Small Craft Advisory 469, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 PM AKDT FRI JUL 8 2011

.MODEL DISCUSSION...
MODELS REMAIN IN GREAT AGREEMENT THROUGH THE WEEKEND WITH THE MAIN
SYNOPTIC FEATURES. BY MONDAY THERE BEGINS TO BE SOME SPREAD WITH THE
EXACT POSITION OF THE UPPER LOW IN THE BERING SEA AND THE UPPER LOW
IN THE BEAUFORT SEA. THERE IS MUCH BETTER AGREEMENT WITH A BUILDING
RIDGE EXTENDING UP THROUGH THE GULF OF ALASKA AND A SHORTWAVE TROUGH
GETTING PULLED INTO THE BERING CIRCULATION TOWARDS THE SOUTHWESTERN
COAST BY EARLY NEXT WEEK. NAM SOLUTION PREFERRED IN THE SHORT TERM.

.ANALYSIS AND UPPER LEVELS...
THE MAIN UPPER LEVEL FEATURE CONTINUES TO BE THE STACKED LOW PRESSURE
OVER THE BERING FOR THE SHORT TERM. WIDESPREAD CLOUDINESS WITH THIS
FEATURE IS EVIDENT ACROSS THE BERING. ENERGY ROTATING AROUND THE LOW
ALSO CONTINUES TO BRING WAVES OF RAIN TO THE KUSKOKWIM DELTA AND
BRISTOL BAY REGIONS. WEAK EMBEDDED DISTURBANCES ON THE SOUTHERN
PERIPHERY OF THE LOW CONTINUE TO BRING RAIN TO THE EASTERN ALEUTIANS.
FURTHER EAST ACROSS THE MAINLAND...WEAK FLOW BEHIND A DEPARTING
EASTERN GULF OF ALASKA TROUGH HAS LEFT RESIDUAL MOISTURE AND CLOUDS
TRAPPED UNDER A SUBSIDENCE INVERSION AS HIGH PRESSURE SITS OVER THE
NORTHEASTERN GULF OF ALASKA. A BROAD THERMAL TROUGH OVER THE CENTRAL
INTERIOR REMAINS THE FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS
MAINLY NORTH OF THE ALASKA RANGE.

.SHORT TERM FORECAST...SOUTHCENTRAL ALASKA...MOSTLY CLOUDY CONDITIONS
FOR ANCHORAGE AND THE MAT-SU WITH SOME PARTIAL CLEARING THIS EVENING
BEFORE CLOUDS ROLL BACK IN EARLY SATURDAY MORNING. AS THE WEEKEND
PROGRESSES A MOIST SOUTHWESTERLY FLOW ALOFT WILL KEEP CLOUDS IN THE
FORECAST WITH A CHANCE FOR RAIN. A CHANCE FOR SHOWERS IN THE COPPER
RIVER BASIN BUT MOST OF THE ACTIVITY SHOULD STAY JUST TO THE NORTH OF
THE ALASKA RANGE.

SOUTHWEST ALASKA...RAIN SPREADING EASTWARD INTO THE KUSKOKWIM VALLEY
THIS AFTERNOON AND EVENING AND INTO THE BRISTOL BAY AREA BY SATURDAY
MORNING.  GUSTY WINDS ALONG COASTAL AREAS AND THE ALASKAN PENINSULA.

BERING SEA AND ALEUTIANS...CLOSED LOW AND ASSOCIATED LOW STRATUS AND
FOG WILL HANG AROUND THROUGH THE WEEKEND. AN APPROACHING DISTURBANCE
WILL BRING RAIN TO THE WESTERN ALEUTIANS SATURDAY NIGHT INTO SUNDAY
SPREADING EASTWARD SUNDAY AFTERNOON.

.LONG TERM FORECAST...
THOUGH DISAGREEMENT IS PRESENT WITH THE POSITION OF THE UPPER LOW BY
THE EXTENDED PERIOD THE CLOSED LOW WILL BE CENTERED SOMEWHERE NEAR
THE NORTHERN BERING SEA AND BERING STRAIT AREA. SENSIBLE WEATHER
EFFECTS IN THIS PATTERN WOULD BE INCREASED MOISTURE AND EMBEDDED
SHORTWAVE TROUGHS MOVING UP THE ALEUTIANS INTO THE SOUTHWESTERN
INTERIOR.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALES 180 185
FIRE WEATHER...NONE

MTL JUL 11