High Wind in Alaska, November 16 to 18, 2013

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
428 PM AKST SAT NOV 16 2013

.SHORT TERM...A WEAK LOW ALONG THE CENTRAL OUTER COAST IS
KEEPING MUCH OF THE PANHANDLE UNDER CLOUDY SKIES AND PRODUCING
SOME LIGHT SNOW ALONG THE OUTER COAST. THE LOW IS FORECAST TO
CONTINUE TRACKING TO THE SOUTHEAST THROUGH THE SHORT TERM
FORECAST PERIOD, TAKING THE CLOUDS AND SNOW WITH IT AND LEAVING
AN INVERTED TROUGH EXTENDING TO THE NORTHWEST OVER THE EASTERN
GULF AND PARTLY CLOUDY TO MOSTLY CLEAR SKIES. SNOWFALL TONIGHT
MAINLY ALONG THE SOUTHERN OUTER COAST AND THE KETCHIKAN AREA WITH
SOME POSSIBLE AS FAR NORTH AND EAST AS ZAREMBO ISLAND. SNOW
TOTALS TONIGHT SHOULD BE 1 INCH OR LESS.

THE LOW ITSELF IS NOT CREATING ANY SIGNIFICANT WINDS. THERE IS,
HOWEVER, A STRONG SURFACE HIGH BUILDING INTO THE SOUTHERN YUKON
FROM THE WEST. THIS FEATURE, IN CONJUNCTION WITH THE LOW, WILL
PRODUCE ANOTHER STRONG NORTHERLY/NORTHEASTERLY PRESSURE GRADIENT
THAT WILL EXTEND INTO THE LONG RANGE FORECAST PERIOD. HAVE OUTFLOW
WINDS ALONG THE NORTH COAST EAST OF YAKUTAT, BUT DO NOT EXPECT
ANYTHING REMARKABLE IN TOWN. SIMILARLY, HAVE GALE FORCE OUTFLOW
WINDS OUT OF CROSS SOUND. OVER THE FAR NORTHERN INNER CHANNELS,
WINDS ARE STARTING TO PICK UP IN SKAGWAY, BUT BASED ON THE
PRESSURE DIFFERENTIAL BETWEEN SKAGWAY AND JUNEAU AND THE
SIGNIFICANTLY STRONGER WINDS AT ELDRED ROCK, THINK THERE MAY BE
SOME DECOUPLING OCCURRING IN THE IMMEDIATE AREA AROUND SKAGWAY.
NOT A LOT OF WIND IN HAINES, BUT WINDS OVER THE CHILKAT PENINSULA
ARE MORE IN LINE WITH THOSE OVER NORTHERN LYNN CANAL. HAVE STRONG
WIND HEADLINES FOR BOTH THESE PUBLIC ZONES AND GALE WARNINGS UP
FOR NORTHERN AND SOUTHERN LYNN CANAL. FARTHER SOUTH, WINDS IN THE
DOWNTOWN JUNEAU AND DOUGLAS AREA HAVE BEEN GUSTING REGULARLY TO 40
MPH ALL DAY. AM FORECASTING EVEN STRONGER WINDS OVERNIGHT AND FOR
TOMORROW FOR THIS AREA. CURRENTLY, AM NOT SEEING A TRUE TAKU WIND
EVENT AS THE INVERSION IS NOT STRONG ENOUGH. NEVERTHELESS, CROSS
BARRIER FLOW WILL KEEP WIND GUSTS SOLIDLY IN THE STRONG WIND
RANGE. OUTFLOW WINDS WILL INCREASE IN INTENSITY OUT OF INNER
PASSES AND CHANNELED TERRAIN OVER CENTRAL AND SOUTHERN LOCATIONS
CLOSE TO THE COAST MOUNTAINS AS THE LOW MOVES OVER THE CENTRAL
DIXON ENTRANCE TOMORROW. HAVE MENTIONED THIS IN THE FORECAST FOR
MISTY FJORDS BUT HAVE NOT INCLUDED A STRONG WIND HEADLINE.

