Small Craft Advisory 704, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
357 PM AKST MON NOV 4 2013

.SHORT TERM...SATELLITE IMAGERY THIS AFTERNOON SHOWING HIGH
PRESSURE RIDGE OVER BRITISH COLUMBIA AND A 985 MB LOW PRESSURE
SYSTEM SOUTH OF PRINCE WILLIAM SOUND WITH AN ASSOCIATED OCCLUDED
FRONT MOVING OVER THE AK PANHANDLE. THIS LOW WILL WEAKEN
OVERNIGHT THEN BEGIN TO TRACK TO THE SOUTHEAST BY TUESDAY. THE
FRONT WILL MOVE OVER THE PANHANDLE OVERNIGHT AND DISSIPATE
THROUGH TUESDAY MORNING.

THE FRONT HAS BEEN ROTATING OVER THE PANHANDLE FROM SOUTH TO
NORTH WITH PRECIP COVERING THE SOUTHERN PANHANDLE EARLY MONDAY
MORNING AND PUSHING NORTH THROUGH THE AFTERNOON. COLD AIR MASS
THAT DEVELOPED OVER THE PANHANDLE THROUGH THE WEEKEND STAYED IN
PLACE BIT LONGER THAN EXPECTED FOR THE CENTRAL AND NORTHERN
PANHANDLE. PRECIP BEGAN THIS MORNING AS SNOW OR A RAIN SNOW MIX
FOR LOCATIONS NORTH OF FREDERIC SOUND WITH RAIN TO THE SOUTH. THE
EXCEPTION FOR THE SOUTHERN PANHANDLE BEING HYDER WHICH RECEIVED
ABOUT 1 INCH OF SNOW THIS MORNING AS A COLD POOL OF 850 MB AIR
REMAINED IN PLACE. UNSTABLE AIR MASS BEHIND THE FRONT IS
TRANSITIONING PRECIP TO SHOWERS THROUGH THE AFTERNOON INTO THE
EVENING. WITH WARMER AIR MASS MOVING IN TONIGHT TEMPERATURES
LIKELY REMAIN STEADY OR RISE SLIGHTLY OVERNIGHT WITH COASTAL AREAS
DROPPING A FEW DEGREES. WHAT SHOULD HAPPEN IS WITH MID LEVEL WINDS
SHIFTING TO THE SOUTHWEST, WARMER AIR ALOFT MOVING IN AND MIXING
AT THE SURFACE, AND RISING DEWPOINTS...SHOWERS TONIGHT THROUGH
TUESDAY SHOULD BE ALL RAIN. JUNEAU PROFILERS ARE SHOWING THE
WARMER AIR MOVING THROUGH THE AFTERNOON WITH DEEPER LAYER OF
LIQUID PRECIP. HOWEVER SOME VALLEYS WHERE COLD AIR COULD SILL BE
TRAPPED SUCH AS HAINES, THE MENDENHALL VALLY AND HYDER MAY STILL
HAVE A RAIN SNOW MIX.

UPPER LEVEL GALE FORCE WINDS OVER THE COASTAL WATERS THIS MORNING
SHOWING RAPID DROPS AS THE FRONT PASSES. SEA HEIGHT WILL REMAIN
HIGH THROUGH TUESDAY WITH THE SURFACE LOW MOVING SOUTHEAST. INNER
CHANNEL GALE FORCE WINDS ARE ALSO DECREASING THIS AFTERNOON AND
EARLY EVENING WITH SOME LINGERING SMALL CRAFT WINDS IN CROSS SOUND
AND NORTHERN PORTIONS OF CLARENCE STRAIT. PRESSURE GRADIENT HAS
BEEN SHIFTING SO WINDS WILL FLIP TO THE SOUTH OVER THE NORTHERN
REGIONS LATE IN THE AFTERNOON. THE HIGHER GUSTS OVER THE SOUTHERN
AND COASTAL PANHANDLE THIS MORNING HAVE DROPPED OFF WITH WINDS
GENERALLY LESS THAN 20 MPH THROUGH TUESDAY.

MODELS WERE IN BETTER AGREEMENT WITH THE POSITION OF THE LOW IN
THE NORTHERN GULF. SOME DIFFERENCES WITH PRESSURE PATTERN OVER THE
NORTHERN PANHANDLE. KEPT WITH A GFS/GEM BLEND WITH LITTLE CHANGE
TO PRESSURE AND WIND FIELDS. MAIN ISSUE WILL BE OVERNIGHT
TEMPERATURES AND RESULTING PRECIP TYPE. FORECAST CONFIDENCE IS
BELOW AVERAGE.

&&

.LONG TERM.../ TUESDAY NIGHT TO MONDAY / THE LOW IN THE GULF OF
ALASKA CONTINUES TO WEAKEN AND DRIFT SOUTHEAST AND DISSIPATES ALONG
PRINCE OF WALES ISLAND THURSDAY AFTERNOON. A WEAK RIDGE BUILDS
OVER THE GULF AND IS BEING MOVED ACROSS THE PANHANDLE BY FRIDAY
MORNING. SPREADING INTO THE GULF AND INTO THE EASTERN HALF AS A
SHEERING APART FEATURE THROUGH FRIDAY. THIS FRONT WAS PREVIOUS
ASSOCIATED WITH A VERY DEEP LOW (UPPER 940S) THAT MOVE TO THE
NORTHWEST BERING SEA EARLY IN WEEK AND CONSIDERING THE INITIAL
SOURCE FOR IT OUT OF THE CENTRAL PACIFIC...THERE LOOKS TO BE SOME
GOOD MOISTURE WITH THE FRONT TO START. HOWEVER BY END THE OF WEEK
WITH THE PARENT LOW ON THE NORTHWEST SIDE OF THE BERING AND A
TRIPLE POINT TYPE LOW ON THE FRONT TAKING OVER BY KODIAK ISLAND
THROUGH THE END OF THE WEEK. I DON'T THINK THAT THE EXCESSIVE
AMOUNTS OF RAIN WILL STILL BE PERSISTING AT THE END OF THE
CONSIDERING THE NEGATIVE TILT TO THROUGH AND ORIENTATION AFFECTING
SOUTHEAST ALASKA AT THE END OF THE WEEK BUT THE SOURCE REGION WILL
BE OUT OF MID PACIFIC.

IT DOES LOOK LIKE THERE IS A COOLER POOL OF AIR ALOFT THAT WILL
BE ADVECTING INTO SOUTHEAST ALASKA OVER THE WEEKEND BEHIND THE
FRONT...THAT WILL BE LOWERING TEMPERATURES BACK TWO WHERE
PRECIPITATION TYPE FOR LOWER LEVELS MAY BE AN ISSUE AGAIN.
CONFIDENCE IS AVERAGE OR SLIGHTLY ABOVE THAT THROUGH THE WEEK AND
AND LOWER FOR THE WEEKEND AND INTO VETERANS DAY HOLIDAY ON MONDAY.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ052.
         SMALL CRAFT ADVISORY FOR PKZ022-036-043-051-053.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041-042.

&&

PRB/BEZENEK