Gale Warning 383, NWS Anchorage, AK

897 
FZAK61 PAFC 042247
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
247 PM AKDT WED MAY 4 2016

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.

PKZ399-051315-
247 PM AKDT WED MAY 4 2016
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A FRONT IN THE NORTHERN GULF WEAKENS OVERNIGHT...MEANWHILE A
STRONGER FRONT ENTERS THE SOUTHERN GULF THU MORNING AND MOVES
INTO THE NORTHERN GULF THU AFTERNOON. A 987 MB NORTH PACIFIC LOW
MOVES TO 53N 155W AT 990 MB FRI MORNING...THEN MOVES TO 55N 152W
AT 998 MB FRI AFTERNOON.

$$

PKZ351-051315-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W-
247 PM AKDT WED MAY 4 2016

...GALE WARNING THURSDAY...

.TONIGHT...S WIND 10 TO 25 KT. SEAS 6 TO 10 FT. RAIN.
.THU...SE WIND 20 TO 35 KT. SEAS 7 TO 13 FT. RAIN.
.THU NIGHT...S WIND 15 TO 25 KT. SEAS 7 TO 11 FT.
.FRI...S WIND 20 KT. SEAS 10 FT.
.FRI NIGHT...E WIND UP TO 15 KT. SEAS 10 FT.
.SAT THROUGH MON...SW WIND 15 KT. SEAS 5 TO 9 FT.

$$

PKZ352-051315-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W-
247 PM AKDT WED MAY 4 2016

...GALE WARNING THURSDAY...

.TONIGHT...S WIND 10 TO 20 KT BECOMING SE 15 TO 30 KT AFTER
MIDNIGHT. SEAS 6 TO 11 FT. RAIN.
.THU...S WIND 20 TO 35 KT. SEAS 8 TO 13 FT. RAIN.
.THU NIGHT...S WIND 15 TO 25 KT. SEAS 7 TO 11 FT.
.FRI...S WIND 10 TO 25 KT. SEAS 11 FT.
.FRI NIGHT...W WIND UP TO 20 KT. SEAS 8 TO 12 FT.
.SAT THROUGH MON...S WIND 10 TO 20 KT. SEAS 6 TO 10 FT.

$$

019 
FZAK61 PAFC 051142
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
342 AM AKDT THU MAY 5 2016

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.

PKZ399-060130-
342 AM AKDT THU MAY 5 2016
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A FRONT OVER THE SOUTHERN GULF OF ALASKA MOVES TO THE NORTH GULF
COAST THIS AFTERNOON AND STALLS THROUGH TONIGHT. A 990 MB NORTH
PACIFIC LOW ENTERS THE GULF OF ALASKA NEAR 54N 155W FRI MORNING
AND MOVES TO 57N 142W SAT MORNING AT 1005 MB.

$$

PKZ351-060130-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W-
342 AM AKDT THU MAY 5 2016

...GALE WARNING TODAY...

.TODAY...SE WIND 20 TO 35 KT. SEAS 7 TO 12 FT. RAIN.
.TONIGHT...S WIND 15 TO 25 KT. SEAS 10 FT. RAIN IN THE EVENING.
.FRI...S WIND 10 TO 20 KT. SEAS 10 FT.
.FRI NIGHT...VARIABLE WIND UP TO 15 KT. SEAS 11 FT.
.SAT...W WIND 10 TO 20 KT. SEAS 6 TO 10 FT.
.SUN THROUGH MON...SW WIND 15 KT. SEAS 6 FT.

$$

PKZ352-060130-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W-
342 AM AKDT THU MAY 5 2016

.TODAY...SE WIND 20 TO 30 KT BECOMING S 20 KT IN THE AFTERNOON.
SEAS 8 TO 12 FT. RAIN IN THE MORNING.
.TONIGHT...S WIND 20 KT. SEAS 11 FT.
.FRI...S WIND 10 TO 25 KT. SEAS 12 FT.
.FRI NIGHT...VARIABLE WIND UP TO 15 KT. SEAS 8 TO 13 FT.
.SAT THROUGH MON...SW WIND 10 TO 20 KT. SEAS 6 TO 11 FT.

$$

311 
FZAK61 PAFC 052259
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
259 PM AKDT THU MAY 5 2016

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.

