High Wind Watch 5, NWS Anchorage, AK

284 
WWAK71 PAFC 090105
NPWAER

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE ANCHORAGE AK
405 PM AKST FRI FEB 8 2013

...STRONG STORM MOVING INTO SOUTHERN ALASKA ON SATURDAY...

.A PACIFIC WEATHER SYSTEM WILL MOVE ACROSS SOUTHCENTRAL ALASKA ON
SATURDAY. AS AN ASSOCIATED WEATHER FRONT PUSHES INLAND SATURDAY
MORNING...WINDS WILL INCREASE THROUGH TURNAGAIN ARM AND HIGHER
ELEVATIONS OF ANCHORAGE. 

AKZ101-091415-
/X.UPG.PAFC.HW.A.0005.130209T1500Z-130210T0300Z/
/X.NEW.PAFC.HW.W.0005.130209T1500Z-130210T0100Z/
ANCHORAGE-
INCLUDING THE CITIES OF...ANCHORAGE...EAGLE RIVER...INDIAN...
EKLUTNA
405 PM AKST FRI FEB 8 2013

...HIGH WIND WARNING IN EFFECT FROM 6 AM TO 4 PM AKST SATURDAY
ALONG TURNAGAIN ARM AND HIGHER ELEVATIONS...

THE NATIONAL WEATHER SERVICE IN ANCHORAGE HAS ISSUED A HIGH WIND
WARNING...WHICH IS IN EFFECT FROM 6 AM TO 4 PM AKST SATURDAY. THE
HIGH WIND WATCH IS NO LONGER IN EFFECT. 

* LOCATION...TURNAGAIN ARM AND HIGHER ELEVATIONS.

* WIND...SOUTHEAST 50 TO 65 MPH WITH GUSTS TO 85 MPH.

* TIMING...WINDS WILL INCREASE SATURDAY MORNING AND CONTINUE
  THROUGH EARLY AFTERNOON. WINDS WILL BEGIN TO DIMINISH LATE
  SATURDAY AFTERNOON.

* IMPACTS...TRAVEL MAY BE DIFFICULT. 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.

&&

$$

AKZ125-091415-
/X.UPG.PAFC.HW.A.0005.130209T1500Z-130210T0300Z/
/X.NEW.PAFC.HW.W.0005.130209T1500Z-130210T0100Z/
WESTERN PRINCE WILLIAM SOUND-
INCLUDING THE CITIES OF...WHITTIER...SEWARD...GIRDWOOD...
MOOSE PASS
405 PM AKST FRI FEB 8 2013

...HIGH WIND WARNING IN EFFECT FROM 6 AM TO 4 PM AKST SATURDAY
THROUGH PORTAGE VALLEY AND EASTERN TURNAGAIN ARM...

THE NATIONAL WEATHER SERVICE IN ANCHORAGE HAS ISSUED A HIGH WIND
WARNING...WHICH IS IN EFFECT FROM 6 AM TO 4 PM AKST SATURDAY. THE
HIGH WIND WATCH IS NO LONGER IN EFFECT. 

* LOCATION...PORTAGE VALLEY AND TURNAGAIN ARM.

* WIND...SOUTHEAST 50 TO 65 MPH WITH GUSTS TO 85 MPH.

* TIMING...WINDS WILL INCREASE SATURDAY MORNING AND CONTINUE
  THROUGH THE AFTERNOON. WINDS WILL DIMINISH BY LATE SATURDAY AFTERNOON.

