Gale Warning 342, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
113 PM AKST MON NOV 10 2008

.SHORT TERM...EMPHASIS ON WIND EVENTS IS GIVEN BELOW. WEAK SNOW
EVENT IN NORTHERN HALF OF PNHDL IS TAKING PLACE AT  THIS TIME,
BUT CHG TO MOSTLY LIQUID SHOULD OCCUR THIS AFTRN.

 STRONG SECTION OF POLAR FRONT ZONE IN BAND FM 600 NM S OF  COLD
BAY TO 700 NM S OF YAKUTAT.  JETSTREAM VALUES AS HIGH AS 185 KT
HAVE BEEN OBTAINED FROM CLOUD DRIFT WINDS FOR CYCLOGENETIC SYSTEM
700 S PAYA.  NEXT MAJOR WAVE UPSTREAM HAD A JETSTREAM VALUE OF
217 KT.  THESE VALUES ARE AS MUCH AS 40 KT HIGHER THAN THE MODELS
AND ARE CONSISTENT WITH CYCLONE  EVOLOTIONS DIFFERENT FM THE AVBL
MODELS.  IN GENERAL THE NAM  FAVORS A NE TRACK WITH THE FIRST
SYSTEM MOVG THROUGH SRN SE AK  WHEREAS THE GFS FAVORS A SHARPER
TURN N ALG THE OUTER COAST  OF THE PNHDL. WE ARE TRYING TO BE AS
PROBALISTIC AS WE CAN TO  REPRESENT THE THE
DETERMINISTIC SOLNS HAVE A  WIDE SPREAD. CONFIDENCE IN THE
DETERMINISTIC MODELS IS LOW.

 BEST ESTIMATE AT THIS TIME IS FOR THE FIRST WAVE TO TRACK  NE
AND HAVE A RAPID CLYCLOGENESIS SLOWG THE LOW FASTER AND THEREFORE
FARTHER OFFSHORE THAN THE MODELS.  THE FIRST SYSTEM  IS THE
REASON FOR THE HIGH WIND WATCHES ISSUED FOR PUBLIC  ZONES 23, 27,
AND 28.  ALSO NOTE THE AMD TO MARINE ZONES HAVE STORM WARNINGS IN
THE SOUTHERNMOST ZONES.

 RAPID CYCLOGENESIS OF THE FIRST SYSTEM IS UNDERWAY WITH DATA
BUOY 46004 GOOD SITE TO MONITOR WITH PRESFR.  BUOY 46184 IS IN
THE BEST LOCATION BUT IS OTS.

.LONG TERM...CONTINUING 500 MB LONG WAVE PATTERN WITH A RIDGE
BUILDING OVER THE THE PNHDL WED-THURS WITH A DEVELOPING TOUGH
MOVING ACROSS THE AKGULF THROUGH SAT. MOST MODELS ARE IN GOOD
AGREEMENT WITH THIS PATTERN BUT THEN DIFFER GREATLY AT THE LOWER
LEVELS.

ON WED CURRENTLY HAVE A WEAK LOW MOVING ACROSS THE S PNHDL...PLAN
ON NEAR SMCRFT WINDS OVER THIS AREA. MODELS VARIED WIDELY
REGARDING THE LOCATION OF THIS LOW. WENT WITH 12Z GFS FOR
CONTINUITY BETWEEN THE SHORT TERM. WILL ALSO SEE WINDS
DIMINISHING OVER THIS TIME PERIOD.

THE NEXT SYSTEM MOVING INTO THE AREAS ON FRI IS THE REAL
QUESTION. PREVIOUS EC RUNS AND HPC KEPT THE LOW ON A MORE
WESTERLY TRACK WITH THE GFS MORE TO THE EAST AND DEEPER. THE 12Z
EC TRACK THEN SWITCHED TO FOLLOW THE GFS. AFTER COORDINATING WITH
ANCHORAGE DECIDED TO BLEND WITH THE EC AND GFS TO MOVE THE
POSITION A BIT FARTHER TO THE EAST BUT STILL KEPT CLOSE TO THE
PREVIOUS GRIDS. THE TRACK OF THIS LOW WILL BE SIGNIFICANT IN THE
PRECIPITATION TYPE AND INTENSITY. WITH THE MORE WESTERLY TRACK
EXPECTING A MIX OF RAIN AND SNOW WITH IN THE LOW WARM SECTOR. IF
THE TRACK DOES MOVE EAST THEN COULD BE SEEING A SIGNIFICANT SNOW
EVENT OVER THE NORTHERN AND CENTRAL PNHDL. SEEING SIGNIFICANT
COLD AIR DROPPING SOUTH THE THE EASTERLY TRACK BUT MOS
TEMPERATURES WERE NOT REFLECTING A SIGNIFICANT DROP. OTHER ISSUES
WITH THE LOW TRACK ARE THE INTENSITY OF THE JET WHICH WAS UNDER
DEVELOPED IN MOST MODELS AND COULD ACT TO SLOW DOWN THE LOW AND
TRACK IT MORE TO THE WEST.

WITH THE SIGNIFICANT DIFFERENCES IN THE MODEL RUNS AND SOLUTION
SPREADS HAVE PRETTY LOW CONFIDENCE IN THE FORECAST FOR DAY 3 AND
DAY 5 THROUGH DAY 7. SAW ENOUGH CHANGES TO MAKE ALTERATIONS TO
THE CURRENT GRIDS BUT NOT ENOUGH CONFIDENCE TO MAKE SIGNIFICANT
STATEMENTS REGARDING THE FRIDAY LOW.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND ADVISORY FROM 6 PM THIS EVENING TO 3 AM AKST
TUESDAY FOR
     AKZ027.
         HIGH WIND WATCH FROM LATE TONIGHT THROUGH TUESDAY
AFTERNOON FOR
     AKZ023-027-028.
         WIND ADVISORY FROM 6 AM TO 4 PM AKST TUESDAY FOR AKZ022.
         WIND ADVISORY FROM 9 PM THIS EVENING TO 3 AM AKST
TUESDAY FOR
     AKZ028.
MARINE...STORM WARNING FOR PKZ036-041.
         GALE WARNING FOR PKZ022-033>035-042-043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ011>013-021-031-032.

&&

JBT/PRB