Storm Warning 158, NWS Anchorage, AK

000 
FZAK52 PAFC 222302
CWFALU

COASTAL WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE ALASKA
400 PM AKDT TUE SEP 22 2009

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.

PKZ199-231400-
400 PM AKDT TUE SEP 22 2009
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

A 982 MB LOW 200 NM SOUTH OF ADAK WILL MOVE TO 250 NM SOUTH OF COLD
BAY BY WED AFTERNOON AND THEN MOVE TO 150 NM SOUTH OF KODIAK BY THU
AFTERNOON. A DEVELOPING WESTERN BERING 1012 MB LOW 450 NM NORTH OF
SHEMYA WED NIGHT WILL MOVE TO 250 NM NORTH OF AMCHITKA AT 1005 MB THU
NIGHT.

$$

PKZ150-231400-
COASTAL WATERS SOUTH OF THE ALASKA PENINSULA SITKINAK TO CASTLE
CAPE
400 PM AKDT TUE SEP 22 2009

...GALE WARNING WEDNESDAY NIGHT...

.TONIGHT...NW WIND 15 KT BECOMING VARIABLE 10 KT BY MIDNIGHT.
SEAS 4 FT. 
.WED...VARIABLE WIND 10 KT BECOMING E 20 KT IN THE AFTERNOON.
SEAS 5 FT. 
.WED NIGHT...E WIND INCREASING TO 35 KT. SEAS BUILDING TO 11 FT.
RAIN.
.THU...N WIND 35 KT. SEAS 12 FT. 
.THU NIGHT AND FRI...NW WIND 35 KT. SEAS 13 FT. 
.SAT...SW WIND 30 KT. SEAS 10 FT. 
.SUN...NW WIND 15 KT. SEAS 9 FT.  

$$

PKZ155-231400-
COASTAL WATERS SOUTH OF THE ALASKA PENINSULA CASTLE CAPE TO CAPE
SARICHEF
400 PM AKDT TUE SEP 22 2009

...GALE WARNING WEDNESDAY NIGHT...

.TONIGHT...E WIND 10 KT INCREASING TO 20 KT AFTER MIDNIGHT.
SEAS 5 FT. 
.WED...E WIND INCREASING TO 30 KT. SEAS BUILDING TO 9 FT. RAIN.
.WED NIGHT...NE WIND 40 KT. SEAS 18 FT. RAIN.
.THU...N WIND 35 KT. SEAS 13 FT. 
.THU NIGHT AND FRI...NW WIND 35 KT. SEAS 11 FT. 
.SAT...SW WIND 25 KT. SEAS 10 FT. 
.SUN...NW WIND 15 KT. SEAS 7 FT.  

$$

PKZ160-231400-
BRISTOL BAY WATERS CAPE NEWENHAM TO PORT HEIDEN
400 PM AKDT TUE SEP 22 2009

.TONIGHT...W WIND 15 KT. SEAS 4 FT. 
.WED...VARIABLE WIND 10 KT. SEAS 4 FT. 
.WED NIGHT...NE WIND 20 KT. SEAS 5 FT. 
.THU AND THU NIGHT...N WIND 30 KT. SEAS 9 FT. 
.FRI...NW WIND 25 KT. SEAS 8 FT. 
.SAT...NW WIND 15 KT. SEAS 5 FT. 
.SUN...VARIABLE WIND 10 KT. SEAS 4 FT.  

$$

PKZ165-231400-
PORT HEIDEN TO CAPE SARICHEF
400 PM AKDT TUE SEP 22 2009

...SMALL CRAFT ADVISORY WEDNESDAY AND WEDNESDAY NIGHT...

