High Wind Watch 15, NWS Anchorage, AK

925 
WWAK71 PAFC 291402
NPWAER

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE ANCHORAGE AK
502 AM AKST MON DEC 29 2014

AKZ101-300315-
/O.UPG.PAFC.HW.A.0015.141230T0900Z-141230T2100Z/
/O.NEW.PAFC.HW.W.0019.141230T0300Z-141230T1800Z/
ANCHORAGE-
INCLUDING THE CITIES OF...ANCHORAGE...EAGLE RIVER...INDIAN...
EKLUTNA
502 AM AKST MON DEC 29 2014

...HIGH WIND WARNING IN EFFECT FROM 6 PM THIS EVENING TO 9 AM
AKST TUESDAY FOR TURNAGAIN ARM AND HIGHER ELEVATIONS...

THE NATIONAL WEATHER SERVICE IN ANCHORAGE HAS ISSUED A HIGH WIND
WARNING...WHICH IS IN EFFECT FROM 6 PM THIS EVENING TO 9 AM AKST
TUESDAY. THE HIGH WIND WATCH IS NO LONGER IN EFFECT. 

* LOCATION...TURNAGAIN ARM AND HIGHER ELEVATIONS.

* WIND...SOUTHEAST 50 TO 65 MPH WITH GUSTS TO 80 MPH.

* TIMING...WINDS WILL INCREASE TO WARNING LEVELS BY EARLY EVENING
  AND CONTINUE INTO THE MID MORNING HOURS ON TUESDAY BEFORE
  DIMINISHING.

* IMPACTS...LOOSE OBJECTS MAY BECOME PROJECTILES AND DRIVING 
  ALONG TURNAGAIN ARM WILL BE HAZARDOUS. 

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...CORRECTED
NATIONAL WEATHER SERVICE ANCHORAGE AK
522 AM AKST SUN DEC 28 2014

CORRECTION FOR ADDITION OF MARINE WARNING

.ANALYSIS AND UPPER LEVELS...
HIGH AMPLITUDE MAY NOT BE ENOUGH TO DESCRIBE THE FLOW ALOFT THIS
MORNING. THE HEIGHT PATTERN ALOFT IS ANCHORED BY A BROAD AREA OF
LOW PRESSURE CENTERED JUST EAST OF KAMCHATKA. THE EAST ASIAN JET
IS PURELY ZONAL IN THE MID-LATITUDES AS IT COMES OFF THE
CONTINENT...BUT THEN FLOWS STRAIGHT MERIDONAL FROM 40N THROUGH THE
ARCTIC BRINGING COPIOUS AMOUNTS OF MOISTURE AND WARM AIR TOWARD
THE GREAT LAND. ON THE OTHER SIDE OF THE UPPER JET A RIDGE AXIS
EXTENDS FROM THE TROPICS PRETTY MUCH THROUGH THE POLE. THE AREA
BETWEEN THESE TWO FEATURES WILL CONTAIN MUCH OF THE ACTIVE
AND UNSETTLED WEATHER THROUGH THE MIDDLE OF THE WEEK.

A FRONTAL BOUNDARY STRETCHES FROM THE WEST COAST OF ALASKA SOUTH
OVER THE ALASKA PENINSULA AND INTO THE NORTHERN PACIFIC WHERE IT
IS SIGNIFICANTLY STRONGER. CLOUD TOPS ASSOCIATED WITH THE FRONT
ARE AS COLD AS -70C FOR A WIDESPREAD AREA...OWING TO THE STRONG
FLOW OVER THE MOUNTAINS AND DEEP LAYER MOISTURE. RAIN AND SNOW
ARE SPREADING INLAND FROM THE KUSKOKWIM DELTA THROUGH INTERIOR
BRISTOL BAY AS WELL AS GUSTY SOUTHEASTERLY WINDS.

