Gale Warning 145, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
300 PM AKST SUN FEB 14 2010

.ANALYSIS AND UPPER LEVELS...
UPPER LEVEL RIDGING CURVES WEST OUT OF THE YUKON TERRITORY AND
ENCOMPASSES MUCH OF MAINLAND ALASKA. ANTI-CYCLONIC FLOW AROUND THIS
RIDGE WILL STILL GIVE THE UPPER LEVEL WIND PATTERN A SOUTHWARD
COMPONENT...CONTINUING THE UNSEASONABLY WARM WEATHER ACROSS THE
STATE. A PERSISTENT UPPER LEVEL TROUGH REMAINS FIXED OVER THE BERING
SEA AND THE ALEUTIANS. A STACKED 966 MB LOW IN THE NORTH CENTRAL GULF
IS SLOWLY FILLING AS IT MOVES TOWARDS KODIAK ISLAND. SHOWERS ARE
SPREADING ACROSS PRINCE WILLIAM SOUND AND THE WINDWARD SLOPES OF THE
KENAI AND CENTRAL ALEUTIAN MOUNTAIN RANGES AS THE OCCLUDED FRONT
PUSHES NORTH AND WEST ACROSS SOUTH CENTRAL ALASKA. A WEAK LINE OF
CONVECTIVE CELLS SOUTHEAST OF THE KENAI PENINSULA EVEN PRODUCED A FEW
LIGHTNING STRIKES THIS MORNING. CYCLONIC FLOW AROUND THIS LOW IS
DRAWING SLIGHTLY COLDER AIR ACROSS SOUTHWEST ALASKA THIS MORNING.
QUIET WEATHER ENCOMPASSES MUCH OF THE BERING SEA AS THE REMNANTS OF A
SURFACE LOW DISSIPATE NORTH OF THE PRIBILOFS. CLOUDS AND SHOWERS ARE
SPREADING ACROSS THE WESTERN AND CENTRAL ALEUTIANS COURTESY OF AN
ELONGATED SURFACE LOW JUST SOUTHWEST OF ATKA.

.MODEL DISCUSSION...
MODELS ARE HANDLING THE CURRENT GULF SYSTEM FAIRLY WELL...THOUGH
THERE IS A 120 MILE SPREAD BETWEEN THE GFS AND THE ECMWF AS TO WHERE
THE CENTER OF THE SURFACE LOW WILL COME ASHORE IN SOUTHWEST ALASKA
TOMORROW MORNING. THE EVOLUTION OF THE LOW INTO A SHORTWAVE TROUGH ON
TUESDAY IS ALSO CAPTURED WELL OVERALL. MODELS ARE CONVERGING ON A
SOLUTION FOR THE TRACK OF THE NEXT GULF SYSTEM...WHICH UNSURPRISINGLY
IS ALMOST IDENTICAL TO THE TRACKS OF THE LAST FEW SYSTEMS. MODELS
CONTINUE TO STRUGGLE IN DIAGNOSING SYSTEMS WHICH HAVE YET TO
DEVELOP...AS IS EVIDENT BY THE LARGE SOLUTION SPREADS OUT PAST
WEDNESDAY MORNING.

MODELS INITIALIZED RATHER POORLY WITH REGARDS TO THE CENTER OF THE
LOW SOUTHWEST OF ATKA...WITH ITS ELONGATED NATURE LIKELY CONTRIBUTING
TO THESE DISCREPANCIES. DESPITE THESE INITIAL PROBLEMS...MODELS HAVE
REMAINED CONSISTENT IN THE DEVELOPMENT OF A STRONG LOW THAT TRACKS
ACROSS THE WESTERN ALEUTIANS ON WEDNESDAY. ALL OF THE MODELS ARE IN
GOOD AGREEMENT OUT THROUGH WEDNESDAY MORNING...BUT DIVERGE QUICKLY
LATER IN THE WEEK WITH THE ECMWF MAINTAINING THE LOW JUST NORTH OF
THE ALEUTIANS MUCH LONGER THAN THE GFS.

.SHORT TERM FORECAST...

.SOUTH CENTRAL ALASKA...THE LOW IN THE NORTH CENTRAL GULF MOVES
INLAND NEAR KODIAK LATE TONIGHT AND QUICKLY TROUGHS OUT LATE ON
MONDAY. GUSTY WINDS CAN BE EXPECTED TONIGHT AND MONDAY ALONG
TURNAGAIN ARM AND OTHER FAVORABLE PASSES AS THE CENTER OF THE LOW
PASSES WEST OF COOK INLET. SHOWERS PERSIST ACROSS THE GULF COAST
THROUGH MID WEEK AS THE NEXT LOW TRACKS UP INTO THE GULF ON TUESDAY.
HOWEVER...AREAS WEST OF THE CHUGACH WILL REMAIN DOWNSLOPED FOR THESE
EVENTS AND PRECIPITATION WILL REMAIN LIMITED IN THESE AREAS.
ANCHORAGE MAY EVEN PUSH 40 DEGREES IF STRONG DOWNSLOPING WINDS MAKE
IT TO THE CITY. THE CURRENT UPPER LEVEL SHORTWAVE RIDGE WILL PUSH
NORTHWARD AS THE GULF LOW MOVES INLAND AND ALLOW THE MEAN FLOW TO
VEER TO THE SOUTH AS BROAD RIDGING OVER WESTERN CANADA ONCE AGAIN
ASSUMES CONTROL OF THE REGION'S WEATHER. THUS EXPECT CONTINUED ABOVE
NORMAL TEMPERATURES THROUGH THE WEEK ACROSS MUCH OF THE MAINLAND.

.SOUTHWEST ALASKA...ISOLATED SHOWERS SPREAD ACROSS THE REGION ON
MONDAY AS THE REMNANTS OF THE CURRENT GULF LOW EVOLVE INTO A
STATIONARY TROUGH CENTERED OVER THE SOUTHWEST ALASKA COAST. THE NEXT
GULF LOW MERGES WITH THIS TROUGH ON WEDNESDAY...BUT THE WHOLE SYSTEM
WONT EXIT THE REGION UNTIL LATE IN THE WEEK. ISOLATED SHOWERS THUS
REMAIN IN THE FORECAST THROUGHOUT THE WEEK.

.ALEUTIAN ISLANDS...THE LOW SOUTHWEST OF ATKA DRIFTS SOUTHEAST ON
MONDAY AND BECOMES LESS OF AN INFLUENCE ON THE ALEUTIANS. A SERIES OF
WEAK MID-LEVEL DISTURBANCES WILL HELP MAINTAIN CLOUDS AND WEAK
SHOWERS ACROSS THE ISLAND CHAIN THROUGH THE BEGINNING OF THE WEEK. A
STRONG WEATHER SYSTEM MOVES INTO THE WESTERN ALEUTIANS ON TUESDAY
NIGHT AND MAY INITIALLY BRING NEAR BLIZZARD CONDITIONS BEFORE
PRECIPITATION SWITCHES TO RAIN.

.LONG TERM FORECAST...
THE WEATHER PATTERN LOOKS TO REMAIN UNCHANGED FOR THE FORESEEABLE
FUTURE...WITH A STEADY SUPPLY OF LOWS ROTATING INTO THE GULF AND A
STRONG UPPER LEVEL RIDGE BUILDING WEST OUT OF CANADA THAT WILL
CONTINUE TO PUMP WARM GULF AIR INTO THE STATE.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 120 125 129 130 138 140.
FIRE WEATHER...NONE.

KS/EZ FEB 10