Storm Warning 100, NWS Anchorage, AK

690 
FZAK62 PAFC 050000
OFFALU

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
300 PM AKST WED NOV 4 2015

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.

PKZ499-051500-
300 PM AKST WED NOV 4 2015
.SYNOPSIS FOR CENTRAL BERING SEA...
A 964 MB LOW NEAR 51N 180 MOVES TO 58N 160W AT 970 MB THU
AFTERNOON...THEN TRACKS INTO THE WESTERN GULF BY FRI MORNING. 
THE ASSOCIATED FRONT WILL TRACK ACROSS THE EASTERN BERING
TONIGHT...THEN TRACK INLAND BY THU MORNING.

$$

PKZ411-051500-
BERING SEA OFFSHORE WEST OF 180 AND EAST OF THE INTERNATIONAL
DATELINE-
300 PM AKST WED NOV 4 2015

...GALE WARNING TONIGHT AND THURSDAY NIGHT...

.TONIGHT...NW WIND 25 TO 40 KT. SEAS 9 TO 16 FT.
.THU...W WIND 15 TO 30 KT. SEAS 9 TO 14 FT.
.THU NIGHT...SW WIND 20 TO 35 KT. SEAS 7 TO 12 FT. RAIN.
.FRI...W WIND 20 TO 30 KT. SEAS 9 TO 14 FT.
.FRI NIGHT...SW WIND 20 TO 30 KT. SEAS 12 FT.
.SAT THROUGH MON...NW WIND 25 TO 40 KT. SEAS 16 TO 24 FT.

$$

PKZ412-051500-
BERING SEA OFFSHORE 171W TO 180 AND NORTH OF 56N-
300 PM AKST WED NOV 4 2015

...GALE WARNING THROUGH THURSDAY NIGHT...

.TONIGHT...N WIND 25 TO 40 KT. SEAS 9 TO 14 FT. RAIN SHOWERS.
.THU...NW WIND 25 TO 35 KT. SEAS 10 TO 15 FT. RAIN SHOWERS.
.THU NIGHT...W WIND 20 TO 35 KT. SEAS 9 TO 15 FT.
.FRI...W WIND 20 TO 35 KT. SEAS 8 TO 13 FT.
.FRI NIGHT...W WIND 20 TO 30 KT. SEAS 10 TO 13 FT.
.SAT...SW WIND 25 TO 40 KT. SEAS 14 TO 22 FT.
.SUN...SW WIND 30 TO 40 KT. SEAS 23 TO 30 FT.
.MON...NW WIND 25 TO 35 KT. SEAS 18 TO 26 FT.

$$

PKZ413-051500-
BERING SEA OFFSHORE 171W TO 180 AND SOUTH OF 56N-
300 PM AKST WED NOV 4 2015

...STORM WARNING TONIGHT...

.TONIGHT...NW WIND 40 TO 55 KT. SEAS 16 TO 26 FT. RAIN SHOWERS.
.THU...NW WIND 30 TO 45 KT. SEAS 15 TO 23 FT. RAIN SHOWERS.
.THU NIGHT...W WIND 25 TO 40 KT DIMINISHING TO 20 TO 30 KT AFTER
MIDNIGHT. SEAS 11 TO 19 FT. RAIN.
.FRI...W WIND 25 TO 35 KT. SEAS 11 TO 14 FT.
.FRI NIGHT...SW WIND 20 TO 30 KT. SEAS 10 TO 13 FT.
.SAT...SW WIND 25 TO 40 KT. SEAS 12 TO 20 FT.
.SUN THROUGH MON...W WIND 40 KT. SEAS 18 TO 27 FT.

$$

PKZ414-051500-
BERING SEA OFFSHORE EAST OF 171W-
300 PM AKST WED NOV 4 2015

...GALE WARNING THROUGH THURSDAY NIGHT...

