Storm Warning 169, NWS Anchorage, AK

307 
FZAK52 PAFC 260007
CWFALU

COASTAL WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE ALASKA
307 PM AKST THU DEC 25 2014

COASTAL WATERS FORECAST FOR SOUTHWEST ALASKA+BRISTOL BAY+THE
ALASKA PENINSULA WATERS AND THE ALEUTIAN ISLANDS UP TO 100 NM OUT.

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.

PKZ199-261300-
307 PM AKST THU DEC 25 2014
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...
A WEATHER FRONT SITUATED FROM THE CENTRAL BERING TO THE KUSKOKWIM
DELTA MOVES INLAND OVER SOUTHWEST ALASKA TONIGHT. A 967 MB LOW
240 NM SOUTH OF ATTU STRENGTHENS TO 959 MB 145 NM NORTHWEST OF
ATTU LATE FRI MORNING...THEN MOVES TO 215 NM WEST-NORTHWEST OF
ATTU FRI AFTERNOON AND REMAINS STATIONARY WITH LITTLE CHANGE IN
STRENGTH THROUGH SAT AFTERNOON. AN ASSOCIATED WEATHER FRONT
CROSSES THE WESTERN ALEUTIANS INTO THE SOUTHWESTERN BERING THIS
EVENING AND THEN BECOMES STATIONARY AND WEAKENS OVER THE NORTHERN
AND EASTERN BERING LATE FRI INTO SAT.

$$

PKZ150-261300-
SOUTH OF THE AK PENINSULA SITKINAK TO CASTLE CAPE-
307 PM AKST THU DEC 25 2014

...SMALL CRAFT ADVISORY THROUGH FRIDAY NIGHT...

.TONIGHT...SW WIND 30 KT. SEAS 16 FT.
.FRI...W WIND 30 KT DIMINISHING TO 20 KT IN THE AFTERNOON.
SEAS 14 FT.
.FRI NIGHT...SW WIND 20 KT. SEAS 11 FT. PATCHY FOG.
.SAT...SE WIND 40 KT. SEAS 14 FT.
.SAT NIGHT AND SUN...SE WIND 40 KT. SEAS 20 FT.
.MON...SE WIND 35 KT. SEAS 15 FT.
.TUE...S WIND 30 KT. SEAS 15 FT.

$$

PKZ155-261300-
SOUTH OF THE AK PENINSULA CASTLE CAPE TO CAPE SARICHEF-
307 PM AKST THU DEC 25 2014

...GALE WARNING TONIGHT...

.TONIGHT...SW WIND 35 KT. SEAS 18 FT.
.FRI...S WIND 30 KT EXCEPT W 25 KT FROM THE SHUMAGIN ISLANDS E.
SEAS 16 FT. PATCHY FOG.
.FRI NIGHT...S WIND 30 KT EXCEPT 20 KT FROM THE SHUMAGIN ISLANDS
E. SEAS 14 FT. PATCHY FOG.
.SAT...SE WIND 40 KT. SEAS 17 FT.
.SAT NIGHT...S WIND 40 KT. SEAS 16 FT.
.SUN...N WIND 25 KT. SEAS 11 FT.
.MON...S WIND 35 KT. SEAS 19 FT.
.TUE...S WIND 30 KT. SEAS 20 FT.

$$

PKZ160-261300-
BRISTOL BAY-
307 PM AKST THU DEC 25 2014

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TONIGHT...SW WIND 30 KT. SEAS 9 FT. RAIN AND SNOW SHOWERS.
.FRI...W WIND 30 KT BECOMING S 20 KT IN THE AFTERNOON. SEAS 11 FT
SUBSIDING TO 7 FT IN THE AFTERNOON. PATCHY FOG.
.FRI NIGHT...S WIND 20 KT. SEAS 6 FT. PATCHY FOG.
.SAT...SE WIND 30 KT. SEAS 6 FT.
.SAT NIGHT...SE WIND 40 KT. SEAS 9 FT.
.SUN...E WIND 35 KT. SEAS 7 FT.
.MON...SE WIND 30 KT. SEAS 6 FT.
.TUE...S WIND 25 KT. SEAS 5 FT.

$$

PKZ165-261300-
PORT HEIDEN TO CAPE SARICHEF-
307 PM AKST THU DEC 25 2014

...GALE WARNING TONIGHT...

