Gale Warning 137, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
300 PM AKST WED FEB 10 2010

.MODEL DISCUSSION...MODELS ARE IN GOOD OVERALL AGREEMENT BUT LOOK TO
BE DOING A LITTLE BETTER IN THE BERING SEA REGION THAN THE GULF AREA.
THERE IS A DIFFERENCE BETWEEN THE SOLUTIONS PRESENTED BY THE NAM/GFS
WHEN COMPARED TO THE UKMET/ECMWF MODELS IN DEALING WITH A LOW THAT
WILL MOVE THROUGH THE GULF THURSDAY THROUGH FRIDAY. PART OF THE
CHALLENGE IS THAT NONE OF THE MODELS HAVE HAD VERY GOOD RUN TO RUN
CONSISTENCY BUT THE GFS ENSEMBLE SEEMS TO HAVE THE UPPER HAND WHEN
LOOKING AT THE OVERALL PICTURE. ONE OTHER NOTE IS THAT THE 12Z NAM
HAS THE BEST HANDLE ON THE SMALL LOW IN THE NORTHWEST GULF.

.ANALYSIS AND UPPER LEVELS...CURRENTLY THERE IS A LONG WAVE RIDGE
THAT EXTENDS UP THE WESTERN COAST OF NORTH AMERICA INTO THE YUKON
TERRITORIES AND BENDS WESTWARD OVER THE ALASKAN ARCTIC COAST. THE
LONG WAVE UPPER LEVEL LOW IS ANCHORED IN EASTERN RUSSIA AND EXTENDS
SOUTHEAST WITH A SECONDARY CENTER NEAR DUTCH HARBOR. THIS SECONDARY
CENTER IS ASSOCIATED WITH THE LOW THAT BROUGHT SEVERE WINTER WEATHER
TO PARTS OF WESTERN ALASKA EARLY THIS WEEK BUT IS NOW WEAKENING.
THE 250 MB JET STREAM IS AND WILL REMAIN ZONAL BUT SOUTH OF THE
FORECAST AREA THROUGH THE REST OF THE WEEK. IT WILL HOWEVER SPIN UP
ANOTHER STRONG LOW THAT WILL MAKE IT INTO THE GULF OF ALASKA THIS
WEEKEND.

.SHORT TERM FORECAST...EAST TO SOUTHEAST FLOW CONTINUES OVER THE GULF
OF ALASKA AND MAINLAND PORTIONS OF THE STATE. A SMALL BUT FAIRLY
STRONG LOW IN THE NORTHWEST GULF OF ALASKA IS ENHANCING PRECIPITATION
ALONG THE NORTH GULF COAST AND IS ALSO CREATING A BARRIER JET ALONG
THE NORTH GULF COAST FROM AROUND HINCHINBROOK ENTRANCE EASTWARD.
SOUTHEAST FLOW WILL KEEP SOUTH CENTRAL ALASKA MAINLY IN THE
PRECIPITATION SHADOW EXCEPT FOR THE WINDWARD SIDES OF MOUNTAIN
RANGES. THIS WILL BE THE SAME SITUATION FOR THE SOUTHWEST ALASKA
MAINLAND AREAS AS WELL.
THE OLD LOW NORTH OF DUTCH HARBOR WILL CONTINUE ITS TRACK OVER THE
PRIBILOF ISLANDS AND BRING SNOW SHOWERS OVERNIGHT WITH A CHANCE OF
SOME FREEZING DRIZZLE MIXED IN AS WELL. THE ALASKA PENINSULA AND
EASTERN ALEUTIANS WILL SEE MOSTLY RAIN SHOWERS FROM THIS SYSTEM AS
THEY REMAIN IN THE WARM SECTOR WHILE THE CENTRAL ALEUTIANS AND
WESTERN ALEUTIANS REMAIN IN SNOW SHOWERS IN COLD ADVECTION AND
NORTHERLY FLOW.

.LONG TERM FORECAST...NO DRAMATIC PATTERN CHANGE IS EXPECTED FOR THE
LONG TERM WITH UPPER LEVEL RIDGING OVER THE NORTHERN PART OF THE
STATE AND A TROUGH STRETCHING FROM THE BERING SEA INTO THE GULF OF
ALASKA. THIS WILL CONTINUE TO KEEP TEMPERATURES RELATIVELY MILD
ACROSS SOUTH CENTRAL AND SOUTHWESTERN ALASKA THROUGH THE WEEKEND. A
SERIES OF SURFACE LOWS WILL PROGRESS THROUGH THE NORTH GULF COAST
WHICH WILL KEEP THE CHANCE OF PRECIPITATION OVER THAT AREA.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 120 130 132 138.
         HEAVY FREEZING SPRAY 179.
FIRE WEATHER...NONE

FEB 10