Gale Warning 355, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
1217 PM AKST FRI NOV 14 2008

.SHORT TERM...A STORM FORCE LOW IN THE CENTRAL GULF CONTINUES TO
STRENGTHEN THIS MORNING AS IT ADVECTS EASTWARD AND IT WILL MOVE
ONSHORE NEAR SITKA EARLY THIS EVENING. ATTM WIND ADVY GUSTS ARE
OCCURRING ALONG THE OUTER AND SOUTHERN COAST WITH LOCALLY WINDY
CONDITIONS ALONG THE INNER CHANNELS...ESPECIALLY NEAR OUTFLOW
AREAS. THESE WINDY CONDITIONS WILL CONTINUE INTO EARLY TOMORROW
MORNING AS AFTER THE INITIAL 65 KNOT LLJ AT 850 MB PASSES OVER
THE PANHANDLE THIS AFTERNOON A 2ND WRAP OUT OF THE SOUTHWEST
WILL MOVE INTO THE EASTERN GULF BEHIND THE MID LEVEL LOW. THIS
2ND WRAP WILL BRING GALE FORCE WINDS ACROSS THE EASTERN GULF INTO
EARLY TOMORROW MORNING WITH WIND ADVY GUSTS CONTINUING ALONG THE
OUTER COAST. THE LLWS WILL REMAIN QUITE STRONG THROUGH THE
EVENING AND SEVERAL PIREPS THIS MORNING HAVE ALREADY INDICATED
HAZARDOUS FLYING CONDITIONS. RAINFALL CONTINUES TO SPREAD
NORTHWARD THIS MORNING WITH THE HEAVIEST RAINFALL OVER THE
SOUTHERN PANHANDLE AS THE LEFT EXIT REGION OF THE 170+ KNOT
300 MB JET MOVES ACROSS DIXON ENTRANCE. THE RAIN/SNOW LINE
REMAINS ALONG LYNN CANAL WHERE THE WINDS CONTINUE TO REMAIN
NORTHERLY THIS MORNING. IT IS CURRENTLY SNOWING ALONG THE HAINES
HIGHWAY AS THE MID LEVEL MOISTURE CONTINUES TO OVERRUN THE AREA.
WENT WITH THE 12Z NAM12 FOR TODAYS PACKAGE AS IT HAS THE BEST
HANDLE ON THE MOVEMENT AND TRACK OF THE SURFACE LOW TODAY WITH
THE SURFACE WIND FIELD.

 FOR TONIGHT THE WINDY CONDITIONS WILL CONTINUE ALL ACROSS THE
PANHANDLE WITH THE STRONG SURFACE PRESSURE GRADIENT OVER THE AREA
AND THE 65 KNOT 850 MB LLJ. AS THE LOW MOVES INLAND DURING THE
EARLY EVENING WINDS ALONG THE OUTER COAST WILL TURN FROM
SOUTHEASTERLY TO SOUTHWESTERLY WITH THE GALE FORCE WINDS
REMAINING. WHILE ACROSS THE INNER CHANNELS THE WINDS WILL
DIMINISH AFTER THE SURFACE LOW MOVES EAST OF THE AREA AND INTO
WESTERN BRITISH COLUMBIA BY LATE TONIGHT. THE STRATIFORM RAIN
WILL BECOME MORE SHOWERY TONIGHT AFTER THE LOW PASSAGE AS COLDER
AIR ALOFT MOVES OVER THE PANHANDLE MAKING THE ATMOSPHERE MORE
CONVECTIVE. AS THE LOW MOVES INLAND CONCERNED FOR A POSSIBILITY
OF HEAVY SNOW UP NEAR HAINES AS A DEFORMATION BAND IS CURRENTLY
LOCATED ON SATELLITE OVER THE HAINES AREA. THE 12Z NAM ALSO
INDICATES THAT A 850 MB DEFORMATION BAND WILL REMAIN OVER THE
HAINES AREA TONIGHT AND THIS WILL FOCUS MODERATE TO HEAVY
SNOWFALL WEST OF HAINES WITH THE INCREASED MID LEVEL
FRONTOGENESIS.

