Small Craft Advisory 845, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
140 PM AKDT SAT NOV 1 2008

.ANALYSIS/UPPER LEVELS AND MODEL DISCUSSION...HIGH PRESSURE IS
CENTERED NORTH OF THE STATE WITH LOW PRESSURE DOMINATING THE GULF OF
ALASKA INTO THE SE PANHANDLE. THE JET STREAM RIDES ALONG ABOUT 45N
LATITUDE KEEPING THE COLD AIR IN PLACE. MODELS IN GOOD AGREEMENT
THROUGH AT LEAST 60 HRS...SO NO BIG CHANGES ARE NEEDED WITH THE
AFTERNOON FORECAST.

.SHORT TERM FORECAST...A WEAK LOW JUST OFF THE COAST NEAR YAKUTAT
WILL CONTINUE TO DISSIPATE AS IT MOVES INLAND. THIS LOW IS SPREADING
CLOUDS AND SOME LIGHT SNOW INTO THE EASTERN COPPER RIVER BASIN.
CLOUDS WILL SLOWLY INCREASE AND MOVE WESTWARD AS A STRONGER LOW
CURRENTLY OFF THE QUEEN CHARLOTTE ISLANDS MOVES UP THE COAST. AS THIS
LOW APPROACHES...THE PRESSURE GRADIENT TIGHTENS CONSIDERABLY
PROMOTING STRONG NORTHWEST WINDS THROUGH THE GAPS OF SOUTHCENTRAL.
THESE WINDS WILL SPILL INTO THE GULF WITH PLENTY OF GALES EXPECTED IN
THE WESTERN GULF BEGINNING LATE TONIGHT LASTING THROUGH SUNDAY NIGHT.

THE BIGGEST CONCERN FOR THE NEXT 24 HOURS IS THE FOG AND STRATUS IN
AND AROUND COOK INLET. FOG HAS PERSISTED AROUND ANCHORAGE AND AS SEEN
ON SATELLITE...IS MOVING SOUTH ALONG THE WESTERN SHORE OF THE KENAI
PENINSULA. SO THE QUESTION IS...WILL THIS FOG/STRATUS SHOW UP AGAIN
TOMORROW MORNING? THE GRADIENT DOES INCREASE OVERNIGHT...AND THERE
WILL BE A SQUEEZE PLAY WITH HIGH CLOUDS FROM THE EAST AND WEST...SO
THE ANSWER IS...WE DONT KNOW. WE WILL KEEP PATCHY FOG MENTION GOING,
BUT DENSE FOG IS CERTAINLY A POSSIBILITY.

AS THE AFOREMENTIONED LOW IN THE SOUTHERN PANHANDLE LIFTS
NORTHWESTWARD TOWARD THE NORTHERN GULF, MOISTURE WILL INCREASE
SUBSTANTIALLY, INTRODUCING MORE PRECIP TO COASTAL LOCATIONS FOR
MONDAY INTO TUESDAY.

FURTHER WEST...A DECAYING FRONT IS PRODUCING A FEW SNOW SHOWERS IN
BRISTOL BAY THIS AFTERNOON...BUT THE FRONT COMPLETELY FALLS APART
TONIGHT AS THE ASSOCIATED UPPER SHORTWAVE PASSES TO THE EAST. ONSHORE
FLOW BEHIND THE FRONT WILL LEND ITSELF TO FOG FORMATION IN SW ALASKA
THROUGH THE DAY ON SUNDAY. RAIN AND SNOW SHOWERS ARE CONTINUING IN A
BROAD WESTERLY FLOW BEHIND THE FRONT IN THE BERING. A WEAK LOW IS
EXPECTED TO TRAVERSE THE BERING OVER THE NEXT 36 HOURS BRINGING A
LITTLE MORE ORGANIZATION TO THE PRECIP. WINDS WILL REMAIN AT SMALL
CRAFT LEVELS OR BELOW WITH THIS FEATURE...SO NO REAL CONCERN. HIGH
PRESSURE TAKES OVER THE WESTERN BERING ON SUNDAY AND BUILDS OVER THE
ENTIRE BERING SEA BY TUESDAY AHEAD OF THE NEXT FRONT COMING IN FROM
THE WEST.

.LONG TERM FORECAST...THE RIDGE OVER THE BERING MEANS A TROUGH OVER
THE MAINLAND. A MULTITUDE OF WEAK LOWS WILL BE FOUND IN THE GULF OF
ALASKA UNDER THE TROUGH BRINGING PERIODIC CHANCES OF SNOW SHOWERS.
BEING UNDER THE TROUGH ALSO MEANS CONTINUED COLD TEMPERATURES.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 130 132.
FIRE WEATHER...NONE.

JCA