.TONIGHT...SE WIND 25 TO 40 KT BECOMING NW 20 TO 35 KT AFTER
MIDNIGHT. SEAS 11 TO 16 FT. RAIN.
.THU...NW WIND 25 TO 40 KT. SEAS 11 TO 19 FT. RAIN SHOWERS.
.THU NIGHT...NW WIND 30 TO 45 KT. SEAS 13 TO 22 FT. RAIN SHOWERS.
.FRI...W WIND 25 TO 40 KT. SEAS 10 TO 18 FT.
.FRI NIGHT...W WIND 20 TO 30 KT. SEAS 9 TO 14 FT.
.SAT...SW WIND 15 TO 30 KT. SEAS 9 TO 17 FT.
.SUN THROUGH MON...W WIND 25 TO 35 KT. SEAS 16 TO 26 FT.

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
454 PM AKST TUE NOV 3 2015

.ANALYSIS AND UPPER LEVELS...

A LOW OVER THE GULF THAT BROUGHT AS MUCH AS 5 INCHES OF SNOW TO
THE WESTERN KENAI PENINSULA THIS MORNING IS NOW DEPARTING
SOUTHCENTRAL TOWARD THE PANHANDLE. MIDDLETON ISLAND RADAR SHOWS
THE LAST OF THE ASSOCIATED PRECIPITATION EXITING THE PRINCE
WILLIAM SOUND REGION THIS AFTERNOON. SNOWFALL TOTALS WERE GREATEST
OVER THE KENAI PENINSULA WITH AROUND AN INCH IN THE ANCHORAGE AREA
AND LESSER AMOUNTS FURTHER NORTH ACROSS THE MATANUSKA VALLEY.

THE JET STREAK SUPPORTING THE LOW OVER THE GULF WILL MOVE EAST
INTO BRITISH COLUMBIA AND WEAKEN. MEANWHILE THE NEXT POTENT JET
STORM SYSTEM IS CURRENTLY MOVING TOWARD THE WESTERN ALEUTIANS.
THE RAPIDLY INTENSIFYING LOW IS CURRENTLY CENTERED SOUTH OF THE
WESTERN ALEUTIANS AND STARTING TO BECOME NEGATIVELY TILTED.

A MUCH WEAKER IS OVER THE NORTHERN BERING IS SLOWLY WEAKENING AS
THE UPPER-LEVEL JET SUPPORT LEAVES THE LOW BEHIND. BETWEEN THIS
LOW AND THE LOW SOUTH OF THE WESTERN ALEUTIANS...SCATTERED CONVECTIVE
ACTIVITY TAKING ADVANTAGE OF THE INSTABILITY PROVIDED BY COLD AIR
ALOFT IS PRODUCING OCCASIONAL LIGHTNING STRIKES OVER THE WESTERN
BERING.

&&

.MODEL DISCUSSION...

THE MODELS ARE IN GENERAL AGREEMENT ON THE TRACK OF THE LOW CURRENTLY
SOUTH OF THE ALEUTIANS. THE REAL DIFFERENCE FROM EARLIER MODEL
RUNS IS THAT THEY ALL ARE SLOWLY SHIFTING THE TRACK OF THE STORM
CENTER FURTHER NORTH. MODEL AGREEMENT IS ALSO GOOD REGARDING THE
EXPECTED VERY STRONG WINDS ASSOCIATED WITH THE STORM. ONCE IN THE
GULF ON FRIDAY IT MOVES SWIFTLY TO THE NORTHEAST GULF COAST. THERE
IS STILL UNCERTAINTY WITH THE STRENGTH AND TRACK OF THIS SYSTEM
AND IS DOWNSLOPING IS EXPECTED WEST OF THE CHUGACH AND KENAI
MOUNTAINS...LIMITING PRECIPITATION TOTALS. ANOTHER COMPLICATING
FACTOR WITH THE STORM IS THE AMOUNT OF WARM AIR THE STORM WILL BE
INGESTING...RESULTING IN PRECIPITATION TYPE ISSUES AND WHERE THE
RAIN-SNOW LINE SETS UP. FOR THE SHORT TERM...FORECAST CONFIDENCE
IS HIGH INITIALLY DUE TO GOOD MODEL AGREEMENT AND THEN DECREASES
ON THURSDAY AS THE STORM TRACKS THROUGH THE GULF.

