Gale Warning 468, NWS Anchorage, AK

711 
FZAK62 PAFC 251135
OFFALU

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 AM AKDT SUN AUG 25 2013

OFFSHORE WATERS FORECAST FOR THE BERING SEA

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.

PKZ499-260300-
400 AM AKDT SUN AUG 25 2013
.SYNOPSIS FOR CENTRAL BERING SEA...
A 989 MB LOW NEAR 61N 180 WILL MOVE TO 64N 177W THIS AFTERNOON 
AND THEN WEAKEN OVER EASTERN RUSSIA ON MON. AN ASSOCIATED FRONT WILL
WEAKEN AS IT MOVES INLAND ACROSS SOUTHWEST ALASKA TODAY. A DEVELOPING
PACIFIC LOW WILL TRACK TO  51N 171E SUN AFTERNOON AT 1000 MB AND THEN
TO 57N 162W LATE MON NIGHT.

$$

PKZ411-260300-
BERING SEA OFFSHORE WEST OF 180 AND EAST OF THE INTERNATIONAL
DATELINE
400 AM AKDT SUN AUG 25 2013

.TODAY...SW WIND 15 TO 25 KT. SEAS 6 TO 9 FT. PATCHY FOG. 
.TONIGHT...VARIABLE WIND 15 KT BECOMING NW 25 KT AFTER MIDNIGHT. SEAS
4 TO 7 FT. PATCHY FOG. 
.MON...W WIND 10 TO 20 KT. SEAS 5 TO 8 FT. PATCHY FOG. 
.MON NIGHT...W WIND 20 KT. SEAS 7 FT. 
.TUE...N WIND 20 KT. SEAS 7 FT. 
.WED...VARIABLE WIND 10 KT. SEAS 9 FT. 
.THU...SE WIND 20 KT. SEAS 12 FT.  

$$

PKZ412-260300-
BERING SEA OFFSHORE 171W TO 180 AND NORTH OF 56N
400 AM AKDT SUN AUG 25 2013

...GALE WARNING TODAY...

.TODAY...W WIND 25 TO 35 KT DECREASING TO 20 TO 30 KT IN THE
AFTERNOON. SEAS 8 TO 12 FT. AREAS OF FOG. 
.TONIGHT...W WIND 25 KT BECOMING S 15 KT AFTER MIDNIGHT. SEAS 10 FT
SUBSIDING TO 6 FT AFTER MIDNIGHT. PATCHY FOG. 
.MON...VARIABLE WIND 15 KT BECOMING NE WIND 20 KT BY NOON. SEAS 5 TO
8 FT. PATCHY FOG. 
.MON NIGHT AND TUE...W WIND 20 KT. SEAS 8 FT. 
.WED...N WIND 20 KT. SEAS 8 FT. 
.THU...N WIND 15 KT. SEAS 8 FT.  

$$

PKZ413-260300-
BERING SEA OFFSHORE 171W TO 180 AND SOUTH OF 56N
400 AM AKDT SUN AUG 25 2013

...GALE WARNING TONIGHT AND MONDAY...

.TODAY...W WIND 15 TO 25 KT. SEAS 7 TO 11 FT. PATCHY FOG. 
.TONIGHT...S WIND 25 KT INCREASING TO 35 KT AFTER MIDNIGHT. SEAS 7
BUILDING TO 14 FT AFTER MIDNIGHT. PATCHY FOG. RAIN.
.MON...SW WIND 35 KT BECOMING W IN THE AFTERNOON. SEAS 14 FT. PATCHY
FOG. 
.MON NIGHT...W WIND 25 KT. SEAS 11 FT. 
.TUE...NW WIND 15 KT. SEAS 6 FT. 
.WED...N WIND 15 KT. SEAS 5 FT. 
.THU...NE WIND 20 KT. SEAS 12 FT.  

$$

PKZ414-260300-
BERING SEA OFFSHORE EAST OF 171W
400 AM AKDT SUN AUG 25 2013

...GALE WARNING TODAY...

.TODAY...W WIND 25 TO 35 KT. SEAS 8 TO 13 FT. AREAS OF FOG. 
.TONIGHT...W WIND 25 KT BECOMING SW 15 KT AFTER MIDNIGHT. SEAS 11 FT
DIMINISHING TO 8 FT AFTER MIDNIGHT. PATCHY FOG. RAIN.
.MON...S WIND 30 KT...EXCEPT E WIND 15 KT N OF 57N. SEAS 7 TO 11 FT.
PATCHY FOG. RAIN.
.MON NIGHT...NW WIND 30 KT. SEAS 11 FT. 
.TUE...W WIND 20 KT. SEAS 9 FT. 
.WED AND THU...NW WIND 20 KT. SEAS 9 FT. 

$$

155 
FZAK62 PAFC 252344
OFFALU

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 PM AKDT SUN AUG 25 2013

OFFSHORE WATERS FORECAST FOR THE BERING SEA

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.