.TONIGHT...VARIABLE WIND 10 KT BECOMING NE WIND 20 KT AFTER MIDNIGHT.
SEAS 4 FT. 
.WED AND WED NIGHT...NE WIND 25 KT. SEAS 8 FT. RAIN.
.THU...N WIND 30 KT. SEAS 9 FT. 
.THU NIGHT...NW WIND 30 KT. SEAS 11 FT. 
.FRI...W WIND 25 KT. SEAS 10 FT. 
.SAT...N WIND 15 KT. SEAS 8 FT. 
.SUN...VARIABLE WIND 10 KT. SEAS 7 FT.  

$$

PKZ180-231400-
SOUTHWEST ALASKA WATERS CAPE NEWENHAM TO DALL POINT
400 PM AKDT TUE SEP 22 2009

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...NW WIND 25 KT. SEAS 9 FT.
.WED...W OF NUNIVAK ISLAND...NW WIND 25 KT. SEAS 9 FT. E OF NUNIVAK
ISLAND...NW WIND 15 KT. SEAS 4 FT. 
.WED NIGHT THROUGH THU NIGHT...N WIND 25 KT. SEAS 8 FT. 
.FRI AND SAT...NW WIND 20 KT. SEAS 5 FT. 
.SUN...VARIABLE WIND 10 KT. SEAS 4 FT.  

$$

PKZ170-231400-
EASTERN ALEUTIANS CAPE SARICHEF TO NIKOLSKI
400 PM AKDT TUE SEP 22 2009

...GALE WARNING WEDNESDAY AND WEDNESDAY NIGHT...

.TONIGHT...E WIND 15 KT BECOMING NE WIND 30 KT BY MIDNIGHT. SEAS
BUILDING TO 9 FT. RAIN.
.WED...NE WIND 40 KT. SEAS 13 FT. RAIN.
.WED NIGHT...N WIND 40 KT. SEAS 14 FT. RAIN.
.THU AND THU NIGHT...NW WIND 30 KT. SEAS 11 FT. 
.FRI...SW WIND 30 KT. SEAS 9 FT. 
.SAT...N WIND 30 KT. SEAS 10 FT. 
.SUN...W WIND 15 KT. SEAS 8 FT.  

$$

PKZ171-231400-
UNALASKA BAY
400 PM AKDT TUE SEP 22 2009

...GALE WARNING WEDNESDAY NIGHT...

.TONIGHT...VARIABLE WIND 10 KT BECOMING E WIND 20 KT BY MIDNIGHT.
SEAS 3 FT. RAIN.
.WED...NE WIND 30 KT. SEAS 9 FT. RAIN.
.WED NIGHT...N WIND 35 KT. SEAS 10 FT. RAIN SHOWERS. 
.THU...NW WIND 30 KT. SEAS 10 FT. 
.THU NIGHT...NW WIND 25 KT. SEAS 9 FT. 
.FRI...SW WIND 20 KT. SEAS 5 FT. 
.SAT...N WIND 20 KT. SEAS 8 FT. 
.SUN...W WIND 15 KT. SEAS 6 FT.  

$$

PKZ172-231400-
EASTERN ALEUTIANS NIKOLSKI TO ADAK
400 PM AKDT TUE SEP 22 2009

...GALE WARNING THROUGH WEDNESDAY NIGHT...

.TONIGHT...NE WIND 40 KT. SEAS 20 FT PACIFIC SIDE...12 FT BERING
SIDE. RAIN.
.WED...N WIND 40 KT. SEAS 19 FT PACIFIC SIDE...14 FT BERING SIDE.
RAIN.
.WED NIGHT...N WIND 35 KT. SEAS 15 FT. 
.THU...NW WIND 30 KT. SEAS 12 FT. 
.THU NIGHT AND FRI...W WIND 30 KT. SEAS 10 FT. 
.SAT...NW WIND 35 KT. SEAS 11 FT. 
.SUN...SE WIND 25 KT. SEAS 7 FT.  

$$

PKZ175-231400-
WESTERN ALEUTIANS ADAK TO KISKA
400 PM AKDT TUE SEP 22 2009

...GALE WARNING TONIGHT...

