Small Craft Advisory 430, NWS Juneau, AK

357 
FZAK53 PAJK 050652
CWFYAK

MARINE FORECAST FOR YAKUTAT BAY...UPDATED
NATIONAL WEATHER SERVICE JUNEAU AK
1052 PM AKDT THU JUN 4 2015

COASTAL WATERS FORECAST FOR YAKUTAT BAY

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.

PKZ053-060100-
YAKUTAT BAY-
1052 PM AKDT THU JUN 4 2015

UPDATED

.REST OF TONIGHT...SE WIND 20 KT BECOMING E 10 KT LATE. SEAS 6 FT.
S SWELL. EAST SIDE OF BAY...SEAS 5 FT SUBSIDING TO 2 FT LATE.
RAIN.
.FRI...SW WIND 10 KT. SEAS 5 FT...EXCEPT 2 FT OR LESS EAST
SIDE OF THE BAY. RAIN.
.FRI NIGHT...SE WIND 10 KT. SEAS 4 FT. SW SWELL. RAIN.
.SAT...SE WIND 10 KT. SEAS 4 FT. RAIN.
.SAT NIGHT...E WIND 15 KT. SEAS 4 FT. RAIN.
.SUN...SW WIND 15 KT. SEAS 4 FT. RAIN.
.MON...SW WIND 15 KT. SEAS 3 FT. 
.TUE...SW WIND 10 KT. SEAS 3 FT. 



$$

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
532 AM AKDT THU JUN 4 2015

.SHORT TERM...WV IMAGERY SHOWS AN UPPER LOW POSITIONED IMMEDIATELY
SW OF KODIAK ISLAND THIS MORNING...WHILE A SHORTWAVE IMPULSE
LOCATED S OF THE LOW WAS QUICKLY PROGRESSING NE TOWARD THE SRN
GULF. AT THE SURFACE...LOW PRESSURE WAS PRESENT E OF KODIAK
ISLAND...WITH AN OCCLUDED FRONT EXTENDING ESE ACROSS THE GULF. AS
THE DAY PROGRESSES...PREVIOUSLY MENTIONED UPPER IMPULSE IS FORECAST
TO MOVE ACROSS THE CNTRL GULF DURING THE AFTERNOON...AND THEN ENTER
THE NRN PANHANDLE BY LATE TONIGHT. MEANWHILE...THE OCCLUDED FRONT AT
THE SURFACE WILL DISSIPATE ALONG THE COAST OF SERN AK BY LATE
AFTERNOON...AND THEN BE FOLLOWED BY A SHARP SURFACE TROUGH THAT WILL
ALSO DISSIPATE AS IT ENCOUNTERS THE NERN GULF COAST.

BUOY 46082 SHOWS GALE FORCE WINDS ARE ONGOING EARLY THIS MORNING
OVER MARINE ZONES 51 AND 52...OCCURRING IN RESPONSE TO A BARRIER
JET PRESENT N OF THE APPROACHING OCCLUDED FRONT. BUOY 46084 AT 09Z
WAS SUSTAINED AT 33 KT...WITH WINDS OVER MARINE ZONES 42 AND 43
FORECAST TO STRENGTHEN TO 35-40 KT AS THE FRONT PROGRESSES E
ACROSS THE AREA BY MID MORNING. THEREAFTER...WINDS WILL SUBSIDE TO
SMALL CRAFT SPEEDS OVER THE OUTSIDE WATERS AS THE FRONT WEAKENS
DURING THE AFTERNOON. OVER THE INSIDE WATERS...SLY 925 MB FLOW
FROM 30-50 KT WILL SPREAD ACROSS THE ENTIRE REGION BY
MIDDAY...WHICH WILL AID IN SMALL CRAFT WINDS PERSISTING FOR MANY
OF THE N-S ORIENTED CHANNELS GOING THROUGH TONIGHT.

