Gale Warning 790, NWS Anchorage, AK

243 
FZAK62 PAFC 071223
OFFALU

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 AM AKST MON NOV 7 2011

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.

PKZ499-080300-
400 AM AKST MON NOV 7 2011
.SYNOPSIS FOR CENTRAL BERING SEA...

A 996 MB LOW NEAR 53N 167W WEAKENS AND MOVES INTO THE GULF OF ALASKA
MON EVENING. A 973 MB LOW NEAR 47N 164E MON AFTERNOON INTENSIFIES TO
952 MB TUE MORNING NEAR 56N 173E. THIS LOW CONTINUES TO INTENSIFY TO
944 MB TUE NIGHT AS IT MOVES INLAND NEAR 65N 176W.

$$

PKZ411-080300-
BERING SEA OFFSHORE WEST OF 180 AND EAST OF THE INTERNATIONAL
DATELINE
400 AM AKST MON NOV 7 2011

...HURRICANE FORCE WIND WARNING TUESDAY...

.TODAY...SW WIND 30 KT. SEAS 13 FT. 
.TONIGHT...S WIND 35 KT BECOMING SE 60 KT AFTER MIDNIGHT. SEAS 13 FT
BUILDING TO 19 FT AFTER MIDNIGHT. RAIN AND SNOW. 
.TUE...S WIND 65 KT. SEAS 23 TO 27 FT. RAIN SHOWERS. 
.TUE NIGHT...SW WIND 60 KT. SEAS 28 FT. 
.WED...W WIND 45 KT. SEAS 28 FT. 
.THU...S WIND 25 KT. SEAS 16 FT. 
.FRI...W WIND 35 KT. SEAS 23 FT.  

$$

PKZ412-080300-
BERING SEA OFFSHORE 171W TO 180 AND NORTH OF 56N
400 AM AKST MON NOV 7 2011

...HURRICANE FORCE WIND WARNING TUESDAY...

.TODAY...SE WIND 20 KT BECOMING SW 25 KT IN THE AFTERNOON. SEAS 8 FT.
.TONIGHT...SW WIND 25 KT BECOMING S 40 KT AFTER MIDNIGHT. SEAS 9 FT
BUILDING TO 14 FT AFTER MIDNIGHT.
.TUE...S WIND 60 TO 70 KT. SEAS 19 FT BUILDING TO 34 FT IN THE
AFTERNOON. RAIN AND SNOW. 
.TUE NIGHT...SW WIND 65 KT. SEAS 36 FT. 
.WED...W WIND 50 KT. SEAS 32 FT. 
.THU...SW WIND 25 KT. SEAS 22 FT. 
.FRI...S WIND 35 KT. SEAS 18 FT.  

$$

PKZ413-080300-
BERING SEA OFFSHORE 171W TO 180 AND SOUTH OF 56N
400 AM AKST MON NOV 7 2011

...HURRICANE FORCE WIND WARNING TUESDAY...

.TODAY...W WIND 30 KT. SEAS 11 FT. 
.TONIGHT...SW WIND 30 KT BECOMING S 55 KT AFTER MIDNIGHT. SEAS 12 FT
BUILDING TO 20 FT AFTER MIDNIGHT. RAIN.
.TUE...S WIND 55 TO 65 KT. SEAS 24 FT BUILDING TO 32 FT IN THE
AFTERNOON. RAIN.
.TUE NIGHT...SW WIND 50 KT. SEAS 28 FT. 
.WED...W WIND 45 KT. SEAS 28 FT. 
.THU...S WIND 25 KT. SEAS 18 FT. 
.FRI...W WIND 30 KT. SEAS 15 FT.  

$$

PKZ414-080300-
BERING SEA OFFSHORE EAST OF 171W
400 AM AKST MON NOV 7 2011

...HURRICANE FORCE WIND WARNING TUESDAY...

.TODAY...NE WIND 25 KT BECOMING VARIABLE 15 KT IN THE AFTERNOON. SEAS
11 FT. 
.TONIGHT...S WIND 25 KT. SEAS 7 FT. 
.TUE...S WIND 35 KT INCREASING TO 65 KT IN THE AFTERNOON. SEAS 12 FT
BUILDING TO 23 FT IN THE AFTERNOON. RAIN AND SNOW. 
.TUE NIGHT...SW WIND 60 KT. SEAS 24 FT. 
.WED...W WIND 45 KT. SEAS 27 FT. 
.THU...SW WIND 25 KT. SEAS 20 FT. 
.FRI...S WIND 30 KT. SEAS 16 FT.  