.TONIGHT...SW WIND 40 KT BECOMING W 30 KT AFTER MIDNIGHT. SEAS
17 FT. RAIN SHOWERS.
.FRI...W WIND 25 KT IN THE MORNING BECOMING S 30 KT. SEAS 12 FT.
.FRI NIGHT...S WIND 30 KT. SEAS 10 FT. 
.SAT...SE WIND 30 KT. SEAS 9 FT.
.SAT NIGHT...S WIND 35 KT. SEAS 9 FT.
.SUN...NE WIND 25 KT. SEAS 6 FT.
.MON...SE WIND 30 KT. SEAS 8 FT.
.TUE...S WIND 30 KT. SEAS 9 FT.

$$

PKZ170-261300-
CAPE SARICHEF TO NIKOLSKI BERING SIDE-
307 PM AKST THU DEC 25 2014

...GALE WARNING THROUGH FRIDAY NIGHT...

.TONIGHT...SW WIND 40 KT BECOMING S 30 KT AFTER MIDNIGHT. SEAS
19 FT. PATCHY FOG. RAIN SHOWERS.
.FRI...S WIND 45 KT. SEAS 15 FT. PATCHY FOG.
.FRI NIGHT...S WIND 35 KT. SEAS 13 FT. PATCHY FOG. RAIN.
.SAT...S WIND 35 KT. SEAS 12 FT.
.SAT NIGHT...S WIND 20 KT. SEAS 8 FT.
.SUN...E WIND 30 KT. SEAS 9 FT.
.MON THROUGH TUE...SW WIND 25 KT. SEAS 12 FT.

$$

PKZ171-261300-
UNALASKA BAY-
307 PM AKST THU DEC 25 2014

...SMALL CRAFT THROUGH FRIDAY NIGHT...

.TONIGHT...SW WIND 25 KT WITH GUSTS TO 40 KT DIMINISHING TO S 20 
AFTER MIDNIGHT. SEAS 3 FT. PATCHY FOG.
.FRI...S WIND 25 KT. GUSTS TO 40 KT. SEAS 4 FT. 
.FRI NIGHT...S WIND 25 KT. GUSTS TO 40 KT. SEAS 4 FT. RAIN.
.SAT...S WIND 25 KT. SEAS 4 FT.
.SAT NIGHT...SW WIND 10 KT. SEAS 2 FT.
.SUN...SE WIND 15 KT. SEAS 3 FT.
.MON THROUGH TUE...S WIND 20 KT. SEAS 3 FT.

$$

PKZ172-261300-
CAPE SARICHEF TO NIKOLSKI PACIFIC SIDE-
307 PM AKST THU DEC 25 2014

...GALE WARNING THROUGH FRIDAY NIGHT...

.TONIGHT...SW WIND 35 KT. SEAS 20 FT. 
.FRI...S WIND 40 KT. SEAS 19 FT. PATCHY FOG.
.FRI NIGHT...S WIND 35 KT. SEAS 23 FT. PATCHY FOG. RAIN AND SNOW.
.SAT...S WIND 30 KT. SEAS 19 FT.
.SAT NIGHT...SW WIND 20 KT. SEAS 11 FT.
.SUN...SE WIND 30 KT. SEAS 11 FT.
.MON...SW WIND 30 KT. SEAS 19 FT.
.TUE...SW WIND 25 KT. SEAS 22 FT.

$$

PKZ173-261300-
NIKOLSKI TO SEGUAM ISLAND BERING SIDE-
307 PM AKST THU DEC 25 2014

...STORM WARNING FRIDAY...

.TONIGHT...SW WIND 35 KT EARLY BECOMING S 45 KT AFTER MIDNIGHT.
SEAS 18 FT. PATCHY FOG. RAIN.
.FRI...S WIND 50 KT. SEAS 20 FT. PATCHY FOG. RAIN.
.FRI NIGHT...S WIND 30 KT. SEAS 18 FT SUBSIDING TO 13 FT AFTER
MIDNIGHT. RAIN.
.SAT...S WIND 25 KT. SEAS 12 FT.
.SAT NIGHT...SE WIND 30 KT. SEAS 10 FT.
.SUN...SE WIND 40 KT. SEAS 12 FT.
.MON...NW WIND 25 KT. SEAS 14 FT.
.TUE...SW WIND 25 KT. SEAS 12 FT.

$$

PKZ174-261300-
NIKOLSKI TO SEGUAM ISLAND PACIFIC SIDE-
307 PM AKST THU DEC 25 2014

...STORM WARNING FRIDAY...