PKZ399-061330-
259 PM AKDT THU MAY 5 2016
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A FRONT OVER THE NORTHERN GULF OF ALASKA MOVES INLAND LATE
TONIGHT. A 986 MB NORTH PACIFIC LOW ENTERS THE GULF OF ALASKA
NEAR 54N 156W FRI MORNING AND MOVES TO 58N 142W SAT MORNING AT
1005 MB...THEN MOVES INLAND NEAR 58N 173W SAT AFTERNOON.

$$

PKZ351-061330-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W-
259 PM AKDT THU MAY 5 2016

.TONIGHT...S WIND 25 KT. SEAS 11 FT.
.FRI...S WIND 10 TO 20 KT. SEAS 10 FT.
.FRI NIGHT...E WIND UP TO 15 KT BECOMING N AFTER MIDNIGHT. SEAS
10 FT.
.SAT...NW WIND 15 KT. SEAS 7 TO 10 FT.
.SAT NIGHT...W WIND 10 TO 20 KT. SEAS 7 FT.
.SUN THROUGH TUE...SE WIND 10 TO 20 KT. SEAS 6 FT.

$$

PKZ352-061330-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W-
259 PM AKDT THU MAY 5 2016

.TONIGHT...S WIND 25 KT. SEAS 11 TO 14 FT.
.FRI...S WIND 10 TO 25 KT. SEAS 11 TO 14 FT.
.FRI NIGHT...W WIND 10 TO 20 KT. SEAS 8 TO 13 FT.
.SAT...W WIND 20 KT. SEAS 7 TO 11 FT.
.SAT NIGHT...W WIND 15 KT. SEAS 7 FT.
.SUN THROUGH TUE...S WIND 20 KT. SEAS 7 FT.

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
307 PM AKDT TUE MAY 3 2016

.ANALYSIS AND UPPER LEVELS...
A VERTICALLY STACKED LOW CONTINUES TO SIT AND SPIN JUST OFF THE
KENAI PENINSULA. IT IS HELPING TO PRODUCE GUSTY SOUTHEAST WINDS
ONCE AGAIN THROUGH THE TYPICAL GAPS...KNIK ARM AND PORTAGE VALLEY.
IT IS ALSO ALLOWING FOR SHOWERS TO DEVELOP ACROSS MUCH OF THE
SOUTHERN HALF OF THE MAINLAND. WITH ABUNDANT CLOUD COVER LIMITING
INSTABILITY AND A LOT OF MOISTURE IN THE VERTICAL COLUMN...IT
WILL BE A BIT MORE DIFFICULT TO GET THUNDERSTORMS THIS AFTERNOON.
STILL CANNOT RULE OUT A STRIKE IN SOME OF THE CLEARER AREAS OF
SOUTHWEST AK.

FURTHER WEST...A FILLING UPPER LEVEL LOW IS TRACKING ALONG THE
ALEUTIAN CHAIN. THIS IS SWINGING A WEAK OCCLUSION INTO THE ALASKA
PENINSULA. MEANWHILE...OVER THE NORTH PACIFIC...A MUCH MORE
MERIDIONAL 135 KT JET IS SETTING THE STAGE FOR A NEW SURFACE LOW
TO DEVELOP. THIS LOW WILL TRACK INTO THE GULF OVER THE NEXT FEW
DAYS AND BE THE PRIMARY WEATHER MAKER.

&&

.MODEL DISCUSSION...
ALL MODELS REMAIN IN GOOD SYNOPTIC AGREEMENT MAKING FOR MODERATE
TO HIGH FORECAST CONFIDENCE. ONE SMALL DIFFERENCE OVER SW AK IS
HOW FAR INLAND THE ALEUTIAN LOW TRACKS AND HOW THAT WILL IMPACT
CONVECTIVE DEVELOPMENT. THE GFS WAS FAVORED OUT THERE DUE TO ITS
CONSISTENT PERFORMANCE OVER THE PAST FEW DAYS. IN THE EAST...THERE
IS NOTABLE DISAGREEMENT WITH THE FRONT THAT SWINGS UP THROUGH THE
GULF ON THU. THE EC...AND EVEN MORE SO THE GEM...ARE QUITE A BIT
FASTER AND SLIGHTLY STRONGER THAN THE AMERICAN MODELS. THE
AMERICAN MODELS HAVE BEEN PREFERRED FOR CONSISTENCY OVER THE PAST
FEW DAYS IN THIS AREA AS WELL. SO THIS PACKAGE LEANS TOWARD A
NAM/GFS BLEND.