&&

.MODEL DISCUSSION...
GIVEN THE COMPLEXITY OF THE SYNOPTIC SITUATION GUIDANCE IS IN
PRETTY GOOD AGREEMENT WITH THE MAJOR PLAYERS IN THIS PATTERN. THE
BIGGEST MODEL DISCREPANCY OCCURS WHEN A SHORTWAVE TROUGH DEVELOPS
UNDER THE EAST ASIAN JET AND IMPINGES ON THE EXISTING FRONTAL
BOUNDARY. ALL OF THE GUIDANCE SUITE MOVES THE DEVELOPING SURFACE
CIRCULATION QUICKLY INTO THE EASTERN BERING SEA WITH VARYING
POSITIONS AND MAGNITUDE. WHILE THE PRECIPITATION FIELDS ARE WELL
AGREED UPON AND LESS DEPENDENT ON SURFACE LOW POSITION...THE
EXACT POSITION OF THE SURFACE CIRCULATION WILL PLAY A BIG PART IN
TIMING AND STRENGTH OF WINDS IN THE ANCHORAGE AREA MONDAY INTO
TUESDAY. THE EASTERN DOMAIN FAVORED THE NAM AND ECMWF IN THE SHORT
TERM. THE WESTERN DOMAIN PREFERRED A BLEND OF HIGHER RESOLUTION
GUIDANCE.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A SERIES OF LOW PRESSURE CENTERS DEVELOPING ALONG A BOARD
BAROCLINIC ZONE STRETCHING ACROSS THE EASTERN PACIFIC TO SW
ALASKA WILL TRACK NORTH THROUGH MON NIGHT. PRESSURE GRADIENTS WILL
STRENGTHEN ACROSS MUCH SOUTHCENTRAL/GULF WITH THE APPROACH OF
THESE FEATURES AND BRING GALES TO LOCALIZED STORMS ACROSS MARINE
AREAS ALONG WITH BRISK TO STRONG GAP FLOWS OVER LAND AREAS.
PRECIPITATION WILL GENERALLY BE RAIN OVER THE GULF/KODIAK
ISLAND(HEAVY AT TIMES). MIXED PRECIPITATION TYPES ARE LIKELY
ALONG THE COASTS AND KENAI PEN TODAY AND TONIGHT AND INTO MON.
TEMPS WILL BE SLOWER TO WARM WEST OF THE CHUGACH...SO MIXED
PRECIPITATION TYPES WILL LIKELY HOLD THROUGH MON NIGHT. RAIN AND
SNOW WILL BE GENERALLY LIGHT ACROSS THE WESTERN KENAI...ANCHORAGE
BOWL...MAT VLY THROUGH MON. THE WESTERN SUSITNA VALLEY SHOULD SEE
MEASURABLE SNOW TONIGHT AND MON WHILE THE EASTERN VALLEY WITH BE
SOMEWHAT DRIER WITH ONLY SCATTERED SHOWERS.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
EAST TO SOUTHEASTERLY FLOW OVER SOUTHWEST ALASKA CONTINUES TO
STRENGTHEN TODAY AS A SHORTWAVE TROUGH ROTATING UP THE WEST SIDE
OF THE HIGH AMPLITUDE RIDGE OVER MAINLAND ALASKA CONTINUES TO
TIGHTEN THE GRADIENT OVER THE AREA. A SURFACE LOW CROSSING THE
ALASKA PENINSULA MIDDAY AND THEN TRACKING INTO BRISTOL BAY WILL
FURTHER INCREASE WINDS THIS AFTERNOON THROUGH TONIGHT...ESPECIALLY
NEAR AND DOWN WIND OF GAPS AND PASSES IN THE ALASKA AND ALEUTIAN
RANGES. A SECOND DEEPER LOW TRACKING UP LATE MONDAY AND MONDAY
WILL CONTINUE TO INCREASE EAST TO SOUTHEAST WINDS ACROSS THE AREA.

