Gale Warning 320, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
330 PM AKDT SUN OCT 11 2015

.SHORT TERM...OUR STORM WITH NO ASSOCIATED NAME IS HERE. AND BY
ALL ACCOUNTS IT IS MORE IMPACTFUL THAN FRIDAY'S STORM.

HIGH WIND GUSTS FROM 60 TO 75 MPH HAVE BEEN REPORTED IN HYDABURG
AND CAPE DECISION LIGHTHOUSE. WINDS BEGAN GUSTING IN EXCESS OF 40
MPH THIS MORNING ACROSS THE SOUTH AND HAVE SPREAD NORTHWARD INTO
THE TENAKEE/JUNEAU AREAS THIS AFTERNOON. PROGGED 925 MB WINDS FROM
50 TO 70 KT COMBINED WITH TIGHT PRESSURE GRADIENTS HAVE RESULTED
IN GENERALLY A GOOD FORECAST THROUGH TODAY. BASED OFF OF TRENDS
AND CONTINUED PERSISTENT 925 MB WINDS THROUGH TONIGHT...WE HAVE
EXTENDED THE PERIODS OF STRONG WINDS INTO LATER THIS EVENING FOR
THE SOUTH...AND DEEPER OVERNIGHT FOR MUCH OF THE NORTH. YAKUTAT
MEANWHILE WILL START FEELING THE EFFECTS OF THE LOW LATER TONIGHT
AND INTO MONDAY MORNING WITH SOUTHEAST GUSTS TO 40 MPH LIKELY. THE
HIGH WIND WARNING IS ON TRACK TO EXPIRE AT 7 PM TONIGHT FOR
WESTERN PRINCE OF WALES.

HEAVY RAIN BANDS HAVE ALSO MOVED INTO THE SOUTH AND CENTRAL AREAS
WITH RATES BETWEEN A QUARTER AND A THIRD INCH PER HOUR. THESE WILL
SPREAD NORTH TODAY...CAUSING SIGNIFICANT RISES IN STREAMS
TONIGHT...BUT NO FLOODING IS EXPECTED. AS THE STORM PULLS TO THE
NORTHWEST...RAIN WILL TRANSITION TO SHOWERS. IN FACT...SOME
SHOWERS WITHIN THE INTERACTION ZONE BETWEEN THE DRY SLOT AND THE
INITIAL FRONT HAVE DEVELOPED INTO THUNDERSTORMS WITH LIGHTNING
BEING REPORTED OVER THE EAST CENTRAL GULF. A WAVE PROGGED TO
ADVANCE NORTHWEST BEHIND THE SYSTEM OVER THE EASTERN GULF WILL
KEEP A SLIGHT CHANCE OF THUNDERSTORMS IN THE FORECAST TOMORROW
OVER THE SOUTHERN WATERS.

USED 00Z ECMWF FOR MAIN CHANGES IN THE FORECAST TRACK. HIGH RES
MODELS SEEM TO SLOW THINGS DOWN UNNECESSARILY...AND PREFER THE
ECMWF FOR ITS CONSISTENCY AND TRACK RECORD FOR THESE STORMS.
FORECAST CONFIDENCE ABOVE AVERAGE.

.LONG TERM...VERY LITTLE CHANGE IN THINKING FROM PREVIOUS FORECAST
IN THE EXTENDED RANGE. ONSHORE FLOW WILL RESULT IN CONTINUED
SHOWERS THROUGH EARLY WEDNESDAY. COLDER AIR ALOFT MOVING INTO THE
GULF COMBINED WITH A COUPLE UPPER LEVEL SHORTWAVES WILL PRODUCE AN
ENVIRONMENT CAPABLE OF THUNDERSTORMS. THEREFORE...HAVE LEFT THE
SLIGHT CHANCE IN FOR THE GULF AND OUTER COAST THROUGH TUESDAY. A
RIDGE OF HIGH PRESSURE BUILDING INTO BRITISH COLUMBIA COMBINED
WITH A LOW MOVING INTO THE CENTRAL GULF WILL TURN WINDS MORE
OFFSHORE ON WEDNESDAY. THIS WILL BRING A BREAK IN THE SHOWERS
WEDNESDAY AND INTO A PORTION OF THURSDAY. MODEL SOLUTIONS DIVERGE
AT THIS POINT WITH THE EVOLUTION OF THE LOW MOVING INTO THE
CENTRAL GULF. HOWEVER...GENERAL CONSENSUS IS INCREASING
PRECIPITATION CHANCES AS WE HEAD INTO NEXT WEEKEND.

USED 12Z ECMWF FOR MINOR UPDATES THROUGH DAY 4 THEN LATEST WPC
GUIDANCE FOR DAY 5 ONWARD. MAIN CHANGE FROM PREVIOUS FORECAST WAS
DECREASING POPS EVEN MORE FOR MID WEEK. OTHERWISE...LITTLE
DIFFERENCE FROM PREVIOUS FORECAST. FORECASTER CONFIDENCE DECREASES
BY LATE WEEK.

&&

.AVIATION...LOW LEVEL WIND SHEAR WILL BE THE MAIN CONCERN OVER THE
NEXT 12 TO 18 HOURS. MULTIPLE REPORTS OF LOW LEVEL WIND SHEAR SO
FAR TODAY AT THE KETCHIKAN...SITKA...AND JUNEAU AIRPORTS. WIND
SHEAR WILL INCREASE THROUGH THE EVENING IN SITKA AND JUNEAU WITH A
SHIFT FROM ESE TO SSW AT AROUND 2000 FEET THIS EVENING. CONDITIONS
IMPROVE ON TUESDAY WITH SHOWERS...IMPROVED CEILINGS...AND
DIMINISHING LOW LEVEL WINDS.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND THROUGH LATE TONIGHT FOR AKZ021-023-026.
         HIGH WIND WARNING UNTIL 7 PM AKDT THIS EVENING FOR AKZ027.
         STRONG WIND FROM 7 PM THIS EVENING TO 1 AM AKDT MONDAY FOR
     AKZ027.
         STRONG WIND THROUGH LATE TONIGHT FOR AKZ024.
         STRONG WIND THROUGH MONDAY MORNING FOR AKZ025.
         STRONG WIND FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR
     AKZ025.
         STRONG WIND THROUGH MONDAY MORNING FOR AKZ022.
         STRONG WIND FROM 7 PM AKDT THIS EVENING THROUGH MONDAY MORNING
     FOR AKZ020.
         STRONG WIND UNTIL 10 PM AKDT THIS EVENING FOR AKZ028.
         STRONG WIND FROM 1 AM AKDT MONDAY THROUGH MONDAY AFTERNOON FOR
     AKZ017.
MARINE...STORM WARNING FOR PKZ022-036-042-043.
         GALE WARNING FOR PKZ012-021-031>035-041-051-052.
         SMALL CRAFT ADVISORY FOR PKZ011-013-053.

&&

JWA/TPS

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

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
526 PM AKDT SUN OCT 11 2015

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0200 PM     NON-TSTM WND GST 18 WNW EDNA BAY         56.01N 134.13W
10/11/2015  M81.00 MPH                          AK   C-MAN STATION

            PEAK GUST MEASURED AT CAPE DECISION LIGHTHOUSE BETWEEN
            NOON AND 1PM

0200 PM     NON-TSTM WND GST HYDABURG                55.21N 132.82W
10/11/2015  M60.00 MPH                          AK   ASOS

            HYDABURG ASOS RECORDED A 60 MPH WIND GUST SHORTLY BEFORE
            2 PM.

&&

DAW