&&

.AVIATION...00Z ANCHORAGE TAF...SOUTHEAST WINDS WILL ONCE AGAIN
BE AN ISSUE TODAY INTO EARLY WED. TIMING OF THE WINDS COULD BE
SLIGHTLY DIFFERENT (BY AN HOUR OR TWO) FROM MON AS WE ARE WAITING
FOR A THERMAL LOW TO DEVELOP OVER THE SUSITNA VALLEY. BUT THE
STRENGTH SHOULD BE VERY SIMILAR. AT THIS TIME...WE ARE NOT
EXPECTING SOUTHEAST WINDS WED AFTERNOON/EVENING AS THE DOWN INLET
GRADIENT SHOULD BE STRONG ENOUGH TO KEEP MOST OF THE WINDS OUT
OVER THE ARM.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE LOW OVER THE NORTHWEST GULF WILL OPEN INTO A DIFFUSE TROUGH
AND HEAD INLAND ACROSS SOUTHCENTRAL TONIGHT. AS HAS RECENTLY BEEN
THE CASE...WITH A FAIRLY UNIFORM WEAKLY UNSTABLE AIR MASS IN PLACE
THERE IS NO REAL PREFERRED LOCATION FOR SHOWERS. USED A BROAD BRUSH
APPROACH IN FORECASTING ISOLATED TO SCATTERED CONVECTION.

A WEAK OCCLUDED FRONT IS ON TRACK TO TRACK NORTHWARD ACROSS THE
GULF TONIGHT AND REACH THE NORTH GULF COAST BY WEDNESDAY AFTERNOON.
UPPER LEVEL FORCING WITH THIS LOOKS MUCH MORE IMPRESSIVE WITH
AMPLIFICATION OF A SHORT-WAVE TROUGH AS IT CROSSES THE GULF.
THUS...EXPECT AREA AND INTENSITY OF RAIN TO INCREASE AS THE FRONT
AND TROUGH REACH THE NORTHERN GULF. THE TROUGH WILL THEN ELONGATE
AND WEAKEN AS IT HEADS INLAND...SO EXPECT A REPEAT OF THE ISOLATED
TO SCATTERED CONVECTION WEDNESDAY AFTERNOON THROUGH WEDNESDAY
NIGHT. ALSO OF NOTE...GUIDANCE NOW ALL HINTS AT A WEAK LOW FORMING
OVER THE NORTHWEST GULF WEDNESDAY AFTERNOON IN RESPONSE TO THE
AMPLIFYING UPPER TROUGH. THIS WILL RESULT IN STRONGER NORTHERLY
FLOW DOWN COOK INLET. BASED ON THIS HAVE COMPLETELY REMOVED
SOUTHEASTERLY WINDS FROM ANCHORAGE PROPER. THIS WILL ALSO LEAD TO
MARGINALLY WEAKER GAP WINDS THROUGH THE KNIK RIVER VALLEY COMPARED
WITH THE PAST FEW DAYS.

