Gale Warning 312, NWS Anchorage, AK

822 
FZAK61 PAFC 111155
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
355 AM AKDT MON APR 11 2016

OFFSHORE WATERS FORECAST FOR THE GULF OF ALASKA WEST OF 144W

WIND FORECASTS REFLECT THE PREDOMINANT SPEED AND DIRECTION
EXPECTED. SEA FORECASTS REPRESENT AN AVERAGE OF THE HIGHEST
ONE-THIRD OF THE COMBINED WIND WAVE AND SWELL HEIGHT.

PKZ399-120115-
355 AM AKDT MON APR 11 2016
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A FRONT MOVES INTO THE SOUTHERN GULF THIS MORNING AND DRIFTS INTO
THE CENTRAL GULF LATE TONIGHT...THEN DISSIPATES TUE MORNING. A
987 MB NORTH PACIFIC LOW TUE MORNING MOVES TO 55N 143W AT 993 MB
LATE TUE NIGHT.

$$

PKZ351-120115-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W-
355 AM AKDT MON APR 11 2016

.TODAY...E WIND 15 TO 30 KT. SEAS 9 FT.
.TONIGHT...E WIND 30 KT. SEAS 8 TO 13 FT. RAIN.
.TUE...E WIND 25 KT. SEAS 12 FT.
.TUE NIGHT...NE WIND 15 TO 25 KT. SEAS 7 TO 11 FT.
.WED...E WIND 10 TO 20 KT. SEAS 6 TO 10 FT.
.THU THROUGH FRI...SE WIND 15 TO 25 KT. SEAS 6 TO 9 FT.

$$

PKZ352-120115-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W-
355 AM AKDT MON APR 11 2016

...GALE WARNING THROUGH TONIGHT...

.TODAY...E WIND 20 TO 35 KT. SEAS 9 TO 14 FT.
.TONIGHT...E WIND 20 TO 35 KT. SEAS 13 FT. RAIN.
.TUE...NE WIND 10 TO 25 KT. SEAS 12 FT. RAIN.
.TUE NIGHT...N WIND 10 TO 20 KT. SEAS 10 FT.
.WED...NE WIND UP TO 15 KT. SEAS 6 TO 10 FT.
.THU THROUGH FRI...SE WIND 10 TO 20 KT. SEAS 7 TO 12 FT.

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
529 AM AKDT SUN APR 10 2016

.ANALYSIS AND UPPER LEVELS...

AN AREA OF LOW PRESSURE HAS CONTINUED TO MOVE ALONG THE SOUTHWEST
COAST OF ALASKA OVERNIGHT AND IS NOW CURRENTLY SITUATED JUST TO
THE NORTH OF NUNIVAK ISLAND. AS THIS LOW TRACKED ALONG THE WESTERN
COAST...DECENT PRESSURE RISES BEHIND THE LOW ALLOWED FOR GUSTY
WINDS TO CONTINUE INTO THE OVERNIGHT HOURS. SOME LOCATIONS HAVE
SHOWN SIGNS OF WEAKENING WINDS WHICH IS LIKELY ATTRIBUTED TO
DECOUPLING OF THE BOUNDARY LAYER AS THE SFC LAYER BEGINS TO COOL.
PRESSURE CONTINUES TO RISE IN THE WAKE OF THIS LOW WHICH SHOULD
ALLOW ANOTHER PERIOD OF GUSTY WINDS TO DEVELOP AGAIN BY LATE
MORNING ACROSS MUCH OF SOUTHWEST ALASKA. RAIN SHOWERS HAVE
REMAINED QUITE SCATTERED DURING THE OVERNIGHT HOURS AS MUCH OF
THE FORCING REMAIN OVER THE BERING SEA. LOOKING AT THE BIG
PICTURE...A BROAD AREA OF LOW PRESSURE ENCOMPASSES MUCH OF THE
BERING SEA THIS MORNING...LEADING TO SOME GAP WINDS ALONG THE
ALEUTIAN ISLANDS AND SOME RAIN SHOWERS. OVERALL THOUGH...THE
WEATHER HAS BEEN PRETTY QUIET WITHOUT ANY SIGNIFICANT STORM
SYSTEMS PASSING THROUGH THE AREA. THERE IS ONE DECENT LOW CENTERED
NEAR 46N 167W THIS MORNING BUT SHOULD MAINTAIN A ZONAL MOVEMENT
AND PASS HARMLESSLY SOUTH OF ANCHORAGE.