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKST SUN NOV 6 2011

.ANALYSIS AND UPPER LEVELS...
IN THE UPPER-LVLS...A BROAD TROUGH ENVELOPS MUCH OF THE AOR...WITH A
130 KT JET STREAKING THROUGH THE CENTRAL ALEUTIAN CHAIN TOWARDS THE
SOUTHERN GULF OF AK. A SHORTWAVE TROUGH IS DIGGING SOUTHEAST FROM THE
SEWARD PENINSULA TOWARDS THE KUSKOKWIM DELTA AMPLIFYING THE SNOW
SHOWER COVERAGE IN THAT AREA. AT THE SURFACE...A TRIPLE POINT LOW HAS
PUSHED ASHORE PRINCE WILLIAM SOUND WITH THE STEADY SNOW EXPERIENCED
EARLY THIS MORNING LARGELY HAVING TAPERED OFF. LIGHT SNOW FALLS
ACROSS BRISTOL BAY AS A SURFACE LOW SLIPS EAST TOWARDS NORTHERN COOK
INLET. THOUGH THE FEATURE IS WEAKENING...A TIGHT PRESSURE GRADIENT
COUPLED WITH A FRESH INFUSION OF COLD ADVECTION BEHIND IT ARE
PRODUCING A SOLID ZONE OF GALES ALONG THE WESTERN CAPES AND AKPEN
WITH THIS AREA LOOKING TO REINFORCE THE ONGOING STRONG WINDS IN THE
GULF OF AK AND ADJACENT MAINLAND COASTAL WATERS. FURTHER WEST...A
COMPACT AREA OF LOW PRESSURE IS QUICKLY DEEPENING SOUTH OF ATKA
ROTATING EAST.

.MODEL DISCUSSION...
MODELS GENERALLY CAPTURE THE SYNOPTIC PICTURE SIMILARLY. IN THE
EAST...MODELS SHOW THE RESIDUAL LOW OVER BRISTOL BAY MOVING ACROSS
COOK INLET OVERNIGHT AND TO PRINCE WILLIAM SOUND MONDAY MORNING.
LOCAL EFFECT WINDS ARE DEPICTED SATISFACTORILY BY THE NAM...HOWEVER
THE QPF FIELD AND SCOPE MAY BE A TAD UNDERDONE. 500 MB TEMPERATURES
ALOFT ACROSS THE SOUTHERN MAINLAND ARE EXPECTED TO COOL ALOFT 8 TO 11
DEGREES CELSIUS AS EVIDENCED BY UPSTREAM SOUNDINGS AT KING SALMON AND
KODIAK. THIS INSTABILITY WHEN AIDED BY SYNOPTIC LIFT SHOULD YIELD
PRECIPITATION. A SHORTWAVE ROTATING AROUND THE BRISTOL BAY LOW LOOKS
TO PROVIDE SOME OF THIS INITIAL LIFT BY THIS EVENING...AND BELIEVE
THE GFS HAS A BETTER HANDLE ON THE CONTINUED QPF TREND ONCE THE
SHORTWAVE OVER THE KUSKOKWIM DELTA DIPS DOWN TO THE RESIDUAL LOW THAT
IS EXPECTED TO BE DRIFTING NEAR WESTERN PRINCE WILLIAM SOUND ON
MONDAY. MODELS THEN SHOW ENERGY FROM THE LOW BRUSHING THE ALEUTIAN
CHAIN TRACKING TO THE NORTH-CENTRAL GULF TUESDAY MORNING. TENDED TO
PREFER THE STRONGER GFS/ECMWF SOLUTIONS AT THAT JUNCTURE.

IN THE WEST...THE MODELS HAVE GOOD AGREEMENT SHOWING THE COMPACT LOW
NEAR ATKA SKIMMING THE CHAIN OVERNIGHT AND EJECTING INTO THE GULF OF
AK BY MONDAY NIGHT. FOCUS THEN SHIFTS TO A MONSTER LOW THAT RAPIDLY
DEEPENS OVER THE WESTERN PACIFIC TRACKING TO NEAR ATTU EARLY TUESDAY
MORNING. BELIEVE THE NAM AND ECMWF HAVE A BETTER CONSISTENCY ON LOW
CENTRAL PRESSURE...THOUGH THE GFS POSITION IS REASONABLE.
REGARDLESS...THERE IS AGREEMENT THAT THE STORM WILL HAVE FAIRLY
WIDESPREAD WIND/WAVE IMPACTS THROUGH THE BERING/CHAIN AND EVENTUALLY
THE SOUTHWEST MAINLAND.

