Gale Warning 505, NWS Anchorage, AK

416 
FZAK61 PAFC 182341
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
341 PM AKDT THU SEP 18 2014

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.

PKZ399-191500-
341 PM AKDT THU SEP 18 2014
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 974 MB LOW NEAR 57N 144W WILL MOVE ONSHORE NEAR 61N 147W FRI
AFTERNOON AND WEAKEN THROUGH SAT AS IT CONTINUES INLAND.

$$

PKZ351-191500-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W-
341 PM AKDT THU SEP 18 2014

...GALE WARNING TONIGHT...

.TONIGHT...W WIND 20 TO 35 KT. SEAS 8 TO 14 FT.
.FRI...SW WIND 15 TO 30 KT. SEAS 8 TO 14 FT. RAIN.
.FRI NIGHT...SW WIND 15 KT. SEAS 7 TO 10 FT.
.SAT...S WIND 10 KT. SEAS 6 FT.
.SAT NIGHT...SE WIND UP TO 10 KT. SEAS 3 TO 6 FT.
.SUN THROUGH TUE...E WIND UP TO 20 KT. SEAS 4 TO 9 FT.

$$

PKZ352-191500-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W-
341 PM AKDT THU SEP 18 2014

...GALE WARNING TONIGHT...

.TONIGHT...W WIND 20 TO 35 KT. SEAS 11 TO 17 FT. RAIN.
.FRI...SW WIND 25 KT DIMINISHING TO 15 KT IN THE AFTERNOON. SEAS
9 TO 14 FT.
.FRI NIGHT...SW WIND 10 TO 15 KT. SEAS 7 TO 10 FT.
.SAT...SW WIND UP TO 15 KT. SEAS 6 FT.
.SAT NIGHT...E WIND UP TO 10 KT. SEAS 4 FT.
.SUN THROUGH TUE...E WIND UP TO 20 KT. SEAS 4 TO 9 FT.

$$

138 
FZAK61 PAFC 191140
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
340 AM AKDT FRI SEP 19 2014

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.

PKZ399-200115-
340 AM AKDT FRI SEP 19 2014
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A 981 MB LOW NEAR 59N 147W WILL MOVE ONSHORE NEAR 60N 148W FRI
AFTERNOON AND WEAKEN THROUGH SAT AS IT CONTINUES INLAND. WEAK 
HIGH PRESSURE WILL BUILD ALONG THE NORTH GULF COAST THROUGH 
LATE SAT NIGHT.

$$

PKZ351-200115-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W-
340 AM AKDT FRI SEP 19 2014

.TODAY...SW WIND 20 TO 30 KT. SEAS 9 TO 14 FT. RAIN.
.TONIGHT...SW WIND 20 KT. SEAS 6 TO 11 FT.
.SAT...SW WIND 15 KT. SEAS 7 FT.
.SAT NIGHT...SE WIND UP TO 15 KT. SEAS 3 TO 7 FT.
.SUN...N WIND 25 TO 40 KT. SEAS 5 TO 10 FT.
.MON THROUGH TUE...E WIND 25 TO 40 KT. SEAS 4 TO 9 FT.

$$

PKZ352-200115-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W-
340 AM AKDT FRI SEP 19 2014

.TODAY...SW WIND 15 TO 25 KT. SEAS 9 TO 14 FT.
.TONIGHT...SW WIND 10 TO 20 KT. SEAS 7 TO 10 FT.
.SAT...SW WIND 10 TO 15 KT. SEAS 7 FT.
.SAT NIGHT...E WIND UP TO 20 KT. SEAS 4 TO 7 FT.
.SUN...N WIND 25 TO 40 KT. SEAS 6 TO 11 FT.
.MON...SW WIND 20 TO 35 KT. SEAS 6 TO 11 FT.
.TUE...E WIND UP TO 10 KT. SEAS 3 TO 5 FT.

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
145 PM AKDT WED SEP 17 2014

.ANALYSIS AND UPPER LEVELS...
THE UPPER LEVEL PATTERN HAS A LONG WAVE TROUGH THAT EXTENDS OUT OF
THE ARCTIC AND DOWN THE WESTERN COAST OF ALASKA AND INTO THE
EASTERN BERING SEA. WEST OF THIS TROUGH THERE IS A LARGE UPPER
LEVEL RIDGE THAT IS BUILDING OVER THE KAMCHATKA PENINSULA. THIS
RIDGE WILL MOVE EASTWARD OVER THE NEXT FEW DAYS.
SOUTHCENTRAL ALASKA IS UNDER THE SOUTHWEST FLOW ALOFT AHEAD OF THE
LONGWAVE TROUGH.
THE JET STREAM IS CURRENTLY RUNNING SOUTH OF THE ALEUTIAN ISLANDS
AROUND 45N LATITUDE.
AT THE SURFACE THERE ARE TWO DISTINCT LOWS THAT WILL BE OF NOTE
FOR SOUTHERN ALASKA. THE FIRST IS SITUATED ALONG THE COAST OF EASTERN
BRISTOL BAY. THE SECOND IS SOUTH OF THE ALASKA PENINSULA AND
MOVING TO THE NORTHEAST. THIS SECOND LOW WILL ABSORB THE LOW IN
BRISTOL BAY AND STRENGTHEN AS IT MOVES INTO THE GULF OF ALASKA
TOMORROW.
&&

