Small Craft Advisory 272, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
119 PM AKDT WED APR 2 2014

.ANALYSIS AND UPPER LEVELS...
THE UPPER LEVEL PATTERN STILL LOOKS BLOCKY WITH A CLOSED HIGH
PRESSURE SYSTEM OVER THE BERING STRAIT AND A CLOSED LOW PRESSURE
SYSTEM OVER THE WESTERN/CENTRAL BERING SEA. HOWEVER THE BERING SEA
SYSTEM HAS BEEN REJUVENATED BY A 140KT JET STREAK. THE BLOCKING
HIGH PRESSURE IS LIMITING THE NORTHERN PROGRESSION BUT IS ALSO
GETTING SQUEEZED BY A TROUGH FROM THE NORTH. ANOTHER FRONT
ASSOCIATED WITH THE COMPLEX LOW PRESSURE SYSTEM IS APPROACHING
KODIAK ISLAND AS WELL AS THE SOUTHWESTERN COAST...BEHIND THAT
FRONT AN AREA OF BROKEN LOW STRATUS SITS OVER THE BERING WHILE THE
SHOWERS WITHIN THE UPPER LOW PRESSURE ARE AFFECTING MAINLY THE
WESTERN ALEUTIANS AND BERING SEA.

HIGH PRESSURE AT THE SURFACE STILL DOMINATES THE SOUTHCENTRAL'S
SENSIBLE WEATHER. ONLY A FEW HIGH CLOUDS ARE SPILLING OVERTOP OF
THE RIDGE AHEAD OF THE NORTHERLY TROUGH. THE SERIES OF FRONTS OVER
THE LAST COUPLE DAYS ARE MAKING MORE AND MORE PROGRESS IN THE GULF
TOWARD THE SOUTHCENTRAL WITH CLOUD COVER SNEAKING UP TO THE
SOUTHERN EDGE OF THE KENAI PENINSULA.

&&

.MODEL DISCUSSION...
GUIDANCE REMAINS IN EXCELLENT AGREEMENT BOTH IN THE UPPER LEVELS
AND AT THE SURFACE THROUGH THE REST OF THE WEEK. THE COMPLEX
BERING SEA UPPER LOW WILL REMAIN THE MAIN PLAYER IN SIGNIFICANT
WEATHER AS SEVERAL DISTURBANCES ROTATE AROUND THE LONG-WAVE. THE
FEATURE WHICH MODELS ARE NOW LATCHING ONTO THAT THEY PREVIOUSLY
WERE NOT IS AN AMPLIFYING SHORTWAVE OVER THE CHUKCHI MOVING TOWARD
THE SOUTHCENTRAL. WHILE THE MODELS ARE IN GREAT AGREEMENT NOW THE
PATTERN LOOKS TO GET COMPLEX AS THE THESE TWO SYSTEMS INTERACT
WITH ONE ANOTHER AND WILL HAVE A HUGE EFFECT ON THE FORECAST FOR
THE SOUTHCENTRAL OVER THE WEEKEND. FORECAST CONFIDENCE WITH THIS
PACKAGE IS HIGH FOR THE NEXT DAY OR TWO THEN BEGINS TO DEGRADE
OVER THE WEEKEND.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...
SEASONABLE TEMPERATURES...DRY CONDITIONS...AND CLEAR SKIES ARE
CONTINUING OVER THE AREA. THAT LOOKS TO CHANGE OVER THE NEXT
COUPLE OF DAYS AS SEVERAL FRONTS AND ASSOCIATED UPPER LEVEL
DISTURBANCES ROTATE AROUND THE BERING SEA SYSTEM INTO THE WESTERN
GULF. MID LEVEL CLOUDS WILL BE ON THE INCREASE TOMORROW FROM SOUTH
TO NORTH AS THE FIRST DISTURBANCE MOVES OVERHEAD. CHANCES FOR
PRECIPITATION INCREASE TOMORROW THROUGH THE WEEKEND...ESPECIALLY
FOR THE NORTH GULF COAST.

SOUTHWEST ALASKA...
RAIN AND SNOW WILL MOVE INLAND THIS EVENING AND OVERNIGHT AS AS
FRONT MOVES OVERHEAD...THOUGH THE FRONT WILL FALL APART QUICKLY
LIKE THE PREVIOUS INCARNATIONS. THE BERING SEA TROUGH WILL SLIDE
EASTWARD TOWARD THE WEEKEND KEEPING RAIN AND SNOW CHANCES IN THE
FORECAST WITH AN INCREASE IN NORTHERLY FLOW. THE KUSKOKWIM DELTA
WILL DRY OUT ON SATURDAY WHILE THE BRISTOL BAY REGION WILL
CONTINUE TO SEE CHANCES FOR SNOW.

BERING SEA/ALEUTIANS...
SCATTERED RAIN SHOWERS WILL CONTINUE FOR MOST ZONES AS THE
PERSISTENT TROUGH ROTATES OVERHEAD. IT DOES HOWEVER SHIFT EASTWARD
TOWARD THE WEEKEND FILTERING IN COLDER AIR AND THE CHANCE FOR SNOW
SHOWERS BEFORE A PERIOD OF DRYING TOWARD THE WEEKEND WITH GUSTY
NORTHERLY FLOW.

&&

.LONG TERM FORECAST...
A BIT OF A PATTERN IS IN STORE AFTER THE WEEKEND. THE LONG-WAVE
PATTERN BECOMES MORE PROGRESSIVE AFTER THE WEEKEND WITH A PAIR OF
UPPER TROUGHS SIT OVER NORTHERN ALASKA AND THE GULF. A LARGE UPPER
LOW WILL SIT OVER KAMCHATKA AND ANCHOR THE PATTERN KEEPING MUCH OF
THE EASTERN BERING AND WESTERN MAINLAND DRY AND COLD WHILE THE
EASTERN MAINLAND AND GULF WILL BE COOLER AND WETTER.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE 177 178.
FIRE WEATHER...NONE.

&&

MTL APR 14