Gale Warning 227, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
1254 PM AKDT MON OCT 20 2008

.SHORT TERM...MORNING SATELLITE LOOP SHOWS A STRONG LOW IN THE
CENTRAL GULF SLOWLY MOVING NORTHEASTWARD TO CAPE FAIRWEATHER WITH
AN OCCLUDED FRONT WRAPPING ACROSS THE PANHANDLE. AN EMBEDDED RAIN
BAND WITHIN THE FRONTAL BOUNDARY IS PASSING ACROSS THE PANHANDLE
AT THIS TIME AND ANOTHER RAIN BAND CLOSER TO THE LOW CENTER IS
MOVING ONSHORE ACROSS THE OUTSIDE WATERS. MODELS ARE IN GENERAL
AGREEMENT WITH THIS LOW TRACKING NORTHEAST THROUGH TONIGHT AND
WEAKENING. BY TUESDAY MORNING...THE LOW WILL DISSIPATE BUT SOME
DIFFERENCES ARE NOTED AMONG THE MODELS WITH RESPECT TO THE
POSITION AND INTENSITY OF THE DISSIPATING LOW. WILL BLEND WITH
THE 12Z RUN GFS AND NAM INTO THE INHERITED GRIDS FOR TONIGHT AND
TUESDAY. THIS WILL MAKE A GOOD CONSENSUS FOR THE WEAKENING LOW IN
THE NORTHEAST GULF TONIGHT BUT A LITTLE DELAY FOR THE INCOMING
STORM FROM THE SOUTH. WILL TWEAK A LITTLE ON THE WIND FIELD FOR
TUESDAY AFTERNOON ALONG THE LEADING EDGE OF THE FRONTAL BOUNDARY
TO BRING THE EXPECTED HIGH WINDS A BIT EARLIER OVER THE SOUTHERN
ZONES.

 EXPECT GALE FORCE WINDS DEVELOPING LATE TONIGHT INTO TUESDAY FOR
OFFSHORE WATERS AND OUTSIDE WATERS WITH ROUGH SEAS EXCEPT FROM
ICY CAPE TO CAPE SUCKLING. INSIDE WATERS WITH OPEN OCEAN
CONNECTION WILL SEE GALE FORCE WINDS AS WELL ON TUESDAY. REST OF
THE MARINE ZONES WILL GO WITH SMALL CRAFT ADVISORY. MAIN CONCERN
SHOULD GO WITH THE INCOMING STORM FROM THE SOUTH. IT SEEMS LIKE
THE LEADING EDGE OF THE FRONT ASSOCIATED WITH THE STORM WILL
ARRIVE NEAR DIXON ENTRANCE BY MIDDAY TUESDAY. A RAPID INCREASE OF
BOUNDARY LAYER WINDS IS EXPECTED BY EARLY TUESDAY AFTERNOON
ACROSS THE SOUTHERN THREE ZONES TO MEET THE HIGH WIND WARNING
CRITERIA AND WIND ADVISORY FOR REST OF SOUTHERN PANHANDLE AND
CENTRAL COAST. WILL COORDINATE WITH THE LONG TERM FOR TIMING OF
HIGH WIND WARNING OVER THE SOUTHERN ZONES.

.LONG TERM...THE MODELS ARE IN GOOD AGREEMENT WITH THE VERY
STRONG LOW MOVING INTO THE CENTRAL GULF TUE NIGHT. THEY ARE STILL
STRUGGLING WITH THE STRENGTH AND PLACEMENT OF THE NEXT SYSTEM
MOVING INTO THE GULF WED NIGHT INTO THURS. THERE IS ALSO STILL
ABOUT A 24HR DIFFERENCES ON THE VERY COLD AIR MOVING ACROSS THE
GULF LATE ON FRI INTO THE WEEKEND. WITH THAT SAID MODIFIED THE
FORECAST FROM TUE NIGHT THROUGH WED NIGHT AND USED A BLEND OF THE
12Z GFS AND EC.

