Gale Warning 271, NWS Juneau, AK

555 
FZAK67 PAJK 071128
OFFAJK

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE JUNEAU AK
400 AM AKDT FRI SEP 7 2012 

OFFSHORE WATERS FORECAST FOR GULF OF ALASKA EAST OF 144W

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

PKZ398-080100-
400 AM AKDT FRI SEP 7 2012 
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A GALE FORCE LOW WILL MOVE INTO THE NORTHEASTERN GULF FRI
AFTERNOON. THE LOW WILL WEAKEN AS IT MOVES OVER THE NORTHERN
PANHANDLE FRI NIGHT THEN DISSIPATE OVER THE SOUTHWESTERN YUKON
SAT MORNING. A DEVELOPING LOW IN THE WESTERN GULF SAT MORNING
WILL MOVE EASTWARD ACROSS THE CENTRAL GULF SAT NIGHT THEN INTO
THE EASTERN GULF BY SUN MORNING. 

$$

PKZ310-080100-
GULF OF ALASKA NORTH OF 55 DEGREES NORTH AND EAST OF 144 DEGREES
WEST-
400 AM AKDT FRI SEP 7 2012 

...GALE WARNING THIS MORNING...

.TODAY...SW WIND 35 KT DIMINISHING TO 25 KT IN THE AFTERNOON.
SEAS 8 FT. RAIN IN THE MORNING.
.TONIGHT...SW WIND 20 KT. SEAS 8 FT. SW SWELL. 
.SAT...S WIND 15 KT. SEAS 6 FT. SW SWELL. SHOWERS.
.SAT NIGHT...NW WIND 25 KT. SEAS 8 FT. SW SWELL. SHOWERS.
.SUN...W WIND 30 KT. SEAS 9 FT. 
.MON...S WIND 20 KT. SEAS 7 FT. 
.TUE...S WIND 20 KT. SEAS 6 FT. 

$$

732 
FZAK67 PAJK 072048 AAA
OFFAJK

OFFSHORE WATERS FORECAST...UPDATED
NATIONAL WEATHER SERVICE JUNEAU AK
1248 PM AKDT FRI SEP 7 2012

OFFSHORE WATERS FORECAST FOR GULF OF ALASKA EAST OF 144W

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

PKZ398-080100-
1248 PM AKDT FRI SEP 7 2012
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A GALE FORCE LOW WILL MOVE INTO THE NORTHEASTERN GULF FRI
AFTERNOON. THE LOW WILL WEAKEN AS IT MOVES OVER THE NORTHERN
PANHANDLE FRI NIGHT THEN DISSIPATE OVER THE SOUTHWESTERN YUKON
SAT MORNING. A DEVELOPING LOW IN THE WESTERN GULF SAT MORNING
WILL MOVE EASTWARD ACROSS THE CENTRAL GULF SAT NIGHT THEN INTO
THE EASTERN GULF BY SUN MORNING. 

$$

PKZ310-080100-
GULF OF ALASKA NORTH OF 55 DEGREES NORTH AND EAST OF 144 DEGREES
WEST-
1248 PM AKDT FRI SEP 7 2012

UPDATED

.REST OF TODAY...SW WIND 25 KT. SEAS 8 FT. 
.TONIGHT...SW WIND 20 KT. SEAS 8 FT. SW SWELL. 
.SAT...S WIND 15 KT. SEAS 6 FT. SW SWELL. SHOWERS.
.SAT NIGHT...NW WIND 25 KT. SEAS 8 FT. SW SWELL. SHOWERS.
.SUN...W WIND 30 KT. SEAS 9 FT. 
.MON...S WIND 20 KT. SEAS 7 FT. 
.TUE...S WIND 20 KT. SEAS 6 FT. 

$$

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
358 PM AKDT THU SEP 6 2012

.SHORT TERM...FROM AFTERNOON SATELLITE IMAGERY CLOUD BAND ALONG
THE BOUNDARY CAN BE SEEN FLOWING TO THE NORTHEAST RIDING OVER
HIGH PRESSURE RIDGE IN THE EASTERN GULF AND AK PANHANDLE.
SCATTERED SHOWER ACTIVITY OVER THE NORTHERN AND CENTRAL PANHANDLE
EARLY TODAY HAS DIMINISHED WITH INCREASING BREAKS IN CLOUD COVER.
EXPECTING CYCLOGENESIS ALONG THIS WAVE IN THE NORTH PACIFIC WITH
THE LOW TRACKING INTO THE AK GULF LATE THURSDAY NIGHT. THE TRACK
AND STRENGTH OF THIS LOW IS STILL IN QUESTION. THE EUROPEAN
MODELS HAVE THE LOW TRACKING INTO THE NORTHEAST GULF AND
STRENGTHENING TO GALE FORCE WHILE THE NORTH AMERICAN MODELS WERE
TRACKING A WEAKER LOW FURTHER TO THE SOUTHEAST. WHILE INITIALLY
DID NOT SEE SIGNIFICANT DIFFERENCES IN MODEL INITIALIZATION BEGAN
TO SEE GREATER CONSENSUS AMONG ENSEMBLE MEMBERS FOR THE EUROPEAN
MODEL SOLUTION. THAT SAID HAVE KEEP WITH THE GALE FORCE LOW
MOVING INTO THE GULF...BUT DID NOT GO WITH AS STRONG A LOW CENTER
AS THE OPERATIONAL ECMWF BY USING A BLEND OF THE UKMET. AS THE
LOW MOVES TOWARD THE PANHANDLE COAST EXPECT WINDS WITH INCREASE
ALONG COASTAL AREAS WITH GUSTS UPWARDS OF 35 MPH. MAY SEE HIGHER
WINDS AND GUSTS WITH A DEEPER LOW CENTER. AS THE LOW MOVES
ONSHORE WILL SEE A SOUTHERN PUSH OF WINDS SO EXPECTING THE
NORTHERN PANHANDLE AND INNER CHANNEL WINDS TO INCREASE FRIDAY
AFTERNOON.

