Small Craft Advisory 405, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
400 AM ADT TUE MAY 02 2006

.DISCUSSION...
ANALYSIS...SATELLITE IMAGERY SHOWS LOW MOVING OVER CHIGNIK ON THE
ALASKA PENINSULA EARLY THIS MORNING AND ITS ASSOCIATED FRONTAL
BOUNDARY EXTENDING NORTHEAST TOWARD SOUTHCENTRAL ALASKA. THE OCCLUDED
FRONT EXTENDS ALL THE WAY BACK INTO THE NORTH PACIFIC WHERE A STRONG
SHORT WAVE IS FLOWING W-E ALONG THE 45TH PARALLEL. GFS AND ETA
INITIALIZE WELL WITH THE AKPEN LOW BUT ARE HAVING A HARD TIME WITH
THE DETAILS SURROUNDING THE DEVELOPING SYSTEM IN THE NORTH PACIFIC.
ETA HAS COME MORE IN LINE WITH THE GFS WITH THIS NEXT SYSTEM BUT
STILL A DIFFERENCE IN THE RATE IN WHICH THIS LOW DEEPENS. AT THIS
POINT THE CONFIDENCE IS HIGH REGARDING THE TRACK AND TIMING BUT SOME
OF THE DETAILS WILL HAVE TO BE WORKED OUT DURING THE NEXT COUPLE OF
RUNS.

UPPER AIR...THE CUTOFF UPPER LOW NEAR THE AKPEN IS THE FOCUS FOR ALL
OF THE SOUTHERN ALASKA WEATHER AS IT SLOWLY ROTATES AROUND THE
EASTERN BERING SEA. WE WILL CONTINUE TO SEE A VERY SIMILAR WEATHER
PATTERN AS LONG AS THIS UPPER FEATURE REMAINS IN THAT REGION. SHORT
WAVES WILL DEVELOP SURFACE FEATURES THAT WILL EJECT NORTHWARD AROUND
THE EASTERN PERIPHERY OF THE PARENT LOW TOWARDS SOUTHCENTRAL ALASKA.
THE EXTENDED FORECAST DEPICTS THE UPPER LOW DEEPENING AND A
MEANDERING JET BECOMING MORE ZONAL AND FOCUSED ALONG 45N.

SOUTHCENTRAL SURFACE...ABUNDANT MOISTURE AND STRONG WINDS ALONG
COASTAL SECTIONS OF SOUTHCENTRAL ASSOCIATED WITH THE OCCLUSION IN THE
NORTHERN GULF NEAR MIDDLETON ISLAND AT 11Z THIS MORNING. EXPECT THIS
FRONT TO MOVE ONSHORE AND WASH OUT OVER THE INTERIOR DURING THE NEXT
12 TO 24 HOURS. LOOK FOR CLOUDY SKIES TODAY WITH RAIN ALONG THE COAST
AND SOUTH AND EAST FACING RANGES. THERE WILL BE A BREAK IN THE ACTION
LATE THIS EVENING AND EARLY WEDNESDAY MORNING BEFORE THE NEXT SYSTEM
APPROACHES. PARTIAL CLEARING WILL RESULT IN RADIATIVE COOLING AND
TEMPERATURES 10 TO 15 DEGREES COOLER THAN THIS MORNING IN PLACES.
OVER THE COASTAL WATERS...GALES WILL DIMINISH QUICKLY TODAY BUT
RETURN OVERNIGHT AS THE PRESSURE GRADIENT TIGHTENS AND THE BARRIER
JET DEVELOPS AGAIN ALONG THE COAST...STORM FORCE WINDS LIKELY WITH
THIS FEATURE BY EARLY WEDNESDAY AFTERNOON.

SOUTHWEST SURFACE...MOISTURE FROM THE OCCLUSION IS BEING DRAINED ON
THE EASTERN SIDE OF THE ALASKA AND ALEUTIAN RANGES LEAVING MOST OF
THE SOUTHWEST IN A RAIN SHADOW. THE EXCEPTION IS ALONG THE KILBUCK
AND AHKLUN MOUNTAINS IN OUR ZONES 161 AND 155. THE NEXT SYSTEM SEEMS
TO HAVE MORE MOISTURE TO WORK WITH AND A MORE FAVORABLE TROF AXIS
WILL LEAD TO A BETTER CHANCE OF RAIN AND SNOW COME WEDNESDAY.
OTHERWISE RELATIVELY QUIET IN THIS REGION WITH CLOUDY SKIES
DOMINATING. FURTHER WEST THE UPPER LOW NEAR THE PRIBILOFS AND THE
REMNANTS OF THE AKPEN LOW ARE KEEPING LOW CEILINGS OVER MOST OF THE
BERING SEA AND ALEUTIAN ISLANDS. THIS QUIET PATTERN WILL CHANGE
SLIGHTLY OVER THE WESTERN ALEUTIANS WEDNESDAY AS A 981 MB LOW MOVES
JUST SOUTH OF THE CHAIN BRINGING GALES BACK INTO THE FORECAST AND
THEN COLD AIR ADVECTION BY THE END OF THE WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORM...120. GALES 130 150 175 176.
FIRE WEATHER...NONE.

AB MAY 06