USED GEM FOR UPDATES TO PRESSURE AND WIND BASED ON IT DOING THE
BEST JOB INITIALIZING THE PRESSURE GRADIENT OVER THE NORTHERN
INNER CHANNELS. THIS RESULTED IN AN INCREASE IN WIND SPEEDS OVER
MUCH OF THE PANHANDLE. POTENTIAL IS THERE FOR EVEN STRONGER WINDS,
BUT DID NOT HAVE ENOUGH CONFIDENCE TO ISSUE STORM WARNINGS FOR
LYNN CANAL. OFFSHORE, ALL MODELS IN GOOD AGREEMENT. TWEAKS TO POP
AND QPF USING GEM, ECMWF, GFS, AND NAM WITH LITTLE TO NO CHANGE IN
THE FORECAST. CONFIDENCE IS ABOVE AVERAGE FOR ANOTHER COLD SHORT
TERM FORECAST PERIOD WITH VALUES WELL BELOW NORMAL AND STRONG
WINDS OVER THE NORTHERN INNER CHANNELS. CONFIDENCE IS BELOW
AVERAGE FOR MARINE WIND SPEEDS OVER NORTHERN AND SOUTHERN LYNN
CANAL, WHERE AN UPGRADE TO A STORM WARNING MAY BECOME NECESSARY.

.LONG TERM...WIND RELATED EVENTS ARE THE PREDOMINANT TOPIC AT THE
OUTSET OF THE LONG RANGE PERIODS. PLEASE NOTE THE FREEZING SPRAY
FOR THE NORTHERN INNER CHANNELS AS WELL AS OUT OF TAKU INLET IN
THE EARLY PERIODS. ALSO A HIGH WIND WATCH HAS BEEN ISSUED FOR SUN
NIGHT THROUGH MONDAY MORNING FOR DOWNTOWN JUNEAU AND DOUGLAS.
NOTE ALSO THAT WIND CHILLS WILL BECOME MORE SIGNIFICANT IN
NORTHERN PANHANDLE INCLUDING 20 BELOW FOR HAINES ZONE SUN NIGHT
AND MON NIGHT. OVERALL CONFIDENCE IS AVERAGE.

THE SHORT RANGE SECTION DESCRIBES THE WEAK LOW ALONG THE CENTRAL
OUTER COAST THAT IS FORECAST TO CONTINUE TRACKING TO THE SOUTHEAST
THROUGH SUNDAY. THIS LOW TRACK WILL BE ASSOCIATED WITH AN INCREASE
IN LARGE SCALE NW FLOW ALOFT. THE NW FLOW, AND AN ARCTIC OUTBREAK
FOR THE LOWER LEVELS, ARE HIGH CONFIDENCE EVENTS.

THE LARGE SCALE FLOW ALOFT WILL BECOME MORE WNW BY MON AFTERNOON.
A 500H LOW OVER FAIRBANKS AT 06Z TUE WILL DROP OVER THE VICINITY
OF CORDOVA ABOUT 12Z WED AS THE FLOW ALOFT AT THAT LEVEL BECOMES
ZONAL. THE TRANSITION TOWARD ZONAL FLOW, AND THE OVERRUN OF
ARCTIC AIR, IS THE REASON FOR PRECIPITATION STARTING AT LEAST
MIXED WITH SNOW IN MANY LOCATIONS.

THE HIGH WIND WATCH FOR SUN NIGHT THROUGH MONDAY MORNING FOR
DOWNTOWN JUNEAU AND DOUGLAS IS FOR A MOUNTAIN WAVE EVENT ALSO
SOMETIMES CALLED A TAKU WIND. SEVERAL INGREDIENTS ARE ALREADY IN
PLACE FOR SUCH A MOUNTAIN WAVE EVENT, BUT A STABLE LAYER IS
NEEDED AND THE ARCTIC OUTBREAK SHOULD PROVIDE ONE.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND THROUGH SUNDAY AFTERNOON FOR AKZ018-019-025.
         HIGH WIND WATCH FROM SUNDAY EVENING THROUGH MONDAY MORNING FOR
     AKZ025.
MARINE...GALE WARNING FOR PKZ012-013-022-051.
         SMALL CRAFT ADVISORY FOR PKZ011-021-031-032-034>036-041>043-052.

&&

FRITSCH/JBT