820 FXAK67 PAJK 110037 AFDAJK SOUTHEAST ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JUNEAU AK 337 PM AKST THU DEC 10 2015 .SHORT TERM...AN UPPER DISTURBANCE OVER THE WRN GULF WILL DISSIPATE THU EVENING AS A WEAK TROUGH SPREADS E FROM THE ALEUTIANS. MEANWHILE...AN UPPER LOW CURRENTLY POSITIONED SW OF VANCOUVER ISLAND IS FORECAST TO MOVE E ACROSS WRN WA/ORE BY FRI AFTERNOON. AS THIS TAKES PLACE...PREVIOUSLY MENTIONED TROUGH WILL ENTER THE ERN GULF. SURFACE LOW PRESSURE WILL EXPAND EWD BENEATH THE TROUGH...WITH SHOWER ACTIVITY ENTERING COASTAL AREAS OF SERN AK DURING LATE FRI AFTERNOON. THESE SHOWERS COULD BE MIXED WITH SNOW NEAR YAKUTAT DUE TO INITIALLY DRY SURFACE AIRMASS AND ENE WINDS...WHICH WILL PROMOTE BOUNDARY LAYER TEMPERATURES HOVERING NEAR FREEZING AS LIGHT PRECIPITATION INITIATES. SHORT TERM FORECAST CONFIDENCE IS LOWEST FOR CLOUD COVER AND TEMPERATURES OVER THE INNER CHANNEL LAND ZONES. LARGE PLUME OF HIGH LEVEL CLOUDINESS IS SPREADING N OVER THE SRN PANHANDLE FROM THE VANCOUVER ISLAND LOW THU AFTERNOON....WHILE A WEAK MIDLEVEL DEFORMATION ZONE IS YIELDING ENHANCED CLOUD COVER FROM CROSS SOUND TO JUNEAU. EXPECT BOTH AREAS OF CLOUD COVER TO GENERALLY THIN GOING INTO THU NIGHT. THIS WILL RESULT IN POTENTIALLY STRONG RADIATIONAL COOLING...WHICH GIVEN WEAK DAYTIME HEATING THU...WILL LEAD TO TEMPERATURES FALLING INTO THE 20S TO LOW 30S. PATCHY FOG WILL ONCE AGAIN BE A CONCERN...BUT IT COULD DISSIPATE RELATIVELY QUICKLY IF MOISTURE IS DEPLETED AS FROST. OTHERWISE...THE SURFACE PRESSURE GRADIENT IS FORECAST TO WEAKEN OVER THE SRN PANHANDLE AS THE VANCOUVER LOW EXITS E. FARTHER N...THE GRADIENT WILL LOCALLY TIGHTEN OVER NRN LYNN CANAL RESULTING IN STRENGTHENING NLY WINDS TO SMALL CRAFT...AND MODEST GUSTS OUT OF THE NE AT SKAGWAY...AND NW AT HAINES. IF DOWNSLOPE WINDS/WARMING ARE STRONGER THAN ANTICIPATED AT SKAGWAY...THEN THE FORECAST LOW OF 31 WILL LIKELY BE TOO COLD /SUBSEQUENT SHIFTS WILL NEED TO MONITOR/. .LONG TERM...NOT A LOT OF CHANGE IN THE MID RANGE FORECAST AS AN UPPER TROUGH OVER THE GULF GIVES WAY TO A PROGRESSIVE RIDGE BY THE END OF THE WEEKEND. AT THE SURFACE, A WEAKENING FRONT WILL BE MOVING ONSHORE FRI NIGHT. BRINGING PRECIP TO MOST OF THE NORTHERN PANHANDLE AND OUTER COAST. LINGERING WEAK OUTFLOW AS WELL AS INCREASING EASTERLY FLOW FROM A LOW THAT IS MOVING SOUTH OF HAIDA GWAII WILL CAUSE THE FRONT TO STALL THEN FALL APART OVER THE OUTER COAST. WITH THE COOL AIR FROM THE CURRENT WEAK OUTFLOW COOLING THINGS OFF, PRECIP FROM THIS FRONT WILL MOSTLY BE SNOW FOR THE NORTHERN PANHANDLE. HOWEVER AMOUNTS WILL BE LOW AS THE FRONT SHEARS APART. HIGHEST AMOUNTS ARE EXPECTED OVER YAKUTAT, THE NORTHERN OUTER COAST, AND INTO GUSTAVUS AND HOONAH. HOW FAR EAST THE HIGHER PRECIP AMOUNTS WILL GET IS UP FOR DEBATE AS THE PRECIP MAX THAT MODELS WERE EXPECTING OVER JUNEAU YESTERDAY HAS MOVED WEST OF JUNEAU IN THE LATEST RUNS. SO DECIDED TO KEEP JUNEAU AT CHANCE POPS FOR FRI NIGHT WITH LIKELY POPS FARTHER WEST. ANOTHER DRY PERIOD IS IN THE WORKS FOR THE LATE WEEKEND AND EARLY MON. THIS TIME A MUCH MORE ROBUST COLD AIR MASS IS AVAILABLE IN THE YUKON. WINDS IN THE INNER CHANNELS SUN AND EARLY MON ARE LIKELY TO GET INTO SMALL CRAFT CRITERIA DUE TO PRESSURE GRADIENT AND COLD AIR FLOWING THROUGH THE VARIOUS PASSES. TEMPERATURE WILL ALSO BE GETTING COLDER AS WELL. FOR THE NEXT FRONT ON MON INTO TUE, MODELS ARE STILL BOUNCING AROUND AS FAR AS FRONTAL TIMING. THEY ARE STARTING TO SETTLE ON A MON AFTERNOON TO MON EVENING TIMING FOR THE FRONT. HOWEVER THEY HAVE SWITCHED PLACES COMPARED TO YESTERDAY WITH THE 12Z GFS AND GEM NOW THE FASTEST WITH FRONTAL TIMING AND THE ECMWF A LITTLE SLOWER. DECIDED TO STICK WITH THE ECMWF FOR GUIDANCE AS THAT MODEL HAS SHOWED THE MOST CONSISTENCY FOR THE LAST FEW DAYS. ANOTHER THING TO WATCH WITH THIS FRONT IS THAT WITH ALL THE COLD AIR THAT IS EXPECTED TO FLOW INTO THE INNER CHANNELS SUN AND EARLY MON, SNOW IS A GOOD POSSIBILITY FOR THE NORTHERN HALF OF THE PANHANDLE MON AFTERNOON INTO MON NIGHT. A FEW INCHES OF SNOW IS POSSIBLE BEFORE SOME RAIN MAY MIX IN FOR SOME AREAS ON TUE. FORECAST CONFIDENCE IS GETTING BETTER BUT WITH FRONTAL TIMING STILL SOMEWHAT DEBATED THIS FORECAST IS NOT VERY HIGH CONFIDENCE YET. FORECAST CONFIDENCE GOES EVEN FURTHER DOWNHILL MID NEXT WEEK. ABOUT THE ONLY THING MODELS AGREE ON IS THE POSSIBILITY OF MORE COLD AIR COMING DOWN FROM THE BERING SEA AREA WITH SOME DRY WEATHER IN THE WORKS. && .AJK WATCHES/WARNINGS/ADVISORIES... PUBLIC...NONE. MARINE...SMALL CRAFT ADVISORY FOR PKZ012-031-034-036-041. SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ022-042-043-051>053. && $$ GARNER/EAL VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU