Gale Warning 13, NWS Juneau, AK

095 
FZAK67 PAJK 190030
OFFAJK

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE JUNEAU AK
400 PM AKST SUN JAN 18 2015 

OFFSHORE WATERS FORECAST FOR GULF OF ALASKA EAST OF 144W

WIND FORECASTS REFLECT THE PREDOMINANT SPEED AND DIRECTION
EXPECTED. SEA FORECASTS REPRESENT THE AVERAGE OF THE HIGHEST
ONE-THIRD OF THE COMBINED WINDWAVE AND SWELL HEIGHT.

PKZ398-191400-
400 PM AKST SUN JAN 18 2015 
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A LOW PRESSURE SYSTEM OVER THE EASTERN GULF WILL MOVE OVER SITKA
SUN NIGHT...THEN WEAKEN AND SLOWLY DRIFT N OVER THE NORTHERN
PANHANDLE ON MON. THE ASSOCIATED FRONT WILL MOVE NORTHWARD OVER
THE PANHANDLE AND SE GULF SUN NIGHT.

$$

PKZ310-191400-
GULF OF ALASKA NORTH OF 55 DEGREES NORTH AND EAST OF 144 DEGREES
WEST-
400 PM AKST SUN JAN 18 2015 

.TONIGHT...NW WIND 30 KT BECOMING W 25 KT LATE. SEAS 10 FT. SW
SWELL. 
.MON...W WIND 20 KT BECOMING S 15 KT IN THE AFTERNOON. SEAS 8 FT.
SW SWELL. 
.MON NIGHT...SE WIND 15 KT BECOMING E 30 KT. SEAS 9 FT. RAIN.
.TUE...S WIND 30 KT. SEAS 10 FT. 
.TUE NIGHT...SE WIND 25 KT. SEAS 10 FT. S SWELL. 
.WED...S WIND 25 KT. SEAS 13 FT. S SWELL. RAIN.
.THU...S WIND 30 KT. SEAS 15 FT. 
.FRI...S WIND 30 KT. SEAS 17 FT. 

$$

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
550 AM AKST SUN JAN 18 2015

.SHORT TERM...GENERAL TREND TOWARDS MUCH LESS WIND OVERNIGHT THAN
IN THE PREVIOUS SEVERAL DAYS AS UPPER AIR SUPPORT FOR LOWS AND
FRONTAL DEVELOPMENT HAS DIMINISHED SIGNIFICANTLY. SOME CLEARING TONIGHT OVER
NORTHERN PORTIONS HAS LED TO PATCHY FOG WITH VIS AS LOW AS 1/2 MI
AT A COUPLE SPOTS...GROUND FOG HAS BEEN COMMON AND MODERATE IN
SOME DIRECTIONS AT SEVERAL TAF SITES. SEVERAL OF THE NORTHERN
COMMUNITIES ALONG WITH PETERSBURG IN THE SOUTH HAVE BEEN SEEING
GENERALLY ERRATIC FOG DEVELOPMENT IN AND OUT OVER THE LAST SEVERAL
HOURS. WITHIN THE PERIOD FROM 5AM OR SO THROUGH SUNRISE THE TREND
SHOULD BE DECREASING FOR AREAS THAT SEE AN INCREASE IN MID-LEVEL
CLOUDS FROM THE SOUTH.

AFTER THE FOG THIS MORNING THE PRIMARY FORECAST CHALLENGE IS THE
NEW LOW AND FRONT MOVING UP FROM THE SOUTH...MUCH WEAKER IN
INTENSITY THAN THE LAST SEVERAL DUE TO LACK OF STRONG UPPER AIR
SUPPORT AND NEARLY VERTICALLY STACKED. MODELS HAVE FINALLY COME
INTO AGREEMENT ON POSITIONING/MOVEMENT OF THE LOW TO BARANOF
ISLAND BY 15Z MON. THE LOW WILL CAUSE SCA WINDS TO DEVELOP BY THIS
AFTERNOON OVER THE SOUTHERN OUTER WATERS AND OVER CLARENCE STRAIT.
ALSO LYNN CANAL WILL BE KICKING IN SHORTLY IN RESPONSE TO THE LOW
DEVELOPMENT TO THE SOUTH. FOLLOWING WILL BE SCAS OVER SOUTHERN
CHATHAM SUMNER...THEN FREDERICK. STILL DON'T HAVE THE STRONG WIND
LEVELS IN ZONES 27/28 AS AT THIS POINT WE EXPECT SURFACE GUSTS TO
35MPH IN THESE AREAS. 850 LEVEL WINDS IN THE MODELS MAX OUT AT
ABOUT 35-40KTS. SO THIS WILL NEED TO BE MONITORED. KETCHIKAN
APPEARS TO BE THE ONLY TAF THAT INCLUDES LLWS AT THIS POINT FOR
03Z MONDAY ONWARDS. TWEAKED THE SOUTHERN CHANNEL WINDS UPWARDS A
BIT AND A FEW AREAS OF DIRECTION OVER THE CENTRAL PANHANDLE UPON CLOSE
EXAMINATION OF INHERITED WINDS. RAINFALL AMOUNTS SHOULD RANGE FROM
A QUARTER TO PERHAPS 2/3 INCH BY MONDAY MORNING.