.TONIGHT...SW WIND 35 KT INCREASING TO S 45 KT AFTER MIDNIGHT.
SEAS 21 FT. PATCHY FOG.
.FRI...S WIND 50 KT. SEAS 25 FT. PATCHY FOG. RAIN.
.FRI NIGHT...S WIND 25 KT. SEAS 23 FT. RAIN.
.SAT...S WIND 25 KT. SEAS 16 FT.
.SAT NIGHT...S WIND 35 KT. SEAS 13 FT.
.SUN...SE WIND 40 KT. SEAS 13 FT.
.MON...NW WIND 25 KT. SEAS 15 FT.
.TUE...SW WIND 25 KT. SEAS 19 FT.

$$

PKZ175-261300-
SEGUAM ISLAND TO ADAK BERING SIDE-
307 PM AKST THU DEC 25 2014

...GALE WARNING THROUGH FRIDAY...

.TONIGHT...S WIND 45 KT. SEAS 15 FT. PATCHY FOG. RAIN.
.FRI...S WIND 45 KT EARLY DIMINISHING TO SW 30 KT BY AFTERNOON.
SEAS 15 FT. RAIN AND SNOW.
.FRI NIGHT...S WIND 30 KT. SEAS 12 FT.  SNOW SHOWERS.
.SAT...S WIND 25 KT. SEAS 11 FT.
.SAT NIGHT...S WIND 20 KT. SEAS 9 FT.
.SUN...NW WIND 25 KT. SEAS 10 FT.
.MON...NW WIND 25 KT. SEAS 13 FT.
.TUE...SW WIND 25 KT. SEAS 13 FT.

$$

PKZ176-261300-
SEGUAM ISLAND TO ADAK PACIFIC SIDE-
307 PM AKST THU DEC 25 2014

...GALE WARNING THROUGH FRIDAY...

.TONIGHT...S WIND 45 KT. SEAS 24 FT. PATCHY FOG. RAIN.
.FRI...S WIND 45 KT DIMINISHING TO SW 30 KT BY AFTERNOON. SEAS 25
FT. RAIN.
.FRI NIGHT...S WIND 25 KT. SEAS 19 FT. SNOW SHOWERS.
.SAT...S WIND 25 KT. SEAS 16 FT.
.SAT NIGHT...SE WIND 35 KT. SEAS 14 FT.
.SUN THROUGH MON...W WIND 30 KT. SEAS 15 FT.
.TUE...SW WIND 30 KT. SEAS 17 FT.

$$

PKZ177-261300-
ADAK TO KISKA-
307 PM AKST THU DEC 25 2014

...GALE WARNING THROUGH FRIDAY NIGHT...

.TONIGHT...SE WIND 45 KT IN THE EVENING BECOMING SW 30 KT. SEAS
21 FT. RAIN.
.FRI...SW WIND 35 KT. SEAS 20 FT.  SNOW SHOWERS.
.FRI NIGHT...S WIND 35 KT. SEAS 18 FT. RAIN AND SNOW SHOWERS.
.SAT...S WIND 35 KT. SEAS 19 FT.
.SAT NIGHT...S WIND 30 KT. SEAS 16 FT.
.SUN...W WIND 15 KT. SEAS 12 FT.
.MON...W WIND 25 KT. SEAS 12 FT.
.TUE...S WIND 30 KT. SEAS 13 FT.

$$

PKZ178-261300-
KISKA TO ATTU-
307 PM AKST THU DEC 25 2014

...STORM WARNING TONIGHT...

