Small Craft Advisory 642, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
329 PM AKDT FRI NOV 2 2012

.SHORT TERM...RAIN AND SNOW SHOWERS IN THE NORTHERN INNER
CHANNELS THROUGH LATE SATURDAY, WITH RAIN SHOWERS ELSEWHERE.
INCREASING RAIN AND WIND ESPECIALLY FOR THE EASTERN GULF AND THE
NORTH GULF COAST  SATURDAY. CHANGES ARE SMALL. CONFIDENCE IS
AVERAGE.

 GOOD MODEL CONSENSUS ON LARGER SCALES AND IN THE GULF. AT 18Z
SAT THE GFS/ECMWF/NAM/EC ALL HAVE THE LOW 300 NM S OF MIDDLETON
ISLAND, WITHIN ABOUT 30 NM OF EACH OTHER. CENTRAL PRESSURES
GFS/NAM 968, EC 966, UKMET 971. EVEN A QUITE LOW AMPLITUDE TROUGH
EXTENDING E FM LOW TO OVER THE SOUTHERN PANHANDLE IS A REASONABLE
MATCH. THERE ARE DIFFERENCES, BUT THIS IS NOT A DAY TO PICK A
SINGLE MODEL, AND BLENDING IS TO BE DONE EXCEPT FOR FEATURES THAT
INDIVIDUAL MODELS ARE NOT BEST AT.

.LONG TERM...ON SATURDAY NIGHT THE SURFACE LOW PRESSURE SYSTEM
IN THE CENTRAL GULF WILL CONTINUE TO FILL AND DRIFT TO THE NORTH.
THIS LOW WILL BECOME NEARLY STATIONARY IN THE FAR NORTHERN GULF
THIS WEEKEND AND REMAIN THERE INTO EARLY NEXT WEEK. A SEPARATE
RAPIDLY INTENSIFYING LOW PRESSURE SYSTEM IN THE NORTHERN PACIFIC
WILL LIFT TO THE NORTHEAST AND REACH THE SOUTHEAST GULF SUNDAY
EVENING. DEVELOPMENT OF THIS SYSTEM WILL BE AIDED BY BEING
LOCATED IN THE LEFT EXIT AND RIGHT ENTRANCE REGION OF A 120 KT
SPLIT UPPER LEVEL JET. THIS SYSTEM IS EXPECTED TO STRENGTHEN TO
AROUND 970MB BEFORE PUSHING INLAND. THE FORECASTED TRACK AT THIS
MOMENT TAKES THE LOW OVER FAR SOUTHERN BARANOF ISLAND
NORTHEASTWARD ACROSS THE CENTRAL PANHANDLE AND INTO BRITISH
COLUMBIA WHICH IS SUPPORTED BY THE EC...UKMET...AND NAM. WITH THIS
TRACK...AM EXPECTING VERY WINDY CONDITIONS FOR THE SOUTHERN
PANHANDLE AND SOUTHERN PORTIONS OF ZONE 26. IF THE STRENGTH AND
TRACK OF THIS SYSTEM VERIFY...WIND GUSTS WILL LIKELY REACH UP THE
HIGH WIND CRITERIA OF 60 MPH. THE OUTSIDE WATERS AND CLARENCE
STRAIT WILL EXPERIENCE STORM FORCE WINDS SUNDAY INTO EARLY MONDAY.
A MAJORITY OF THE REST OF THE INNER CHANNELS ARE EXPECTED TO
EXPERIENCE GALE FORCE WINDS DURING THIS TIME PERIOD. IT SHOULD BE
NOTED THE GFS TRACKS THE SYSTEM FARTHER TO THE NORTHWEST WHICH
WOULD EXPAND THE HIGH WIND THREAT TO ALSO INCLUDE MUCH OF CENTRAL
PANHANDLE BUT IS BEING CONSIDERED AN OUTLIER AT THIS TIME. HAVE
ISSUED AN SPS TO HIGHLIGHT THE POTENTIAL STRONG WINDS WITH THIS
SYSTEM.