* IMPACTS...TRAVEL MAY BE DIFFICULT. 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
100 PM AKST THU FEB 7 2013

.ANALYSIS AND UPPER LEVELS...A HIGH AMPLITUDE TROUGH IS CENTERED
OVER THE BERING SEA WITH A SHORT-WAVE RIDGE DOWNSTREAM FROM THE
NORTHEAST PACIFIC UP TO SOUTHCENTRAL. A 100+ KT JET STREAK IS
TRACKING NORTHEASTWARD ALONG THE EAST SIDE OF THE TROUGH ACROSS
THE WESTERN GULF. DYNAMIC FORCING ASSOCIATED WITH THIS JET STREAK
ALONG WITH SHORT-WAVES EMBEDDED WITHIN THE FLOW ARE PRODUCING
WIDESPREAD PRECIPITATION ACROSS SOUTHCENTRAL ALASKA THIS MORNING.
AT THE SURFACE A TRIPLE POINT LOW HAS DEVELOPED NEAR KODIAK ISLAND
AND IS TRACKING NORTHEASTWARD. STRONG EASTERLY FLOW OUT AHEAD OF
THIS IS CAUSING SOME DOWNSLOPE DRYING IN THE LEE OF THE CHUGACH
AND KENAI MOUNTAINS...BUT SOUTHERLY FLOW ALOFT IS STILL PRODUCING
SOME LIGHT SNOW IN THESE AREAS. OUT WEST A VERTICALLY STACKED LOW
CONTINUES TO SLOWLY WEAKEN SOUTH OF THE ALEUTIAN CHAIN. AN OCCLUDED
FRONT IS NEARLY STATIONARY FROM NORTHWEST OF THIS LOW CENTER TO THE
SOUTHWEST ALASKA COAST. THE EASTERN PORTION OF THE FRONT HAS LOST '
ITS DEFINITION THANKS TO DEVELOPMENT OF WEAK LOWS NEAR THE PRIBILOF
ISLANDS AND IN BRISTOL BAY. THEREFORE...PRECIP HAS BECOME LESS
ORGANIZED ACROSS THE REGION.

.MODEL DISCUSSION...MODELS HAVE STRUGGLED WITH TRACK OF TRIPLE
POINT LOW IN THE NORTHWEST GULF THIS AFTERNOON AND EVENING. LATEST
SOLUTIONS INDICATE THE ENERGY WILL BE SPLIT ON EITHER SIDE OF THE
KENAI MOUNTAINS. THIS COMBINED WITH STRENGTH OF VERTICAL MOTION
AND PRESENCE OF SOUTHERLY FLOW ALOFT MEANS THAT SNOWFALL IS MORE
FAVORABLE ON THE LEE SIDE OF THE CHUGACH AND KENAI MOUNTAINS...FROM
THE WESTERN KENAI TO ANCHORAGE AND THE MAT VALLEY.

MODELS ARE IN VERY GOOD AGREEMENT WITH EVOLUTION OF SYNOPTIC SCALE
FEATURES AS WE HEAD THROUGH THE WEEKEND. WHERE THERE ARE MINOR
POSITION OR TIMING DIFFERENCES PREFER THE ECMWF/NAM SOLUTIONS WHICH
LINE UP VERY CLOSELY.

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...AS TRIPLE POINT LOW MOVES TO PRINCE WILLIAM
SOUND LATE THIS AFTERNOON THROUGH EARLY EVENING DOWNSLOPING WINDS
WILL WEAKEN. MEANWHILE A STRONG SHORT-WAVE WITH ACCOMPANYING UPPER
LEVEL JET STREAK WILL CROSS SOUTHCENTRAL. EXPECT SNOW TO BECOME
MORE WIDESPREAD AND HEAVIER AS WE HEAD INTO THE LATE AFTERNOON
HOURS. AREAS IN UPSLOPE FLOW...PRIMARILY THE EASTERN SUSITNA VALLEY
AND EASTERN PRINCE WILLIAM SOUND WILL SEE THE HEAVIEST SNOWFALL.
THIS STORM SYSTEM WILL EXIT TO THE NORTH AND EAST LATE TONIGHT
THROUGH EARLY MORNING BRINGING AN END TO MOST OF THE SNOW. HOWEVER
AREAS OF LIGHT SNOW WILL LINGER ALONG THE WESTERN SLOPES OF THE
MOUNTAINS THROUGH FRIDAY AFTERNOON AS WEAK UPPER LEVEL WAVES CONTINUE
TO MOVE THROUGH.

THERE WILL BE A BRIIF BREAK BEFORE THE NEXT MAJOR STORM MOVES IN
FRIDAY NIGHT. THIS STORM WILL BE CHARACTERIZED BY A DEEP LOW TRACKING
TO THE WEST ACROSS SOUTHWEST ALASKA. THIS TYPE OF TRACK MEANS THE
OBSERVED WEATHER WILL BE VERY DIFFERENT THAN TODAYS SYSTEM. MUCH
WARMER AIR WILL ADVECT NORTHWARD ACROSS THE GULF AND CHANGE PRECIP
TO RAIN ALONG THE COAST. THIS STORM TRACK IS ALSO VERY FAVORABLE FOR
VERY STRONG DOWNSLOPE WINDS. THUS...AS WE GET CLOSER TO THE EVENT
WILL NEED TO CONSIDER POSSIBILITY OF HIGH WIND WARNING FOR TURNAGAIN
ARM AND WHETHER ANY PRECIP ADVISORIES OR WARNINGS WILL BE NEEDED FOR
THE EASTERN SIDE OF MOUNTAINS. BOTTOM LINE FOR THIS STORM IS THE
POPULATION CENTERS WILL STAY MOSTLY DRY THANKS TO STRONG DOWNSLOPE
WINDS WHILE UPSLOPE AREAS WILL SEE HEAVY PRECIPITATION.