.TONIGHT...SE WIND 45 KT IN THE EVENING BECOMING SW 50 KT AFTER
MIDNIGHT. SEAS 25 FT. RAIN AND SNOW.
.FRI...SW WIND 45 KT. SEAS 25 FT. RAIN AND SNOW.
.FRI NIGHT...SW WIND 40 KT. SEAS 23 FT. RAIN AND SNOW SHOWERS.
.SAT...SW WIND 40 KT. SEAS 23 FT.
.SAT NIGHT...SW WIND 35 KT. SEAS 18 FT.
.SUN THROUGH MON...W WIND 25 KT. SEAS 12 FT.
.TUE...SE WIND 30 KT. SEAS 13 FT.

$$

PKZ179-261300-
PRIBILOF ISLANDS NEAR SHORE WATERS-
307 PM AKST THU DEC 25 2014

...GALE WARNING FRIDAY AND FRIDAY NIGHT...

.TONIGHT...VARIABLE WIND 15 KT BECOMING SE 20 KT TOWARD MORNING.
SEAS 13 FT. RAIN AND SNOW.
.FRI...SE WIND 40 KT. SEAS 19 FT. PATCHY FOG. RAIN.
.FRI NIGHT...S WIND 35 KT DIMINISHING TO 25 KT AFTER MIDNIGHT.
SEAS 19 FT. PATCHY FOG. RAIN.
.SAT...S WIND 20 KT. SEAS 14 FT.
.SAT NIGHT...S WIND 25 KT. SEAS 11 FT.
.SUN...SE WIND 30 KT. SEAS 11 FT.
.MON...SE WIND 25 KT. SEAS 9 FT.
.TUE...S WIND 25 KT. SEAS 13 FT.

$$

PKZ180-261300-
KUSKOKWIM DELTA AND ETOLIN STRAIT-
307 PM AKST THU DEC 25 2014

...SMALL CRAFT ADVISORY THROUGH FRIDAY NIGHT...

.TONIGHT...SW WIND 30 KT IN THE EVENING BECOMING NW 20 KT. SEAS
IN ICE FREE WATERS 10 FT. FREEZING SPRAY.
.FRI...NW WIND 20 KT BECOMING SE 25 KT IN THE AFTERNOON. SEAS IN
ICE FREE WATERS 10 FT. PATCHY FOG.
.FRI NIGHT...SE WIND 25 KT. SEAS IN ICE FREE WATERS 10 FT. PATCHY FOG.
.SAT...SE WIND 30 KT. SEAS IN ICE FREE WATERS 11 FT.
.SAT NIGHT...SE WIND 35 KT. SEAS IN ICE FREE WATERS 11 FT.
.SUN...NE WIND 25 KT. SEAS IN ICE FREE WATERS 6 FT.
.MON...SE WIND 30 KT. SEAS IN ICE FREE WATERS 8 FT.
.TUE...S WIND 30 KT. SEAS IN ICE FREE WATERS 10 FT.

$$

PKZ181-261300-
NORTH AND WEST OF NUNIVAK ISLAND-
307 PM AKST THU DEC 25 2014

...GALE WARNING FRIDAY NIGHT...
...HEAVY FREEZING SPRAY WARNING THROUGH FRIDAY...

.TONIGHT...N WIND 25 KT. SEAS IN ICE FREE WATERS 8 FT. HEAVY
FREEZING SPRAY.
.FRI...N WIND 20 KT BECOMING E 30 KT IN THE AFTERNOON. SEAS IN
ICE FREE WATERS 7 FT. SNOW. HEAVY FREEZING SPRAY.
.FRI NIGHT...E WIND 35 KT IN THE EVENING BECOMING S 25 KT. SEAS
IN ICE FREE WATERS 12 FT. PATCHY FOG. RAIN AND SNOW.
.SAT AND SAT NIGHT...SE WIND 30 KT. SEAS IN ICE FREE WATERS 13 FT.
.SUN...SE WIND 20 KT. SEAS IN ICE FREE WATERS 7 FT.
.MON...E WIND 30 KT. SEAS IN ICE FREE WATERS 7 FT.
.TUE...S WIND 25 KT. SEAS IN ICE FREE WATERS 10 FT.

$$

PKZ185-261300-
SAINT MATTHEW ISLAND WATERS-
307 PM AKST THU DEC 25 2014

...STORM WARNING FRIDAY AND FRIDAY NIGHT...
...HEAVY FREEZING SPRAY WARNING THROUGH FRIDAY NIGHT...