ONE COMPLICATION IS THAT THE EXITING STRONG SYSTEM FROM THE PAST
24 HRS OR SO ALONG WITH RELAXED WINDS WILL LIKELY ALLOW FOR A
MODIFIED ARCTIC FRONT TO SET UP OVER THE NORTHERN PANHANDLE BY
MONDAY MORNING IN ADVANCE OF THE NEW LOW...TEMPERATURES ARE
ALREADY DECREASING QUICKLY IN THESE AREAS AIDED BY CLEARING SKIES
AND LITTLE WIND. MODEL 1000-850 THICKNESS PLOTS PACK UP THE
GRADIENT JUST NORTH OF JUNEAU EXTENDING FROM BC OUT TOWARDS
YAKUTAT FOR A PERIOD LATE BEGINNING LATE TONIGHT. THIS SCENARIO
LEADS TO A BRIEF PERIOD OF OVERRUNNING AS THE WEAK/MODERATE LOW
AND FRONT MOVE NORTHWARD. CURRENT GUIDANCE HAS SNOW LEVELS BY
MONDAY MORNING IN SKAGWAY AND HAINES AT THE GROUND...HOWEVER QPF
VALUES ARE LESS THAN A QUARTER INCH FOR THE SNOWY PERIOD. WILL
NEED TO MONITOR AS THIS SHALLOW COLD AIR WILL POSE PROBLEMS FOR
THE MODELS. FRONT RETREATS NORTHWARD AFTER 15Z MON AS PROGRESSIVE
SOUTHERLY FLOW ALOFT BEGINS TO DEVELOP AGAIN.

WENT WITH A BLENDED EC/GFS/NAM COMBINATION ON THE MOISTURE FIELDS
FOR THE PERIOD AND THESE GENERALLY AGREED WITH INHERITED GRIDS.

.LONG TERM...EXTENDED RANGE FORECAST IS MADE UP OF A SERIES OF
FAIRLY COMPACT GALE FORCE LOWS AND THEIR RESPECTIVE FRONTS
TRACKING ACROSS THE GULF AND OVER SOUTHEAST ALASKA. MODE AGREEMENT
IN THIS REGARD IS VERY GOOD. MODEL DIFFERENCES IN TERMS OF TIMING,
TRACK, AND INTENSITY MAKE THE USE OF ANY ONE MODEL AN ALL-OR-
NOTHING AFFAIR. SIMILARLY, BLENDING MODELS HAS THE RESULT OF
GENERALLY WASHING OUT FEATURES AND DILUTING INTENSITY OF FRONTS
AND WINDS. THIS SAID, CONFIDENCE IN PERIODS OF GUSTY, STRONG WINDS
OVER PUBLIC ZONES WITH MARINE GALES AND PRECIPITATION HEAVY AT
TIMES OVER THE COMING WEEK IS ABOVE AVERAGE. ALSO TRENDING ABOVE
AVERAGE IS PRECIPITATION TYPE BEING RAIN FOR THE MAJORITY OF THE
PANHANDLE. HAINES, SKAGWAY, AND HYDER ARE STILL LOOKING LIKE THEY
WILL RECEIVE SOME SIGNIFICANT SNOW FROM MONDAY NIGHT THROUGH
WEDNESDAY NIGHT. FORECAST CONFIDENCE DETERIORATES RAPIDLY WHEN
TRYING TO PIN DOWN THE TIMING AND TRACK OF ANY PARTICULAR
LOW/FRONT. GIVEN THIS CONUNDRUM, OPTED TO BLEND GFS AND ECMWF IN A
25%/75% PROPORTION FOR PRESSURE AND WIND THROUGH TUESDAY EVENING,
FOLLOWED BY STRAIGHT GFS THROUGH WEDNESDAY NIGHT. WPC THEREAFTER.
REMAINED WITH ECMWF AS A FOUNDATION FOR POP AND QPF. NO CHANGES TO
TEMPERATURES.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-013-033>036-041-042.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ043-051-052.

&&

WESLEY/FRITSCH

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