Gale Warning 780, NWS Anchorage, AK

889 
FZAK61 PAFC 190027
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
327 PM AKST THU DEC 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.

PKZ399-191230-
327 PM AKST THU DEC 18 2014
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A LARGE AND BROAD 971 MB LOW WILL REMAIN NEAR 54N 146W THROUGH
SUNDAY WITH NUMEROUS FRONTS TRACKING INTO THE NORTH GULF COAST
THROUGH THE PERIOD.

$$

PKZ351-191230-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W
327 PM AKST THU DEC 18 2014

...GALE WARNING THROUGH FRIDAY NIGHT...

.TONIGHT...E WIND 40 KT. SEAS 23 FT. RAIN.
.FRI...E WIND 35 KT. SEAS 16 FT. RAIN.
.FRI NIGHT...E WIND 20 TO 35 KT. SEAS 15 FT. RAIN.
.SAT...E WIND 25 KT. SEAS 13 FT. 
.SAT NIGHT...S WIND 20 KT. SEAS 12 FT. 
.SUN...S WIND 20 KT. SEAS 14 FT. 
.MON...SW WIND 15 KT. SEAS 12 FT. 
.TUE...W WIND 20 KT. SEAS 9 FT.  

$$

PKZ352-191230-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W
327 PM AKST THU DEC 18 2014

...GALE WARNING TONIGHT...

.TONIGHT...E WIND 20 TO 35 KT. SEAS 22 FT. RAIN.
.FRI...SE WIND 15 TO 30 KT. SEAS 16 FT. RAIN.
.FRI NIGHT...SE WIND 20 KT. SEAS 12 FT. 
.SAT...SE WIND 15 KT. SEAS 11 FT. 
.SAT NIGHT...SW WIND 25 KT. SEAS 14 FT. 
.SUN...SW WIND 25 KT. SEAS 15 FT. 
.MON...W WIND 25 KT. SEAS 15 FT. 
.TUE...W WIND 25 KT. SEAS 10 FT.  

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
336 PM AKST WED DEC 17 2014

.ANALYSIS AND UPPER LEVELS...
THERE IS AN UPPER LEVEL LOW IN THE SOUTHWEST GULF OF ALASKA. THERE
IS ANOTHER LOW OVER THE NORTHERN BERING SEA. THERE IS A LOW
CENTERED SOUTH OF THE KAMCHATKA PENINSULA...AND ASSOCIATED WITH IT
IS A 200 KT JET AT AROUND 35 TO 40 DEGREES NORTH LATITUDE POKING
INTO THE MID PACIFIC (AROUND 170 DEGREES EAST LONGITUDE). THERE IS
AN UPPER LEVEL RIDGE BEGINNING TO BUILD OVER SOUTHERN ALASKA.