.TONIGHT...E OF SAINT MATTHEW ISLAND...N WIND 25 KT. W OF SAINT
MATTHEW ISLAND...NE WIND 30 KT BECOMING E 40 KT AFTER MIDNIGHT.
SEAS 13 FT. HEAVY FREEZING SPRAY FROM SAINT MATTHEW ISLAND NORTH.
.FRI...E OF SAINT MATTHEW ISLAND...NE WIND 30 KT BECOMING E 45 KT
IN THE AFTERNOON. W OF SAINT MATTHEW ISLAND...E WIND 50 KT. SEAS
19 FT. SNOW. HEAVY FREEZING SPRAY FROM SAINT MATTHEW ISLAND NORTH.
.FRI NIGHT...E WIND 50 KT IN THE EVENING BECOMING S 30 KT. SEAS
19 FT. SNOW IN THE EVENING CHANGING TO RAIN. HEAVY FREEZING SPRAY
IN THE EVENING NORTH OF SAINT MATTHEW ISLAND.
.SAT AND SAT NIGHT...SE WIND 30 KT. SEAS 18 FT.
.SUN...SE WIND 30 KT. SEAS 15 FT.
.MON...E WIND 30 KT. SEAS 12 FT.
.TUE...S WIND 25 KT. SEAS 13 FT.

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
424 PM AKST WED DEC 24 2014

.ANALYSIS AND UPPER LEVELS...
A VERY ACTIVE PATTERN IS IN PLACE ACROSS THE ALASKA REGION WITH
A VERY LARGE UPPER LEVEL CLOSED LOW IN THE VICINITY OF THE
WESTERN ALEUTIANS/FAR WESTERN BERING SEA AND A VERY WINTER-LIKE
200+ KT SUBTROPICAL JET TO THE SOUTH. THIS IS PROVIDING FAVORABLE
CONDITIONS FOR CYCLOGENESIS OVER THE NORTHWEST PACIFIC. THE
DEVELOPING SYSTEMS THEN GET PULLED NORTHWARD ACROSS THE ALEUTIANS
ON THE EAST SIDE OF THE UPPER LOW...WHILE THE FRONTAL SYSTEMS AND
UPPER LEVEL WAVES (WHICH HELPED INDUCE CYCLOGENESIS) CONTINUE
EAST- NORTHEAST TO MAINLAND ALASKA. THE RAPID DEVELOPMENT AND
MOVEMENT OF FEATURES IN THIS PATTERN PROVIDES QUITE A FORECAST
CHALLENGE FOR FORECAST TIMING.

THE FIRST DEEP LOW WHICH LED THE WAY INTO THIS PATTERN IS NOW
WEAKENING OVER THE FAR SOUTHWEST BERING SEA. THE OCCLUDED FRONT
IS STRETCHED OUT ACROSS THE NORTH CENTRAL BERING SEA THEN
SOUTHEASTWARD ACROSS MAINLAND ALASKA. SATELLITE IMAGERY IS
BEGINNING TO SHOW SIGNS OF A WEAK TRIPLE POINT LOW FORMING NEAR
KODIAK ISLAND. THE HEAVIEST PRECIP IS OVER INTERIOR SOUTHWEST
ALASKA AND THE WESTERN GULF OUT AHEAD OF A FAIRLY STRONG UPPER
LEVEL SHORT-WAVE. A STRONG VORT-MAX OVER THE SOUTHWESTERN GULF
IS BRING DRIVEN EASTWARD WHILE THE REST OF THE TROUGH LIFTS
NORTH-NORTHEASTWARD. THIS IS LEADING TO DEAMPLIFICATION OF THE
TROUGH AS IT APPROACHES SOUTHCENTRAL ALASKA. RADAR IMAGERY SHOWS
LIGHT SNOW GRADUALLY OVERSPREADING SOUTHCENTRAL FROM SOUTHWEST
TO NORTHEAST...BUT NOT ALL OF THIS IS REACHING THE GROUND. IN
PARTICULAR THERE IS A SHALLOW LAYER OF SOUTHEAST FLOW ACROSS THE
KENAI AND CHUGACH MOUNTAINS WHICH IS PRODUCING SOME WEAK
DOWNSLOPE DRYING IN THE LOWEST LEVELS. AS MORE INTENSE SNOW MOVES
IN THIS EVENING EXPECT TO SEE MORE OF THE AREA FILL IN WITH LIGHT
SNOW BRIEFLY BEFORE THE TROUGH MOVES PAST.