.TONIGHT...NE WIND 35 KT. SEAS 17 FT. RAIN.
.WED...NE WIND 30 KT DISSIPATING TO 20 KT IN THE AFTERNOON. SEAS 14
FT. PATCHY FOG. 
.WED NIGHT...N WIND 25 KT BECOMING NW 15 KT AFTER MIDNIGHT. SEAS
11 FT. PATCHY FOG. 
.THU...W WIND 20 KT. SEAS 8 FT. 
.THU NIGHT...W WIND 25 KT. SEAS 8 FT. 
.FRI...NW WIND 25 KT. SEAS 11 FT. 
.SAT...E WIND 25 KT. SEAS 8 FT. 
.SUN...SE WIND 30 KT. SEAS 12 FT.  

$$

PKZ176-231400-
WESTERN ALEUTIANS KISKA TO ATTU
400 PM AKDT TUE SEP 22 2009

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...NE WIND 30 KT BECOMING N WIND 20 KT AFTER MIDNIGHT. SEAS
14 FT. 
.WED...N WIND 20 KT BECOMING VARIABLE 10 KT IN THE AFTERNOON. SEAS 10
FT. PATCHY FOG. 
.WED NIGHT...VARIABLE WIND 10 KT. SEAS 8 FT. PATCHY FOG. 
.THU...W WIND 20 KT. SEAS 7 FT. 
.THU NIGHT...NW WIND 25 KT. SEAS 9 FT. 
.FRI...N WIND 20 KT. SEAS 11 FT. 
.SAT...SE WIND 35 KT. SEAS 14 FT. 
.SUN...S WIND 35 KT. SEAS 15 FT.  

$$

PKZ185-231400-
ST MATTHEW ISLAND WATERS
400 PM AKDT TUE SEP 22 2009

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...N WIND 25 KT. SEAS 10 FT. 
.WED AND WED NIGHT...N WIND 25 KT. SEAS 10 FT. 
.THU THROUGH FRI...N WIND 20 KT. SEAS 7 FT. 
.SAT...NW WIND 20 KT. SEAS 6 FT. 
.SUN...VARIABLE WIND 10 KT. SEAS 3 FT.  

$$

PKZ179-231400-
PRIBILOF ISLANDS NEAR-SHORE WATERS
400 PM AKDT TUE SEP 22 2009

...SMALL CRAFT ADVISORY WEDNESDAY AND WEDNESDAY NIGHT...

.TONIGHT...NE WIND 20 KT. SEAS 6 FT. 
.WED THROUGH THU...N WIND 25 KT. SEAS 9 FT. 
.THU NIGHT...NW WIND 20 KT. SEAS 7 FT. 
.FRI...N WIND 15 KT. SEAS 5 FT. 
.SAT...NW WIND 20 KT. SEAS 6 FT. 
.SUN...VARIABLE WIND 10 KT. SEAS 5 FT.  

$$

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
140 PM AKDT MON SEP 21 2009

.ANALYSIS AND UPPER LEVELS...MAJOR FEATURES OF INTEREST TODAY
INCLUDE A DEEP LOW SOUTHWEST OF THE ALEUTIANS (FORMERLY TYPHOON
CHOI-WAN) WHICH IS TRACKING EASTWARD ALONG THE SUBTROPICAL JET.
AN 18Z QUIKSCAT WIND IMAGE SHOWS A BAND OF GALE TO STORM FORCE
WINDS NORTH OF THE LOW CENTER...WHICH WILL TRANSLATE EASTWARD
WITH THE LOW. JUST DOWNSTREAM FROM THIS STORM A SHORT-WAVE RIDGE
IS MAINTAINING TRANQUIL CONDITIONS OVER THE CENTRAL TO EASTERN
BERING AND ALEUTIANS. HEADING FURTHER DOWNSTREAM...A CLOSED LOW
IS DROPPING SOUTHWARD ACROSS WESTERN ALASKA WHILE A WEAKENING
LOW OVER THE NORTHERN GULF LIFTS NORTHWARD TOWARD SOUTHCENTRAL.
COLD ADVECTION ASSOCIATED WITH THE UPPER LOW IS HELPING TO KICK
UP WINDS ALONG THE SOUTHWEST COAST. SCATTERED SHOWERS ARE IN THE
FORM OF RAIN...ALTHOUGH THAT WILL CHANGE BY TONIGHT AS THE AIR
BECOMES COLD ENOUGH TO GENERATE SNOW. GALE FORCE WINDS CONTINUE
ON THE EAST SIDE OF THE NORTH GULF LOW...WITH SOME ENHANCEMENT
FROM A BARRIER JET ALONG THE IMMEDIATE COAST...BUT THESE WINDS
WILL DIMINISH QUICKLY AS THE LOW MOVES INLAND THIS EVENING AND
WINDS VEER TOWARD THE SOUTH.

