Small Craft Advisory 276, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
400 PM AKDT TUE MAR 22 2016

.SHORT TERM...GALE FORCE FRONTAL SYSTEM WAS ENTERING THE SRN GULF
DURING MIDDAY TUE...WHILE SUBSIDENCE AHEAD OF THIS FEATURE WAS
YIELDING BREAKS IN CLOUD COVER AND MILD CONDITIONS OVER THE
PANHANDLE. STRAY SHOWERS WILL BE POSSIBLE OVER SERN AK DURING THE
EVENING...WHICH WILL TRANSITION TO STRATIFORM RAINFALL...FIRST
OVER THE SRN PANHANDLE LATE TONIGHT...AND THEN CNTRL/NRN PORTIONS
OF THE PANHANDLE WED MORNING/AFTERNOON. IN ADDITION...GALES WILL
DEVELOP THIS EVENING OVER MARINE ZONE 310...THEN THE REMAINDER OF
THE GULF WATERS BY LATE TONIGHT. TIGHTENING GRADIENT OVER CLARENCE
STRAIT WILL ALSO FAVOR A PERIOD OF GALES...AS WELL AS CROSS SOUND
AS GAP WINDS STRENGTHEN IN ADVANCE OF THE FRONT. STRONG WIND
HEADLINE WAS ALSO POSTED FOR AKZ027...WITH GUSTS TO 40 MPH
ANTICIPATED DURING FROPA LATE TONIGHT/WED MORNING.

MODIFICATION TO INHERITED WINDS WERE GENERALLY LIMITED TO LOCAL
EFFECTS. REMAINDER OF THE GRIDS WERE NUDGED TOWARD A NAM/GFS/ECMWF
ENSEMBLE BLEND.

.LONG TERM...WEAKENING LOW WILL MOVE ACROSS THE FAR S GULF WED
NIGHT THEN TO NRN HAIDA GWAII BY THU AFTERNOON. THE LOW SHOULD
PUSH ONSHORE THE CENTRAL BC COAST BY THU EVENING. ANOTHER FRONTAL
SYSTEM WILL MOVE NE INTO THE GULF FRI THEN ACROSS SE AK FRI NIGHT
AND SAT. THERE WILL LIKELY BE A LOW ON THIS FRONT AS WELL...BUT
MODELS DIFFER GREATLY ON THIS. MAY SEE ANOTHER SYSTEM AROUND SUN
BEFORE A LARGE SCALE RIDGE STARTS TO BUILD OVER THE ERN GULF NEXT
WEEK. USED BLEND OF THE 12Z ECMWF AND CANADIAN FOR WED NIGHT AND
THU...THEN WENT WITH 12Z GFS AND ECMWF BLEND FOR THU NIGHT AND
FRI. USED MAINLY WPC FOR FRI NIGHT ONWARD.

FOR WED NIGHT AND THU...PRECIP WILL DIMINISH OVER THE N DURING WED
EVENING...AND LOOKS LIKE THU WILL BE A FAIRLY NICE DAY OVER THE N
WITH SOME SUNSHINE LIKELY. THE S WILL SEE MORE PRECIP WITH THE LOW
MOVE IN WED NIGHT...BUT IT SHOULD DIMINISH THU AS LOW MOVES PAST
THAT AREA.

FOR THU NIGHT...AS MID-LEVEL RIDGE MOVES PAST THE AREA...FLOW WILL
BECOME MORE ONSHORE SO EXPECT SOME STRATOCU TO POP UP OVER THE
AREA ESPECIALLY THE LATTER PART OF THE NIGHT.

FOR FRI-SAT...PRECIP WITH FRONTAL SYSTEM SHOULD MOVE INTO THE GULF
FRI...THEN ONSHORE SE AK FRI NIGHT. MAY BE SOME PRECIP WELL OUT
AHEAD OF THE FRONT THOUGH ASSOCIATED WITH ONSHORE FLOW AND VERY
WEAK SHORTWAVE MOVING ACROSS THE AREA FRI. WIND FORECAST WILL BE
TRICKY DUE TO MODEL ISSUES HANDLING LOW ALONG THE FRONT...BUT
LOOKING LIKE AT LEAST SCA LEVEL WINDS.

FOR SAT NIGHT AND SUN...ANOTHER SYSTEM WILL KEEP ONSHORE FLOW
GOING AND KEEP THINGS MOSTLY ON THE WET SIDE ALTHOUGH IT MAY DRY
OUT SOME LATE SUN AS RIDGE STARTS TO BUILD IN.

NEXT WEEK...BIG STORY WILL BE THE MASSIVE RIDGE BUILDING OVER THE
AREA. STILL SOME MODEL DIFFERENCES ON HOW MUCH ENERGY MIGHT TRY TO
MOVE THRU THE RIDGE TOP AND HOW FAR W THE RIDGE AXIS SETS UP. AT
THIS POINT...LOOKING LIKE THE FAR NW PART OF THE AREA WILL HAVE
BEST CHANCES FOR PRECIP (WHICH COULD BE HEAVY DEPENDING ON HOW FAR
W RIDGE IS) AND THE FAR SE PART WILL SEE THE WARMEST AND DRIEST
WEATHER. TEMPS LOOK LIKE THEY WILL BE WELL ABOVE AVERAGE BY
MIDWEEK FOR MOST OF THE AREA.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND FROM 1 AM AKDT WEDNESDAY THROUGH WEDNESDAY MORNING
     FOR AKZ027.
MARINE...GALE WARNING FOR PKZ022-036-041>043-051-052.
     SMALL CRAFT ADVISORY FOR PKZ012-013-021-031>035.
&&

GARNER/RWT

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