Gale Warning 371, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
332 PM AKST SUN DEC 1 2013

.SHORT TERM...MOST THINGS ARE GOING AS PLANNED. THE WINDS ARE
LOCALIZED IN DOWNTOWN JUNEAU...WITH ONLY BREEZY CONDITIONS IN THE
FLATS...BUT PROBABLY BLOWING PRETTY GOOD ON FRANKLIN AT
TIMES...AND DEFINITELY AT DOUGLAS AND THAT AREA OF TOWN THAT I
LIKE TO THINK OF AS SODO...SOUTH OF DOWNTOWN, BUT NOT QUITE
THANE. OCCASIONAL WIND GUSTS UP TO 80 PLUS MPH...BUT AS IS
GENERALLY THE CASE WITH MOUNTAIN WAVES, THERE ARE LULLS AND THEN
BURSTS. AND DIRECTIONS ARE DIFFICULT TO ASCERTAIN AS THEY CAN BE
RANDOM AND SQUIRRELLY OWING TO THE TURBULENCE. THE HIGH WIND
WARNING CONTINUES THROUGH 5 AM MONDAY MORNING FOR DOWNTOWN JUNEAU
AND DOUGLAS. THE GRADIENT IS STRONG WITH OVER 10 MB BETWEEN
JUNEAU AND SKAGWAY. THE WINDS THROUGH LYNN CANAL HAVE BEEN
SCREAMING ALL DAY AND ALL NIGHT...AS WINDS ARE GENUINE STORM
FORCE WITH GUSTS CLOSE TO 90 MPH AT TIMES. THESE WILL CONTINUE
BUT SLOWLY BEGIN TO WEAKEN LATE TONIGHT INTO MONDAY.

 THE WEAK LOW IN HECATE STRAIT WILL SLOWLY CONTINUE MOVING
SOUTHEASTWARD. ITS TRAILING TROUGH ACROSS THE NORTHEAST GULF
WILL WEAKEN AS HIGH PRESSURE OVER THE YUKON SLIDES SOUTHWARD
BEHIND THE LOW INTO NORTHERN BC TONIGHT. THIS SHOULD HELP THE
NORTH-SOUTH GRADIENTS WEAKEN ESPECIALLY WHILE INCREASING EAST AND
WEST GRADIENTS A LITTLE TONIGHT...BEFORE ALL GRADIENTS WEAKEN
TOMORROW. IN TURN STRONG WINDS WILL ONLY RUN TONIGHT FOR YAKUTAT
PASSES AND LIKELY LET UP ALONG WITH THE STORM FORCE WINDS FOR
AREAS NEAR LYNN CANAL. REPORTS THIS MORNING OF 30 TO 40 MPH WINDS
FROM SKAGWAY CUSTOMS OF WINDS AT THE SUMMIT OF WHITE PASS SEEM
CAST MUCH DOUBT ON THE RWIS SITE WINDS OF WHITE PASS...SHOWING
LIGHT WINDS. THUS WIND CHILL ADVISORY WAS PLACED THROUGH 9 AM
MONDAY MORNING AS WINDS FALL AND TEMPERATURES BEGIN TO WARM UP
THEN.

 SOME FLURRIES OVER THE SOUTH, BUT DIMINISHING FAST THIS
AFTERNOON, SO HAVE ONLY CONFINED SHOWERS OVER THE SOUTHERN
EXTREMES THIS EVENING...EXITING HYDER LATE TONIGHT. ANYTHING THAT
FALLS SHOULD BE ALL SNOW AS TEMPERATURES ACROSS THE SOUTH HAVE
BEEN FALLING MOST OF THE DAY. CLEAR AND FRIGID FOR MOST AREAS
TONIGHT...ESPECIALLY AWAY FROM THE WATER WITH TEMPERATURES GOING
INTO THE SINGLE-DIGITS IN THE MENDENHALL VALLEY/GLACIER
BAY/NORTHEAST GULF/LYNN CANAL TONIGHT. TEMPERATURES SHOULD FALL
INTO THE LOWER 20S AS FAR SOUTH AS KETCHIKAN. MONDAY AFTERNOON
TEMPERATURES REBOUND INTO THE LOWER TO MIDDLE 30S FOR THE SOUTH
AND COAST AND 20S IN THE NORTHERN INTERIOR INTO THE TEENS FOR
LYNN CANAL.

