Gale Warning 483, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 PM AKDT SUN AUG 4 2013

.ANALYSIS AND UPPER LEVELS...

MASSIVE UPPER LEVEL TROUGH EXTENDS ACROSS EASTERN RUSSIA...THE BERING
SEA...AND ALL OF ALASKA THIS AFTERNOON...WITH AN EMBEDDED LOW OVER
THE NORTHERN BERING AND A WAVE MOVING TO THE NORTH GULF COAST. UPPER
RIDGES ARE OVER KAMCHATKA AND BRITISH COLUMBIA. AT THE SURFACE...LOWS
ARE OVER THE NORTHERN BERING AND SOUTH OF THE CENTRAL ALEUTIANS.
SURFACE HIGHS ARE OVER THE EXTREME WESTERN BERING AND THE EASTERN
GULF OF ALASKA.

.MODEL DISCUSSION...

MODELS ARE IN VERY GOOD AGREEMENT. THE LOW SOUTH OF THE ALEUTIANS
WILL ROTATE PAST KODIAK ISLAND MON NIGHT THROUGH TUE NIGHT. DURING
THIS TIME THE RIDGE OVER THE GULF WILL PINCH ALONG THE GULF
COAST...CREATING SIGNIFICANT PRESSURE GRADIENTS THROUGH CHANNELED
TERRAIN IN SOUTH CENTRAL AS WELL AS SHELIKOF STRAIT. AS THE LOW
CROSSES THE AKPEN TUE NIGHT IT WILL MERGE WITH THE BERING LOW OVER
BRISTOL BAY. THIS COMBINED LOW WILL REACH THE Y-K DELTA AREA ON
THU...WEAKENING THE PRESSURE GRADIENTS ACROSS SOUTHCENTRAL.
THROUGHOUT THESE EVENTS ABUNDANT MOISTURE WILL BE OVER SOUTHWEST
ALASKA...WITH SIMILAR AMOUNTS OVER SOUTHCENTRAL. THE FORECAST
UTILIZES THE GFS IN THE WEST FOR THE SHORT TERM. IN THE EAST THE GFS
IS USED THROUGH TUE...AND THEN THE NAM IS USED FOR DETAILS IN THE
CHANNELED TERRAIN WIND FORECASTS TUE NIGHT THROUGH WED AFTERNOON.

.SHORT TERM FORECAST...

IN THE WEST...SHOWERS WILL ACCOMPANY BOTH LOWS THROUGH
MIDWEEK...ALTHOUGH SOME DRYING WILL OCCUR OVER THE WESTERN HALF OF
THE BERING AND ALEUTIANS TONIGHT AND MON AS WEAK HIGH PRESSURE
BUILDS. A THIRD LOW DIVING OUT OF KAMCHATKA WILL RETURN SHOWERS TO
THAT REGION TUE AND WED.

FOR SOUTHWEST AK...THE EASTERN FLANK OF THE BERING LOW WILL BRING
RAIN AND SHOWERS INLAND TONIGHT AND MON. BY MON NIGHT RAIN WILL BE
ASSOCIATED WITH THE LOW MOVING ACROSS THE AKPEN AND WILL PERSIST
THROUGH TUE. THESE LOWS WILL ALSO BE ASSOCIATED WITH STRONG CHANNELED
WINDS ACROSS THE ALEUTIAN RANGE...ESPECIALLY ON TUE AND WED.

SOUTH AND EAST OF THE AK RANGE...RAIN WILL BE MAINLY ALONG THE COAST
WITH SOME SHOWERS MOVING ACROSS THE COASTAL MOUNTAINS THROUGH WED.
WIND WILL DEVELOP THROUGH CHANNELED TERRAIN LATER ON TUE INTO
WED...WITH STRONG WIND FOR TURNAGAIN ARM DURING THAT PERIOD.

.LONG TERM FORECAST...

SHOWERS WILL PERSIST IN THE WEST AND OVER SOUTHWEST AK THROUGH THE
END OF THE WEEK BEFORE BEING REPLACED BY FOG BENEATH HIGH PRESSURE.
SOUTHEAST OF THE AK RANGE WILL HAVE PRECIPITATION LIMITED TO THE
NORTH GULF COAST THROUGH THE END OF THE WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALES 132 150 155
FIRE WEATHER...NONE

DS AUG 13