Gale Warning 425, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
314 PM AKST MON DEC 23 2013

.SHORT TERM...MAIN CHANGES FOR THIS PACKAGE WAS MOVING THE WARM
FRONTAL FEATURE FARTHER TO THE NORTH ALONG ALONG WITH THE TROUGH
AXIS A FEW MILES UP STEPHENS PASSAGE AND THE PRECIPITATION FIELD
NORTH BY ONE ZONE...FOR THE AFTERNOON OF THE 24TH...CHANCE OF
SNOW/RAIN IN JUNEAU/GUSTAVUS/HOONAH. SLIGHT CHANCE OF SNOW
HAINES/YAKUTAT. AND MAINLY RAIN LIKELY FOR
SITKA/PETERSBURG/KAKE/WRANGELL. DOWN SOUTH, FEELING MORE
CONFIDENT THAT THE RAIN WILL ARRIVE THERE.

 OVERALL, FORECAST PANNED OUT FAIRLY WELL...PERHAPS REALITY WAS
SLIGHTLY BEHIND THE FORECAST...AND THE PEAKS GREATER THAN THE
MAXES FORECAST FOR WINDS. CROSS SOUND HAS PEAKED AT 45 TODAY.
NORTHERN LYNN DEFINITELY MADE GALE. AND SKAGWAY CAME UP AS WE
KNEW IT WOULD. SOME SURPRISES...HAINES WINDS CAME UP EVEN AT THE
AIRPORT TO GUSTS OF AT LEAST 40 MPH. REPORTS FROM MUD BAY
INDICATED 15 TO 30 THIS AFTERNOON...NOT CLEAR IF THIS REFLECTED
GUSTS. WHATEVER THE CASE, WINDS SHOULD BE ON THEIR WAY DOWN.
WHITEHORSE WINDS HAVE STARTED GUSTING FROM THE NORTH AND THUS THE
NEGATIVE GRADIENT WILL BEGIN TO SLACKEN THROUGH THE EVENING AND
FLIP TO POSITIVE LATE IN THE NIGHT. SKAGWAY'S WINDS SHOULD GO
LIGHT, ALTHOUGH CONFIDENCE NOT GREAT WITH HOW STRONG THE NORTH
WINDS WILL BE TOMORROW. OFTEN AS COLDER AIR SETTLES DOWN THE PASS
INTO THE THE TOWN, AN INVERSION SETS UP ALLOWING THE WINDS TO
OVERSHOOT TOWN. STUCK WITH 5 TO 15 FROM PREVIOUS SHIFT. HAINES
SHOULD FLIP TONIGHT AS WELL AS THE COLDER AIR WILL BEGIN DRAINING
DOWN THE CHILKAT VALLEY. THE COLD AIR ADVECTION SHOULD KEEP
TEMPERATURES NEAR STEADY TOMORROW FOR MUCH OF THE CANAL AREA.
GRADIENTS SUGGEST THAT WINDS SHOULD BE STRONGER IN THE JUNEAU
AREA, BUT PERHAPS SINCE THE GRADIENT SUPPORTS MORE OF A SOUTHWEST
FLOW, THERE MAY BE TOO MUCH BLOCKAGE FROM DOUGLAS. DID GO WITH
HIGHER GUSTS TO 35 MPH NEAR CROSS SOUND THIS EVENING.