.MODEL DISCUSSION...MODELS ARE IN GOOD AGREEMENT THROUGH WEDNESDAY
ACROSS THE ANCHORAGE FORECAST AREA. AFTER THAT SOLUTIONS BEGIN TO
DIVERGE WITH TRACK OF ALEUTIAN STORM AND DISPLAY POOR RUN-TO-RUN
CONSISTENCY. MODEL STORM TRACKS HAVE RANGED FROM BRISTOL BAY TO
THE WESTERN GULF...WHICH OF COURSE MAKES A LARGE DIFFERENCE IN
THE FORECAST. ALL OF THE 12Z MODELS DO INDICATE A TRACK SOUTH OF
THE ALASKA PENINSULA AND THERE IS SUPPORT FOR THIS FROM THE GFS
ENSEMBLES. THEREFORE...WILL LEAN TOWARD THIS MORE EASTERLY TRACK.

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...BASED ON CURRENT LOW POSITION WEST OF
MIDDLETON ISLAND AND NORTHWARD DRIFT...LOW WILL TRACK ACROSS
WESTERN PRINCE WILLIAM SOUND AND THEN INLAND OVERNIGHT.
MEANWHILE...AS THE UPPER LOW CONTINUES TO DROP SOUTHWARD INTO
SOUTHWEST ALASKA A SHORT-WAVE WILL ROTATE EASTWARD TOWARD
SOUTHCENTRAL...HELPING TO ENHANCE PRECIPITATION ACROSS THE
REGION. ADDITIONAL SHORT-WAVES TIGHT ON THE PERIPHERY OF THE
UPPER LOW WILL CONTINUE TO ROTATE ACROSS SOUTHCENTRAL ON TUESDAY
BEFORE HEADING INTO THE INTERIOR TUESDAY NIGHT INTO WEDNESDAY.
MEANWHILE...COLDER AIR WILL FILTER INTO SOUTHCENTRAL. THE PROBLEM
OF THE DAY IS DETERMINING PRECIPITATION TYPE AS THE COLDER AIR
MOVES IN. BASED ON MODEL 1000-850MB THICKNESSES...WHICH REMAIN
MOSTLY ABOVE 1300M ACROSS MOST OF SOUTHCENTRAL THROUGH TUESDAY
MORNING...PRECIPITATION WILL REMAIN RAIN NEAR SEA LEVEL. IT DOES
APPEAR THAT THE UPPER SHORT-WAVES WILL PRODUCE A SIGNIFICANT
AMOUNT OF DYNAMIC LIFT...SO THERE MAY BE BANDS OF HEAVY
PRECIPITATION. PRECIPITATION WILL ALSO BE ENHANCED ALONG THE
MOUNTAINS FROM ANCHORAGE UP TO THE NORTHERN SUSITNA VALLEY LATE
TONIGHT AND TUESDAY AS SOUTH TO SOUTHWEST LOW LEVEL FLOW DEVELOPS
BEHIND THE EXITING SURFACE LOW. HEAVIER PRECIPITATION WILL HELP
COOL THE COLUMN AND LOWER THE SNOW LEVEL. THEREFORE...MINOR SNOW
ACCUMULATION IS LIKELY OVER HIGHER ELEVATIONS OF SOUTHCENTRAL.
AREAS NEAR SEA LEVEL MAY SEE A PERIOD OF SNOW MIXED IN WITH THE
RAIN IN HEAVIER BANDS OF PRECIPITATION...BUT DONT EXPECT IT TO
CHANGE TO ALL SNOW. THE GREATEST POTENTIAL FOR ACCUMULATION IS THE
NORTHERN SUSITNA VALLEY WHICH WILL SEE THE COLDEST AIR AND WHERE
PRECIPITATION WILL LAST THE LONGEST. SHOWERS WILL LINGER ACROSS
THE REGION THROUGH TUESDAY NIGHT...AND WITH COLDER AIR CONTINUING
TO MOVE IN...SOME OF THESE COULD BE IN THE FORM OF SNOW. THERE WILL
THEN BE A BRIEF BREAK WEDNESDAY BEFORE THE ALEUTIAN SYSTEM BEGINS
TO AFFECT SOUTHCENTRAL...QUICKLY ADVECTING WARMER AIR BACK INTO
THE REGION.