 FEW CHANGES TO THE FORECAST. CONTINUED TO USE NAM...AND SREF FOR
GUIDANCE ON WIND/POPS. ALSO EMPLOYED GFS AND NAM MOS FOR TEMPS.

.LONG TERM...MOST ADJUSTMENTS TO THE FORECAST WERE DURING THE
LATTER HALF OF THE LONG RANGE...BUT THEY WERE MOSTLY SMALL
CHANGES. LARGE SCALE RIDGE WILL REMAIN OVER THE GULF THRU THE
UPCOMING WEEK...BUT THERE IS SOME QUESTION WHETHER ANY SYSTEMS MAY
BREAK THRU THE RIDGE AND INTO THE AREA ESPECIALLY DURING LATE WEEK
AND THE WEEKEND. FOR THE LATTER HALF OF THE PERIOD...USED LATEST
WPC FOR MOST FIELDS...BUT DID ONLY BLEND THEIR LATEST POPS WITH
PREVIOUS...AND EVEN THIS WAS TWEAKED SOME TO SLOW THE EWD MOVEMENT
OF THE POPS INTO THE INNER CHANNELS. ONE ISSUE WITH THE FURTHER
OUT TIME FRAME IS...A HIGHER POP SCENARIO WOULD MOST LIKELY BE
SOMEWHAT WARMER THAN WHAT IS IN CURRENT FORECAST...WHICH WOULD
MEAN THAT PTYPE WOULD BE MOSTLY RAIN. BUT...THE DRIER SCENARIO
WOULD LIKELY MEAN COOLER TEMPS AS WELL. FORECAST CONFIDENCE IS
VERY LOW DUE TO THIS REASON FOR THE LATTER HALF OF THE PERIOD.

FOR THE FIRST HALF OF THE PERIOD...THRU WED...MAIN FORECAST
ADJUSTMENT WAS TO WARM TEMPS ALOFT AS RIDGE EDGES IN. DID LIMIT
THE FOG TO THE PAYA AREA AS THE REMAINING AREA WILL NOT LIKELY
HAVE A DEEP ENOUGH ABOVE FREEZING LAYER ALOFT TO MELT SNOW AND
ALLOW THIS MOISTURE TO SETTLE OUT. ALSO...THERE WILL BE OUTFLOW
FROM THE CANADIAN SIDE THAT SHOULD ADVECT IN DRIER AIR. IF THE
UPPER RIDGE WERE TO SHIFT DIRECTLY OVERHEAD AND CAUSE A DEEPER
LAYER OF ABOVE FREEZING AIR ALOFT...THEN FOG WOULD BE MORE OF AN
ISSUE. WINDS IN THE MORE N-S CHANNELS SHOULD BE DIMINISHING MON
NIGHT INTO WED AS SFC HIGH SHIFTS TO A POSITION MORE TO THE E OF
THE AREA.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...HIGH WIND WARNING UNTIL 5 AM AKST MONDAY FOR AKZ025.
         STRONG WIND THROUGH MONDAY MORNING FOR AKZ019.
         STRONG WIND UNTIL 3 PM AKST THIS AFTERNOON FOR AKZ020.
         STRONG WIND THROUGH MONDAY AFTERNOON FOR AKZ018.
         WIND CHILL ADVISORY UNTIL 9 AM AKST MONDAY FOR AKZ018.
         STRONG WIND THROUGH LATE TONIGHT FOR AKZ017.
MARINE...HEAVY FREEZING SPRAY WARNING FOR PKZ012.
         STORM WARNING FOR PKZ012.
         GALE WARNING FOR PKZ011-013-021-022-031-032-035-043-051.
         SMALL CRAFT ADVISORY FOR PKZ033-034-036-041-042-053.

&&

JWA/RWT