Small Craft Advisory 1, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
339 PM AKST FRI DEC 31 2010

.SHORT TERM...UPPER LEVEL TROUGH ASSOCIATED WITH WEAK COLD FRONT
FEATURE MOVING ACROSS THE EASTERN GULF OF ALASKA. IT IS
APPROACHING THE YAKUTAT AREA FRIDAY EVENING. FAIRLY SHARP LOOKING
BORDER TO THE COLDER CLOUD IMAGERY AND RADAR IMAGES CONCUR WITH
BOUNDARY. DO NOT THINK THAT THE RAIN WILL END ABRUPTLY AFTER IT
PASSES THOUGH. SURFACE FEATURE SEEMS TO VANISH AS THE FEATURE
APPROACHES THE PANHANDLE BUT IN THE LOWER ATMOSPHERE ABOVE THE
SURFACE CAN SPOT THE TROUGH MOVING ACROSS THE PANHANDLE THROUGH
FRIDAY NIGHT INTO SATURDAY MORNING.

 WINDS LIMITED PRIMARILY TO A FEW AREAS OF SMALL CRAFT LEVELS OR
INNER CHANNELS... BUT THE OVER THE OUTER WATERS THE SMALL CRAFT
ADVISORIES ARE DUE TO SEAS PREDOMINATELY.

 SOME WINDY CONDITIONS IN THE WHITE PASS AREA RESULTING IN WHITE
OUT CONDITIONS WITH BLOWING SNOW AND GUSTY WINDS TO 35 MPH. THINK
THAT THIS WILL LIKE CONTINUE INTO SATURDAY.

 ONLY SOME MINOR MODIFICATIONS OVERALL TO THE FORECAST PACKAGE.
FOR THE ADJUSTMENTS THAT WERE MADE... THE NAM12 SOLUTIONS WAS
PREFERRED FOR THE TIME RANGE.

.LONG TERM...THE MODELS CONTINUE TO BE IN FAIR AGREEMENT THROUGH
EARLY NEXT WEEK WITH INCREASING UNCERTAINTY IN THE UPPER LEVEL
PATTERN FROM WED THROUGH THE END OF NEXT WEEK. THE MAIN DIFFERENCE
IS THE SPEED OF A UPPER LEVEL TROF MOVING INTO THE GULF MID WEEK
ALONG WITH A MORE BLOCKY PATTERN TREND SETTING UP FOR NEXT
WEEKEND. THE EC WAS MORE CONSISTENT WITH THE ENSEMBLE MEMBERS AND
MEAN WITH THE SPEED OF THE UPPER TROF BUT THE JURY IS STILL OUT ON
THE BLOCKY TREND. THERE WAS NOT MUCH CHANGE IN THE LONG TERM
FORECAST FROM THIS MORNING. THE PANHANDLE WILL CONTINUE TO SEE
ABOVE AVERAGE TEMPS THROUGH THE WEEK SO ANY PRECIP THAT MOVES
OVER THE AREA WILL REMAIN IN THE LIQUID FORM. WHERE CHANGES WERE
MADE USED A BLEND OF THE NAM AND EC THROUGH MONDAY THEN REFRESHED
THE EXTENDED FORECAST WITH HPC GUIDANCE THROUGH END OF NEXT WEEK.

AT THE BEGINNING OF THE LONG TERM PERIOD A UPPER RIDGE WILL BE OVER
THE PANHANDLE WITH WEAK ONSHORE FLOW TO KEEP A CHANCE OF PRECIP
OVER THE FORECAST AREA. TEMPS WILL BE ON THE MILD SIDE WITH FLOW
BEING ONSHORE AT ALL LEVELS. A WEAK UPPER TROF WILL MOVE OVER THE
PANHANDLE THROUGH SUNDAY. THIS WILL INCREASE THE THREAT OF PRECIP
OF THE PANHANDLE TO LIKELY BUT CAT POP OVER THE NORTHERN GULF
ALONG WITH STRONG GALES WINDS DEVELOPING OVER THE GULF. ANOTHER
SHORTWAVE TROF/LOW WILL SLIDE SOUTH OF THE CHAIN AND MOVE INTO THE
GULF AND ESTABLISH ITS SELF THERE THROUGH MOST OF THE WEEK. THE
FIRST AND STRONGEST UPPER LOW WILL LIFT A 970 MB LOW INTO THE
WESTERN GULF AND LIFT A STRONG FRONT OVER THE PANHANDLE BY TUES.
BEHIND THIS FRONT THERE IS SOME COLDER AIR AND THERE MAY BE PLACES
THAT SEE SOME SNOW MIXED IN OR OVER THE FAR NORTHERN AREAS SEE ALL
SNOW.

AFTER WED THERE SIGNIFICANT SPREAD IN THE ENSEMBLES WITH THE UPPER
LEVEL PATTEN OVER THE GULF. THE EC SHOW A RIDGE BUILDING OVER THE
PANHANDLE BY FRIDAY WITH A LARGE UPPER HIGH OVER THE BERING. THE
GFS IS A BIT SLOWER IN BUILDING THE HIGH AND KICKING OUT THE UPPER
TROF OVER THE GULF BUT IT IS MUCH MORE SHARPER. SO WILL NEED TO
KEEP AN EYE ON THIS AS WITH THE SHARPER HIGH IT WILL INCREASE THE
CAA. THERE IS LOW FORECASTER CONFIDENCE FROM WED THROUGH THE WEEKEND.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-022-036-041>043-051-052.

&&

BEZENEK/ABJ