 FOR TOMORROW A SURFACE RIDGE WILL BUILD INTO THE GULF AND ACROSS
THE PANHANDLE INTO THE AFTERNOON. WITH THE CONTINUED ONSHORE LOW
AND MID LEVEL FLOW SHOWER ACTIVITY WILL CONTINUE ALONG THE
CENTRAL AND SOUTHERN PANHANDLE. HOWEVER WITH THE BEST PVA MOVING
INTO BRITISH COLUMBIA EARLY IN THE MORNING, EXPECTING THE SHOWER
ACTIVITY TO BECOME SCATTERED TO ISOLATED IN THE AFTERNOON WITH A
FEW SUNNY BREAKS. EXPECT LOCALLY BREEZY CONDITIONS NEAR SHOWERS
THROUGH THE DAY TOMORROW...BUT THE WINDY SPOT WILL REMAIN IN LYNN
CANAL AND NEAR SKAGWAY AS A STRONG SOUTHERLY SURFACE PRESSURE
GRADIENT BUILDS THERE INTO THE AFTERNOON. ATTM WITH THE GRADIENT
ORIENTATION DO NOT EXPECT WIND ADVY GUSTS NEAR SKAGWAY...BUT WILL
MONITOR AFTERNOON MODEL RUNS. SNOW ACROSS THE NORTHERN PANHANDLE
WILL REMAIN LIGHT TOMORROW AS THE MID LEVEL DEFORMATION BAND WILL
HAVE DISSIPATED BY THE EARLY MORNING LEAVING ONLY SCATTERED SNOW
SHOWERS INTO THE AFTERNOON.

 &&

.LONG TERM...MODELS INITIALIZED WELL TODAY AND WERE IN FAIRLY
GOOD AGREEMENT ON THE LONG WAVE PATTERN WITH RIDGE OVER WRN US
AND CANADA SAT-SUN AND TROF MOVING IN TO THE AK GULF SUN-MON. A
SHARP RIDGE OVER WRN AK ON THURS FLATTENS OUT WITH A DEEPENING
TROF MOVING E FROM THE W PACIFIC.

SIGNIFICANT MODEL DIFFERENCES WITH THE TRACK AND INTENSITY OF THE
NEXT LOW SUN-MON. GFS KEEPS THE LOW WEAKER AND MORE TO THE EAST
THAN THE STRONGER EC WITH THE NAM IN THE MIDDLE. FOLLOWING
PREVIOUS GUIDANCE SUGGESTING THE GFS EASTERLY TRACK IS DUE TO THE
MODEL WEAKENING THE RIDGE OVER THE WRN US, GOING WITH THE EC.
COORDINATION WITH ANCHORAGE. 12Z EC TRACKS THE MON LOW A BIT MORE
TO THE SE. WILL BLEND A BIT OF THE NEW EC RUN INTO THE CURRENT
GRIDS. HPC GUIDANCE AFTER DAY 4 TRACKS MORE WITH THE EC RUN.

WITH THE MORE EASTERLY TRACK OF THE LOW ON MON BROUGHT TEMPS DOWN
SLIGHTLY OVER THE CENTRAL AND N PANHANDLE. THIS BROUGHT UP
CHANCE OF SNOW SLIGHTLY OVER THE N BUT STILL NOT EXPECTING MUCH
ACCUMULATION. ON MON WINDS EXPECTED TO BE UPPER END OF GALES
FORCE OVER THE S GULF WITH SMCR IN THE N GULF. POSSIBLE HIGH WIND
EVENT OVER COASTAL AND SRN ZONES WITH THE FRONTAL PASSAGE.

KEEPING WITH AN ACTIVE SURFACE PATTERN NEXT WEEK WITH A COMPLEX
LOW PRESSURE SYSTEM DEVELOPING IN THE N PACIFIC AND AK GULF WED-
THURS.

FORECAST CONFIDENCE IS FAIR FOR THE SUN-MON EVENT BUT WITH THE
CHANGING TRACK WILL EXPECT SIGNIFICANT CHANGES TO WIND EVENT AND
SNOW OVER THE N.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND ADVISORY UNTIL MIDNIGHT AKST TONIGHT FOR
AKZ026-028.
         WIND ADVISORY UNTIL 6 AM AKST SATURDAY FOR
AKZ022-023-027.
         WIND ADVISORY UNTIL 3 PM AKST THIS AFTERNOON FOR AKZ029.
         WINTER WEATHER ADVISORY UNTIL MIDNIGHT AKST TONIGHT FOR
AKZ019.
MARINE...STORM WARNING FOR PKZ033-042-043.
         GALE WARNING FOR PKZ011>013-022-031-034>036-041-051-052.

         SMALL CRAFT ADVISORY FOR PKZ021-032.

&&

PSS/PRB