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FXAK67 PAJK 211409
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
609 AM AKDT SUN SEP 21 2014

.SHORT TERM...FUN WITH FRONTS CONTINUES. A NEW LOW IS CURRENTLY
MOVING NORTH BEFORE CURVING NORTHWEST ACROSS THE EASTERN GULF
LATER TODAY. BY THIS EVENING THE LOW WILL PUSH ASHORE SOMEWHERE
WEST OF YAKUTAT BAY. A WARM FRONT ASSOCIATED WITH THE LOW IS
PUSHING A BAND OF MODERATE TO HEAVY RAIN NORTHWESTWARD ACROSS THE
PANHANDLE WITH THE LOW`S PROGRESSION INTO THE NORTHEAST GULF.
HOWEVER...COLD AIR ALOFT CONTRIBUTING TO THE LOW`S STRENGTH
WRAPPING AROUND THE SYSTEM WILL INFILTRATE THE ATMOSPHERE OVER THE
PANHANDLE TONIGHT CHANGING THE NATURE OF THE PRECIPITATION TO
SHOWERS.

THE LOW WILL PACK STORM FORCE WESTERLIES BEHIND THE SYSTEM AS IT
DRIVES NORTHWARD...STRADDLING THE BOUNDARY BETWEEN OUR OUTSIDE
WATERS AND OUR OFFSHORE ZONE OF 310. AS COLDER AIR WRAPS AROUND
THE SYSTEM IN ITS LEE...FELT THE NEED TO INCREASE SOUTHERLY WINDS
THROUGH SOME OF THE INSIDE CHANNELS THIS AFTERNOON. THESE SURFACE
WINDS OVER THE MARINE WATERS SHOULD BE BETTER SUPPORTED FROM WINDS
ALOFT THAN YESTERDAY`S SYSTEM WHERE SCRIPTED WINDS FELL FLAT FROM
WEAKER COLD AIR ADVECTION IF ANY AT ALL. COOLER AIR IS MORE DENSE
AND LESS BUOYANT, AND THUS THE UPPER LEVEL WINDS...APPROACHING 50
KT OVER THE PANHANDLE THIS AFTERNOON WILL FIND IT EASIER TO EXCITE
WINDS AT THE SURFACE. THE PAST FEW SYSTEMS SEEM TO BE HAVE MOVED
FASTER THAN THE MODELS CAN KEEP UP, AND THUS WENT WITH THE FAST
ECMWF. THE SPEED OF THE GFS WAS DISCOUNTED EARLY ON. MOST ALL THE
MODELS BACKED OFF ON THE STORM FORCE SOUTHEAST WINDS, BUT ELECTED
TO KEEP THE STORM FORCE WESTERLIES BEHIND THE SYSTEM. THE STRONG
WIND HEADLINES POSTED FOR ZONES 27 AND 28 ARE NOT LOOKING AS MONEY
AS AS ONCE WERE. THINK THE SOUTHEASTERLIES WILL BE STRONGEST IN
THE MORNING, BUT FOR AREAS THAT RECEIVE GOOD S/SW WINDS, WHICH
FOR THE MOST PART DO NOT HAPPEN TO BE WHERE WE HAVE AIRPORT SITES,
A SHORT BURST OF SOUTHWESTERLIES MAY GUST TO 40 MPH AS THE COLD
FRONT PASSES. STRONG WIND EXTENDED FOR ZONE 22 TO COVER STRONG
WESTERLIES THIS EVENING AS THE WELL AS THE STRONG EASTERLIES THIS
AFTERNOON. JUNEAU`S WINDS WILL RISE THROUGH THE AFTERNOON TO
DIMINISH BY MID-EVENING. SKAGWAY WILL SEE 50 MPH GUSTS LATER THIS
EVENING INTO TONIGHT.