&&

.MODEL DISCUSSION...
THE NUMERICAL MODELS ARE NOT IN VERY GOOD AGREEMENT TODAY. THEY
QUICKLY BEGIN TO DIVERGE ON SOLUTIONS FOR A COMPLEX LOW SOUTH OF
THE ALEUTIANS (24 TO 36 HOURS INTO THE FORECAST) AND ALSO WITH THE
LOW IN THE GULF OF ALASKA AS IT BECOMES COMPLEX. SOME OF THE
MODELS STRUGGLES PROBABLY ARE RELATED TO THE 200 KT JET...WHERE
SMALL PERTURBATIONS IN THE FLOW CAN QUICKLY DEVELOP INTO LARGE
DIFFERENCES. THEREFORE FORECAST CONFIDENCE IS BELOW NORMAL TODAY.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 THROUGH 3)...
THERE IS A WEAK FRONT OVER SOUTH CENTRAL ALASKA THAT WILL
DISSIPATE TONIGHT AS RIDGING BUILDS AHEAD OF THE LOW APPROACHING
FROM THE SOUTHWEST. THIS LOW (CURRENTLY OVER THE SOUTHWEST GULF)
WILL PUSH EAST INTO THE SOUTH CENTRAL GULF TONIGHT...TURN
NORTHWARD ON THURSDAY...THEN PUSH WESTWARD TO THE WESTERN
GULF/ALASKA PENINSULA WHERE IT WILL SETTLE IN THROUGH SATURDAY. A
STRONG FRONT ASSOCIATED WITH THIS LOW WILL PUSH INTO THE NORTH
GULF TONIGHT THEN STALL OFF THE GULF COAST. THIS IS WHERE THE
MODELS BEGIN TO DISAGREE...BUT ESSENTIALLY A TRIPLE POINT LOW WILL
FORM ON THE FRONT THURSDAY NIGHT THEN MOVE NORTHWARD THROUGH
FRIDAY. FOR FRIDAY NIGHT AND SATURDAY...VARIOUS SURFACE LOW
CENTERS WILL BE SPINNING AROUND THE MAIN UPPER LOW.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
THE REMAINDER OF TODAY WILL BE FAIRLY QUIET ACROSS THE MAINLAND AS
THE AREA REMAINS BETWEEN WEATHER SYSTEMS. HIGHER CLOUDS WILL
CONTINUE TO STREAM OVERHEAD FROM THE SOUTH TONIGHT AS A FRONTAL
BOUNDARY SWINGS UP TOWARD THE ALASKA PENINSULA ASSOCIATED WITH A
LOW PRESSURE SYSTEM IN THE NORTH PACIFIC. SOME WEAK DISTURBANCES
IN THE FLOW COULD BRING AREAS OF RAIN MIXED WITH SNOW TO MAINLY
SOUTHERN AREAS OF INTERIOR BRISTOL BAY ALONG WITH NORTHERLY WINDS
OF 10 TO 20 MPH. TEMPERATURES WILL CONTINUE TO RUN ABOVE NORMAL
WITHOUT A DEEP ARCTIC AIR MASS IN THE INTERIOR. THE PATTERN HOLDS
THROUGH FRIDAY WITH ANY POTENTIAL PRECIPITATION CHANCES STAYING
IN INTERIOR BRISTOL BAY.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE BERING SEA ALSO CURRENTLY SITS BETWEEN THREE SYSTEMS. A
FRONTAL BOUNDARY CLOSE TO THE ALASKA PENINSULA WILL KEEP RAIN
SHOWERS IN THE FORECAST...BUT CLOUD COVER SHOULD BE ON THE
DECREASE TONIGHT. MOST OF THE BERING SEA SITS UNDER AN UNSTABLE
SHOWERY REGIME LEFT OVER BY THE LAST SYSTEM. THESE CONDITIONS
WILL TAPER TONIGHT AS A NEW FRONT FORMS SOUTH OF THE CHAIN
BRINGING AN INCREASE IN EASTERLY WINDS AND SNOW.

&&

.LONG TERM FORECAST (DAYS 4 THROUGH 7)...
THE MAIN STORY IS THAT THE UPPER LEVEL PATTERN WILL BECOME MORE
PROGRESSIVE NEXT WEEK. THE LOW OVER THE WESTERN GULF/ALASKA
PENINSULA WILL BE PUSHED EASTWARD ON SUNDAY AND MONDAY AS A LARGE
UPPER LOW DEVELOPS OVER THE WESTERN BERING SEA. STRONG WESTERLY
FLOW ALOFT WILL PROGRESSIVELY PUSH EAST UNTIL ALL OF THE BERING
SEA AND SOUTHERN ALASKA ARE INVOLVED BY WEDNESDAY NIGHT. THE WPC
FORECAST FAVORS THE 00Z ECMWF AND 00Z ECMWF ENSEMBLE MEAN...WITH
SOME 12Z GFS SPRINKLED IN.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALES...119 120 127 130-132 138 139 150 175-178
FIRE WEATHER...NONE.

&&