&&

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

A WEAKENING GALE FORCE LOW IS MAKING RAPID PROGRESS EAST INTO
CANADA THIS EVENING...WITH SNOW SHOWERS RAPIDLY DIMINISHING OVER
THE COPPER BASIN AND LARGE SCALE CLEARING DEVELOPING ACROSS MOST
OF SOUTHCENTRAL. SOME HIGH CLOUDS WILL FILTER IN OVERNIGHT...BUT
WITH WINDS WEAKENING INLAND...THIS MAY SUPPORT THE DEVELOPMENT OF
LOCALIZED PATCHY FOG. HIGH PRESSURE WILL HOLD THROUGH THE DAY
WEDNESDAY BEFORE MORE CLOUDS AND MOISTURE STREAM INTO
SOUTHCENTRAL WITH A WARM/OCCLUDED FRONT MOVING INTO THE GULF OF
ALASKA WEDNESDAY NIGHT INTO THURSDAY. SOUTHEAST WINDS WILL RAMP UP
ACROSS PORTAGE VALLEY AND DOWN TURNAGAIN ARM WITH THE APPROACHING
FRONT...REACHING INTO THE 60 MPH RANGE ACROSS WEST TURNAGAIN ARM
BY THURSDAY MORNING. A RATHER STRONG EASTERLY FLOW NEAR MOUNTAIN
TOP WILL RESULT IN VERY EFFICIENT DOWNSLOPE DRYING DOWNWIND OF
THE CHUGACH MOUNTAINS...WITH ONLY SLIGHT CHANCES FOR RAIN AND SNOW
SHOWERS INLAND FROM ANCHORAGE NORTHWARD THROUGH THURSDAY.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
A WEAK FRONTAL SYSTEM WILL TRACK ACROSS THE EASTERN BERING AND PUSH
INTO THE WESTERN COAST TONIGHT. THIS WILL BRING A MIX OF RAIN AND
SNOW TO THE KUSKOKWIM DELTA AND LOWER KUSKOKWIM VALLEY THROUGH
WEDNESDAY MORNING AS IT TRACKS FURTHER INLAND. A FRONT ASSOCIATED
WITH A STRONG BERING SEA LOW WILL QUICKLY TRACK INTO THE WESTERN
COAST WEDNESDAY NIGHT...BRINGING GUSTY WINDS AND PRECIPITATION
BACK TO THE SOUTHWEST MAINLAND THROUGH THE END OF THE WEEK. RAIN
WILL BE THE DOMINANT PRECIPITATION TYPE WITH THIS SYSTEM GIVEN
THE WARMER SOUTHERLY FLOW WRAPPING INTO THIS SYSTEM AS IT TRACKS
INTO THE ALASKA PENINSULA OVERNIGHT THURSDAY.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
A WEAK FRONTAL SYSTEM WILL CONTINUE TO TRACK THROUGH THE EASTERN
BERING TONIGHT AND MOVE INLAND OVERNIGHT TONIGHT...BRINGING SOME
RAIN AND GUSTY WINDS TO THE PRIBILOFS AND PARTS OF THE EASTERN
BERING SEA THROUGH TONIGHT. THE FOCUS THEN SHIFTS TO A STRONG LOW
TRACKING INTO THE CENTRAL ALEUTIANS WEDNESDAY MORNING...THEN
TRACKING ALONG THE BERING SIDE OF THE ALEUTIAN CHAIN AND INTO THE
ALASKA PENINSULA BY THE END OF THE WEEK. THIS SYSTEM WILL PRODUCE
STRONG WINDS AND RAIN TO MUCH OF THE ALEUTIAN CHAIN THROUGH THE
END OF THE WEEK...WITH THE STRONGEST WINDS ON THE WESTERN FLANK
REACHING HIGH WIND CRITERIA OVER THE CENTRAL ALEUTIANS WED THROUGH
LATE WEDNESDAY NIGHT.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
THE FORECAST AREA IS EXPECTED TO REMAIN IN AN ACTIVE PATTERN IN
THE MID TO LONG TERM AS A SERIES OF ROBUST LOWS MOVE THROUGH THE
REGION. FRIDAY EVENING...THE STRONG LOW MOVING THROUGH THE
ALEUTIANS WILL ENTER THE GULF OF ALASKA WITH THE WITH THE
ASSOCIATED FRONT PUSHING INTO THE NORTHERN GULF COAST THURSDAY
NIGHT INTO FRIDAY MORNING. AT THE SAME TIME...A WEAK RIDGE WILL BE
BUILDING INTO THE CENTRAL BERING BY SATURDAY MORNING. THE LOW
WILL SLOWLY WEAKEN IN PLACE OVER PRINCE WILLIAM SOUND THROUGH
SATURDAY MORNING...KEEPING SOUTHWEST ALASKA IN A SHOWERY NORTHWEST
FLOW. THIS PATTERN WILL ALSO PRODUCE DOWNSLOPING OVER THE SUSITNA
VALLEY/WESTERN KENAI PENINSULA AND THE ANCHORAGE BOWL WITH
PRECIPITATION REMAINING IN THE FORECAST MOSTLY ALONG THE GULF
COAST AS WELL AS PARTS OF THE COPPER RIVER BASIN. THE RIDGE OVER
THE CENTRAL BERING WILL PUSH EASTWARD ON SATURDAY...FORCING THE
LOW SOUTHEASTWARD OUT OF THE FORECAST AREA.