THE NORTHERN PANHANDLE SHOULD RECEIVE ANYWHERE BETWEEN 1 AND 2
INCHES OVER THE NEXT 24 HOURS WHILE THE CENTRAL/SOUTHERN PANHANDLE
SHOULD ROUNDLY RECEIVE BETWEEN 1 AND ONE QUARTER INCH. RISES IN
STREAMS LIKE THE STIKINE AND THE STANEY SEEM TO HAVE PLATEAUED OR
BEGUN TO PLATEAU. RIVERS ARE RELATIVELY HIGH OVER THE NORTH AND
WILL BE MONITORED TODAY FOR TRENDS AS THE HEAVIER RAIN BANDS PUSH
NORTHWARD AND STALL. YAKUTAT SHOULD RECEIVE MOST OF ITS RAIN THIS
AFTERNOON AND TONIGHT.

ECMWF USED FOR WIND/PRESSURE UPDATES. FORECAST CONFIDENCE AVERAGE
FOR WINDS...MUCH BETTER FOR POPS/QPF.

.LONG TERM...A RESIDUAL LOW FROM THE REMAINS OF THE SUNDAY
SURFACE LOW THAT DID NOT MANAGE TO CROSS THE ST. ELIAS RANGE WILL
REMAIN ALONG THE NORTH GULF COAST DRIFTING WEST TO SOUTH OF THE
KENAI PENINSULA WHILE SURFACE RIDGE BUILD OVER SOUTHEAST ALASKA
PANHANDLE ON MONDAY. EXPECT TO SEE THE RIDGE TO DRIFT EAST INTO
BRITISH COLUMBIA BY EARLY TUESDAY IN RESPONSE TO A LARGE LOW THAT
BECOMES VERTICALLY STACKED ALONG 45 NORTH SOUTH OF THE GULF OF
ALASKA. THIS LOW WILL DRIFT EAST AND WEAKEN THROUGH THE LATER HALF
OF THE WEEK...THOUGH THERE SEEMS TO BE LIGHT NORTHEAST TURN
TOWARDS THE CENTRAL BRITISH COLUMBIA COAST. A WEAK INVERTED TROUGH
IS EXPECTED TO DEVELOP ALONG THE OUTER COAST.

EXPECT SHOWERS TO TAPER OFF FROM THE NORTHWEST MONDAY TO WEDNESDAY
TO THE SOUTHEAST PANHANDLE ON WEDNESDAY. HOWEVER ABOUT WEDNESDAY
FRONTAL PRECIPITATION WILL BE ROTATING NORTH TROUGH BRITISH
COLUMBIA AND SLOWLY THOUGH THE SOUTHERN PANHANDLE THE LAST PART OF
THE. OVER ALL NOT EXPECTING MUCH IN RAIN TOTALS FOR WEDNESDAY ON
OVER THE PANHANDLE.

THE NORTHERN AND CENTRAL PANHANDLE MAY BE EVEN SEE SOME SUNSHINE
TUESDAY TO THURSDAY. WILL NEED TO WATCH FOR FOG ISSUES TUESDAY
NIGHT I THINK ONCE WE GET SOME BETTER CLEARING OVER THE PANHANDLE
BUT HAVEN`T STARTED ADVERTISING IT SIGNIFICANTLY JUST YET.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND THROUGH THIS EVENING FOR AKZ027-028.
         STRONG WIND FROM 4 PM AKDT THIS AFTERNOON THROUGH THIS EVENING
     FOR AKZ025.
         STRONG WIND FROM 1 PM AKDT THIS AFTERNOON THROUGH LATE TONIGHT
     FOR AKZ022.
         STRONG WIND FROM 10 AM AKDT THIS MORNING THROUGH THIS EVENING
     FOR AKZ023.
         STRONG WIND FROM THIS EVENING THROUGH MONDAY MORNING FOR AKZ018.
MARINE...GALE WARNING FOR PKZ012-013-021-022-033-035-036-041>043-051.
         SMALL CRAFT ADVISORY FOR PKZ011-031-032-034-052-053.

&&

$$

JWA/BEZENEK

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