Small Craft Advisory 852, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
230 PM AKST MON NOV 3 2008

.MODEL DISCUSSION...MODELS CONTINUE TO DO WELL WITH THE FIRST 84
HOURS. AFTER THAT THEY RAPIDLY BREAK DOWN TO THE POINT IT IS HARD TO
USE ANY OF THEM. FOR THE SHORT TERM THE GFS IS DOING FINE FOR OVERALL
USE. THE NAM MAY BE THE BETTER ONE TO USE FOR THE LOW ALONG THE NORTH
GULF COAST DUE TO ITS HIGHER TERRAIN RESOLUTION AND PERFORMANCE IN
HANDLING THE LOWS SUPPORTED BY GAP AND OUTFLOW WINDS.
THE LONGER TERM GFS AND ECMWF ARE VERY ERRATIC WITH THE HANDLING OF
THE LOW MOVING INTO THE GULF LATE IN THE WEEK. RUN TO RUN CONSISTENCY
IS VERY POOR WITH BOTH MODELS. THE MODELS ARE ALSO IN DISAGREEMENT
WITH EACH OTHER AS WOULD BE EXPECTED WITH SUCH POOR INTERNAL
CONSISTENCY. ALL IS NOT LOST HOWEVER. THOUGH IN DISARRAY THE GFS AND
ECMWF ARE BOTH INDICATING THE LOW WILL BE WEAKER THAN SOLUTIONS
OFFERED UP JUST A DAY OR TWO AGO. IF THIS TREND CONTINUES THE MODELS
MAY BE ABLE TO LOCK IN ON A REASONABLE SOLUTION SOON.

.ANALYSIS AND UPPER LEVELS...IN THE UPPER LEVELS A TROUGH FROM THE
SEWARD PENINSULA THROUGH SOUTH CENTRAL ALASKA WILL STRENGTHEN AND
CULMINATE IN A CUT OFF LOW OVER OR JUST SOUTH OF THE KENAI PENINSULA
BY WEDNESDAY. AN UPPER LEVEL RIDGE OVER THE CENTRAL BERING SEA WILL
REMAIN NEARLY STATIONARY THROUGH MID WEEK AND HELP KEEP THE STORM
TRACK SOUTH OF THE ALEUTIANS.
THE JET STREAM IS SOUTH OF THE AREA AND WILL PULL AWAY EVEN MORE OVER
THE NEXT FEW DAYS.
THE SURFACE LOW ALONG THE NORTH GULF COAST WILL MOVE SLOWLY
SOUTHWESTWARD OVER THE NEXT TWO DAYS.

.SHORT TERM FORECAST...SNOW IN THE ANCHORAGE AREA WILL TAPER OFF BY
THE EVENING WITH SCATTERED SNOW SHOWERS PERSISTING THROUGH THE NIGHT.

THE EASTERN KENAI PENINSULA WILL SEE NUMEROUS SNOW SHOWERS AS THE LOW
WILL CONTINUE TO PUSH THEM ASHORE.
THE COPPER RIVER BASIN SHOULD ALSO SEE SNOW SHOWERS DIMINISHING
THROUGH THE NIGHT.
OVER THE ALASKA PENINSULA AND EASTERN ALEUTIANS AND BERING SEA THE
FLOW HAS TURNED NORTHWESTERLY AND THERE WILL BE SOME SNOW SHOWERS IN
THE COLD ADVECTION OVER THOSE AREAS.

.LONG TERM FORECAST...AS DISCUSSED EARLIER THERE IS A LARGE DEGREE OF
UNCERTAINTY TOWARD THE END OF THE WEEK. WHAT SEEMS LIKELY AT THIS
TIME IS THAT THE UPPER LEVEL TROUGH WILL PERSIST OVER THE CENTRAL AND
SOUTH CENTRAL PART OF THE STATE AND SOME LOW WILL MOVE INTO THE GULF
OF ALASKA FROM THE SOUTH OR SOUTHEAST. THIS WILL ACTUALLY CREATE A
PATTERN SIMILAR TO WHAT IS OUT THERE TODAY. HOPEFULLY THE MODELS WILL
BECOME MORE CONSISTENT AND RAISE THE CONFIDENCE LEVEL.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 176.
FIRE WEATHER...NONE.

NOV 08