OUT WEST...A WEAK LOW DEVELOPING OVER THE NORTHWEST PACIFIC ON
SATURDAY MORNING WILL MOVE INTO THE WESTERN ALEUTIANS WHERE IT
WILL MERGE WITH A STRONGER LOW DEVELOPING OVER THE NORTHWESTERN
BERING SEA. THIS DEEPER LOW IS EXPECTED TO STRENGTHEN FURTHER AND
MOVE INTO THE CENTRAL BERING BY MONDAY MORNING. GLOBAL MODELS ARE
IN BROAD AGREEMENT WITH A STRONG LOW OVER THE NORTHERN BERING BY
18Z MONDAY. HOWEVER...THE GFS IS PLACING A 981 MB LOW NEAR GAMBELL
WHILE THE EC SOLUTION IF BRINGS THE LOW TO 962 MB AT A POSITION
SOUTHWEST OF SAINT MATTHEW ISLAND WITH STORM FORCE WINDS OVER THE
CENTRAL BERING. THE EC HAS BEEN REASONABLY CONSISTENT WITH THE
POSITIONING OF THIS LOW AND THE EC ENSEMBLE SHOWED A CLOSED LOW AT
THIS TIME AS WELL. WITH THIS IN MIND...THE EXTENDED FORECAST
LEANED HEAVY ON THE WPC FORECAST WHICH UTILIZED THE EC ENSEMBLE.
THIS BRINGS THE WINDS OVER THE ALEUTIANS/BERING TO GALE FORCE
SUNDAY INTO MONDAY TO SHOW AN UPWARD TREND FROM THE PREVIOUS
FORECAST PACKAGE.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...HIGH WIND WARNING 187.
MARINE...HURRICANE FORCE WIND WARNING 177.
         STORM WARNING 170 172 173 174 175 176 178.
         GALE WARNING 130 131 132 150 155 160 165 171 179 180 181 185.

&&

SYNOPSIS AND MODEL DISCUSSION...JW
SOUTHCENTRAL ALASKA...JA
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP
LONG TERM...RF