A MODERATE LOW WHICH CROSSED THE ALEUTIANS OVERNIGHT HAS NOW
SLOWED ITS FORWARD MOTION AND IS SITTING JUST NORTH OF THE
WESTERN ALEUTIANS. IT IS SENDING ANOTHER FRONTAL SYSTEM EASTWARD
ACROSS THE ALEUTIANS AND SOUTHERN BERING SEA. COLD AIR FEEDING IN
BEHIND THIS SYSTEM HAS DESTABILIZED THE ATMOSPHERE WITH CONVECTION
NOTED IN SATELLITE IMAGERY SOUTH OF THE WESTERN ALEUTIANS. THIS IS
AN AREA TO WATCH AS IT MOVES INTO THE FORECAST AREA BECAUSE OF THE
POTENTIAL FOR STRONG AND GUSTY WINDS WITH A WELL MIXED BOUNDARY
LAYER.

A THIRD LOW HAS FORMED ON THE SOUTH SIDE OF THE DEEP LOW OVER THE
SOUTHWEST BERING SEA AND IS POISED TO EJECT EASTWARD ACROSS THE
WESTERN ALEUTIANS.

&&

.MODEL DISCUSSION...
CONSIDERING THE VERY PROGRESSIVE NATURE OF THE PATTERN MODEL
SPREAD IS RELATIVELY LOW FOR THE FIRST 48 HOURS OF THE FORECAST.
THERE ARE DEFINITELY SOME DIFFERENCES WITH DEPICTION OF SMALLER
SCALE FEATURES...ESPECIALLY IN TIMING.

MODELS ARE ALL VERIFYING WELL THIS MORNING WITH CURRENT FEATURES
BUT DIFFERENCES QUICKLY DEVELOP THIS AFTERNOON AND EVENING...
PRIMARILY WITH LOCATION OF THE TRIPLE POINT LOW IN THE GULF AND
TIMING OF THE UPPER TROUGH MOVING THROUGH SOUTHCENTRAL. PREFER
THE HIGHER RESOLUTION MODELS WHICH TRACK THE TRIPLE POINT LOW
FARTHER NORTH RESULTING IN STRONGER WINDS ALONG THE NORTH GULF
COAST AND INTO PRINCE WILLIAM SOUND. WITH PROGRESSIVE FLOW ALOFT
PREFER THE FASTER MOVEMENT OF THE UPPER TROUGH.

THE GEMGLB AND GEMREG ARE OUTLIERS WITH DEVELOPMENT OF A TRIPLE
POINT LOW NEAR THE EASTERN ALEUTIANS THIS AFTERNOON. THE UPPER
LEVEL TROUGH IS LOW AMPLITUDE AND THERE ISN'T MUCH LOW LEVEL
BAROCLINICITY IN THAT AREA...SO WILL COMPLETELY DISCOUNT THIS
SOLUTION. ALL MODELS HAVE TRENDED STRONGER WITH THE WINDS BEHIND
THE OCCLUSION...POSSIBLY PICKING UP ON THE LOW LEVEL INSTABILITY
MENTIONED ABOVE. WILL INCREASE WINDS IN THIS AREA AND CARRY THEM
ALL THE WAY INTO BRISTOL BAY.

NUMERICAL GUIDANCE IS CONVERGING ON A COMMON SOLUTION WITH TRACK
OF THE NEXT PACIFIC LOW CROSSING THE WESTERN ALEUTIANS THURSDAY
NIGHT...SO FORECAST CONFIDENCE HAS INCREASED. THE BIGGER CHALLENGE
WILL BE A SERIES OF THREE UPPER LEVEL SHORT-WAVES WHICH QUICKLY
TRACK FROM THE ALEUTIANS TO MAINLAND ALASKA THROUGH FRIDAY. EACH
SOLUTION IS JUST A LITTLE DIFFERENT IN TRACK AND AMPLITUDE OF
THESE FEATURES WHICH MAKES IT HARD TO FORECAST SNOW AMOUNTS. THE
FORECASTS WILL ADEQUATELY REFLECT THE HIGH PROBABILITY OF PRECIP
AS THESE WAVES MOVE ACROSS THE REGION. SNOW AMOUNT OVER SOUTHWEST
AND SOUTHCENTRAL WILL HAVE TO BE FINE-TUNED JUST PRIOR TO EACH
EVENT WHEN MODEL GUIDANCE TENDS TO CONVERGE ON KEY DETAILS OF
THE FEATURES.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...

