351  
FXAK67 PAJK 180001  
AFDAJK  
 
SOUTHEAST ALASKA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE JUNEAU AK  
301 PM AKST TUE DEC 17 2024  
   
SHORT TERM.../THROUGH WEDNESDAY/  
LOW PRESSURE IS DEVELOPING AS  
IT TRACKS NORTHWARD OFF THE COAST OF HAIDA GWAII. THIS WILL BE  
THE MAIN WEATHER MAKER FOR THE NEXT 24 HOURS. WIND GUSTS OF AROUND  
40KT HAVE BEEN RECORDED AROUND HAIDA GWAII SO FAR AND EXPECT SOME  
GUSTS OF 35MPH TO BE FELT THIS EVENING OVER SOUTHERN PRINCE OF  
WALES AND ANNETTE ISLANDS.  
 
WHILE TEMPERATURES ARE ABOVE FREEZING OVER THE SOUTH AFTER A SUNNY  
DAY, DEWPOINTS ARE IN THE TEENS WITH A DRY AIRMASS. THEREFORE, AS  
PRECIP MOVES IN THROUGH THE EVENING AND THE COLUMN SLOWLY BECOMES  
SATURATED, TEMPERATURES WILL FALL BELOW FREEZING. DUE TO THE  
PREVAILING WIND BEING E-NE, EXPECT GREATEST SNOWFALL  
ACCUMULATIONS TO OCCUR ALONG EAST FACING SLOPES. POTENTIAL FOR  
FREEZING RAIN REMAINS AND SOME MODELS WERE HIGHLIGHTING THE  
HOLLIS ROAD FOR THE GREATEST THREAT. MODELS ARE ALSO NOW SHOWING  
THE LOW TAKING A JOG EASTWARD JUST SOUTH OF DIXON ENTRANCE WITH  
PRECIP MOVING OUT SLIGHTLY EARLIER. THIS RESULTED IN LOWER OVERALL  
SNOWFALL TOTALS, PARTICULARLY FOR AREAS LIKE COFFMAN COVE. THE  
WINTER WEATHER ADVISORY REMAINS IN EFFECT.  
 
THE LOW TO THE SOUTH IS CAUSING A NORTHERLY PRESSURE GRADIENT  
THROUGH THE INSIDE WATERS. SUSTAINED WIND SPEEDS INCREASED NEAR  
WHITE PASS TO AROUND 20MPH TODAY AND EXPECT THOSE SPEEDS TO  
CONTINUE OVERNIGHT WHILE TEMPERATURES TREND DOWN. THIS WILL LEAD  
TO WIND CHILLS FALLING TO THE LOCAL THRESHOLD FOR A COLD WEATHER  
ADVISORY OF -30F NEAR WHITE PASS THROUGH MID MORNING ON WEDNESDAY.  
   
LONG TERM.../THURSDAY THROUGH TUESDAY NIGHT/  
MAIN STORY FOR  
THE MID AND LONG RANGE FORECAST PERIOD REMAINS AN ACTIVE PATTERN  
DRIVEN BY A LARGE UPPER LEVEL 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 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 DURING ANY HEAVIER  
SHOWERS, ESPECIALLY AT HIGHER ELEVATIONS. 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. MODELS  
HAVE COME INTO BETTER AGREEMENT THAT THIS FRONT WILL BEGIN TO  
SPLIT AS IT MAKES ITS WAY NORTHWARD, WHICH COULD SLOW DOWN THE  
TRANSITION TO RAIN, BUT ALSO LIMIT THE AMOUNT OF PRECIPITATION  
THAT REACHES INLAND AND NORTHWARD TOWARDS THE ICY STRAIT CORRIDOR.  
REGARDLESS, MINOR SNOW ACCUMULATION AS MENTIONED ABOVE IS  
EXPECTED THROUGHOUT THE DAY THURSDAY.  
 
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 15 - 20+ FT DUE TO AN ONGOING SSE SWELL  
AND THE WINDS ASSOCIATED WITH EACH SYSTEM ROTATING THROUGH.  
 
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. THERE WILL BE SNOW OVER THE  
SOUTHERN PANHANDLE HOWEVER, AND SNOW RATES MAY CAUSE IMPACTFUL  
REDUCTIONS TO LOW LEVEL FLIGHT VISIBILITY OVERNIGHT TUESDAY INTO  
WEDNESDAY MORNING. THE SNOW THREAT, STRONGER OUTFLOW WINDS AND  
LLWS WILL REDUCE THROUGH WEDNESDAY AFTERNOON AS THE LOW PRESSURE  
SYSTEM THAT PRODUCED THOSE CANDIDNESS WILL DISSIPATE AS IT DRIFTS  
EAST INTO DIXON ENTRANCE AND BC COAST.  
 
 
   
MARINE  
THE GALE FORCE LOW OVER THE SOUTHEASTERN GULF WEAKENS AS  
IT TRACKS EASTWARD AND INLAND OVERNIGHT. GRADIENT BETWEEN THIS LOW  
AND HIGH PRESSURE OVER NORTHERN CANADIAN KEEPS OUTFLOW CONDITIONS  
GOING WITH A INCREASE IN SPEED AND EXTEND IN THE EVENING HOURS.  
FULLY DEVELOPED SEAS FROM THE LONG FETCH LYNN CANAL SOUTHWARD HAVE  
BEEN KEPT IN FOR THIS TIME FRAME. AS THE LOW MOVES INLAND, OUTFLOW  
CONDITIONS SHOULD DECREASE BUT WILL PERSIST THOUGH AS HIGH PRESSURE  
REMAINS OVER CANADA. AFTER A BRIEF LULL NEXT MAX GALE FORCE FRONT  
CROSSES INTO THE EASTERN GULF WEDNESDAY NIGHT INTO THURSDAY. WILL  
SEE A SHIFT FROM NORTHERLY FLOW TO SOUTHERLY FOR THE SOUTHERN HALF  
OF THE PANHANDLE.  
 
 
   
AJK WATCHES/WARNINGS/ADVISORIES  
 
PUBLIC...STRONG WIND UNTIL MIDNIGHT AKST TONIGHT FOR AKZ318.  
COLD WEATHER ADVISORY UNTIL 11 AM AKST WEDNESDAY FOR AKZ318.  
STRONG WIND FROM 9 PM AKST THIS EVENING THROUGH LATE TONIGHT FOR  
AKZ325.  
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM AKST  
WEDNESDAY FOR AKZ328-330-332.  
MARINE...GALE WARNING FOR PKZ012-013-661.  
SMALL CRAFT ADVISORY FOR PKZ021-022-031>036-053-641>644-651-652-  
662>664-671-672.  
 
 
 
 
 
SHORT TERM...FERRIN  
LONG TERM....STJ  
AVIATION...ABJ  
MARINE...PRB  
 
VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU  
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