.MODEL DISCUSSION...
MODELS ARE IN VERY GOOD SYNOPTIC AGREEMENT THROUGH THE REST OF
THE WEEK. THE BIGGEST PROBLEM TO RESOLVE WITH THE MODELS IS THE
BEHAVIOR OF THE LOW THAT IS STRENGTHENING AS IT MOVES INTO THE
GULF OF ALASKA TOMORROW. THE NAM AND EC SHOW A COMPLEX LOW WITH
TWO DISTINCT CENTERS WITH THE GFS CONSOLIDATING THE ENERGY INTO A
SINGLE CENTER. THE MOST LIKELY SCENARIO IS THAT THERE WILL BE TWO
CENTERS BUT THIS ALSO WILL MAKE THE LOWS TRACK AFTER THAT A LITTLE
LESS CERTAIN AS THE MODELS USUALLY HAVE AN EASIER TIME WITH A
SINGLE CENTER LOW.

&&

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...
THE FRONT ASSOCIATED WITH THE LOW IN BRISTOL BAY IS MAKING IT WAY
THROUGH SOUTHCENTRAL ALASKA THIS AFTERNOON AND EVENING. THIS IS
BRINGING MORE WIDESPREAD RAIN...ESPECIALLY IN COASTAL AREAS.
THE TYPICAL DOWNSLOPE AREAS SUCH AS ANCHORAGE AND THE COPPER RIVER
BASIN HAVE SEEN LIMITED RAINFALL DUE TO THE DOWNSLOPE PROCESS.
HOWEVER THIS WILL DECREASE THIS EVENING AND STEADY RAINFALL WILL
DEVELOP OVERNIGHT IN THESE AREAS AS WELL.

SOUTHWEST ALASKA...
THE LOW IN EASTERN BRISTOL BAY HAS MADE THE ATMOSPHERE VERY
UNSTABLE IN THAT REGION WITH HEAVY SHOWERS ROTATING AROUND THIS
LOW. THESE SHOWERS WILL DIMINISH IN COVERAGE AND INTENSITY
OVERNIGHT AS THE LOW WEAKENS AND IS ABSORBED INTO THE LOW MOVING
INTO THE GULF OF ALASKA.
FOG MAY BECOME AN ISSUE OVERNIGHT INTO TOMORROW MORNING ACROSS THE
BRISTOL BAY REGION AS THE RAINFALL HAS SATURATED THE AIR ACROSS
THE ARE AND THE LONGER NIGHTS MAY BE ENOUGH TO PRODUCE AREA OF
FOG.
THESE MAY BE SOME FOG IN THE KUSKOKWIM DELTA AREA TONIGHT BUT THIS
IS LESS LIKELY THAN IN BRISTOL BAY AS THE AMOUNT OF FOG OVER THE
NORTHEAST BERING SEA IS LIMITED. THIS IS THE TYPE OF SITUATION
WHERE THE FOG WILL NEED TO FORM OVER THE BERING SEA AND THEN MOVE
ON SHORE OVER THE AREA FROM THERE.

BERING SEA/ALEUTIANS...
THE BERING SEA HAS A BIT OF SHOWERS OVER IT WHICH IS ALLOWING SOME
BREAKS IN THE CLOUDS...ESPECIALLY TO THE WEST. THE ALASKA
PENINSULA AND ALEUTIANS ARE IN THE NORTHWEST WINDS AROUND THE LOW
AND THIS IS BRINGING QUITE A BIT OF SHOWER ACTIVITY AS WELL AS
GUSTY WINDS. WHILE THE SHOWERS WILL SLOWLY DIMINISH OVER THE
COURSE OF THE NIGHT AND INTO TOMORROW THE BREEZY CONDITIONS WILL
PERSIST.

&&

.LONG TERM FORECAST...
BEGINNING THE EXTENDED PERIOD ON SUNDAY...THE UPPER AIR PATTERN
WILL CONSIST OF A BLOCKING HIGH OVER THE BERING AND A SPLIT TROUGH
OVER ALASKA AND THE GULF OF ALASKA. A SHARP NORTH AMERICAN RIDGE
WILL TRACK A SUBTROPICAL FRONT NORTHWARD INTO THE GULF LATE SUNDAY
INTO MONDAY. THE EXACT TRACK REMAINS UNCERTAIN...WITH MORE BULLISH
SCENARIOS FROM THE ECMWF AND CANADIAN GDPS FAVORING DEEP AND
STRONG LOW LIFTING INTO THE NORTHERN GULF COAST...WHILE THE GFS
FAVORS AN EASTWARD TRACK ALONG THE ALASKA/CANADA BORDER. THE
CURRENT FORECAST FAVORS A LESS AGGRESSIVE GFS/WPC APPROACH GIVEN
LARGE TRACK AND STRENGTH VARIABILITY AMONG THE DETERMINISTIC AND
ENSEMBLE GUIDANCE. WITH THAT SAID...PRECIPITATION CHANCES WILL
REMAIN THROUGH WEDNESDAY AS ALASKA REMAINS IN BETWEEN TWO LARGE
HIGH PRESSURE CENTERS ACROSS THE BERING AND WESTERN NORTH AMERICA.
NO SIGNIFICANT WET OR COLD PATTERNS ARE EXPECTED THROUGH THE
EXTENDED PERIOD.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE 119 125.
FIRE WEATHER...NONE.
&&

SEP 14