 THE REMNANT PARENT LOW IN THE NORTHERN GULF WILL CONTINUE TO
WEAKEN AND BEGIN TO DRIFT TO THE SOUTHEAST TUESDAY...REACHING THE
SOUTHEAST GULF LATER WEDNESDAY. AS THIS OCCURS...A STRONG HIGH
PRESSURE SYSTEM OVER THE INTERIOR AND YUKON WILL BEGIN TO BUILD
SOUTHWARD INTO THE PANHANDLE. THIS WILL CREATE A TIGHTENING
NORTHERLY PRESSURE GRADIENT WITH OUTFLOW WINDS INCREASING LATE
TUESDAY INTO WEDNESDAY. WITH THE DEPARTING LOW PRESSURE SYSTEM
AND HIGH BUILDING INTO THE AREA PRECIPITATION WILL DIMINISH FROM
NORTH TO SOUTH TUESDAY AND WEDNESDAY. TEMPERATURES WILL STRUGGLE
TO GET ABOVE FREEZING OVER THE NORTHERN PANHANDLE THE LATTER
PORTION OF NEXT WEEK. THE SOUTHERN PANHANDLE CAN EXPECT HIGHS
NEAR 40 AND LOWS NEAR FREEZING.

 BLENDED IN THE 12Z EC WITH THE INHERITED GRIDS WHICH PROVIDED A
GOOD REPRESENTATION OF THE SUNDAY STORM FORCE LOW. THE LATTER
PERIODS TRANSITIONED TO HPC WHICH WAS HEAVILY DOMINATED BY THE
EC. FORECASTER CONFIDENCE REMAINS AVERAGE THROUGH THE PERIOD.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ022-042-043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ011>013-021-031-033>036-041-053.

&&

JBT/TPS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JUNEAU AK
349 PM AKDT FRI NOV 2 2012

AKZ026>029-031300-
INNER CHANNELS FROM KUPREANOF ISLAND TO ETOLIN ISLAND-
DIXON ENTRANCE TO CAPE DECISION COASTAL AREA-
SOUTHERN INNER CHANNELS-MISTY FJORDS-
INCLUDING THE CITIES OF...PETERSBURG...WRANGELL...KAKE...CRAIG...
KLAWOCK...KETCHIKAN...METLAKATLA...HYDER
349 PM AKDT FRI NOV 2 2012

...VERY WINDY CONDITIONS EXPECTED SUNDAY INTO EARLY MONDAY...

A STRENGTHENING LOW PRESSURE SYSTEM MOVING INTO THE SOUTHEAST GULF
HAS THE POTENTIAL TO BRING VERY STRONG WINDS TO A LARGE PORTION OF
THE SOUTHERN PANHANDLE MIDDAY SUNDAY INTO EARLY MONDAY. AT THIS
TIME THE STORM IS EXPECTED TO MAKE LANDFALL NEAR SOUTHERN BARANOF
ISLAND AND QUICKLY WEAKEN AS IT MOVES NORTHEAST INTO BRITISH
COLUMBIA LATE MONDAY. SOUTHEAST WINDS COULD GUST TO 60 MPH OR MORE
ACROSS THE SOUTHERN PANHANDLE AND THE SOUTHERN PORTIONS OF KUIU
AND KUPREANOF ISLANDS. WINDS WILL SHIFT TO THE SOUTHWEST WITH A
SECOND BURST OF WINDS OVERNIGHT SUNDAY. VERY STRONG SOUTHERLY
WINDS WILL ALSO IMPACT THE SURROUNDING MARINE AREAS WITH LINCOLN
ROCK LIKELY REACHING STORM FORCE.

THE EXACT TRACK OF THE SYSTEM IS STILL UNCERTAIN AND WILL
DETERMINE EXACTLY WHICH AREAS SEE THE STRONGEST WINDS. IF THE
SYSTEM TRACKS FARTHER NORTH THAN EXPECTED THE STRONGER WINDS WILL
NEED TO BE EXPANDED TO COVER MORE OF THE CENTRAL PANHANDLE.