 SCATTERED RAIN SHOWERS OVER THE NORTHERN PANHANDLE WILL
TRANSITION TO STEADY RAIN AS THE LOW DEVELOPS AND MOVES INTO THE
NORTHEAST GULF. HAVE EXTENDED PRECIP FURTHER TO THE SOUTH TO
COVER SOME UNCERTAINTY WITH THE TRACK OF THE LOW. LONG FETCH OF
TROPICAL MOISTURE SEEN IN WATER VAPOR SATELLITE WILL BEING IN
HIGHER QPF VALUES TO THE NORTHERN PANHANDLE WITH POSSIBLE HEAVY
RAIN FRIDAY AFTERNOON WITH 6 HOUR QPF VALUES OVER HALF AN INCH.
AS WITH WINDS IF THE LOW DOES TRACK FURTHER SOUTH WILL ALSO SEE A
SHIFT OF THE HIGHER QPF VALUES TO THE CENTRAL PANHANDLE.

 DUE TO EARLY MODEL SPREAD WITH POSITION OF THE LOW FRIDAY
AFTERNOON FORECAST CONFIDENCE IS BELOW AVERAGE. USED A BLEND OF
00Z ECMWF AND 12Z UKMET TO UPDATE WINDS AND PRESSURE FOR THE
SHORT TERM. USED A BLEND OF SREF AND ECMWF FOR POP AND QPF.

 &&

.LONG TERM...PER THE SHORT TERM DISCUSSION MUCH UNCERTAINTY
REMAINS IN THE STRENGTH AND TRACK OF THE LOW DEPARTING THE
NORTHEAST GULF ON FRIDAY NIGHT. THE PREFERRED SOLUTION OF THE
ECMWF AND UKMET WILL RESULT IN A SOUTHERLY PUSH AND BURST OF WINDS
LATE FRIDAY AFTERNOON INTO THE EVENING AS THE RIDGE BUILDS OVER
THE INNRE CHANNELS. WINDS WILL REACH SMALL CRAFT LEVELS IN THE
NORTHERN INNER CHANNELS WITH HIGHER GUSTS DEVELOPING IN THE
SKAGWAY AND HAINES AREAS. IF THE LOW DOES TAKE THIS TRACK...WINDS
COULD BE HIGHER THAN CURRENTLY FORECASTED. RAIN WILL CONTINUE TO
BE HEAVY AT TIMES IN THE NORTHERN PANHANDLE FRIDAY EVENING BEFORE
SHIFTING TO THE SOUTH AND EAST. SOME LOCATIONS WILL RECEIVE
0.75 TO 1.25 INCHES OF RAIN FROM FRIDAY AFTERNOON INTO THE NIGHT.
ANY SHIFT IN TRACK OF THE LOW TO THE SOUTH FROM CURRENT THINKING
WILL RESULT IN HEAVY RAINFALL AND STRONGER WINDS ACROSS THE
CENTRAL PANHANDLE.

AN UPPER LEVEL LOW WILL DROP SOUTHEAST INTO THE GULF ON SATURDAY
WITH AN ASSOCIATED SURFACE REFLECTION. MODELS HAVE ALSO HAD A HARD
TIME COMING TO A CONSENSUS ON THIS SYSTEM AND THE DEVELOPMENT OF
THE WAVE ALONG THE FRONTAL ZONE. TOOK A MIDDLE OF THE ROAD
APPROACH AND BLENDED THE WEAKER 12Z NAM AND THE STRONGER ECMWF. IT
SHOULD BE NOTED THE 18Z NAM HAS TRENDED TOWARD THE STRONGER
SOLUTION ADVERTISED BY THE ECMWF. ANOTHER FETCH OF TROPICAL
MOISTURE PICKED UP BY THIS SYSTEM WILL RESULT IN A SECOND ROUND
OF HEAVY RAINFALL ACROSS THE CENTRAL AND SOUTHERN PANHANDLE.
THIS AREA CAN ALSO EXPECT STRONG WINDS BUT AT THIS POINT THE
DETAILS ON EXACTLY WHEN AND WHERE ARE TOO HARD TO DETERMINE BASED
ON POOR MODEL CONSENSUS. AS THE FRONT PUSHES THROUGH AND THE COLD
UPPER LEVEL LOW MOVES OVERHEAD SUNDAY...STEADY RAIN WILL
TRANSITION TO SHOWERS. ANOTHER FRONT LOOKS TO MOVES ACROSS THE
GULF AND INTO SOUTHEAST ALASKA TUESDAY INTO WEDNESDAY.

USED A BLEND OF THE ECMWF/UKMET IN THE VERY EARLY PORTION OF THE
LONG TERM THROUGH 12Z SATURDAY. WITH THE NEXT APPROACHING WAVE
USED MAINLY THE ECMWF WITH A LITTLE BIT OF NAM THROWN IN. WENT
STRAIGHT HPC FROM DAY 5 ONWARD. AS NOTED ABOVE FORECASTER
CONFIDENCE THROUGH THE WHOLE PERIOD IS BELOW AVERAGE.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ043-051.
         SMALL CRAFT ADVISORY FOR PKZ011-012-021-022-033-036-041-042-052-
     053.

&&

PRB/TPS/ABJ