PKZ499-261500-
400 PM AKDT SUN AUG 25 2013
.SYNOPSIS FOR CENTRAL BERING SEA...
A 993 MB LOW NEAR 63N 178W WILL WEAKEN AS IT MOVES TO EASTERN 
RUSSIA ON MON. A 1000 MB LOW NEAR 52N 174E WILL MOVE TO 57N 168W 
MON AFTERNOON AND THEN QUICKLY EXIT TO THE NORTHEAST PACIFIC ON 
TUE. ANOTHER PACIFIC LOW WILL TRACK TO 52N 178W TUE AFTERNOON 
AT 1005 MB.

$$

PKZ411-261500-
BERING SEA OFFSHORE WEST OF 180 AND EAST OF THE INTERNATIONAL
DATELINE
400 PM AKDT SUN AUG 25 2013

.TONIGHT...VARIABLE WIND 20 KT BECOMING NW AFTER MIDNIGHT. SEAS 6 FT.
PATCHY FOG. 
.MON...W WIND 10 TO 20 KT. SEAS 7 FT. PATCHY FOG. 
.MON NIGHT...W WIND 20 KT. SEAS 6 FT. 
.TUE...N WIND 20 KT. SEAS 6 FT. 
.TUE NIGHT...N WIND 15 KT. SEAS 6 FT. 
.WED...NE WIND 20 KT. SEAS 9 FT. 
.THU...SE WIND 20 KT. SEAS 12 FT. 
.FRI...NE WIND 15 KT. SEAS 9 FT.  

$$

PKZ412-261500-
BERING SEA OFFSHORE 171W TO 180 AND NORTH OF 56N
400 PM AKDT SUN AUG 25 2013

.TONIGHT...SW WIND 15 TO 25 KT. SEAS 10 FT SUBSIDING TO 6 FT AFTER
MIDNIGHT. PATCHY FOG. 
.MON...N WIND 15 KT. SEAS 7 FT. PATCHY FOG. 
.MON NIGHT AND TUE...W WIND 20 KT. SEAS 7 FT. 
.TUE NIGHT...W WIND 15 KT. SEAS 6 FT. 
.WED...N WIND 15 KT. SEAS 6 FT. 
.THU...N WIND 15 KT. SEAS 9 FT. 
.FRI...NE WIND 15 KT. SEAS 8 FT.  

$$

PKZ413-261500-
BERING SEA OFFSHORE 171W TO 180 AND SOUTH OF 56N
400 PM AKDT SUN AUG 25 2013

...GALE WARNING THROUGH MONDAY...

.TONIGHT...S WIND 20 KT IN THE EVENING INCREASING TO 35 KT. SEAS 7 FT
BUILDING TO 11 FT AFTER MIDNIGHT. AREAS OF FOG. RAIN.
.MON...W WIND 35 KT BECOMING NW 20 KT IN THE AFTERNOON. SEAS 11 FT.
PATCHY FOG. 
.MON NIGHT...NW WIND 15 KT. SEAS 7 FT. PATCHY FOG. 
.TUE...E WIND 15 KT. SEAS 5 FT. 
.TUE NIGHT AND WED...N WIND 15 KT. SEAS 5 FT. 
.THU...NE WIND 20 KT. SEAS 12 FT. 
.FRI...N WIND 15 KT. SEAS 8 FT.  

$$

PKZ414-261500-
BERING SEA OFFSHORE EAST OF 171W
400 PM AKDT SUN AUG 25 2013

.TONIGHT...W WIND 25 KT. SEAS 10 FT. PATCHY FOG. 
.MON...S WIND 20 TO 30 KT BECOMING N 25 KT IN THE AFTERNOON. SEAS 8
FT. PATCHY FOG. RAIN.
.MON NIGHT...NW WIND 10 TO 20 KT. SEAS 8 FT. PATCHY FOG. 
.TUE AND TUE NIGHT...W WIND 15 KT. SEAS 7 FT. 
.WED...NW WIND 20 KT. SEAS 7 FT. 
.THU...NW WIND 20 KT. SEAS 9 FT.
.FRI...N WIND 15 KT. SEAS 8 FT.  

