Small Craft Advisory 587, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 AM AKDT MON AUG 5 2013

.ANALYSIS AND UPPER LEVELS...
A BROAD TROUGH SPANS OVER WESTERN ALASKA TO THE CENTRAL BERING WITH A
LOW CENTER NORTH OF THE PRIBILOF ISLANDS AND ANOTHER DEVELOPING SOUTH
OF THE EASTERN ALEUTIANS. LOW AND MID LEVEL CLOUDS ARE STREAMING
ACROSS THE STATE AND SURROUNDING WATERS. AT THE SURFACE...A LOW IS
WEAKENING NEAR NUNIVAK ISLAND AND ANOTHER LOW IS MOVING FROM THE
NORTH PACIFIC TOWARD THE EASTERN ALEUTIANS. A BAND OF LIGHT
RAIN...ASSOCIATED WITH THE LOW NEAR NUNIVAK...STRETCHES FROM THE YK
DELTA TO THE ALASKA PENINSULA. SCATTERED SHOWERS CONTINUE TO DEVELOP
ALONG AN ERODING TROUGH AXIS ACROSS SUSITNA VALLEY AND THE KENAI
PENINSULA WITH ISOLATED SHOWER ACTIVITY FARTHER EAST. ON EITHER SIDE
OF THE EXPANSIVE TROUGH...RIDGING IS BUILDING OVER THE EASTERN GULF
OF ALASKA AND THE WESTERN BERING.

.MODEL DISCUSSION...
MODELS CONTINUE IN GOOD AGREEMENT WITH THE OVERALL SYNOPTIC PATTERN
THROUGH WEDNESDAY NIGHT. THE GFS CONSISTENCY CONTINUES TO BE SUPERIOR
OF ALL THE MODELS AND WAS USED TO UPDATE THE FORECAST FOR BOTH EAST
AND WEST DOMAINS. THROUGH MID WEEK THE UPPER TROUGH WILL DEEPEN OVER
THE EASTERN BERING AND ALASKA PENINSULA...THE TWO CENTERS WILL STAY
CONNECTED FEEDING OFF EACH OTHER UNTIL THE BERING CENTER DOMINATES
AND ABSORBS THE OTHER CENTER.

THE NORTH PACIFIC SURFACE LOW DEEPENS TO A 985 MB LOW SOUTH OF THE
ALASKA PENINSULA THROUGH TUESDAY. THIS LOW WILL PUSH A FRONT ACROSS
THE GULF THROUGH MID WEEK. THE ENERGY ASSOCIATED WITH THIS SYSTEM
WILL FOCUS AROUND THE CENTER OF THE LOW WHICH PASSES OVER THE ALASKA
PENINSULA AND TRACKS NORTHWEST INTO THE EASTERN BERING. MODERATE TO
HEAVY RAINFALL AND GUSTY WINDS WILL ACCOMPANY THIS SYSTEM AS IT
PUSHES NORTH.

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...
MOSTLY CLOUDY CONDITIONS WITH SCATTERED SHOWERS WILL CONTINUE THROUGH
WEDNESDAY NIGHT. WINDS WILL INCREASE ACROSS THE WESTERN GULF OF
ALASKA TONIGHT. THIS LOW WILL PUSH A FRONT ACROSS THE GULF THROUGH
MID WEEK WITH PERIODS OF RAIN AND GUSTY CONDITIONS AS THE WAVE OF
ENERGY PUSHES NORTH.

SOUTHWEST ALASKA...
LIGHT RAIN WILL CONTINUE ACROSS SOUTHWEST ALASKA AND THE ALASKA
PENINSULA TODAY AND DEVELOP INTO MODERATE TO HEAVY RAINFALL AS THE
PACIFIC LOW MOVES NORTH. GUSTY WINDS WILL INCREASE ACROSS THE ALASKA
PENINSULA LATER TODAY AND THEN ACROSS BRISTOL BAY BY TONIGHT. RAIN
AND WINDS WILL TAPER OFF WEDNESDAY NIGHT AS THE SURFACE LOW TRANSITS
TO THE EASTERN BERING.

ALEUTIANS/BERING SEA...
THE PACIFIC LOW WILL BRING GUSTY WINDS AND RAIN TO THE EASTERN
ALEUTIANS AND BERING WITH SCATTERED ACTIVITY ACROSS THE WEST. RIDGING
WILL BUILD IN BEHIND THE LOW DEVELOPING AREAS OF FOG ACROSS THE
WESTERN ALEUTIANS.

.LONG TERM FORECAST...
MODELS ARE COMING INTO BETTER AGREEMENT WITH THE LONG WAVE PATTERN
WITH A STRENGTHENING THE CENTER OVER THE BERING FOR THE UPCOMING
WEEKEND. THIS PATTERN WILL KEEP CLOUDY AND WETTER CONDITIONS IN THE
FORECAST THROUGH THE WEEKEND WITH TEMPERATURES CLOSER TO NORMAL
ACROSS SOUTHERN ALASKA AND THE BERING.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...130 132 136 137 138 150 155 170
FIRE WEATHER...NONE.

KH AUG 13