THE VERY STRONG LOW PRESSURE SYSTEM MOVING OUT OF THE NORTH
PACIFIC MENTIONED IN THE SHORT TERM WILL DEEPEN TO NEAR 965MB BY
TUE NIGHT AND LIFT INTO THE CENTRAL GULF. THIS LOW WILL CONTINUE
TO PUSH NORTH THROUGH GULF AS IT RIDES A VERY STRONG 160KT JET
THAT WILL MOVE OVER SE AK THROUGH TUE NIGHT. THE MAIN UPPER TROF
OVER THE GULF TUE NIGHT WILL PUSH THE RIDGE OVER WESTERN CANADA
TO THE EAST AND MOVE OVER THE PANHANDLE THROUGH WED. THE
WARM FRONT ASSOCIATED WITH THE STRONG 965 LOW TUE NIGHT WILL LIFT
NORTH OVER THE PANHANDLE BEFORE THE COLD FRONT MOVES OVER THE AREA
LATE WED AFTERNOON. THE FRONT PRODUCE VERY STRONG WINDS OVER THE
FAR SOUTHERN AREAS WITH A 70+KT LLJ THAT WILL REMAIN OVER THE
SOUTHERN HALF OF THE PANHANDLE THROUGH TUE NIGHT. SO WILL CONTINUE
THE HIGH WIND WARNING FOR THE SOUTHERN THREE ZONE AS WITH THE
STRONG THERMAL GRADIENT IT WILL CONTINUE TO MIX DOWN GUSTS 60 TO
70 MPH THROUGH TUE NIGHT. FOR THE CENTRAL INNER CHANNELS WILL
CONTINUE THE HIGH WIND WATCH BUT THERE IS A LIKELY CHANCE THAT THE
HIGH WIND WARNING WILL BE NEEDED. THE NORTHERN AREAS WILL SEE THE
WIND OUT OF THE NE 15 TO 25 MPH EARLY TUE NIGHT BUT AS THE FRONT
LIFTS NORTH THE WINDS WILL REALLY INCREASE TO A STRONG SE AND WIND
ADVY WILL BE NEED LAT TUE INTO WED AS THE PRESSURE GRADIENT
BECOMES MORE OUT OF THE SE TO BE MORE FAVORABLE.

OVER THE MARINE AREAS THE FRONT WILL CONTINUE TO PRODUCE STORM
FORCE WINDS OVER THE EASTERN GULF TUE NIGHT ALONG WITH CLARANCE
STRAIT. THE CENTRAL INNER CHANNELS WILL SEE GALES OUT OF THE EAST
THEN SE AS THE FRONT LIFTS OVER THE AREA. THE NORTHERN AREAS WILL
SEE NORTH WINDS TO 20 KT TROUGH TUE NIGHT BUT E/W ORIENTED
CHANNELS WILL SEE GALE FORCE WINDS WITH THE LOW MOVING INTO THE
NORTHERN GULF. AS THE LOW LIFTS INTO THE YUKON THE WINDS OVER THE
NORTHERN AREAS WILL SEE THE WINDS SWITCH TO A VERY STRONG SOUTH
WIND WITH SOLID GALS.

AS FOR RAIN...RAIN WILL BE HEAVY AT TIMES WITH STRONG UPPER LEVEL
DIVERGENCE WITH THE JET MOVING RIGHT OVER THE SOUTHERN
PANHANDLE EARLY TUE NIGHT. THE HEAVY RAIN WILL CONTINUE TO LIFT
NORTH THROUGH TUE NIGHT AND PERSIST INTO WED WITH STRONG ONSHORE
FLOW AND PVA OVER SE AK.

THERE WILL BE ANOTHER LOW THAT WILL ENTER THE GULF LATE WED INTO
THUR BUT THERE STILL REMAINS TO BE TIMING AND POSITION ISSUES WITH
THIS SYSTEM. THE OVER ALL PICTURE THROUGH IS THAT GALE FORCE WINDS
WILL CONTINUE ACROSS THE GULF AND WINDY AND WET CONDITIONS OVER
THE PANHANDLE.

A STRONG COLD FRONT IS FORECASTED TO MOVE ACROSS THE GULF THU INTO
FRI BY THE GFS BUT THE EC IS 24HR SLOW WITH THIS CAA. IT IS SAFE
TO SAY THAT THIS COLD AIR WILL GET TO THE PANHANDLE BY THE WEEKEND
BUT THE EXACT TIMING IS DIFFICULT ATTM. WILL NEED TO KEEP AN EYE
ON THIS COLD AIR AS IT WILL BE THE FIRST OF THE WINTER SEASON BUT
ALSO IT COULD PRODUCE SOME VERY STRONG WINDS.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...HIGH WIND WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY MORNING
     FOR AKZ023-026.
         HIGH WIND WARNING FROM 3 PM TUESDAY TO 6 AM AKDT WEDNESDAY FOR
     AKZ027>029.
MARINE...STORM WARNING FOR PKZ036-041>043.
         GALE WARNING FOR PKZ021-022-031>035-051-052.
         SMALL CRAFT ADVISORY FOR PKZ011-013.

&&

SJA/ABJ