OF ADDITIONAL CONCERN IS THE BROAD FRONTAL SYSTEM THAT WILL
REMAIN STRETCHED OVER MUCH OF THE ALASKA PENINSULA AND SOUTHWEST
ALASKA BRINGING AN ABUNDANT SUPPLY OF PRECIPITATION FOR THE NEXT
COUPLE OF DAYS. WHILE THE UPWIND SOUTHEAST FACING SLOPES WILL SEE
THE HEAVIEST AMOUNTS EVEN THE MORE SHELTERED LEE SIDE LOCATIONS
WILL RECEIVE SOME AS WELL. TEMPERATURES ARE CURRENTLY MARGINAL FOR
PRECIPITATION TO START OF AS A MIX OF WET SNOW AND RAIN IN SOME
AREAS BEFORE TURNING TO PREDOMINATELY RAIN AS WARMER AIR PUSHES
NORTH WITH THE LOW TODAY AND THEN IS MAINTAINED BY THE CONTINUING
STRONG SOUTHEASTERLY FLOW.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE TWO MAIN FEATURES OF NOTE EARLY THIS MORNING INCLUDE THE
GRADUALLY FILLING OLDER LOW SLOWLY DRIFTING NORTH ALONG 170E AND
THE STRONGER MORE TIGHTLY WRAPPED LOW SOUTH OF ATKA. THE MORE
WESTERN LOW WILL CONTINUE TO WEAKEN AS IT DRIFTS NORTH ALLOWING
THE LAST OF THE GALES IN THE WESTERN MOST MARINE AREAS TO TAPER
OFF TO SMALL CRAFT LEVEL WINDS TODAY. THE FRONT ASSOCIATED NEWER
LOW IS CURRENTLY LIFTING NORTH ACROSS THE ALEUTIANS AND INTO THE
BERING SEA IN THE VICINITY OF ADAK AND ATKA. BOTH FAIRLY RECENT
ASCAT SCATTEROMETER WINDS AND BUOY 72 ARE SHOWING SOLID GALE
FORCE WINDS ASSOCIATED WITH THIS SYSTEM WHICH WILL CONTINUE TO
LIFT NORTH INTO THE CENTRAL BERING SEA TODAY AND TONIGHT.
FOLLOWING THIS...QUIETER CONDITIONS WILL PREVAIL OUT WEST ON
MONDAY BEFORE THE NEXT STRONGER LOW LIFTS NORTH INTO BRISTOL BAY
AND THE EASTERN BERING MONDAY EVENING.

&&

.LONG TERM FORECAST (TUESDAY THROUGH SATURDAY)...

A HIGHLY AMPLIFIED FLOW PATTERN WILL BE IN PLACE BEGINNING THE
EXTENDED PERIOD TUESDAY...WITH A STRONG PACIFIC LOW MOVING INTO
THE EASTERN BERING...AND A STRONG NORTH AMERICAN RIDGE EXTENDING
THROUGH ALASKA. PRECIPITATION WILL BE WIDESPREAD ACROSS MOST OF
SOUTHERN ALASKA...WITH WARM AIR RESULTING IN MOSTLY RAIN AND RAIN
SHOWERS...WITH THE EXCEPTION OF HIGHER ELEVATION SNOW OVER HIGH
MOUNTAINS. RAIN WILL BE HEAVIEST ACROSS THE GULF COAST INTO PRINCE
WILLIAM SOUND. THE WARM FRONT WILL PUSH INLAND TUESDAY EVENING
INTO WEDNESDAY MORNING...WITH A TEMPERATURES RISING WELL ABOVE
AVERAGE ACROSS MOST INLAND LOCATIONS IN THE FORM OF A WEAK
CHINOOK. THE TROUGH WILL MOVE ACROSS ALASKA LATE WEDNESDAY AND
THURSDAY...BRINGING A BRIEF REPRIEVE TO THE AMPLIFIED RIDGE
PATTERN AND WARM TEMPERATURES. BOTH THE ECMWF AND GFS DEPICT THE
DEVELOPMENT OF UPPER LEVEL RIDGING ACROSS NORTHERN ALASKA AND THE
BEAUFORT SEA...WITH A WEAK OFFSHORE PRESSURE GRADIENT. THIS SHOULD
ALLOW FOR A DRY AND COLDER REGIME TO DEVELOP OVER SOUTHERN ALASKA
FRIDAY AND SATURDAY.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...STORMS...130 131 351 352.
GALES 119 120 125 129 132 136 137 138 139 141 150 160 173
      174 175 176 185 411 412 413.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...ML
SOUTHCENTRAL ALASKA...RMC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...JR
LONG TERM...AHSENMACHER