AN INITIAL WAVE MOVING ACROSS THE REGION WILL BRIEFLY BRING SOME
SNOW SHOWERS TO INTERIOR ZONES TONIGHT...WITH A MIX OF RAIN AND
SNOW ALONG THE COAST. PRECIPITATION WILL TAPER OFF OVERNIGHT
BEFORE THE NEXT WAVE ARRIVES WITH SNOW SPREADING NORTHEAST ACROSS
THE KENAI PENINSULA AND INTO SOUTHCENTRAL. A LOW LEVEL SOUTHWEST
JET WILL ENHANCE SNOWFALL IN UPSLOPE FLOW...WITH GREATEST AMOUNTS
EXPECTED OVER HIGHER ELEVATIONS OF THE SUSITNA VALLEY. A WINTER
WEATHER ADVISORY FOR 6 TO 14 INCHES OF SNOW HAS BEEN ISSUED FOR
THAT AREA. SIMILAR AMOUNTS OF SNOWFALL ARE EXPECTED AROUND PRINCE
WILLIAM SOUND...WITH LESSER AMOUNTS FOR THE REST OF SOUTHCENTRAL.
SNOW WILL BEGIN TO END LATE THURSDAY NIGHT AS THE NEXT SHORTWAVE
RIDGE ARRIVES. ON FRIDAY...ANY LINGERING SNOWFALL ACTIVITY NEAR
PRINCE WILLIAM SOUND AND ACROSS THE COPPER RIVER BASIN WILL ALSO
END BENEATH THE BUILDING RIDGE.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
AS THE FRONT OVER THE SOUTHWEST MAINLAND TRACKS FURTHER INTO THE
INTERIOR THIS EVENING...A TRIPLE POINT LOW WILL BEGIN TO DEVELOP
OVER THE EASTERN BERING AND QUICKLY TRACK INLAND OVERNIGHT. THIS
FEATURE WILL BE THE FIRST IN A SERIES OF WAVES THAT WILL KEEP
SHOWERY CONDITIONS AND GUSTY WINDS IN THE FORECAST FOR PARTS OF
THE SOUTHWEST MAINLAND THROUGH THE END OF THE WEEK. MODELS ARE IN
GOOD AGREEMENT WITH A FAIR AMOUNT OF INSTABILITY DEVELOPING OVER
THE SOUTHWEST COAST THURSDAY MORNING AND SPREADING INLAND THROUGH
FRIDAY AFTERNOON...HELPING TO PRODUCE EVEN GUSTIER WINDS AT THE
SURFACE OVER PARTS OF THE BRISTOL BAY AREA EARLY TOMORROW MORNING.
WEAK HIGH PRESSURE WILL BUILD OVER THE ALASKA PENINSULA FRIDAY
MORNING...CAUSING SHOWERY CONDITIONS OVER THE AREA TO TEMPORARILY
DIMINISH. THIS BREAK WILL BE SHORT LIVED THOUGH WITH THE FRONT
OVER THE EASTERN BERING BEGINNING TO TRACK INLAND FRIDAY
AFTERNOON...BRINGING ANOTHER ROUND OF GUSTY WINDS AND
PRECIPITATION TO THE SOUTHWEST COAST.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
AS THE LOW OVER THE WESTERN BERING BROADENS OUT ACROSS MUCH OF
THE BERING TONIGHT...EXPECT GUSTY WINDS TO PERSIST OVER PARTS OF
THE ALEUTIAN CHAIN THROUGH TOMORROW AFTERNOON. PRECIPITATION OVER
THE AREA SHOULD REMAIN PREDOMINANTLY RAIN...BUT WITH SOME COLDER
AIR BEING ADVECTED IN OVER THE WESTERN ALEUTIANS/BERING...A MIX OF
RAIN AND SNOW WILL BECOME MORE PREVALENT. A DEVELOPING LOW OVER
THE NORTH PACIFIC TOMORROW MORNING WILL DEEPEN AS IT TRACKS
THROUGH THE WESTERN ALEUTIANS AND INTO THE SOUTHWESTERN BERING BY
FRIDAY AFTERNOON. STRONG GUSTY WINDS ARE EXPECTED TO DEVELOP OVER
THE WESTERN BERING AND ALEUTIANS TOMORROW NIGHT AND PERSIST
THROUGH FRIDAY AFTERNOON. THE FRONT ASSOCIATED WITH THIS SYSTEM
WILL PUSH NORTH AND EAST THROUGH THE WESTERN AND CENTRAL
BERING/ALEUTIANS FRIDAY MORNING...AND THEN TRACK OVER THE EASTERN
BERING/ALEUTIANS BY FRIDAY AFTERNOON BEFORE DISSIPATING. GUSTY
SOUTHERLY WINDS AND RAIN ARE EXPECTED TO TRAVERSE THROUGH THE
ALEUTIAN CHAIN FROM WEST TO EAST...AS THE FRONTAL SYSTEM
PROGRESSES THROUGH THE AREA.