SOUTHCENTRAL ALASKA CONTINUES TO FEEL THE EFFECTS OF THE FRONTAL
BOUNDARY ATTACHED TO THE LOW NEAR NUNIVAK ISLANDS. CROSS BARRIER
FLOW OVER THE KENAI AND CHUGACH MOUNTAINS HAS KEPT THE WESTERN
HALF OF THE KENAI PENINSULA...ANCHORAGE AND THE MATANUSKA VALLEY
ON THE DRY SIDE. THE PAST SEVERAL RAOBS OF PANC SHOW THE DRY LAYER
ASSOCIATED WITH THE DOWNSLOPING WINDS. RAIN SHOWERS HAVE BEEN
UPSLOPING ALONG THE COASTAL RANGE THROUGH THE OVERNIGHT HOURS WITH
SOME LOCATIONS SEEING PERIODS OF HEAVY RAINFALL. THE COASTAL RIDGE
HAS REMAINED WELL ENTRENCHED WHICH HAS ALLOWED GUSTY GAP WINDS TO
CONTINUE THROUGH THIS MORNING.

&&

.MODEL DISCUSSION...

MODELS HAVE ACTUALLY BEEN DOING QUITE A GOOD JOB TRACKING THE LOW
NEAR NUNIVAK ISLAND FRIDAY AND SATURDAY. BY LOOKING AT SATELLITE
OBSERVATIONS...RADAR DATA AND SFC OBSERVATIONS...IT LOOKS LIKE
THE 00Z AND 06Z MODELS HAD PRETTY GOOD INITIALIZATION. THE
FORECAST PACKAGE WILL UTILIZE THE NAM FOR THE MAJORITY OF THE
UPDATES IN THE SHORT TERM DUE TO THE HIGHER RESOLUTION AS MODELS
REMAIN IN GOOD AGREEMENT.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...

THE LATEST SATELLITE IMAGERY INDICATES THAT THE COASTAL FRONT IS
STILL TAPPING INTO A RICH MOISTURE SUPPLY FROM THE NORTH
PACIFIC...BUT IS WEAKENING AS IT PUSHES TOWARDS THE COAST.
RAINFALL IS EXPECTED TO PERSIST THROUGHOUT THE DAY ALONG THE GULF
COAST BUT DIMINISH IN INTENSITY TOWARDS THIS EVENING AS THE FRONT
WEAKENS AND AN ASSOCIATED UPPER LEVEL WAVE PUSHES INLAND. CROSS
BARRIER FLOW WILL CONTINUE TO BE SUFFICIENT TO LIMIT SHOWERS
ACROSS THE ANCHORAGE BOWL...MATANUSKA VALLEY AND WESTERN KENAI
PENINSULA. WHILE WINDS ARE GUSTY THIS MORNING ACROSS TURNAGAIN
ARM...PORTAGE VALLEY AND MATANUSKA VALLEY...THEY ARE EXPECTED TO
DIMINISH THIS EVENING AS PRESSURE GRADIENTS RELAX. FOR
MONDAY...RAIN SHOWERS WILL PERSIST ALONG THE GULF COAST AS MOIST
ONSHORE FLOW CONTINUES AFTER THE FRONT DISSIPATES. DUE TO MUCH
WEAKER FORCING THE MAJORITY OF PRECIPITATION WILL BE LIMITED TO
UPSLOPE REGIONS ALONG THE COAST.

