUCTIONS TO LOW
LEVEL FLIGHT VISIBILITY. MUCH WINDIER CONDITIONS OFFSHORE OF THE
OUTER COAST BELOW RIDGETOPS, SO IT WOULD BE BEST TO AVOID THE
OUTER COAST UNLESS YOU WILL BE UP IN THE FLIGHT LEVELS.
MARINE
A GALE FORCE LOW IS EXPECTED TO MOVE INTO THE SOUTHERN
GULF TODAY BRINGING INCREASING WINDS AND SEAS FOR THE OUTSIDE
WATERS. ELSEWHERE, OUTFLOW CONDITIONS ARE EXPECTED TO INCREASE IN
RESPONSE TO THE APPROACHING LOW. AS THE LOW MOVES INLAND, OUTFLOW
CONDITIONS SHOULD DECREASE BUT WILL PERSIST THOUGH AS HIGH
PRESSURE REMAINS OVER CANADA. ANOTHER GALE FORCE FRONT IS EXPECTED
TO MOVE INTO THE AREA THURSDAY.
AJK WATCHES/WARNINGS/ADVISORIES
PUBLIC...COLD WEATHER ADVISORY FROM 6 AM THIS MORNING TO 6 AM AKST
WEDNESDAY FOR AKZ318.
STRONG WIND FROM 6 AM AKST THIS MORNING THROUGH THIS EVENING FOR
AKZ318.
STRONG WIND FROM THIS EVENING THROUGH LATE TONIGHT FOR AKZ325.
WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM AKST WEDNESDAY FOR
AKZ328-330-332.
MARINE...GALE WARNING FOR PKZ012-013-641-661-662.
SMALL CRAFT ADVISORY FOR PKZ021-022-031>036-053-642>644-651-652-
663-664-671-672.
SHORT TERM...SF
LONG TERM....STJ/EAL
AVIATION...FRITSCH
MARINE...SF
VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU
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