&&

.LONG TERM FORECAST (SATURDAY THROUGH WEDNESDAY)...

THE OVERALL SYNOPTIC PATTERN WILL SHIFT SIGNIFICANTLY STARTING
THIS WEEKEND AS A DEEP AREA OF LOW PRESSURE OVER THE WESTERN
ALEUTIAN COLLIDES WITH A STOUT NORTHEASTERN PACIFIC RIDGE. THIS
WILL RESULT IN A LARGE SCALE AMPLIFICATION OF THE RIDGE...WHICH
WILL RAPIDLY BUILD ACROSS PARTS OF THE ALASKA MAINLAND. THIS WILL
LIKELY PUSH A CHINOOK ACROSS SOUTHCENTRAL ALASKA (POSSIBLY THE
ALASKA PENINSULA TOO DEPENDING ON THE OVERALL DEVELOPMENT OF THE
RIDGE) AND BRING VERY UNSEASONABLY WARM TEMPERATURES. WIDESPREAD
RAINFALL (POTENTIALLY HEAVY AT TIMES) WILL EXTEND FROM KODIAK
ISLAND AND ALONG THE NORTHERN GULF COAST. WITH TEMPERATURES
WARMING INTO THE UPPER 30S TO POTENTIALLY MID 40S INLAND...
PRECIPITATION TYPE WILL LIKELY TRANSITION TO PURELY RAINFALL FOR
INLAND LOCATIONS INCLUDING ANCHORAGE AND PARTS OF THE MAT-SU
VALLEY. WHILE MODELS PREVIOUSLY HINTED AT THE RIDGE BEGINNING TO
FLATTEN OUT DURING THE BEGINNING/MIDDLE OF NEXT WEEK...MODELS NOW
SUGGEST ADDITIONAL SHORTWAVE ENERGY ENTERING THE UPPER LEVEL
TROUGH OVER THE BERING SEA WILL AMPLIFY THE TROUGH AND IN TURN
AMPLIFY THE UPPER RIDGE.

MODELS ARE IN FAR LESS AGREEMENT OVER THE BERING SEA AND SOUTHWEST
ALASKA. WHILE AN OVERALL STORMY PATTERN IS ON TAP WITH MULTIPLE
AREAS OF LOW PRESSURE TRAVERSING THE BERING SEA...THE STORM TRACKS
AND STRENGTH OF THESE LOW IS IN QUESTION. THIS IS DUE TO MULTIPLE
KEY FEATURES BEING HANDLED DIFFERENTLY BY BOTH DETERMINISTIC AND
ENSEMBLE GUIDANCE. NEVERTHELESS...A PERIOD OF SNOW RAIN IS LIKELY
ACROSS MUCH OF THE BERING SEA AND SOUTHWEST ALASKA WITH PERIODS OF
WINDS RANGING FROM 25 TO 35 KT.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...SNOW ADVISORY 145.
MARINE...GALE 150 155 160 165 170 172 173 174 175 176 177 178 180
              185.
         HEAVY FREEZING SPRAY WARNING 181 185.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...SEB
SOUTHCENTRAL ALASKA...DS
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP
LONG TERM...MC