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
112 PM AKDT SAT AUG 24 2013

.ANALYSIS AND UPPER LEVELS...SATELLITE IMAGERY SHOWS A HIGHLY
AMPLIFIED BUT PROGRESSIVE PATTERN IN PLACE ACROSS THE ALASKA
REGION WITH A RIDGE CENTERED OVER THE NORTH CENTRAL PACIFIC AND
CENTRAL BERING SEA AND TROUGHS ON EITHER SIDE OF IT. THE SUBTROPICAL
JET EXITS ASIA AT 40N LATITUDE AND THEN CURVES NORTHWARD OVER THE
BERING RIDGE AND THEN DIVES SOUTHEASTWARD ACROSS SOUTHWEST ALASKA
INTO THE NORTHEAST PACIFIC. A STRONG SHORT-WAVE TRACKING INTO THE
SOUTHWEST BERING IS LEADING TO DEEPENING OF A SURFACE LOW WHICH IS
TRACKING NORTHWARD OVER THE WEST-CENTRAL BERING. A WARM FRONT IS
PROGRESSING NORTH AND EASTWARD RAPIDLY SPREADING RAIN AND FOG
ACROSS THE EASTERN BERING AND ALEUTIANS TOWARD SOUTHWEST ALASKA.

MEANWHILE...A COUPLE STRONG VORTICITY MAXIMA ARE RAPIDLY DIGGING
SOUTHEASTWARD ACROSS THE WESTERN GULF WITH A FEW WEAKER WAVES JUST
UPSTREAM. WATER VAPOR IMAGERY SHOWS STRONG SUBSIDENCE AND DRYING
FROM SOUTHWEST ALASKA TO THE WESTERN GULF. THIS IS CAUSING STRONGER
WINDS ALOFT TO MIX DOWN TO THE SURFACE ACROSS PORTIONS OF BRISTOL
BAY...THE WESTERN GULF AND COOK INLET AREAS. THERE IS ALSO A TIGHT
PRESSURE GRADIENT ACROSS MUCH OF SOUTHCENTRAL AS A SURFACE LOW OVER
THE NORTHERN GULF EXITS AND HIGH PRESSURE BUILDS IN FROM THE NORTH
AND WEST. THIS IS COMBINING WITH THE UPPER LEVEL SUBSIDENCE TO
PRODUCE STRONG GAP WINDS ALONG THE GULF COASTAL AREAS.

.MODEL DISCUSSION...MODELS HAVE BEEN STRUGGLING WITH CONSISTENCY
IN HANDLING OF SYSTEMS ORIGINATING IN THE NORTHWEST PACIFIC WHICH
IS LIKELY DUE TO A COMBINATION OF DATA SPARSITY AND DIFFICULTY IN
TIMING FEATURES IN SUCH PROGRESSIVE FLOW. THEY HAVE ALL INITIALIZED
WELL WITH THE STRONG FEATURES NOTED IN THE ANALYSIS SECTION ABOVE.
HOWEVER...DIFFERENCES DEVELOP WITH THE TRACK OF THE THE UPPER WAVE
OVER THE SOUTHWEST BERING AS IT REACHES SOUTHWEST ALASKA ALONG WITH
HANDLING OF WEAKER UPSTREAM WAVES WHICH CROSS A FLATTENED OUT RIDGE
AND THEN DIVE SOUTHEASTWARD AS THEY REACH SOUTHWEST ALASKA. THEY
ALL INDICATE THE SAME PRIMARY IMPACT...AN ELONGATING AND WEAKENING
FRONTAL SYSTEM OVER SOUTHWEST ALASKA. THE UNCERTAINTY LIES IN HOW
FAR EAST THE FRONTAL PRECIP AND CLOUDS WILL MAKE IT.

MODEL SPREAD AND UNCERTAINTY IS MUCH GREATER WITH TRACK OF NEXT
SYSTEM MOVING OVER TOP OF THE RIDGE SUNDAY NIGHT AND MONDAY. WITH
NEAR ZONAL FLOW IN THE WAKE OF THE CURRENT SYSTEM THE MODELS DO
SEEM TO BE TRENDING THE CORRECT WAY WITH A MORE SOUTHERLY TRACK
ACROSS THE BERING SEA. THUS...WILL ALSO TREND THE FORECAST HEAVILY
THAT DIRECTION.

