High Wind Watch 41, NWS Anchorage, AK

900 
WWAK71 PAFC 200109
NPWAER

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE ANCHORAGE AK
409 PM AKST MON DEC 19 2011

AKZ101-201430-
/X.UPG.PAFC.HW.A.0041.111221T0000Z-111221T0900Z/
/X.NEW.PAFC.HW.W.0054.111221T0000Z-111221T0900Z/
ANCHORAGE-
INCLUDING THE CITIES OF...ANCHORAGE...EAGLE RIVER...INDIAN...
EKLUTNA
409 PM AKST MON DEC 19 2011

...HIGH WIND WARNING IN EFFECT FROM 3 PM TUESDAY TO MIDNIGHT AKST
TUESDAY NIGHT FOR ALONG TURNAGAIN ARM AND THE HILLSIDE...

THE NATIONAL WEATHER SERVICE IN ANCHORAGE HAS ISSUED A HIGH WIND
WARNING...WHICH IS IN EFFECT FROM 3 PM TUESDAY TO MIDNIGHT AKST
TUESDAY NIGHT. THE HIGH WIND WATCH IS NO LONGER IN EFFECT. 

* LOCATION...ALONG TURNAGAIN ARM AND THE HILLSIDE.

* WIND...SOUTHEAST WIND 55 TO 70 MPH WITH GUSTS TO 90 MPH.

* TIMING...WINDS WILL RAPIDLY INCREASE BEGINNING LATE TUESDAY 
  MORNING AND THEN PEAK EARLY TUESDAY EVENING. WINDS WILL 
  GRADUALLY DIMINISH TUESDAY NIGHT THROUGH WEDNESDAY MORNING. 

* IMPACTS...TRAVEL MAY BE DIFFICULT. TREES MAY BE BLOWN OVER.
  LOOSE DEBRIS CAN BE MOVED AND DAMAGE PROPERTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HIGH WIND WARNING MEANS A HAZARDOUS HIGH WIND EVENT IS EXPECTED
OR OCCURRING. PEOPLE ARE URGED TO SECURE LOOSE OBJECTS THAT COULD
BE BLOWN AROUND OR DAMAGED BY THE WIND.

&&

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
520 AM AKST MON DEC 19 2011

.ANALYSIS AND UPPER LEVELS...
THE REGION REMAINS UNDER THE INFLUENCE OF A BROAD LONGWAVE TROUGH
CENTERED OVER THE BERING SEA WITH CORRESPONDING SOUTHERLY FLOW ACROSS
MUCH OF MAINLAND ALASKA. AN 80 KT JET STREAM WITH EMBEDDED 125+ KT
JET MAXES CONTINUE TO STEER FAST-MOVING STORMS INTO THE SOUTHERN
MAINLAND. ON THE MORNING SATELLITE IMAGE...THE STRONG LOW AND FRONT
FROM YESTERDAY HAS WEAKENED AND MOVED RAPIDLY INTO THE INTERIOR...AND
IS NOW A DISTANCE MEMORY. A PAIR OF LOWS APPROACHING THE GULF OF
ALASKA ARE TAKING CENTER STAGE...AND WILL BE THE PRIMARY FEATURES
IMPACTING THE STATE TODAY. THE FIRST LOW IS NEAR THE FAR SOUTHERN
GULF AND WILL PRIMARILY IMPACT SOUTHEAST ALASKA TODAY. THE SECOND AND
SMALLER OF THE TWO LOWS IS DEVELOPING RAPIDLY SOUTHWEST OF KODIAK
ISLAND IN RESPONSE TO A CORRESPONDING MID-LEVEL TROUGH. THE SHIELD OF
RAIN AND SNOW ASSOCIATED WITH THIS LOW HAS JUST BECOME VISIBLE ON THE
KING SALMON RADAR SPREADING FROM SOUTHWEST TO NORTHEAST ALONG THE
ALEUTIAN RANGE. FURTHER WEST...COLD AIR ALOFT HAS HELPED AN AREA OF
SCATTERED HEAVY SNOW SHOWERS DEVELOP ACROSS MOST OF THE ALEUTIAN
ISLANDS AND SOUTHERN BERING SEA. THIS FEATURE IS MOVING NORTHEAST
TOWARD THE MAINLAND AND IS FOLLOWING ON THE HEELS OF THE
AFOREMENTIONED LOW AFFECTING THE BRISTOL BAY AREA.

