Area Forecast Discussion
Issued by NWS

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000
FXAK67 PAJK 280310 CCA
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
353 PM AKDT THU AUG 27 2015

.SHORT TERM...THE PANHANDLE IS BECOMING GRADUALLY WETTER AS THE
DAY WEARS ON. AN UPPER LEVEL TROUGH IS DROPPING SE FROM THE
ALASKA PENINSULA AND IS DRAGGING WHAT IS LEFT OF AN ATMOSPHERIC
RIVER THAT WAS DRAWING SIGNIFICANT TROPICAL MOISTURE INTO SW
ALASKA FOR THE LAST TWO DAYS. WHILE THE REMAINS OF THIS MOISTURE
STREAM ARE NOT AS POTENT AS WHEN IT WAS IN THE BERING, PW VALUES
ARE STILL REGISTERING AROUND 1 INCH OR 120 TO 140 PERCENT OF
NORMAL ACROSS THE GULF. AT THE SURFACE THE UPPER TROUGH IS
SPINNING UP A SURFACE LOW IN THE NORTHERN GULF WITH A FRONT THAT
IS SPREADING ACROSS THE EASTERN GULF. THE INITIAL HEAVY RAIN BANDS
HAVE BEEN IN YAKUTAT MOST OF THE MORNING AND HAVE JUST REACHED THE
NORTHERN PANHANDLE JUST AFTER NOON. THESE RAIN BANDS WILL SPREAD
INTO THE CENTRAL AND SOUTHERN PANHANDLE BY THIS EVENING.

WINDS HAVE ALSO STARTED TO KICK UP ACROSS THE NORTHERN PANHANDLE WITH
GUSTS TO 33 KT AT SKAGWAY, 39 KT AT ELDRED ROCK, AND GUSTS TO 25
KT AT JUNEAU BEING THE HIGHEST OBSERVED GUSTS SO FAR. THESE WINDS
WILL REMAIN GUSTY THROUGH THE EVENING BUT WILL GRADUALLY SUBSIDE
BY LATE EVENING. THE SOUTHERN PANHANDLE WILL BE THE OPPOSITE AS
WINDS WILL BE INCREASING THIS EVENING AS THE FRONT APPROACHES THAT
AREA. AS A RESULT SMALL CRAFT ADVISORIES AND A FEW STRONG WIND
HEADLINES REMAINS UP IN VARIOUS AREAS OF THE PANHANDLE TONIGHT.

INTO TOMORROW THE RAIN WILL BE LIGHTENING UP ACROSS THE NORTH BUT
WILL BE CONTINUING AND BE HEAVY AT TIMES ACROSS THE SOUTHERN
PANHANDLE AS THE FRONT STALLS. AREAS FROM AROUND KAKE AND CAPE
DECISION EASTWARD WILL SEE THE BRUNT OF THE HEAVY RAIN ON FRI WITH
UPWARDS OF 2 TO 3 INCHES EXPECTED THROUGH FRI AFTERNOON. WINDS
WILL ALSO REMAIN GUSTY WITH SMALL CRAFT WINDS CONTINUING FOR
CLARENCE STRAIT TOMORROW BUT THEY SHOULD REMAIN BELOW STRONG WIND
CRITERIA.

BEHIND THE LOW, WINDS SWITCH AROUND TO THE NORTH AND WITH A COOL
HIGH PRESSURE SYSTEM STRENGTHENING IN THE YUKON SOME OUTFLOW WINDS
WILL BE BLOWING OUT OF THE USUAL PASSES IN THE NORTHERN PANHANDLE.
EXPECT WINDS TO REACH SMALL CRAFT CRITERIA FRI MORNING BUT I DO
NOT EXPECT ANYTHING HIGHER AS THE PRESSURE GRADIENT IS NOT THAT
STRONG AND THE AIR MASS IN CANADA IS COOL NOT COLD PLUS THE
STRONGEST PART OF IT IS OVER THE ALASKA INTERIOR FARTHER WEST.

SHORT RANGE MODELS WERE IN GOOD AGREEMENT THROUGH THE PERIOD WITH
ONLY A FEW DIFFERENCES NOTED HERE AND THERE. GENERALLY USED HI-RES
NAM FOR UPDATES TODAY.