ELSEWHERE...EARLY MORNING OBSERVATIONS AT SHEEP MOUNTAIN NEAR
JUNEAU REVEAL PEAK SPEEDS NEAR 40 KT OUT OF THE SE. WINDS ARE
FORECAST TO CONTINUE INCREASING AND DESCEND TOWARD THE SURFACE
DURING THE DAY...WITH FLOW EVENTUALLY ACCELERATING THROUGH
GASTINEAU CHANNEL RESULTING IN STRONG WINDS GUSTS FOR DOWNTOWN
AREAS NW TO THE AIRPORT DURING THE AFTERNOON INTO PART OF THE
EVENING. WINDS WILL ALSO STRENGTHEN FOR COASTAL AREAS AROUND SITKA
SE TO HYDABURG...AS WELL AS KETCHIKAN...AS THE FRONT AND
ASSOCIATED LLJ SPREAD E TOWARD THE AREA TODAY AND TONIGHT.
HOWEVER...WINDS ARE CURRENTLY FORECAST TO REMAIN BELOW STRONG WIND
CRITERIA.

UPPER JET STREAK ASSOCIATED WITH THE IMPULSE CURRENTLY APPROACHING
THE SRN GULF WILL SPREAD NEWD TOWARD THE ERN GULF COAST BY 00Z
FRI. THIS WILL PLACE THE NRN HALF OF THE CWA WITHIN A FAVORABLE
ZONE OF UPPER DIVERGENCE AND LARGE-SCALE ASCENT. IN
ADDITION...COMBINATION OF VERTICAL MOTION ABOVE THE NRN GULF
BARRIER JET...AS WELL AS OROGRAPHIC ASCENT INVOF THE SAINT ELIAS
MOUNTAINS...WILL YIELD STRONG MESOSCALE ASCENT OVER AKZ017/YAKUTAT
AREA. THIS VERTICAL MOTION/RESULTANT DEEP-LAYER SATURATION
COMBINED WITH AN INFLUX OF PW VALUES NEAR 0.8 INCH /PER SATELLITE
DERIVED TPW GUIDANCE/ WILL FAVOR HEAVY RAINFALL TODAY AND TONIGHT.
FARTHER E...PERIODS OF MODERATE RAIN CAN BE EXPECTED FOR AREAS
FROM ELFIN COVE TO JUNEAU AND POINTS N AS MOISTURE INFLUX
INCREASES WITH THE STRENGTHENING LLJ. S OF THIS AREA...PW VALUES
WILL APPROACH 1 INCH...BUT LARGE-SCALE ASCENT WILL BE LESS
SUPPORTIVE OF DEEP COLUMN SATURATION /AS EVIDENT IN MODEL FORECAST
SOUNDINGS/...THUS LIGHTER RAINFALL AMOUNTS WILL GENERALLY BE
OBSERVED.

FEW MODIFICATIONS TO THE INHERITED GRIDS WERE NECESSARY WITH THIS
SHORT TERM FORECAST PACKAGE. QPF WAS NUDGED TOWARD THE
ARW/NMM...BUT CHANGES WERE NOT SIGNIFICANT. CHANGES TO WINDS WERE
GENERALLY LIMITED TO LOCAL EFFECT TWEAKS.

.LONG TERM...LONG RANGE FORECAST RETAINS A MOSTLY WET PATTERN
THROUGH THE WEEKEND. AN UPPER LEVEL TROUGH THAT EXTENDS SOUTH
THROUGH WESTERN ALASKA INTO THE NORTHERN PACIFIC COMBINED WITH A
WEAK RIDGE OVER THE ROCKY MOUNTAINS KEEPS THE MAIN JET STREAM
POINTED RIGHT AT THE PANHANDLE WITH A FEW SHORT WAVES EMBEDDED IN
THE SW FLOW. THESE FEATURES WEAKEN A BIT EARLY NEXT WEEK RESULTING IN
MORE ZONAL FLOW BY MID WEEK.