SOUTHWEST ALASKA...AS THE UPPER LOW MOVES TO SOUTHWEST ALASKA
TONIGHT THE AIRMASS WILL CONTINUE TO COOL...CHANGING SHOWERS
FROM RAIN TO SNOW. THERE IS LESS MOISTURE TO WORK WITH OVER
SOUTHWEST ALASKA COMPARED WITH SOUTHCENTRAL...AND THE BEST
LIFT WILL BE DOWNSTREAM OF THE UPPER LOW...SO PRECIPITATION
WILL REMAIN PREDOMINANTLY SHOWERY. THERE WILL BE SOME ENHANCED
UPSLOPE SNOW IN WESTERLY FLOW ALONG THE ALASKA RANGE AND OTHER
SIMILARLY ORIENTED MOUNTAINS. THESE SHOWERS WILL CONTINUE TUESDAY
ALONG THE SOUTHERN PERIPHERY OF THE UPPER LOW...PRIMARILY FROM
THE KUSKOKWIM DELTA TO KUSKOKWIM VALLEY...AND THEN TAPER OFF
TUESDAY NIGHT AS THE UPPER LOW LIFTS BACK NORTHWARD. THERE IS
STILL SOME UNCERTAINTY IN THE TRACK OF THE ALEUTIAN LOW...BUT
AT THIS POINT IT LOOKS LIKE IT WILL TRACK JUST SOUTH OF THE
ALASKA PENINSULA...WHICH WOULD SPREAD RAIN AND WIND NORTH AND
WEST ACROSS SOUTHWEST ALASKA ON THURSDAY.

BERING SEA/ALEUTIANS...THE STRONG ALEUTIAN LOW WILL TRACK ALMOST
DUE EAST...REMAINING JUST SOUTH OF THE ALEUTIANS...BUT CLOSE
ENOUGH TO SPREAD GALES AND RAIN ALONG THE ENTIRE CHAIN ALONG
THE WAY. AS THE SYSTEM MOVES SOUTH OF THE ALASKA PENINSULA THURSDAY
A COUPLE SHORT-WAVES WILL DROP SOUTHWARD ACROSS THE BERING...HELPING
TO ADVECT COLDER AIR SOUTHWARD AND INTO THE SYSTEM AND MAINTAIN
STRONG AND GUSTY NORTHERLIES ACROSS THE CENTRAL TO EASTERN BERING.

.LONG TERM FORECAST...ASSUMING THE ALEUTIAN LOW DOES IN FACT TRACK
INTO THE GULF AT THE END OF THE WEEK SOUTHCENTRAL WILL REMAIN WET
THROUGH THE WEEKEND AS THIS SYSTEM DISSIPATES. THIS TRACK ALSO
MEANS THAT COLDER AIR WILL LIKELY MOVE BACK IN BEHIND IT SUNDAY
INTO MONDAY. MEANWHILE...ANOTHER STORM SYSTEM WILL MOVE TO THE
ALEUTIANS OVER THE WEEKEND...ALTHOUGH THE DETAILS ON POSITION
AND STRENGTH ARE VERY MUCH IN QUESTION AT THIS POINT IN TIME.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORM WARNING...176.
         GALE WARNING...170 172 175 180.
FIRE WEATHER...NONE.

SEB SEP 09