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...GUSTY WINDS WILL DEVELOP ACROSS MUCH OF
SOUTHCENTRAL THIS AFTERNOON DUE TO MIXING DOWN OF STRONGER WINDS
FROM ALOFT AS WELL AS TIGHT SURFACE PRESSURE GRADIENTS. THESE WINDS
WILL THEN QUICKLY DIE OFF DURING THE EVENING...ESPECIALLY INLAND...AS

THE GULF LOW RE-FORMS OVER THE SOUTHEAST GULF ALLOWING GRADIENTS AND
WINDS AT ALL LEVELS TO WEAKEN ACROSS SOUTHCENTRAL. WITH CLEAR SKIES
AND DRY AIR SETTLING IN ACROSS THE REGION RADIATIONAL COOLING WILL
LEAD TO DECOUPLING OF THE BOUNDARY LAYER WHICH IN TURN WILL LEAD
TO THE COLDEST NIGHT-TIME TEMPERATURES IN QUITE A WHILE. EXPECT
THE COPPER RIVER BASIN TO DROP DOWN TO FREEZING OR BELOW WITH
WIDESPREAD LOWER TO MID 40S ACROSS MUCH OF THE REST OF SOUTHCENTRAL.

ON SUNDAY SOME MID TO HIGH CLOUDS ASSOCIATED WITH THE SYSTEM
CROSSING THE BERING SEA WILL LIKELY MOVE THROUGH...BUT ANY PRECIP
CHANCES WILL BE CONFINED TO PORTIONS OF KODIAK ISLAND. UNCERTAINTY
GROWS WITH TRACK OF THE NEXT BERING SYSTEM BUT CURRENT INDICATIONS
ARE THAT IT WILL REMAIN SOUTH OF THE REGION AND DRY WEATHER MAY
HOLD FOR SOUTHCENTRAL ALL THE WAY THROUGH TUESDAY.

SOUTHWEST ALASKA...THOSE LOCATIONS EXPERIENCING GUSTY WIND TODAY
WILL SEE THE WINDS QUICKLY LIGHTEN UP THIS EVENING AS HIGH PRESSURE
MOVES OVERHEAD. THE FRONTAL SYSTEM CROSS THE BERING SEA WILL ARRIVE
ALONG THE KUSKOKWIM DELTA LATE TONIGHT AND SPREAD INLAND DURING THE
DAY SUNDAY. THE FRONT WILL ELONGATE AND WEAKEN AS IT MOVES INLAND...
SO THE SOUTHERN KUSKOKWIM VALLEY AND INTERIOR BRISTOL BAY WILL
LIKELY SEE LIGHTER RAIN THAN COASTAL AREAS. ANOTHER SYSTEM WILL
RAPIDLY CROSS THE BERING SEA MONDAY...ALTHOUGH FORECAST CONFIDENCE
IN THE TRACK IS BELOW AVERAGE. BASED ON A MODEL TREND TOWARD A MORE
SOUTHERLY TRACK BRISTOL BAY WILL HAVE THE BEST SHOT OF RECEIVING
ANOTHER ROUND OF RAIN MONDAY AFTERNOON THROUGH MONDAY NIGHT.

BERING SEA/ALEUTIANS...MARGINALLY COOLER LOW LEVEL AIR MOVING IN
THE BACK SIDE OF THE CURRENT STORM WILL ERODE SOME OF THE STEEP
TEMPERATURE INVERSIONS CURRENTLY IN PLACE ACROSS THE BERING SEA
AND ALEUTIANS...HELPING BRING AN END TO WIDESPREAD DENSE FOG. THE
UPPER LEVEL RIDGE WILL FLATTEN OUT WHICH MEANS THE NEXT SYSTEM WILL
TAKE A FARTHER SOUTH TRACK ON SUNDAY AND MONDAY WITH RAIN AND FOG
PRIMARILY CONFINED TO THE ALEUTIANS AND SOUTHERN ALASKA PENINSULA.

.LONG TERM FORECAST...AT THE BEGINNING OF THE EXTENDED PERIOD MODELS
ARE LOCKED ON TO AN UPPER LOW/SHORT-WAVE MOVING OUT OF RUSSIA AND
AMPLIFYING OVER THE WESTERN MAINLAND ON WEDNESDAY...LIKELY BRINGING
RAIN AND COOLER TEMPERATURES TO THE SOUTHWEST AND SOUTHCENTRAL
ALASKA. THERE IS MUCH LARGER UNCERTAINTY WITH THE SOUTHERN STREAM
FLOW OVER THE FLATTENED NORTH CENTRAL PACIFIC RIDGE. LATEST MODELS
ARE COMPLETELY OUT OF PHASE WITH NEXT SYSTEM TRACKING ALONG THE
ALEUTIANS MID TO LATE NEXT WEEK. THUS...WILL HOLD TIGHT UNTIL
MODELS GAIN SOME SORT OF HOLD ON THE PROGRESSION OF SHORT-WAVES.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING...172 175 176 179 185.
FIRE WEATHER...NONE.

SEB AUG 13