AT THE SURFACE, THINGS WILL BE QUIETING DOWN FRI AND SAT IN THE
WAKE OF THE FRONT AND SUBSEQUENT WAVES THAT MOVED THROUGH THE
PANHANDLE ON THU AND THU NIGHT. A SURFACE RIDGE WILL BE BUILDING
OVER THE PANHANDLE BUT ITS AXIS WILL BE TOO FAR EAST TO PREVENT
CONTINUING SHOWERS FROM SW ONSHORE FLOW SO FRI INTO SAT REMAIN
DAMP. WINDS WILL ALSO BE LIGHTENING UP BUT FRI WILL BE WINDY FOR
THE NORTHERN PANHANDLE AS PRESSURE GRADIENTS TIGHTEN UP BETWEEN
THE RETREATING FRONT AND THE BUILDING RIDGE. 30 KT SOUTHERLY WINDS
WILL LIKELY BLOW UP LYNN CANAL AND INTO HAINES AND SKAGWAY FRI AS
A RESULT BEFORE QUIETING DOWN FRI NIGHT.

THE FORECAST BECOMES MORE UNCERTAIN BY SAT NIGHT AND SUN AS A NEW
LOW SPEEDS INTO THE EASTERN GULF FROM THE SOUTH. MODEL STRENGTH
AND TRACK HAVE VARIED ON THIS SYSTEM OVER THE LAST 24 HOURS WITH
THE 0Z GFS SHOWING ITSELF TO BE QUITE AN OUTLIER AS IT PRODUCED A
LOW 10 TO 15 MB DEEPER THEN JUST ABOUT ANY OTHER MODEL AND A TRACK
FURTHER TO THE WEST. THE NEW 6Z RUN HAS WEAKENED THE LOW AND
TWEAKED ITS TRACK MORE TO THE EAST POSSIBLY DUE TO THE MAIN UPPER
LOW AND VORTICITY MAX SUPPORT STAYING FURTHER WEST WHILE THE LEFT
EXIT REGION OF A WEAK JET STREAK STAYS OVER THE DEVELOPING SURFACE
LOW. STILL THAT LEAVES US WITH A FEW ALTERNATIVES BETWEEN THE
VARIOUS MAJOR MODELS. NAM AND GFS ARE OPTING FOR A 1002 MB LOW
HEADING TOWARD CROSS SOUND EARLY SUN. MEANWHILE THE ECMWF IS GOING
WEAKER AT AROUND 1009 MB WHILE THE GEM GLOBAL DOES NOT HAVE MUCH
OF A LOW AT ALL IN THE EASTERN GULF. WITH THE ONGOING MODEL SPREAD
DECIDED TO LEAVE THE CURRENT FORECAST OF SOME SORT OF WAVE MOVING
THROUGH THE EASTERN GULF INTACT AS THERE IS GOOD SUPPORT FOR
SOMETHING MOVING THROUGH THE EASTERN GULF AND PANHANDLE SAT NIGHT
INTO SUN JUST NOT NECESSARILY WHAT AND WHERE YET. THOUGH THE
NEWEST 6Z RUNS ARE POINTING TOWARD MORE AGREEMENT SOME VARIANCE IS
STILL POSSIBLE AS THE VARIOUS UPPER LEVEL FORCING MECHANISMS
CONTINUE TO BE REFINED.

INTO EARLY NEXT WEEK, A SURFACE RIDGE BEGINS TO BUILD OVER THE
GULF, AND THIS TIME IT IS FAR ENOUGH WEST TO LEAVE MOST OF THE
PANHANDLE WITH PARALLEL-TO-SHORE SURFACE FLOW THAT SHOULD KEEP US
MOSTLY DRY UNTIL MID WEEK. BY THIS POINT, LONG RANGE MODELS BEGIN
TO VARY ON HOW FAR EAST THE NEXT FRONT GETS. ECMWF OPS FOR
WEAKENING IT OVER THE CENTRAL GULF LEAVING THE PANHANDLE DRY WHILE
THE GFS HAS IT CHARGE STRAIGHT ACROSS THE GULF BRINGING MORE WET
WEATHER BY WED. NO CONFIDENCE ON EITHER SCENARIO BUT ENSEMBLE
MEANS POINT MORE TOWARD THE DRIER ECMWF SO LEANED IN THAT
DIRECTION WITH WPC FOR THE EXTENDED PERIODS.

