Gale Warning 215, NWS Anchorage, AK

973 
FZAK62 PAFC 060001
OFFALU

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
301 PM AKST SAT MAR 5 2016

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.

PKZ499-061415-
301 PM AKST SAT MAR 5 2016
.SYNOPSIS FOR CENTRAL BERING SEA...
A TROUGH OF LOW PRESSURE DEVELOPS OVER THE EASTERN BERING LATE
TONIGHT...THEN MOVES OVER THE EASTERN ALEUTIANS BY LATE SUN
NIGHT AND STALLS.

$$

PKZ411-061415-
BERING SEA OFFSHORE WEST OF 180 AND EAST OF THE INTERNATIONAL
DATELINE-
301 PM AKST SAT MAR 5 2016

...HEAVY FREEZING SPRAY WARNING THROUGH SUNDAY NIGHT...

.TONIGHT...N WIND 30 KT. SEAS 10 TO 12 FT. HEAVY FREEZING SPRAY
N OF 56N.
.SUN...N WIND 30 KT. SEAS 10 TO 12 FT. HEAVY FREEZING SPRAY
N OF 57N.
.SUN NIGHT...N WIND 25 KT. SEAS 9 TO 12 FT. HEAVY FREEZING SPRAY
N OF 57N.
.MON...N WIND 10 TO 25 KT. SEAS 6 TO 10 FT.
.MON NIGHT...N WIND UP TO 20 KT. SEAS 5 TO 8 FT.
.TUE THROUGH WED...NE WIND 10 TO 25 KT. SEAS 5 TO 10 FT.
.THU...N WIND 25 KT. SEAS 9 FT.

$$

PKZ412-061415-
BERING SEA OFFSHORE 171W TO 180 AND NORTH OF 56N-
301 PM AKST SAT MAR 5 2016

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

.TONIGHT...N WIND 35 KT. SEAS 10 TO 13 FT. HEAVY FREEZING SPRAY.
.SUN...N WIND 35 KT. SEAS 10 TO 13 FT. HEAVY FREEZING SPRAY N OF
57N.
.SUN NIGHT...N WIND 20 TO 30 KT. SEAS 9 TO 12 FT. HEAVY FREEZING
SPRAY N OF 57N.
.MON...N WIND 15 TO 25 KT. SEAS 6 TO 10 FT.
.MON NIGHT...N WIND 10 TO 20 KT. SEAS 5 TO 8 FT.
.TUE THROUGH THU...N WIND 10 TO 25 KT. SEAS 4 TO 9 FT.

$$

PKZ413-061415-
BERING SEA OFFSHORE 171W TO 180 AND SOUTH OF 56N-
301 PM AKST SAT MAR 5 2016

.TONIGHT...N WIND 20 TO 30 KT. SEAS 9 TO 12 FT. SNOW SHOWERS.
FREEZING SPRAY.
.SUN...N WIND 20 TO 30 KT. SEAS 9 TO 12 FT. SNOW SHOWERS.
FREEZING SPRAY.
.SUN NIGHT...N WIND 20 TO 30 KT. SEAS 9 TO 12 FT. SNOW SHOWERS.
FREEZING SPRAY N OF 54N.
.MON...N WIND 15 TO 30 KT. SEAS 7 TO 11 FT.
.MON NIGHT...N WIND 10 TO 20 KT. SEAS 5 TO 9 FT.
.TUE...NW WIND UP TO 15 KT. SEAS 4 TO 7 FT.
.WED...E WIND UP TO 20 KT. SEAS 3 TO 8 FT.
.THU...N WIND 15 TO 25 KT. SEAS 6 TO 9 FT.

$$

PKZ414-061415-
BERING SEA OFFSHORE EAST OF 171W-
301 PM AKST SAT MAR 5 2016

...HEAVY FREEZING SPRAY WARNING THROUGH SUNDAY NIGHT...

.TONIGHT...N WIND 15 TO 30 KT...EXCEPT VARIABLE 15 KT E OF 167W.
SEAS 5 TO 9 FT. SNOW SHOWERS. HEAVY FREEZING SPRAY N OF 57N.
.SUN...NE WIND 15 TO 30 KT...EXCEPT VARIABLE 10 KT E OF 168W. SEAS
4 TO 9 FT. SNOW SHOWERS. HEAVY FREEZING SPRAY N OF 58N.
.SUN NIGHT...NE WIND 10 TO 20 KT...EXCEPT VARIABLE 10 KT E OF
168W. SEAS 3 TO 7 FT. SNOW. HEAVY FREEZING SPRAY N OF 58N.
.MON...NE WIND UP TO 15 KT. SEAS 3 TO 5 FT.
.MON NIGHT...N WIND UP TO 15 KT. SEAS 3 TO 4 FT.
.TUE THROUGH THU...NE WIND 10 TO 25 KT. SEAS 3 TO 8 FT.

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
432 PM AKST FRI MAR 4 2016

.ANALYSIS AND UPPER LEVELS...

