Small Craft Advisory 216, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM ADT MON MAR 10 2008

.MODEL DISCUSSION...
MODELS ARE IN GOOD AGREEMENT IN THE SHORT TERM WITH ONLY MINOR
DIFFERENCES IN THE POSITION OF THE LOW OF THE SOUTHWEST MAINLAND.
THIS IS OF LITTLE CONSEQUENCE AS THE THEME REMAINS ONE OF SHOWERY
CONDITIONS OVER MOST OF THE MAINLAND TO THE ALASKA PENINSULA.

.ANALYSIS AND UPPER LEVELS...
THE LOW NOW OVER THE SOUTHWEST MAINLAND IS SUPPORTED BY AN UPPER LOW
OVER THE EASTERN BERING SEA. THIS LOW IS RELATIVELY COOL AT THE LOWER
LEVELS AND THUS MOST OF THE PRECIPITATION ASSOCIATED WITH THIS SYSTEM
HAS BEEN SNOW OR A MIX OF RAIN AND SNOW. THE PRESSURE GRADIENT ACROSS
THE SOUTH CENTRAL REGION IS RELAXING AND WILL ALLOW THE WIND THROUGH
TURNAGAIN ARM AND ACROSS THE CHUGACH MOUNTAINS TO DIMINISH THROUGH
THIS AFTERNOON. AROUND THE WEST SIDE OF THIS LOW WEAK NORTH FLOW WILL
CONTINUE TO PRODUCE SNOW SHOWERS ALONG THE BERING SEA COAST TO THE
ALASKA PENINSULA. THESE SHOWERS SHOULD TAPER OFF AS THE SURFACE AND
UPPER RIDGE OVER THE CENTRAL BERING SEA MOVES TOWARD THE COAST TODAY
AND TONIGHT.

ANOTHER UPPER LOW IS SOUTH OF THE ALEUTIANS WHILE YET ANOTHER IS
SOUTH OF THE PANHANDLE. BOTH THESE UPPER LOWS SUPPORT MODERATE TO
STRONG SURFACE LOWS. THE LOW AND FRONTAL SYSTEM THAT HAS BEEN
AFFECTING

.SHORT TERM FORECAST...
THE STRONG GUSTY WINDS ACROSS THE KENAI MOUNTAINS WILL CONTINUE
DIMINISHING THIS AFTERNOON. THE PERSISTENT UPPER TROUGH OVER
SOUTHWEST AND SOUTH CENTRAL ALASKA WILL KEEP SHOWERS OVER THE REGION
INTO THE EVENING. A WEAK UPPER LOW IS EXPECTED TO PERSIST OVER
SOUTHWEST ALASKA THROUGH TUESDAY. THIS WILL KEEP THE CHANCE OF
SHOWERS OVER THE SOUTHWEST ZONES THROUGH TOMORROW AFTERNOON.

RIDGING FROM THE NORTH CENTRAL BERING SEA WILL MOVE TO THE BERING
COAST BY WEDNESDAY MORNING. EXPECT THE STABLE CONDITIONS TO KEEP THE
LOW LEVEL STRATUS AND FOG OVER THE BERING UNDER THE HIGH PRESSURE.
ALONG THE COAST TO THE ALASKA PENINSULA EXPECT THE NORTH TO NORTHWEST
FLOW TO CONTINUE AND SNOW SHOWERS WILL PERSIST ON THE BERING SIDE OF
THE ALASKA PENINSULA.

.LONG TERM FORECAST...SOME UNCERTAINTY REMAINS FOR THE END OF THE
WEEK WITH BETTER CONFIDENCE IN THE MID WEEK TIME FRAME. TWO PRIMARY
ISSUES ARE WITH REGARD TO THE LOW MOVING IN FROM THE NORTH PACIFIC
TOWARD SOUTHEAST ALASKA AND THE NEXT MAJOR STORM EXPECTED TO MOVE
INTO THE WESTERN ALEUTIANS. THE SYSTEM HEADING TOWARD SOUTHEAST
ALASKA VARIES IN SPEED AND INTENSITY BETWEEN THE MODELS BUT THIS
SYSTEM WILL BE WELL SOUTH OF THE MAINLAND AREAS AND THE MAIN
INFLUENCE WILL BE IN THE GULF OF ALASKA OFFSHORE AND THE SOUTH SIDE
OF KODIAK ISLAND. OUT WEST THE STORM MOVING INTO THE WESTERN
ALEUTIANS HAS SIMILAR SOLUTIONS BETWEEN THE NAM AND GFS WEDNESDAY.
AFTER WEDNESDAY THE MODELS BECOME LESS CONSISTENT AND THE FORECAST
FOR THE END OF THE WEEK WILL ONLY HAVE SMALL CHANGES UNTIL WE GET A
BETTER FEEL FOR WHAT WE EXPECT.

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

SAMN MAR 08