Gale Warning 855, NWS Anchorage, AK

000 
FZAK61 PAFC 180023
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 PM AKST TUE DEC 17 2013

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.

PKZ399-181500-
400 PM AKST TUE DEC 17 2013
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A TROUGH OF LOW PRESSURE ALONG THE NORTH GULF COAST WILL DISSIPATE BY
WED MORNING. A WEATHER FRONT WILL MOVE INTO THE SOUTHWEST GULF WED
WITH A 994 MB LOW DEVELOPING NEAR 58N 150W WED NIGHT. THIS LOW WILL
THEN MOVE TO 59N 143W AT 999 MB THU AFTERNOON.

$$

PKZ351-181500-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W
400 PM AKST TUE DEC 17 2013

...GALE WARNING WEDNESDAY NIGHT...

.TONIGHT...NW WIND 20 KT. SEAS 7 FT. 
.WED...SW WIND 15 KT BECOMING S 30 KT IN THE AFTERNOON. SEAS 6 FT.
SNOW AND RAIN. 
.WED NIGHT...SE WIND 35 TO 45 KT. SEAS 11 TO 15 FT. RAIN AND SNOW. 
.THU...W WIND 30 KT. SEAS 15 FT. 
.THU NIGHT...SW WIND 15 KT. SEAS 12 FT. 
.FRI...SW WIND 20 KT. SEAS 14 FT. 
.SAT...S WIND 20 KT. SEAS 11 FT. 
.SUN...SW WIND 20 KT. SEAS 12 FT.  

$$

PKZ352-181500-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W
400 PM AKST TUE DEC 17 2013

...STORM WARNING WEDNESDAY NIGHT...

.TONIGHT...W WIND 20 KT. SEAS 8 FT. 
.WED...S WIND 30 KT BECOMING SE 40 KT IN THE AFTERNOON. SEAS 8 FT
BUILDING TO 13 FT IN THE AFTERNOON. RAIN.
.WED NIGHT...SE WIND 40 TO 50 KT BECOMING SW 35 KT AFTER MIDNIGHT.
SEAS 15 FT. RAIN AND SNOW. 
.THU...SW WIND 30 KT. SEAS 15 FT. 
.THU NIGHT AND FRI...SW WIND 25 KT. SEAS 16 FT. 
.SAT...SW WIND 25 KT. SEAS 13 FT. 
.SUN...SW WIND 20 KT. SEAS 14 FT.  

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 PM AKST MON DEC 16 2013

.ANALYSIS AND UPPER LEVELS...

UPPER LEVEL PLANETARY TROUGH EXTENDS FROM EASTERN RUSSIA TO SE AK
THIS MORNING...WITH SMALLER TROUGHS EXTENDING TO THE KAMCHATKA
PENINSULA AND FROM YAKUTAT SOUTHWEST ACROSS THE GULF OF ALASKA. A
WEAK UPPER LEVEL RIDGE IS OVER THE BERING AND WESTERN AK. A JET IS
FOCUSED ON THE NORTHEAST GULF AT IT MOVES INTO CANADA. AT THE
SURFACE...A LOW IS WEAKENING OVER THE NORTHERN GULF AS A SECOND LOW
APPROACHES SOUTHEAST AK. HIGH PRESSURE DOMINATES INTERIOR AK AND THE
EASTERN HALF OF THE BERING. THE NEXT SIGNIFICANT WEATHER FEATURE...A
LOW AROUND 40N 170E...IS SENDING AN ASSOCIATED FRONT TO THE
ALEUTIANS.

.MODEL DISCUSSION...

MODELS AGREE THAT THE WEAKENING LOW OVER THE GULF WILL DRIFT EAST
TONIGHT...AND INCREASE THE PRESSURE GRADIENT OVER PORTIONS OF SOUTH
CENTRAL AS HIGH PRESSURE CONTINUES TO BUILD OVER THE INTERIOR. THIS
GRADIENT WILL DIMINISH AS HIGH PRESSURE BUILDS OVER THE GULF
BEGINNING MON AFTERNOON AND LASTING INTO WED.

IN THE MEANTIME...THE FRONT APPROACHING THE ALEUTIANS WILL ARRIVE TUE
MORNING. A TRIPLE POINT LOW WILL FORM TUE EVENING NEAR ADAK...AND A
SECOND TRIPLE POINT WILL FORM A LOW ON A FRONT NEAR THE AKPEN WED
AFTERNOON. AS HIGH PRESSURE WEAKENS OVER THE GULF...THE LOW AND
ASSOCIATED FRONT WILL MOVE INTO THE GULF WED NIGHT...WITH THE FRONT
REACHING THE NORTH GULF COAST WED NIGHT...AND THE LOW ITSELF ON FRI.

.SHORT TERM FORECAST...

IN THE WEST...LINGERING SNOW SHOWERS OFF THE BERING WILL END AS THE
INFLUENCE OF THE FRONT TAKES OVER TONIGHT. E TO SE GALE TO STORM
FORCE WIND WILL AFFECT MUCH OF THE CHAIN TUE INTO WED...WITH SNOW
CHANGING TO RAIN BEGINNING TUE AFTERNOON. SHOWERS AND GALES CAN THEN
BE EXPECTED THROUGH THU AS REMNANT LOWS CONSOLIDATE AND MAINTAIN
CYCLONIC FLOW THROUGH THAT TIME.

FOR SW AK....COLD AND GENERALLY CLEAR CONDITIONS WILL PERSIST UNTIL
THE FRONT ARRIVES TUE NIGHT INTO WED WITH WIND AND SNOW. AS WARM AIR
ARRIVES WED NIGHT INTO THU...SNOW WILL CHANGE OVER TO RAIN...WITH
SOME FREEZING RAIN POSSIBLE WHERE COLD AIR IS TRAPPED IN VALLEYS.

SOUTH AND EAST OF THE AK RANGE...CLEAR AND COLD CONDITIONS WITH WIND
AND SNOW COMBINING FOR A THOMPSON PASS BLIZZARD WARNING THROUGH TUE
AFTERNOON...AND STRONG WINDS THROUGH CHANNELED TERRAIN FOR SEWARD AND
WHITTIER. BY TUE AFTERNOON THE GRADIENT SHOULD RELAX AND END THE
WIND. THE BERING FRONT WILL ARRIVE OVER KODIAK WED AND REACH THE
NORTH GULF COAST THU WITH GALE TO STORM FORCE WINDS WED NIGHT INTO
THU. SNOW WILL ACCOMPANY THE FRONT...REACHING THE NORTH GULF COAST
WED AFTERNOON AND MOVING INLAND WED NIGHT THROUGH THU. ANY MIXING
WITH RAIN AT SEA LEVEL WILL BE LIMITED TO PORTIONS OF PRINCE WILLIAM
SOUND LATER ON THU.

.LONG TERM FORECAST...

IN THE WEST...RAIN AND SNOW SHOWERS WILL SWITCH OVER TO ALL SNOW BY
SAT...AND THEN ANOTHER WEATHER FRONT ARRIVES SUN OVER THE WESTERN
ALEUTIANS WITH ANOTHER ROUND OF SNOW FOR THE CHAIN...WHICH REACHES SW
AK BY MON. SE OF THE AK RANGE WILL HAVE MAINLY PERIODS OF SNOW
THROUGH THE BEGINNING OF NEXT WEEK,

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING 131
MARINE...HEAVY FREEZING SPRAY 121 126 127 128 129 130 138 141 150
         GALES 127 131 155 165 170 171 172 178 179
         STORMS 173 174 175 176 177
FIRE WEATHER...NONE

DS DEC 13