THE LOW LEVEL FLOW...WHICH HAS BEEN PREDOMINANTLY OUT OF THE
EAST TO SOUTHEAST FOR QUITE A WHILE....WILL BACK TOWARD THE NORTH
ON THURSDAY AS A STRONG WARM FRONT (ORIENTED NORTHEAST TO
SOUTHWEST) MOVES INTO THE GULF AND APPROACHES SOUTHCENTRAL. THIS
SYSTEM CONTINUES TO LOOK MORE AND MORE IMPRESSIVE...WITH STRONG
LOW LEVEL CONVERGENCE AND A BROAD UPPER TROUGH WITH A LONG
SOUTHERLY FETCH OF WARM AIR AND MOISTURE. THUS...EXPECT MODERATE
TO HEAVY RAIN TO QUICKLY SPREAD ACROSS THE GULF ON THURSDAY. WITH
THE CHANGE IN LOW LEVEL FLOW EXPECT MOISTURE TO MAKE IT OVER THE
MOUNTAINS AND BRING LIGHT RAIN TO INLAND PORTIONS OF SOUTHCENTRAL
LATE THURSDAY OR THURSDAY NIGHT. HAVE STARTED TO TREND HIGHER WITH
POPS...THOUGH IF THERE IS GOOD CONSISTENCY IN THE GUIDANCE
TONIGHT MAY NEED TO GO QUITE A BIT HIGHER.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
THE BIGGEST QUESTION FOR SOUTHWEST ALASKA IS THE POTENTIAL FOR
THUNDERSTORMS IN THE AFTERNOON AND EVENING HOURS TODAY AND
WEDNESDAY. INDICES ARE FAVORABLE FOR CONVECTION AND TEMPERATURES
SHOULD ALSO BE HIGH ENOUGH BUT THERE IS NOT MUCH OF A CAP. THIS
WOULD LEAD TO LIGHTER AND MORE WIDESPREAD SHOWERS BUT REDUCE THE
CHANCE FOR THUNDERSTORMS. SATELLITE AND RADAR ARE SHOWING THIS
SCENARIO FOR TODAY LEADING TO A REDUCED THREAT OF THUNDERSTORMS
FOR THE SOUTHWEST. THIS SAME PATTERN LOOKS TO HOLD FOR WEDNESDAY
AS WELL.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
AS THE LOW OVER THE EASTERN ALEUTIANS PUSHES EAST INTO THE
NIGHT...RAIN SHOWERS WILL REMAIN OVER THE AREA. AS THAT LOW EXITS
TO THE EAST RIDGING MOVES IN OVER THE WESTERN ALEUTIANS WEDNESDAY
MORNING DRYING OUT THE AREA. THEN ON THURSDAY TWO NEW LOWS MOVE
INTO THE AREA. ONE WILL FOLLOW THE RIDGING OUT WEST AND BRING RAIN
TO THE WESTERN ALEUTIANS. THE OTHER WILL BRING ITS FRONT TO THE
ALASKA PENINSULA LATER ON THURSDAY.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
THE BIG PICTURE MOVING FORWARD IS THAT THE PATTERN WILL BE MORE
DYNAMIC THAN WE HAVE SEEN IT OVER THE PAST SEVERAL WEEKS. A
STRONGER NORTH PACIFIC LOW TRACKING TOWARD THE WESTERN GULF
THURSDAY AFTERNOON WILL WEAKEN AND BECOME MORE COMPLEX BY FRIDAY
MORNING. THIS SYSTEM WILL PUSH A WARM FRONT INTO THE GULF OF AK ON
THU AND INTO SOUTH CENTRAL ON FRI...PULLING UP A HEALTHY AMOUNT OF
SUB-TROPICAL MOISTURE INTO THE GULF AND BRING MODERATE RAIN TO
THE COASTLINE. WINDS WILL ALSO INCREASE TO GALE-FORCE ACROSS
PORTIONS OF THE GULF...ESPECIALLY THE BARRIER JET REGION. IT DOES
NOT LOOK LIKE MUCH PRECIPITATION WILL MAKE IT INLAND...AS THIS
LOOKS LIKE A SOLID DOWN-SLOPING SCENARIO WHICH SHOULD KEEP MOST OF
THE RAIN CONFINED TO THE GULF COAST. THE LOW THEN QUICKLY EXITS
THE AREA OVER THE WEEKEND LEAVING SOME RIDGING IN PLACE. ANOTHER
LOW QUICKLY MOVES IN TO THE BERING SEA OVER THE WEEKEND WHILE SOME
RIDGING BUILDS FROM THE NORTH PACIFIC OVER THE MAINLAND.

MODELS ARE IN MUCH BETTER AGREEMENT IN HANDLING THE SERIES OF LOWS
PUSHING OFF THE KAMCHATKA PENINSULA AND INTO THE WESTERN BERING
LATER IN THE WEEK AND OVER THE WEEKEND. PREVIOUS MODEL RUNS HAVE
STRUGGLED WITH HOW FAR EAST THESE SYSTEMS WOULD PROGRESS...BUT
WITH THE MOST RECENT MODEL RUNS THEY HAVE ALL BACKED OFF TOWARD A
SLOWER AND MORE WESTERLY SOLUTION. MODELS HAVE ALSO COME INTO
BETTER AGREEMENT WITH THE STRENGTH AND POSITIONING OF THE RIDGE
AHEAD OF THESE SYSTEMS. BOTH THE GFS AND EC ARE NOW SHOWING A
RIDGE SETTING UP OVER THE GULF AND SOUTHCENTRAL BY SUNDAY
MORNING...AND CONTINUING TO STRENGTHEN INTO THE EARLY PART OF NEXT
WEEK. THIS BUILDS HIGHER CONFIDENCE IN THE POTENTIAL FOR SOME
CLEAR SKIES AND WARMER WEATHER FOR GULF COAST AND SOUTHCENTRAL
ALASKA BY THE END OF THE WEEKEND AND INTO EARLY NEXT WEEK.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING 119 130 131.

&&

SYNOPSIS AND MODEL DISCUSSION...MO
SOUTHCENTRAL ALASKA...SB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...DK
LONG TERM...PEPE