Small Craft Advisory 267, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM ADT TUE MAR 20 2007

.DISCUSSION...
MODELS ARE IN GOOD AGREEMENT OUT THROUGH 48 HOURS. THE MAIN
DIFFERENCE BEYOND THAT BEGINS WITH THE DEVELOPING LOW SOUTH OF THE
ALASKA PENINSULA WEDNESDAY NIGHT. WENT MAINLY WITH THE GFS WITH IS
DEEPER AND FASTER THAN THE NAM AND IS ALSO IN LINE WITH THE UKMET.
THE GFS HAS BE FAIRLY CONSISTENT THE PAST RUNS.

THE UPPER LEVEL SHOWS A WEAK RIDGE MOVING THROUGH THE GULF. A TROUGH
WITH ITS AXIS ACROSS THE CENTRAL ALEUTIANS. A STRONG SHORT WAVE SOUTH
OF THE EASTERN ALEUTIAN WILL GENERATE A CLOSED LOW AND MOVE TO JUST
WEST OF KODIAK THIS EVEN THEN CONTINUE ON INTO THE NORTHERN GULF OF
ALASKA BY WEDNESDAY MORNING. THE POLAR LOW WILL BEGIN TO BROADEN AND
DRIFT SOUTH OVER MUCH OF THE NORTHERN AND WESTERN STATE BY WEDNESDAY
NIGHT WHILE THE MAIN TROUGH SLIDES EAST TOWARD THE MAINLAND THROUGH
THE WEEK.

IN THE EAST A STRONG FRONT FROM THE OUT WEST WILL APPROACH KODIAK
THIS AFTERNOON AND PASS THROUGH THE GULF OF ALASKA THIS EVENING. SNOW
SHOULD BEGIN IN KODIAK THIS MORNING AND CONTINUE THROUGH THE DAY AND
DEPENDING ON THE EXACT POSITIONING OF THE LOW KODIAK COULD SEE SOME
MIXING WITH RAIN THIS EVENING OTHERWISE EXPECT MAINLY ALL SNOW IN
OTHER AREAS ALONG THE COAST WITH A CHANCE FOR THE INLAND AREAS AS THE
FRONT APPROACHES. THE LOW WILL MOVE INTO THE NORTHERN GULF BY
WEDNESDAY MORNING AND PUSH ONSHORE WEDNESDAY EVENING WEST OF YAKUTAT.
A SECONDARY LOW WILL SET UP IN NEAR PRINCE WILLIAM SOUND WEDNESDAY
AFTERNOON ALONG WITH A SECOND SHORT WAVE MOVING ACROSS SOUTHCENTRAL
WEDNESDAY WILL BRING ALONG SOME GOOD VORTICITY AND COLD AIR SETTING
UP THE ANCHORAGE BOWL FOR A POSSIBILITY OF SOME SNOW WEDNESDAY
AFTERNOON AND EVENING.

OUT WEST THE LOW WILL MOVE TO JUST SOUTH OF COLD BAY THIS AFTERNOON
WITH STRONG WINDS AND POSSIBLY RAIN AND SNOW AT FIRST BUT QUICKLY
CHANGING TO ALL SNOW. BRISTOL BAY AREAS WILL SEE STRONG EASTERLIES
AHEAD OF THE FRONT WHICH SHOULD CUT BACK ON THE AMOUNT OF
PRICIPITATION. AS THE LOW MOVES OFF INTO THE GULF THE WINDS WILL
LIGHTEN AND GENERALLY BE OUT OF THE NORTH TO NORTHWEST THROUGHOUT THE
BERING AND SOUTHWEST RESULTING IN A GOOD SHOT OF COLD ADVECTION OVER
MOST OF THE AREA AND SNOW SH0WERS. THE REST OF THE WEEK THE GRADIENT
FALLS APART OVER THE BERING AND WINDS WILL BE LIGHT AS A SERIES OF
LOWS PASS TO THE SOUTH OF THE ALEUTIANS.

AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING  181
         BLIZZARD WATCH 125
MARINE...STROM 120
         GALE 125 130 132 138 140 141 150 155 160 165 170 172 176 179
         HEAVY FREEZING SPRAY 130 138 165 179
FIRE WEATHER...NONE

KB MAR 07