 SHOWERS OVER HYDER WILL LIKELY GO BACK TO A RAIN/SNOW MIX
SOMETIME OVERNIGHT WITH THE CHANCE OF AN INCH. JUNEAU PROFILER
ANALYSIS CONFIRMS THE CONVECTION SEEMS TO BE FAIRLY SHALLOW, SO
NOT REALLY WORRIED ABOUT HIGHER AMOUNTS. HOWEVER, SOME
UNCERTAINTY FOR TUESDAY AFTERNOON ON HYDER. GRADIENTS GO
LIGHT...ALLOWING FOR LESS MIXING AND SOME COOLING PERHAPS. WHILE
HIGHS RIGHT NOW 37...FEEL THAT TEMPERATURES MAY BE A BIT COOLER
UP PORTLAND CANAL AFTER SECOND THOUGHT, AND WHILE HAVE A
RAIN-SNOW MIX, THIS COULD GO ALL SNOW LATE IN THE AFTERNOON,
ALLOWING FOR ANOTHER QUICK INCH OR EVEN TWO OR THREE LATE IN THE
AFTERNOON...ESPECIALLY IF LESS RAIN THAN THOUGHT MIXING IN.

 OVERALL PACKAGE INHERITED WAS PRETTY GOOD. MADE ONLY
INSIGNIFICANT CHANGES FOR MONDAY NIGHT, AND CONCENTRATED ON
TUESDAY FOR MOVING THE SYSTEM FORWARD A TAD UP INTO THE
PANHANDLE. CONFIDENCE GOOD TO AVERAGE.

.LONG RANGE...STILL SOME ISSUES AS FAR AS HOW FAR SOUTH COLD AIR
WILL GET AND HOW FAST PRECIP MOVES IN FROM THE SOUTH TUE NIGHT.
MODELS WERE VERY SLIGHTLY FASTER WITH THE PRECIP COMING IN. THE
NAM...WHICH HAS BEEN THE MOST AGGRESSIVE WITH THE COLD AIR COMING
SOUTH...HAS TRENDED A LITTLE WARMER. OTHER MODELS PRETTY MUCH
STAYED THE SAME ON THE COLD AIR. ENDED UP MAKING LITTLE CHANGE TO
THE POPS AND WINDS FOR TUE NIGHT INTO WED. DID TWEAK TEMPS...AND
ENDED UP DOING TWEAKS EVERY 6 HRS FOR TUE NIGHT INTO WED TO HANDLE
THE NON-DIURNAL TREND. CONFIDENCE IS NOT YET HIGH ENOUGH TO
UPGRADE THE WINTER STORM WATCH TO A WARNING FOR THE PAHN AND PAGY
AREAS FOR TUE NIGHT AND WED. LEFT THE QPF GRIDS AS IS...BUT DID
MAKE TWEAKS TO SNOWFALL DUE TO THE TEMP ADJUSTMENTS. MAY NEED
WINTER WEATHER ADVY FOR PAJN/PAGS AREAS BEFORE IT WOULD CHANGE TO
RAIN LATER TUE NIGHT. IF THE COLDER AIR CAN GET FURTHER S LIKE THE
NAM...THE WARM UP WOULD BE DELAYED SOME AND COULD LEAD TO HIGHER
SNOWFALL IN THE PAJN-PAEL CORRIDOR.

AFTER WED...ONLY ADJUSTMENTS MADE WERE TO THE DAY 6 PERIOD ON OUT
TO USE LATEST WPC GRIDS AND EXTEND OUT TO DAY 8. EVEN WPC HAD
BELOW AVERAGE CONFIDENCE FOR DAYS 4 AND 5...THUS THE DECISION TO
LEAVE THEM AS IS. STILL LOOKS LIKE A MILD PATTERN IN GENERAL WITH
SWLY FLOW ALOFT EXPECTED DURING THE LATE WEEK INTO THE WEEKEND
PERIOD. FORECAST CONFIDENCE IS FAIRLY LOW THROUGH THE ENTIRE LONG
TERM PERIOD.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND UNTIL 6 PM AKST THIS EVENING FOR AKZ019.
         WINTER STORM WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY
     AFTERNOON FOR AKZ018-019.
         STRONG WIND UNTIL 9 PM AKST THIS EVENING FOR AKZ018.
MARINE...GALE WARNING FOR PKZ012-022.
         SMALL CRAFT ADVISORY FOR PKZ011-013-021-031>034-036-041>043-
     051>053.

&&

JWA/RWT