.MODEL DISCUSSION...
THE MODELS ARE IN GOOD AGREEMENT FOR THE FIRST 24-36 HOURS OF THE
FORECAST PERIOD...TAKING THE LOW NEAR KODIAK NEARLY DUE NORTHEAST AND
GENERALLY PARALLELING THE SPINE OF THE KENAI MOUNTAINS TODAY. BY LATE
TUESDAY NIGHT MODEL AGREEMENT BEGINS TO BREAK DOWN IN DRAMATIC
FASHION AS A MODERATE STRENGTH LOW DEVELOPS IN THE NORTHEAST PACIFIC
AND EITHER MOVES TOWARD PRINCE WILLIAM SOUND (NAM/EC) OR WEAKENS AND
MOVES INTO THE PANHANDLE (GFS). THE SCENE GOES FROM BAD TO WORSE ON
THURSDAY AS A STRONG LOW DEVELOPS SOMEWHERE SOUTH OF THE CENTRAL
ALEUTIANS. SUCH MODEL DISAGREEMENT IS NOT TERRIBLY SURPRISING GIVEN
THE SIGNS OVER THE LAST SEVERAL DAYS THAT THIS PERSISTENT LONGWAVE
PATTERN IS BECOMING MORE UNSTABLE. OVERALL...THE NAM/EC SOLUTION WAS
PREFERRED FOR THE FIRST 3 DAYS OF THE FORECAST...WITH A QUICK
TRANSITION TO THE LATEST GUIDANCE FROM HPC FOR THE MID AND LONG
RANGE.

.SHORT TERM FORECAST...
SOUTHCENTRAL...GUSTY SOUTHERLY WINDS ACROSS MUCH OF THE REGION WILL
BE DIMINISHING THIS MORNING AS A WEAK RIDGE OF HIGH PRESSURE MOVES
QUICKLY INTO THE AREA. THIS FEATURE WILL ALLOW MANY AREAS TO SEE SOME
BREAKS OF SUN TODAY BEFORE CLOUDS RETURN THIS EVENING. THE EXCEPTION
WILL BE KODIAK ISLAND WHERE CLOUDS AND A MIX OF RAIN AND SNOW WILL
DEVELOP THIS MORNING. THE FAST-MOVING LOW RACES ACROSS THE KENAI
PENINSULA TODAY AND INTO WESTERN PRINCE WILLIAM SOUND TONIGHT MOST
AREAS FROM HOMER TO THE MATANUSKA VALLEY SHOULD SEE A BRIEF PERIOD OF
MODERATE SNOW THIS EVENING AND OVERNIGHT. NOT EXPECTING SIGNIFICANT
ACCUMULATIONS AT THIS TIME...SIMPLY DUE TO THE VERY FAST FORWARD
SPEED OF THIS LOW. AFTER ANOTHER VERY BRIEF BREAK SNOW AND WIND
RETURN TO SOUTHCENTRAL TUESDAY AFTERNOON AS A SIGNIFICANT LOW MAKES
LANDFALL IN BRISTOL BAY. THIS STORM SEEMS TO BE SHAPING UP SIMILAR TO
THE WIND STORM YESTERDAY THAT AFFECTED EAST ANCHORAGE AND THE
HILLSIDE. THE ONE NOTABLE DIFFERENCE WITH THIS LOW IS THAT UPPER
LEVEL WINDS ARE MORE SOUTHWESTERLY WITH THIS STORM THAN WITH THE
PREVIOUS...A SCENARIO WHICH CAN SOMETIMES MAKE WIND EVENTS WORSE AT
THE LOWER ELEVATIONS OF ANCHORAGE. THIS POTENTIALLY SIGNIFICANT EVENT
WILL BE MONITORED CLOSELY THROUGHOUT THE DAY. STAY TUNED TO THE
LATEST FORECAST FOR THE MOST CURRENT INFORMATION.

SOUTHWEST AND BERING SEA...THE LOW NEAR KODIAK WILL BRING A PERIOD OF
SNOW TO PARTS OF THE BRISTOL BAY ZONE EAST OF DILLINGHAM TODAY WITH A
FEW INCHES OF ACCUMULATION LIKELY. ELSEWHERE SNOW SHOWERS AND ONSHORE
FLOW WILL CONTINUE FOR THE REMAINDER OF SOUTHWEST AS WELL AS THE
ALEUTIANS. THE LOW WELL SOUTH OF SHEMYA IS THE STORM THAT WILL GROW
AND AFFECT THE MAINLAND IN A MAJOR WAY ON TUESDAY. AS THIS LOW MOVES
EAST LOCATIONS FROM DUTCH HARBOR EASTWARD WILL EXPERIENCE GALE TO
STORM FORCE WINDS IN ADDITION TO RAIN AND SNOW BEGINNING THIS
EVENING.

.LONG TERM FORECAST...
AS MENTIONED IN THE MODEL DISCUSSION ABOVE THERE IS CONSIDERABLE
DISAGREEMENT AMONG THE LONG RANGE WEATHER MODELS. THE COMMON ELEMENT
SEEMS TO BE A GRADUAL SHIFT EASTWARD IN THE LONGWAVE TROUGH BY THE
END OF THE WEEK. THIS IS A MORE TYPICAL PATTERN FOR ALASKA THIS TIME
OF YEAR AND WOULD ALLOW COLDER AIR TO INFILTRATE BACK INTO MOST PARTS
OF THE STATE.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...STORM 150 155 170
         GALE 120 130 132 138 140 160 165 171 172 179 185
         HEAVY FREEZING SPRAY 185
FIRE WEATHER...NONE

AMD DEC 11