SOUTHWEST ALASKA...WEAK UPPER LEVEL WAVES WILL CONTINUE TO PRODUCE
AREAS OF LIGHT PRECIP ACROSS SOUTHWEST ALASKA TONIGHT. WITH GENERALLY
LIGHT FLOW ACROSS THE REGION AND VERY MOIST LOW LEVELS LOW CLOUDS
AND FOG WILL ALSO PERSIST. LOW VISIBILITIES IN BLOWING SNOW HAVE
BEEN VERY PERISTENT ALONG THE NORTHWEST KUSKOKWIM DELTA COAST.
THERE WILL BE SOME IMPROVEMENT AS WINDS DIMINISH THIS AFTERNOON AND
EVENING. HOWEVER...WINDS WILL INCREASE AGAIN ON FRIDAY AS ANOTHER
UPPER LEVEL WAVE ARRIVES. CONDITIONS WILL LIKELY BECOME MUCH WORSE
FRIDAY NIGHT AND SATURDAY AS SNOWFALL OUT AHEAD OF A STRONG PACIFIC
STORM ARRIVES...WINDS STRENGTHEN...AND TEMPERATURES FALL. PLAN TO
ISSUE A BLIZZARD WATCH FOR THE KUSKOKWIM DELTA COAST TO HIGHLIGHT
WHEN THE WORST CONDITIONS ARE LIKELY...BUT WILL ALSO MENTION THE
DETERIORATING CONDITIONS DURING THE DAY FRIDAY. THERE IS ALSO
POTENTIAL FOR BLIZZARD CONDITIONS WHEN THIS STORM FIRST ARRIVES IN
BRISTOL BAY FRIDAY NIGHT...MAINLY FOR AREAS NORTH AND WEST OF KING
SALMON WHERE WINDS WILL BE STRONGEST. THE FRONT WILL MOVE QUICKLY
THROUGH...SO EXPECT A FAIRLY SHORT DURATION OF MODERATE TO HEAVY
SNOW AND STRONG WINDS (ON THE ORDER OF 4 TO 6 HOURS). WARM AIR
BEHIND THE FRONT WILL END THE BLIZZARD THREAT AND CAUSE A TRANSITION
TO A MIX OF PRECIP TYPES OR TO ALL RAIN DURING THE DAY SATURDAY.
ARCTIC AIR WILL RAPIDLY MOVE BACK IN ON SUNDAY AS THIS SYSTEM EXITS
TO THE NORTH WHICH WILL AID IN DRYING THIS OUT.

BERING SEA/ALEUTIANS...THE LOW SOUTH OF THE ALEUTIANS WILL CONTINUE
TO SLOWLY TRACK TO THE EAST-SOUTHEAST AND THEN MERGE WITH THE
DEVELOPING PACIFIC SYSTEM ON FRIDAY. ARCTIC AIR WILL SPREAD BACK
SOUTH AND EAST BEHIND THE ALEUTIAN LOW. HOWEVER...COLD ADVECTION
WILL KICK INTO A HIGHER GEAR ACROSS THE EBRING SEA ON FRIDAY NIGHT
AND SATURDAY AS PACIFIC STORM TRACKS TO SOUTHWEST ALASKA AND AN
UPPER LEVEL LOW DROPS OUT OF THE ARCTIC. THIS WILL SET UP BLIZZARD
POTENTIAL FOR THE PRIBILOF ISLANDS BEGINNING FRIDAY AFTERNOON AND
LATER ON THIS WEEKEND FOR THE ALASKA PENINSULA. FOR NOW WILL ONLY
ISSUE A WATCH FOR THE PRIBILOFS.

.LONG TERM FORECAST...UPPER LEVEL FLOW WILL REMAIN PROGRESSIVE.
IT LOOKS LIKE THERE MAY BE A A FEW DAYS BREAK FROM ANY MAJOR STORM
SYSTEM EARLY NEXT WEEK BEFORE ANOTHER STRONG LOW ARRIVES THE MIDDLE
TO LATE PART OF NEXT WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WATCH 155 161 195.
MARINE...STORM WARNING...120 130.
         GALE WARNING...125 132 136 137 138 140 141 150 155 160 165
                        170 172 175 176 179 180 185.
FIRE WEATHER...NONE.

SEB FEB 13