Small Craft Advisory 288, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
550 AM AKDT SAT APR 23 2011

.ANALYSIS AND UPPER LEVELS...A BROAD RIDGE EXTENDS ALONG THE WEST
COAST OF NORTH AMERICA AND ACROSS MUCH OF THE ALASKA MAINLAND AND IS
PUSHING NORTHWESTWARD TOWARDS THE CHUCKCHI SEA. A LOW CENTERED SOUTH
OF CHIGNIK IS PROGRESSING NORTH TOWARDS THE ALASKA PENINSULA.
MEANWHILE...AN UPPER LEVEL LOW CONTINUES TO DIVE SOUTHWESTWARD INTO
THE WEST BERING SEA. THE UPPER LEVEL JET REMAINS WELL TO THE SOUTH
IN THE NORTH PACIFIC.

.AT THE SURFACE...AN OCCLUDED LOW SITS BENEATH THE UPPER LEVEL LOW
SOUTH OF CHIGNIK. ONE FRONT ASSOCIATED WITH THIS LOW IS PROGRESSING
ACROSS THE SOUTHWEST MAINLAND WHILE A SECOND FRONT IS APPROACHING
THE GULF COAST. BROAD NORTHERLY FLOW AND STRATUS COVER THE WESTERN
BERING.

.MODEL DISCUSSION...MODELS ARE IN GREAT AGREEMENT TODAY IN THE SHORT
TERM. A BLEND OF THE GFS AND NAM WAS USED TO BEST CAPTURE THE
DETAILS OF THE FRONTS PROGRESSING ACROSS THE FORECAST AREA. THE GFS
CONTINUES TO SHOW THE GREATEST RUN TO RUN CONSISTENCY IN THE LONG
TERM AND WAS THE MODEL OF CHOICE.

.SHORT TERM FORECAST...
.SOUTHCENTRAL...RAIN IS IMPACTING MUCH OF THE GULF COAST AND PRINCE
WILLIAM SOUND THIS MORNING AS A FRONT ASSOCIATED WITH THE LOW SOUTH
OF CHIGNIK MOVES TOWARDS THE GULF COAST.  STRONG WINDS AT 850MB WITH
THIS SYSTEM ARE CONTINUING TO SUPPORT STRONG DOWNSLOPING ACROSS THE
WEST KENAI PENINSULA...MATANUSKA VALLEY AND ANCHORAGE BOWL. STRONG
WINDS ARE OCCURING THROUGH LOCAL GAPS ACROSS THE AREA AS WELL. WINDS
ARE EXPECTED TO INCREASE THROUGH TURNAGAIN ARM AND THROUGH THE KNIK
RIVER VALLEY THIS AFTERNOON AS THE FRONT CONTINUES TO PROGRESS
INLAND. A MUCH WEAKER FRONT WILL MOVE THROUGH THE AREA SUNDAY
AFTERNOON...BUT SHOWERS WILL CONTINUE ALONG THE COAST WHILE GUSTY
WINDS WILL CONTINUE THROUGH LOCAL GAPS.

.SOUTHWEST MAINLAND...A FRONT ASSOCIATED WITH THE CHIGNIK LOW WILL
MOVE WESTWARD ACROSS THE SOUTHWEST MAINLAND TODAY. RAIN AND SNOW
SHOWERS ARE EXPECTED ACROSS MUCH OF THE REGION WITH THIS SYSTEM.
STRONG WINDS ARE ALSO EXPECTED THROUGH THE GAPS IN THE BRISTOL BAY
REGION AND ALONG THE BERING COAST. THE CHANCE FOR RAIN AND SNOW
SHOWERS ACROSS THE REGION WILL PERSIST THROUGH THE WEEKEND AS THE
CHIGNIK LOW PROGRESSES TOWARDS CAPE NEWENHAM. HOWEVER...AS THIS LOW
WEAKENS...WINDS WILL DIMINISH AS WELL.

.ALEUTIANS...SNOW SHOWERS ASSOCIATED WITH THE LOW SOUTH OF CHIGNIK
ARE FALLING ACROSS THE EAST ALEUTIANS THIS MORNING AND EXPECTED TO
CONTINUE THROUGH THE EVENING. LIGHT SHOWERS WILL IMPACT THE AREA
THROUGH THE WEEKEND AS THE CHIGNIK LOW MOVES INTO THE BERING.   A
WEAK LOW WILL MOVE INTO THE WEST BERING THIS AFTERNOON AND BRING
SHOWERS TO THE CENTRAL ALEUTIANS BY SUNDAY MORNING.

.LONG TERM FORECAST...LOW PRESSURE SYSTEMS WILL DOMINATE THE BERING
AND THE GULF THROUGH NEXT WEEK. EXPECT UNSETTLED WEATHER TO
CONTINUE.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE...
         HEAVY FREEZING SPRAY...NONE.
FIRE WEATHER...NONE.

ELN APR 11