Small Craft Advisory 155, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
309 PM AKST TUE FEB 15 2011

.SHORT TERM...MAIN WEATHER STORY FOR SOUTHEAST ALASKA FOR
TONIGHT AND WEDNESDAY IS STRONG OUTFLOW WIND ACROSS THE NORTHERN
PORTION OF THE PANHANDLE. A WEAKENING LOW WILL PERSIST ALONG THE
BRITISH COLUMBIA COAST NEAR HECATE STRAIT. THE HIGH PRESSURE OVER
NORTHWEST CANADA REMAINING ABOUT THE SAME AND AS A RESULT THERE
HAS BEEN A SLOW RELAXING OF THE PRESSURE GRADIENT. SOME OF THE
WINDS ARE CONTINUING TO BE VERY GUSTY THROUGH LYNN CANAL WITH
GUSTS NEAR 65 WHICH IS DOWN FROM EARLIER THIS MORNING.

 ABOUT THE LOW CLOUDS EXTEND NORTH TO JUST NORTH OF FREDERICK
SOUTH ALTHOUGH THE NORTH EDGE SEEMS TO BE RATHER THIN. MAINLY
CLEAR SKIES OVER THE NORTHERN PORTIONS. THERE IS SOME LIGHT SNOW
ACROSS THE SOUTHERN THIRD GENERALLY IT IS VERY LIGHT WITH LITTLE
ACCUMULATIONS EXPECTED IF IT DOES...BEST BET WOULD BE NEAR HYDER
WHERE ROUGHLY 2 INCHES HAS FALLEN TODAY.

 FREEZING SPRAY CONTINUING TO BE AN ISSUE OVER NORTHERN INNER
CHANNELS WITH THE COLD TEMPERATURES...LOWERING TO NEAR ZERO OR
SLIGHTLY BELOW IN AREAS OVER NORTHERN PORTIONS... AND GUSTY WINDS
THAT HEAVY FREEZING SPRAY WARNINGS CONTINUE TO BE ISSUED. WILL
CONTINUE THE WINTER WEATHER ADVISORY FOR THE SKAGWAY ZONE MAINLY
DUE TO WIND CHILLS THROUGH WEDNESDAY NIGHT. WIND ADVISORIES DUE
TO EXPIRE LATE THIS AFTERNOON...AT THE MOMENT DO NOT PLAN TO
EXTEND BUT IF CONDITIONS PERSIST WILL EXTEND A FEW HOURS RIGHT AT
ISSUANCE OF THE FORECAST PACKAGE.

&&

.LONG TERM...EXPECT A RE-ENFORCING SHOT OF COLD AIR MOVING SOUTH
THROUGH THE YUKON TO RE-ENFORCE SURFACE HIGH OVER THE YUKON WED
NIGHT WITH A SLIGHT INCREASE IN OUTFLOW GAP WINDS WEDNESDAY NIGHT
INTO EARLY THURSDAY. UPPER TROUGH DROPPING THROUGH PANHANDLE
THURSDAY DROPS SOUTH BY THURSDAY AFTERNOON ALLOWING OUTFLOW WINDS
TO DIMINISH THURSDAY AFTERNOON THROUGH FRIDAY. LIGHTER WINDS AND
CONTINUED CAA WILL BRING VERY CHILLY NIGHT WEDNESDAY.

THE UPPER RIDGE OVER EASTERN GULF THURSDAY TILTS TO THE SE ON
FRIDAY AS A WEAK SHORT WAVE PUSHES THROUGH THE RIDGE. EXPECT
AROUND A 100 MB LOW TO TRACK ACROSS THE GULF FRIDAY AND ACROSS
SOUTHEAST ALASKA FRIDAY NIGHT AND THROUGH SOUTHERN ZONES SATURDAY.
THIS IS EXPECTED TO BRING INCREASING CLOUDS AND SNOW TO PAYA BY
FRIDAY AFTERNOON AND MOST OF THE PANHANDLE FRIDAY NIGHT AND
SATURDAY. AMOUNTS SEEM TO BE IN ADVISORY LEVELS CENTRAL ZONES
WHERE DEEPER AIR MASS PROVIDES FOR BEST OVERRUNNING BUT ONLY CHANCE
CATEGORY FOR FAR NORTH. THIS ALSO BRINGS A WARMING TREND FRIDAY
NIGHT AND SATURDAY UNTIL LOW MOVES OFF TO SOUTHEAST EARLY SUNDAY
AND NORTHERLY OUTFLOW RE ESTABLISHES ITSELF.

ANOTHER HIGH AMPLITUDE RIDGE BUILDS INTO EASTERN GULF SUNDAY THAT
CROSSES SOUTHEAST ALASKA MONDAY WITH TEMPERATURES ONCE AGAIN
DROPPING AS RE ENFORCING ARCTIC AIR SPILL INTO PANHANDLE. ANOTHER
100 MB LOW DEVELOPS OVER NORTHERN GULF TUESDAY BUT MODELS DIFFER
GREATLY ON TRACK AND INTENSITY OF THIS SYSTEM BUT MOST LIKELY WILL
DIG SE ALONG COAST AND BRING ANOTHER SHOT OF SNOW TO PANHANDLE
EXCEPT IMMEDIATE COAST WHICH SHOULD WARM FOR MIXED RAIN AND SNOW.

GALES THROUGH INNER CHANNELS DIMINISH BY THURSDAY NIGHT WITH HINTS
GRADIENTS WILL TURN SOUTHERLY FRIDAY NIGHT AND SUNDAY.

CONFIDENCE IS BETTER THAN AVERAGE THROUGH SATURDAY BUT FALLS OFF
GREATLY SUNDAY THROUGH DAY 8 WITH A VARIETY OF SOLUTIONS TO CHOOSE
FROM EACH WITH DIFFERENT IMPACTS TO SENSIBLE WEATHER. STAYED WITH
NAM12 THROUGH 84 HRS AND USED GFS/EC BLEND FOR SAT AND FOLLOWED
HPC OR A BLEND OF GFS/EC BEYOND.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND ADVISORY UNTIL 4 PM AKST THIS AFTERNOON FOR AKZ019-025.
         WINTER WEATHER ADVISORY UNTIL 5 AM AKST THURSDAY FOR AKZ018.
MARINE...HEAVY FREEZING SPRAY WARNING FOR PKZ031.
         HEAVY FREEZING SPRAY WARNING FOR PKZ031.
         HEAVY FREEZING SPRAY WARNING FOR PKZ011>013.
         STORM WARNING FOR PKZ012.
         GALE WARNING FOR PKZ011-013-021-022-031>034.
         SMALL CRAFT ADVISORY FOR PKZ035-036-042-043-051.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041.

&&

BEZENEK/MM