INCREASED SOUTHEASTERLY 700 MB FLOW DEVELOPED THIS MORNING INTO
EARLY AFTERNOON COMBINED WITH A VERY DEEP COLD POOL TO MOUNTAIN-
TOP LEVEL TO GENERATE SIGNIFICANT ISENTROPIC UPGLIDE OF MOISTURE
AND LIFT OVER THE WESTERN SLOPES OF THE CHUGACH AND KENAI RANGES.
THIS RESULTED IN AN OVER-PERFORMING MINOR SNOW EVENT FOR THE COOK
INLET REGION DURING TODAY.

THE UPPER LEVEL LOW THAT DEVELOPED YESTERDAY OVER THE INTERIOR
CONTINUES TO MOVE SOUTH AND WEST THROUGH THE BRISTOL BAY
REGION...AND WILL CONTINUE TO MERGE WITH ANOTHER LARGE CYCLONIC
CENTER OVER THE NORTHEAST PACIFIC. A STRONG UPPER LEVEL CUT-OFF
HIGH OVER THE EASTERN ALEUTIANS CONTINUES TO RETROGRADE WEST.
ANOTHER UPPER LOW IS SLOWLY SLIPPING TO THE SOUTH OF THE
RETROGRADING HIGH OVER THE NORTH PACIFIC WELL SOUTH OF THE
ALEUTIAN ISLANDS. A SOUTHEASTERLY UPPER JET IS SUPPLYING A THICK
CANOPY OF MID AND HIGH-LEVEL CLOUDS ACROSS THE WESTERN AND
CENTRAL ALEUTIANS...WITH RAIN AND SNOW SHOWER ACTIVITY CONTINUING
ALONG A SURFACE BOUNDARY MOVING WEST.

COLD ADVECTION SNOW SHOWERS ARE JUST BEGINNING TO START AS LOW-
LEVEL COLD AIR MOVES OVER THE ICE-FREE WATERS OF THE BERING FROM
NEAR SAINT MATTHEW ISLAND TO NEAR NUNIVAK ISLAND...AND WILL
CONTINUE TO EXPAND SOUTH THROUGH THE REMAINDER OF THE AFTERNOON.

TOWARD THE GULF AND SOUTHCENTRAL ALASKA...A TRAIN OF DISTURBANCES
CONTINUES TO ROTATE AROUND THE CYCLONIC UPPER LEVEL LOW WELL SOUTH
OF THE GULF...PUSHING FAST-MOVING YET SMALLER SYSTEMS WEST ACROSS
THE NORTHERN GULF. THE FIRST OF THESE SYSTEMS AS AT LEAST
PARTIALLY RESPONSIBLE FOR THE SNOWFALL TODAY ACROSS THE ANCHORAGE
BOWL AND VICINITY.

&&

.MODEL DISCUSSION...