&&

.AVIATION...SELY WINDS WILL CONTINUE TO STRENGTHEN DURING THE DAY
INTO PART OF TONIGHT AHEAD OF A FRONT OVER THE GULF...WITH GUSTS
TO 25-35 KT POSSIBLE FOR MANY TAF SITES LOCATED ADJACENT TO N-S
ORIENTED CHANNELS. IN ADDITION...A 30-50 KT LLJ WILL YIELD LOW-
LEVEL WIND SHEAR FROM YAKUTAT ESE TO JUNEAU SWD ACROSS THE
PANHANDLE. PERIODS OF MODERATE TO HEAVY RAIN...CEILINGS LOWERING
TO 2500 FT...AND VISIBILITY FROM 3-6 MILES CAN ALSO BE EXPECTED
OVER THE NRN PANHANDLE. LIGHTER RAINFALL RATES WILL BE MORE
PROBABLE OVER THE SRN PANHANDLE.

&&

.HYDROLOGY...MODERATE TO LOCALLY HEAVY RAIN OCCURRING THROUGH THU
NIGHT WILL AID IN RAISING RIVER...STREAM...AND CREEK LEVELS OVER
THE NRN AND CNTRL PANHANDLE. HOWEVER...HYDROLOGICAL GUIDANCE
CURRENTLY INDICATES WATER LEVELS WILL REMAIN WITHIN
BANKFULL...WITH THE EXCEPTION OF THE TAIYA RIVER...WHICH MAY
EXPERIENCE MINOR FLOODING THU NIGHT.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND FROM 1 PM AKDT THIS AFTERNOON THROUGH LATE
TONIGHT
     FOR AKZ025.
MARINE...GALE WARNING FOR PKZ036-042-043-051-052.
         SMALL CRAFT ADVISORY FOR
PKZ012-013-022-031-033>035-041-053.

&&

GARNER/EAL

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JUNEAU AK
324 PM AKDT THU JUN 4 2015

AKZ017>019-025-051500-
CAPE FAIRWEATHER TO CAPE SUCKLING COASTAL AREA-
TAIYA INLET AND KLONDIKE HIGHWAY-HAINES BOROUGH AND LYNN CANAL-
JUNEAU BOROUGH AND NORTHERN ADMIRALTY ISLAND-
INCLUDING THE CITIES OF...YAKUTAT...SKAGWAY...HAINES...JUNEAU
324 PM AKDT THU JUN 4 2015

...SIGNIFICANT RISES POSSIBLE ON AREA RIVERS AND STREAMS SATURDAY NIGHT...

WITH THE FIRST OF TWO SIGNIFICANT RAIN EVENTS NEARLY OVER...AREA
RIVERS HAVE RESPONDED WITH ONLY MODEST INCREASES IN STAGE. THE
VERY DRY GROUND FROM RECORD DRY WEATHER THIS PAST MAY HAS ALLOWED
MOST IF NOT ALL RAINFALL TO EITHER INFILTRATE DOWN OR BECOME
ABSORBED BY VEGETATION RATHER THAN BECOME RUNOFF.
ADDITIONALLY...CLOSE COORDINATION WITH THE RIVER FORECAST CENTER
AND ADJUSTMENTS TO WATERSHED MODELS TO ACCOUNT FOR A LACK OF
HIGHER ELEVATION SNOW PACK HAS RESULTED IN DIMINISHED FORECAST
STAGE LEVELS FOR THE MAJOR RIVERS AND STREAMS. IN SUMMARY, SOME
MINOR RISES OVER AREA STREAMS AND RIVERS WILL OCCUR THURSDAY
NIGHT.

LOOKING FORWARD...THE POTENTIAL OF HEAVIER RAINFALL SATURDAY
NIGHT WITH THE NEXT SYSTEM WILL CAUSE THE GROUND TO APPROACH
SATURATION SO RISES IN THE CHILKAT, THE TAIYA, THE SITUK ARE
FORECAST...BUT ARE EXPECTED TO REMAIN AT OR BELOW ACTION STAGE. IN
THE JUNEAU AREA...MONTANA AND JORDAN CREEKS WILL BE FASTER TO
RESPOND TO MODERATE TO HEAVY RAINFALL. THESE SYSTEMS
ARE...HOWEVER...ALSO FORECAST TO REMAIN AT OR BELOW ACTION STAGE
AT THIS TIME.