&&

.FIRE WEATHER...
THERE ARE NO SIGNIFICANT FIRE WEATHER CONCERNS OVER THE NEXT
COUPLE OF DAYS.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
COLD AIR ALOFT ASSOCIATED WITH A SHORTWAVE MOVING OVER THE
SOUTHWEST MAINLAND TODAY WILL ALLOW FOR CONVECTIVE RAIN SHOWERS TO
BECOME MORE NUMEROUS THIS AFTERNOON THROUGHOUT THE AREA. IT IS
STILL VERY EARLY IN THE CONVECTIVE SEASON HOWEVER...AND WITH LITTLE
CLEARING AHEAD OF THE SHORTWAVE AND LIMITED SOLAR HEATING...NO
THUNDER IS EXPECTED. SKIES WILL THEN PARTIALLY CLEAR BEHIND THE
SHORTWAVE TONIGHT...ALLOWING FOR THE POTENTIAL FOR PATCHY FOG
OVERNIGHT TONIGHT...ESPECIALLY FOR BRISTOL BAY AS IT
SEES ADDITIONAL LOW LEVEL MOISTURE FROM A PERIOD OF ONSHORE FLOW
THIS EVENING. WEAK RIDGING ON MONDAY WILL THEN KEEP SKIES PARTLY
SUNNY WITH JUST PASSING SHOWERS AND TEMPERATURES REMAINING ABOVE
NORMAL. A GALE FORCE FRONT WILL THEN APPROACH THE AKPEN LATE
MONDAY INTO TUESDAY...BRINGING RAIN AND GUSTY WINDS TO THE AKPEN
AND SOUTHERN BRISTOL BAY.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE PERSISTENT UPPER LEVEL TROUGH WILL REMAIN OVER THE CENTRAL
BERING INTO MONDAY...KEEPING CYCLONIC FLOW AND RAIN SHOWERS OVER
THE REGION. MOST OF THESE SHOWERS SHOULD OCCUR OVER THE WESTERN
BERING AND INTO THE PRIBILOFS WHERE COLD AIR ADVECTION IS ADDING
ADDITIONAL INSTABILITY. OTHERWISE THE WEATHER WILL REMAIN
RELATIVELY QUIET WITH WINDS REMAINING BELOW GALE FORCE UNTIL LATE
MONDAY WHEN A WEAKENING FRONT MAY BRING GALE FORCE GUSTS TO THE
EASTERN ALEUTAINS.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
WIDESPREAD PRECIPITATION ACROSS THE GULF AND ALASKA PENINSULA
WILL GRADUALLY TREND DOWNWARD THROUGH TUESDAY AS A LOW SOUTH OF
KODIAK ISLAND WEAKENS AND MOVES OFF TO THE EAST. ATTENTION THEN
TURNS TO THE NEXT LOW POISED TO APPROACH THE WESTERN ALEUTIANS
EARLY TUESDAY. MODEL AGREEMENT REGARDING THIS FEATURE HAS IMPROVED
DRAMATICALLY OVER THE PAST 24 HOURS...WITH A GENERAL CONSENSUS
THAT THE LOW WILL TRACK JUST SOUTH OF THE CHAIN AND STEADILY
WEAKEN AS IT MOVES TO A POSITION SOUTH OF THE AKPEN BY FRIDAY
AFTERNOON. THIS WILL KEEP THE MOST ACTIVE WEATHER FOCUSED ON THE
ALEUTIANS AND SOUTHERN BERING THROUGH MUCH OF THE WEEK BEFORE
EVENTUALLY SPREADING TO THE GULF LATER IN THE WEEK. THE SOUTHERN
MAINLAND WILL CONTINUE TO SEE TEMPERATURES HOVERING ABOVE SEASONAL
NORMAL VALUES AS WEAK UPPER RIDGING EXTENDS INTO THE REGION FROM
WESTERN CANADA...WITH ANY CHANCES FOR PRECIPITATION MAINLY LIMITED
TO DIURNALLY DRIVEN CONVECTIVE ACTIVITY.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE...132 150.

&&

SYNOPSIS AND MODEL DISCUSSION...MC
SOUTHCENTRAL ALASKA...EN
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...DEK
LONG TERM...CB