.LONG TERM.../ FRIDAY NIGHT TO THURSDAY / THE SHORT WAVE ALOFT
THAT MOVED SOUTH TO THE GULF OF ALASKA THROUGH FRIDAY WILL HELP
TO OPEN THE CLOSED LOW THAT HAD BEEN PERSISTING ABOUT 600 NM WEST
OF THE CONUS COAST AROUND 43N. THE NEWLY REFORMED TROUGH WILL BE
`OPEN` EARLY SATURDAY. THE SHORT WAVE FEATURE IS NEXT EXPECTED TO
LIFT THE SOUTHERN END OF THE TROUGH INLAND ACROSS THE PACIFIC
NORTHWEST THROUGH EARLY SUNDAY MORNING.

ANOTHER SHORT WAVE MOVING SOUTHEAST ACROSS WESTERN ALASKA SHOULD
REACH THE WESTERN GULF EARLY SUNDAY MORNING AND BE MOVING INTO THE
SOUTHEAST GULF BY SUNDAY AFTERNOON. MID RANGE MODELS SOLUTIONS
ARE BEGINNING TO CONVERGE ON A MORE ORGANIZED SOLUTION FOR SUNDAY
HOWEVER THERE REMAIN SOME ISSUES. IT DOES LOOKS LIKE A LOW WILL MOVE
ACROSS THE SOUTHERN PANHANDLE SUNDAY AND SUNDAY NIGHT.

DO EXPECT ANOTHER BURST OF MID TROPICAL MOISTURE TO WORK ITS WAY
BACK INTO THE GULF IN A ROUND ABOUT WAY FROM THE SOUTHERN BERING
SEA FOR THE WEEKEND. THAT MOISTURE WILL BE TAPPED FOR THE SUNDAY
FEATURE TO SPREAD MORE RAIN OVER THE SOUTHERN PANHANDLE. BEST
RAINS MAY END UP SOUTH OF THE PANHANDLE BUT WILL NEED TO WATCH THIS
TO SEE IF THE LOW TRACK COULD BE LITTLE FURTHER NORTH...IN WHICH
CASE THE SOUTHERN PANHANDLE WILL GET ANOTHER SOAKING. FOR THE MOMENT
QPF NUMBERS ARE NOT THAT OUT OF ORDINARY FOR AN EARLY FALL STORM
FEATURE.

BUILDING RIDGE ALOFT AND AT SURFACE ALONG ROUGHLY 160W WILL BUILD
EAST FROM THE EARLY PART OF THE WEEK TO BE OVER THE GULF BY
WEDNESDAY NIGHT. THEREFORE THE TAPERING OFF THE PRECIPITATION AND
DRIER PATTERN MID WEEK STILL LOOKS VERY POSSIBLE.

THE FORECAST ADJUSTMENTS TO SUNDAY NIGHT WERE BASED ON A BLEND OF THE
ECMWF AND NAM IN MIND. CONFIDENCE IS GOOD LOWERING TO AVERAGE HEADED
INTO WEEKEND.


&&

.HYDROLOGY...THE MODERATE TO HEAVY RAINFALL WILL MAKE AREA RIVERS
AND STREAMS RISE OVER THE NEXT 24 HOURS. THE TAIYA RIVER AND MONTANA
CREEK HAVE THE POSSIBILITY OF REACHING BANKFULL THIS EVENING AS THE
INITIAL FRONT MOVES THROUGH BUT THAT IS ABOUT IT FOR THE GAGED
RIVERS AND STREAMS. SMALLER NON-GAGED STREAMS MAY REACH BANKFULL
LATER TONIGHT AND TOMORROW ESPECIALLY ACROSS THE SOUTHERN PANHANDLE
AS THE FRONT STALLS.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND UNTIL 10 PM AKDT THIS EVENING FOR AKZ025.
         STRONG WIND UNTIL 4 PM AKDT THIS AFTERNOON FOR AKZ018.
MARINE...GALE WARNING FOR PKZ012.
         SMALL CRAFT ADVISORY FOR PKZ011-013-022-031>036-041>043-051-052.

&&

$$

EAL/BEZENEK

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