Small Craft Advisory 321, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
230 PM ADT SAT APR 8 2006

.DISCUSSION...
UPPER LEVELS...DOMINANT FEATURE IS THE LARGE UPPER LOW OVER THE
NORTHERN KAMCHATKA PENINSULA THIS AFTERNOON. AN UPPER LEVEL LOW IS IN
THE EASTERN BERING AND WILL SLOWLY WORK INLAND OVER THE NEXT 24 HOURS
AND WEAKEN. A COUPLE SHORT WAVE TROUGHS WILL WORK UNDERNEATH THE
LARGE LOW IN THE WESTERN BERING SEA. THESE HELP TO SWING THE LOW
SOUTH AND EAST OVER THE NEXT COUPLE DAYS. EACH SUCCESSIVE WAVE HELPS
DIG A TROUGH IN THE GULF OF ALASKA. THE LOW WILL MOVE TO THE WEST
COAST TUESDAY AND WILL LEAVE A BROAD TROUGH OVER THE BERING AND
MAINLAND INTO THURSDAY. WARMER THAN NORMAL TEMPERATURES TO GIVE WAY
TO NEAR OR SLIGHTLY BELOW NORMAL TEMPERATURES DURING THIS PERIOD AS
COLD AIR ADVECTS AROUND THE BROAD TROUGH.

SURFACE WEST OF THE ALASKA RANGE...LARGE LOW OVER THE BERING SEA WITH
A FRONT WORKING FARTHER INLAND THIS AFTERNOON AND EVENING.
PRECIPITATION A LITTLE HEAVIER ALONG THE FRONT AND STILL EXPECT SOME
MODERATE AMOUNTS IN THE KUSKOKWIM VALLEY. HOWEVER...FRONT IS
SPLITTING OVER THE INTERIOR TONIGHT. MAINLY CONVECTIVE PRECIPITATION
OVER THE BERING SEA AND ALEUTIAN CHAIN AROUND THE LOW TONIGHT AND
TOMORROW. THE LOW SPLITS TONIGHT WITH A PIECE HEADED TOWARD NORTON
SOUND BRINGING MORE ORGANIZED PRECIPITATION TO SOUTHWEST COASTAL
AREAS OF ALASKA TO THE AKPEN. THE OTHER PIECE HEADS TOWARD THE
KAMCHATKA PENINSULA. WITH THE COLD AIR ADVECTION MOST AREAS WILL
CHANGE OVER THE SNOW LATER TONIGHT. GALE FORCE WINDS TO QUIET DOWN
TONIGHT. AN UPPER LEVEL DISTURBANCE TO DEVELOP A LOW OVER THE WESTERN
ALEUTIAN CHAIN LATE TONIGHT KICKING UP WINDS AND PRECIPITATION. THIS
LOW TO TRACK INTO THE CENTRAL BERING AND HOOK UP WITH THE LOW FROM
NEAR KAMCHATKA. THIS COMBINED LOW TO WORK SLOWLY ACROSS THE BERING
SEA AND WEAKEN THROUGH MONDAY. WINDS WILL DIMINISH MONDAY AS WELL. IN
THE MEANTIME...A LOW WILL MOVE TOWARD THE CENTRAL ALEUTIAN CHAIN OUT
OF THE NORTH PACIFIC. THIS LOW HAS SOME GOOD JET SUPPORT AND WILL
BRING GALE FORCE WINDS BY TUESDAY AFTERNOON TO THE PACIFIC SIDE OF
THE ALEUTIAN CHAIN.

THIS IS WHERE THE MODELS TEND TO DIVERGE. CURRENTLY LEANING TOWARD
THE GFS DUE TO THE JET POSITION AND PAST PERFORMANCE AT THIS TIME
RANGE.

PER THE GFS SOLUTION...THIS LOW TO REMAIN SOUTH OF THE AKPEN AND
CROSS INTO THE GULF WEDNESDAY. WITH THE BROAD UPPER LEVEL TROUGH OVER
THE REMAINDER OF THE AREA...WOULD EXPECT MAINLY LIGHT TO MODERATE
WINDS AND CONVECTIVE PRECIPITATION THROUGH WEDNESDAY. ANOTHER LOW
MOVES INTO THE WESTERN ALEUTIANS THURSDAY.

SURFACE EAST OF THE ALASKA RANGE...WEAKENING FRONT TO MOVE OVER SOUTH
CENTRAL THIS AFTERNOON AND EVENING. ALREADY RAINING FROM HOMER SOUTH.
PRECIP WILL PASS KODIAK TONIGHT AS IT PUSHES INLAND. PRECIPITATION
WILL REMAIN RAIN HOMER TO WHITTIER SOUTH. WEAK LOW DEVELOPS OVER THE
NORTHERN GULF WITH THE FRONT LATER TONIGHT. WITH THE WEAK UPPER LEVEL
TROUGH OVER THE AREA AS WELL...THE AIR MASS WILL REMAIN SOMEWHAT
UNSTABLE. THEREFORE...WOULD EXPECT SHOWER ACTIVITY TO REMAIN OVER
SOUTH CENTRAL THROUGH TUESDAY. THE LOW THAT IS MOVING OUT OF THE
NORTHERN PACIFIC TO PUSH INTO THE GULF OF ALASKA TUESDAY NIGHT. GALE
FORCE WINDS TO ACCOMPANY THIS SYSTEM WITH MODERATE TO HEAVY
PRECIPITATION OVER THE GULF. THIS LOW WILL PUSH MOST OF THE
PRECIPITATION OUT OF SOUTH CENTRAL AS A SHORT WAVE RIDGE MOVES ACROSS
THE AREA. THE LOW WILL SETTLE OVER THE GULF WITH MOST OF THE
PRECIPITATION OVER THE LAND CONCENTRATED ALONG THE COASTAL LOCATIONS
AND MOUNTAINS OF SOUTH CENTRAL INTO THURSDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALE 170 172 175 179
FIRE WEATHER...NONE

JN APR 06