.SHORT TERM FORECAST...
SOUTHCENTRAL...
SNOW SHOWERS ARE RE-DEVELOPING AS A SHORTWAVE TROUGH APPROACHES THE
REGION AND THE AFOREMENTIONED COLD AIR ALOFT FILTERS IN. EXPECTING
THE SHOWERS TO GIVE WAY TO A STEADY SNOW LATER THIS EVENING INTO
MONDAY WITH THE APPROACH OF THE BRISTOL BAY LOW AND REINFORCING SHOT
OF LOWER-LVL COLD-ADVECTION. THERE IS MODEST CONFIDENCE IN THE
RE-DEVELOPMENT OF SNOW AND IT'S GENERAL DURATION THROUGH
MONDAY...THOUGH INTENSITY QUESTIONS PERSIST CONCURRENT WITH MODEL
DISAGREEMENT. OMEGA VALUES NOT AS STRONG WITH THIS ROUND OF
PRECIPITATION AS WITH THE SNOW EVENT EARLIER THIS MORNING...SO
BELIEVE THE OVERALL AMOUNTS WILL STAY BELOW ADVISORY LEVELS.
AVAILABLE MOISTURE AND LIFT WEAKENS LATE MONDAY AND THE INCREASING
NORTH-NORTHWEST FLOW TO HELP DRY THINGS OUT AS WELL. THE
COLD-ADVECTION AND STRONG PRESSURE GRADIENT WILL KEEP WINDS STRONG
OVER THE GULF...COASTAL WATERS AND GAPS THROUGH TUESDAY. BLOWING SNOW
MAY ALSO BECOME A CONSIDERATION ALONG TURNAGAIN ARM AND PORTAGE
VALLEY IN THE EVENTUAL SQUEEZED WESTERLY FLOW.

SOUTHWEST...
SHOWERS AND WINDS WILL DIMINISH ACROSS THE SOUTHWEST MAINLAND AS WEAK
RIDGING POKES IN FROM THE WEST...THOUGH THE ALASKA/ALEUTIAN RANGES
WILL BE SLOWER TO IMPROVE DUE TO THE RESIDUAL WEST-NORTHWEST UPSLOPE
FLOW. EXPECT A PERIOD OF RELATIVELY FAIR WEATHER MONDAY/TUESDAY
BEFORE THE PERIPHERAL EFFECTS OF THE BERING SYSTEM NEAR THE AREA
MID-WEEK. COASTAL AREAS OF BRISTOL BAY AND THE KUSKOKWIM DELTA WILL
BEAR CLOSE WATCHING FOR SOUTHWEST-WEST SURGE GENERATED BY THE STORM
LATER THIS WEEK.

BERING SEA/ALEUTIANS...
A QUICK SHOT OF RAIN THROUGH EARLY MONDAY OVER THE EASTERN CHAIN AND
AKPEN WITH THE COMPACT LOW EJECTING TO THE GULF. FOCUS THEN SHIFTS TO
THE MONSTER LOW. HIGH WIND WATCHES TO BE ISSUED WITH THE AFTERNOON
FORECAST PACKAGES FOR THE WESTERN AND CENTRAL ALEUTIAN ISLANDS.
FORECAST CONFIDENCE IS HIGH...AS IS THE EXPECTATION THAT THE ZONE
WILL LIKELY SPREAD EAST TOWARDS THE PRIBILOF ISLANDS AND THE
NORTHERN/EASTERN BERING THROUGH TUESDAY/WEDNESDAY. SIGNIFICANT WEST
TO SOUTHWEST SWELL TO ACCOMPANY THE WINDS AND PRECIPITATION.

.LONG TERM FORECAST...
MODELS AGREE ON SOME RESIDUAL ENERGY AND MOISTURE FROM THE MONSTER
BERING SEA LOW ADVANCING TO SOUTHCENTRAL AK LATE WEEK/THURSDAY.
HOWEVER IN THE WAKE OF THIS...THERE IS SUBSTANTIAL MODEL DISAGREEMENT
AND THUS LOW FORECAST CONFIDENCE.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WATCH...187 191
MARINE...HURRICANE FORCE STORM...175 176 411
         STORM...172 412
         GALE...120 129 130 132 138 140 150 155 160 165 170 351 352
FIRE WEATHER...NONE

JAM NOV 11