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000
FXAK67 PAJK 282333
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
333 PM AKDT THU APR 28 2016

.SHORT TERM...WET AND BREEZY DAY ACROSS THE PANHANDLE AS A
GALE FORCE FRONT MOVES THROUGH THE AREA. CURRENTLY THE FRONT
STRETCHES FROM HAIDA GWAII ACROSS THE NORTHEASTERN GULF TO AROUND
MIDDLETON ISLAND. BUOY 46205 HAS ALREADY SWITCHED TO A SW WIND AS
OF NOON. RAIN HAS BEEN FALLING MUCH OF THE DAY IN MOST AREAS WITH
STORM TOTAL RAINFALL AMOUNTS, AS OF 1 PM, RANGING FROM AROUND A
HALF OF AN INCH IN THE SOUTHERN PANHANDLE AND NEAR YAKUTAT TO
ONLY A FEW HUNDREDTHS IN THE NORTHERN INNER CHANNELS. WINDS HAVE
ALSO BEEN GUSTY WITH THIS FRONT. GALE FORCE WINDS HAVE BEEN
OBSERVED IN CLARENCE STRAIT AND IN THE NORTHERN GULF TODAY. GUSTS
UP TO 35 MPH HAVE ALSO BEEN OBSERVED IN THE SOUTHERN PANHANDLE.

THE FRONT WILL CONTINUE TO MOVE THROUGH THE PANHANDLE AND INTO
CANADA THIS EVENING TAKING ITS RAIN AND WIND WITH IT. MUCH OF THE
PANHANDLE WILL TRANSITION TO SHOWERS THIS EVENING WITH WIND
SWITCHING TO A MORE SW DIRECTION. BEHIND THE FRONT, THE SHOWERS
WILL NOT TAPER OFF VERY FAST AS TWO SHORT WAVE TROUGHS MOVE
THROUGH. THESE TROUGHS WILL STRENGTHEN AND ORGANIZE THE SHOWERS
RESULTING IN TWO ORGANIZED BANDS OF RAIN MOVING THOUGH THE AREA.
THE FIRST IS RIGHT ON THE HEELS OF THE FRONT AND WILL MOVE THROUGH
LATE TONIGHT. THERE WILL NOT BE MUCH FANFARE FOR THIS FEATURE
EXCEPT FOR THE SHOWERS LINGERING AND SOME BRIEF BREEZY CONDITIONS
AS IT MOVES THROUGH. THE SECOND, AND STRONGER OF THE TWO, WILL
ARRIVE FRI AFTERNOON. THIS FEATURE WILL BE MORE NOTICEABLE AS THE
DIMINISHING SHOWERS ON FRI WILL INCREASE IN INTENSITY AND
FREQUENCY. WINDS WILL ALSO BECOME BREEZY AGAIN FRI AFTERNOON BUT
THE HIGHEST WINDS ARE ONLY EXPECTED TO BE AROUND 25 KT IN LYNN
CANAL.

AS FOR MARINE CONDITIONS, PERSISTENT SW FLOW OVER THE GULF WILL
KEEP A HIGH SW SWELL GOING THROUGH THE NEXT 24 HOURS. SMALL CRAFT
ADVISORIES DUE TO SEAS REMAIN UP FOR ALL OF THE COASTAL WATERS OF
THE GULF AS SEAS REMAIN AT AROUND 9 TO 11 FT.

SHORT RANGE MODELS WERE IN GOOD AGREEMENT THROUGH THE PERIOD SO
MAINLY USED SOME NAM AND GFS FOR NEEDED UPDATES TODAY. MAIN
CHANGES WERE FOR POPS AND QPF TO TRY AND GET THE TIMING OF THE
INDIVIDUAL SHORT WAVES FLESHED OUT. OTHERWISE MOST OTHER CHANGES
WERE MINOR.

.LONG TERM...MADE MOSTLY MINOR CHANGES TO THE FRI NIGHT INTO MON
PERIODS. DID SPEED UP THE ONSET OF THE PRECIP FROM THE STRONG
FRONT BY ABOUT 3 HRS FRI NIGHT AND SAT MORNING. STILL LOOKING LIKE
FAIRLY HEFTY RAINFALL AMOUNTS WITH THE FRONT GIVEN THE DEEP UPPER
TROF AND +3 STANDARD DEVIATION PRECIP WATER VALUES. APPEARS THE
FRONT WILL MAKE IT AS FAR E AS THE CENTRAL INNER CHANNELS SSWWD INTO
THE SE GULF SAT NIGHT BEFORE STALLING. MODELS STILL TRYING TO
RESOLVE DIFFERENCES ON LOW PRESSURE WAVE EXPECTED TO MOVE N ALONG
THE FRONT FOR LATE SUN INTO EARLY MON. ENDED UP USING BLEND OF THE
12Z ECMWF WITH PREVIOUS FORECAST FOR THIS FEATURE TO MAINTAIN
TRACK CONTINUITY BUT WITH SLIGHTLY LOWER CENTRAL PRESSURES. MODELS
ALSO DIFFER ON HOW FAST THE FRONT WILL EXIT OUT OF THE AREA EARLY
NEXT WEEK. ENDED UP USING WPC TO HANDLE MON NIGHT ONWARD.

AS FAR AS EXPECTED RAINFALL WITH WEEKEND SYSTEM...MODEL TREND
SEEMED TO BE UPWARD ON QPF DURING THIS TIME. DID BLEND OF
GFS/EC/GEM TO HANDLE RAINFALL FOR THE WEEKEND. LOOKS LIKE 3+
INCHES FOR MOST OF THE AREA WITH LOCAL AMOUNTS ABOVE 6 INCHES
POSSIBLE. THIS WILL ULTIMATELY DEPEND ON TRACK AND STRENGTH OF THE
LOW PRESSURE WAVE FOR LATE SUN INTO EARLY MON. THE DEEPER AND
FURTHER WEST TRACK WOULD SWING THE HEAVIER PRECIP BACK TO THE N
MORE QUICKLY AND EVEN POTENTIALLY DIMINISH PRECIP SOMEWHAT OVER
THE FAR SERN AREA...WITH THE WEAKER AND MORE E TRACK MAINTAINING
PRECIP AREA PRETTY MUCH OVER THE MAIN PART OF THE PANHANDLE WITH
LITTLE IN WAY OF DIMINISHING TREND OVER THE S. WINDS WILL ALSO
NEED TO BE MONITORED WITH THIS WAVE AS POTENTIAL FOR AT LEAST GALE
FORCE WINDS EXISTS WITH IT. DID UPDATE THE SPS ABOUT THIS UPCOMING
STORM WITH NO CHANGES IN THE WORDING NEEDED.

ONCE THE FRONT CLEARS THE AREA EARLY NEXT WEEK...SHOULD SEE PRECIP
DIMINISH SOMEWHAT WITH A MORE SHOWERY PATTERN DEVELOPING AHEAD OF
THE BUILDING LOW LEVEL RIDGE OVER THE GULF. THE NEXT SIGNIFICANT
SYSTEM APPEARS TO MOVE INTO THE AREA LATE IN THE WEEK BUT MODELS
DIFFER SOMEWHAT ON THIS.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ052.
     SMALL CRAFT ADVISORY FOR PKZ012-022-036-043-051.
     SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041-042-053.
&&

$$

EAL/RWT

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