THE PATTERN IS WELL RESOLVED BY THE MODELS...WITH MUCH OF THE
IMPACTED AREAS CONFINED TO COASTAL LOCATIONS AND THE MARINE
WATERS. OFFSHORE FLOW IN THE LOWER LEVELS WILL CONTINUE THROUGH AT
LEAST THE WEEKEND.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A PATTERN CHANGE HAS BEGUN WHICH WILL BRING WAVES OF MOISTURE TO
SOUTHCENTRAL ALASKA. AN UPPER LEVEL LOW CENTERED SOUTH OF THE GULF
WILL SPIN A SERIES OF WEATHER SYSTEMS INTO THE AREA FROM THE
SOUTHEAST OVER THE NEXT COUPLE OF DAYS AS THE RIDGE THAT HAS BEEN
PROTECTING SOUTHERN ALASKA MOVES NORTH. THE FIRST SYSTEM WHICH
MOVED ACROSS THE KENAI PENINSULA EARLIER TODAY WILL SHIFT TO THE
SOUTHWEST THIS EVENING AND SLOWLY DISSIPATE OVER KODIAK ISLAND BY
SATURDAY AFTERNOON. THIS SYSTEM WILL CONTINUE TO BRING LIGHT
PRECIPITATION OVER PARTS OF THE KENAI PENINSULA AND KODIAK ISLAND
THROUGH LATER THIS EVENING. THE NEXT SYSTEM IS A SLIGHTLY STRONGER
AND CLOSED SURFACE LOW WITH GALE FORCE WINDS...WHICH WILL BRING
STRONGER CROSS BARRIER FLOW AND KEEP THE AREAS ON THE LEE SIDE OF
THE CHUGACH AND KENAI MOUNTAINS DRIER THIS TIME AROUND. THIS LOW
WILL RACE INTO THE NORTHERN GULF TONIGHT AND REACH THE KENAI
PENINSULA SATURDAY MORNING...THEN BEGIN TO WEAKEN BY SATURDAY
NIGHT. THE THIRD SYSTEM WILL BE FAIRLY WEAK AND ARRIVE ALONG THE
SOUTHWEST GULF COAST BY SUNDAY.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
THE CLOSED UPPER LEVEL LOW WILL CONTINUE TO TRACK THROUGH THE
SOUTHWEST ALASKA REGION BEFORE MOVING INTO THE EASTERN BERING SEA
BY SATURDAY AFTERNOON. THIS SYNOPTIC FEATURE WILL BRING COOLER AIR
FROM THE NORTH ACCOMPANIED BY LOW LEVEL MOISTURE. THIS WILL
PRODUCE LIGHT FLURRIES THROUGH THE AREA OF RESPONSIBILITY (AOR)
HEADING INTO THE WEEKEND. THERE WILL BE SEVERAL WEAK SHORTWAVES
TRACKING FROM THE WESTERN GULF ACROSS THE ALEUTIAN/ALASKA RANGE.
THIS IS RESULTING IN MOISTURE SPILLING-OVER INTO THE BRISTOL BAY
INTERIOR. THE PRECIPITATION WILL FALL AS A RAIN/SNOW MIXTURE OVER
THE ALEUTIAN/ALASKA RANGE BEFORE TRANSITIONING TO SCATTERED SNOW
SHOWERS AS THE PRECIPITATION MOVES WESTWARD INTO THE BRISTOL BAY
INTERIOR REGION. SOME OF THIS MOISTURE WILL MAKE IT INTO THE LOWER
KUSKOKWIM VALLEY/DELTA. THEREFORE...LOOK FOR ISOLATED SNOW SHOWERS
WITH THE CONTINUED COOLER TEMPERATURES COINCIDING WITH THE
NORTHEASTERLY WINDS THROUGH THE WEEKEND.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE BERING SEA/ALEUTIANS WILL REMAIN UNDER THE INFLUENCE OF
NORTHERLY FLOW. THIS WILL USHER IN COLDER AIR THROUGH THE AOR
WITH A SHOWERY WEATHER REGIME. THE EASTERN ALEUTIANS WILL SEE
NUMEROUS SNOW SHOWERS DEVELOPING LATE TONIGHT AS THE COLDER AIR
FILTERS INTO THIS REGION. BY SATURDAY AFTERNOON THE NUMEROUS SNOW
SHOWERS COVERAGE WILL EXPAND WESTWARD ALONG THE CHAIN TO ADAK AND
NORTHWARD INTO THE CENTRAL BERING TO SAINT PAUL ISLAND AREA. THE
WESTERN ALEUTIANS HAVE A WEAK WAVE MOVING THROUGH BEFORE EXITING
THE CHAIN AFTER MIDNIGHT TONIGHT. THIS WILL BRING SLIGHT WARMER
TEMPERATURES RESULTING IN A MIXTURE OF RAIN/SNOW BEFORE TRANSITIONING
TO ALL SCATTERED SNOW SHOWERS BY SATURDAY WITH THE COLDER AIR
MOVING INTO THE REGION.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

MODELS ARE IN FAIR AGREEMENT IN THE MID TO LONG TERM WITH
SOUTHEASTERLY FLOW PERSISTING ACROSS THE GULF OF ALASKA AND
NORTHERLY FLOW IN THE BERING. BY SUNDAY EVENING THREE SURFACE
FEATURES ROTATING THROUGH THE SOUTHEASTERLY FLOW WILL BE
IMPACTING THE AREA. THE FIRST IS A DIFFUSE AND WEAKENING SURFACE
LOW WHICH WILL BE OVER BRISTOL BAY...THE SECOND A SURFACE LOW IN
THE WESTERN GULF APPROACHING THE BARREN ISLANDS AND THE THIRD
ANOTHER SURFACE LOW OFF OF THE SOUTHERN SOUTHEAST ALASKA
PANHANDLE. THESE FEATURES WILL CONTINUE TO ROTATE ALONG A SIMILAR
TRACK AS A DEEP LOW FROM THE NORTH PACIFIC APPROACHES THE SOUTHERN
GULF.

THE SURFACE FRONT ASSOCIATED WITH THE LARGE SOUTHERN LOW WILL
SPREAD INCREASING EASTERLY WINDS TO THE SOUTHERN GULF MONDAY NIGHT
AND THROUGH OUT THE GULF ON TUESDAY. A FRONTAL SYSTEM COMING IN
FROM THE WEST WILL REACH THE WESTERN ALEUTIANS TUESDAY FOLLOWED BY
A SECOND STRONGER SYSTEM SWINGING IN WEDNESDAY AND CUTTING JUST
SOUTH OF THE ALEUTIANS AS IT CONTINUES EAST. A SIMILAR PATTERN
WILL CONTINUE THROUGH THE END OF THE WEEK WITH THE MEAN UPPER
LEVEL LOW POSITION REMAINING NEAR THE SOUTHERN GULF AND AN UPPER
LEVEL RIDGING EXTENDING FROM CANADA INTO INTERIOR ALASKA.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...HEAVY FREEZING SPRAY 165 179 180 181 185 411 412 414.

&&

SYNOPSIS AND MODEL DISCUSSION...CC
SOUTHCENTRAL ALASKA...TP
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...PD
LONG TERM...JR