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FXAK67 PAJK 061700 CCA
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE JUNEAU AK
857 AM AKDT WED MAY 6 2015

.SYNOPSIS...UPPER FLOW PATTERN DRIVEN BY AN UPPER RIDGE OVER 140W
AT 06/12Z THAT EXTENDS INTO S CENTRAL. THERE IS ALSO AN UPPER
SHORTWAVE TROF ALG THE ALCAN THAT IS MOVING RAPIDLY EASTWARD AS THE
UPPER RIDGE MOVES EAST. THIS TRANSITIONAL PHASE IS A PATTERN CHANGE
FOR SE ALASKA. THE SURFACE RIDGE IS OVER THE GULF AND WILL WEAKEN
AS IT MOVES OVER THE PANHANDLE TONIGHT. THE RESULT IS ONSHORE FLOW
ALOFT LATER WED NIGHT FOR AN APPROACHING FRONT WITH RAIN AND SOME
WIND OUTSIDE BY THU.

&&

.SHORT TERM...THIS MORNING WAS A FIRST DAY MARINE PUSH WITH LOW
LEVEL MOIST AIR GETTING INTO YAKUTAT GUSTAVUS SITKA AND THROUGH
DIXON ENTRANCE INTO KETCHIKAN. THIS CAUSED SOME LOW CLOUDS AND
PATCHY FOG. ALSO LOOK FOR SERIOUS CIRRUS TODAY REDUCING SUNSHINE
BUT WITH SOME DRYING AND TEMPERATURES CLIMBING INTO THE 50S. EXPECT
THE SEA BREEZE TO DIE OUT DUE TO THE SURFACE RIDGE MOVING ONSHORE.
OUTER COASTAL WINDS WILL INCREASE LATER TONIGHT AS THE FIRST IN A
SERIES OF FRONTS MOVES UP TO THE COAST. YAKUTAT MIGHT GET RAIN
LATER TONIGHT AND GOOD CERTAINTY BY MORNING.

.LONG TERM...MODELS REMAIN IN FAIR AGREEMENT AND GOOD CONSISTENCY
THROUGH MOTHERS DAY WEEKEND FOR SEVERAL WAVES MOVING ACROSS
SOUTHEAST ALASKA. MADE A FEW COSMETIC TOUCHES FOR FINE TUNES OVER
THE INHERITED FORECAST PACKAGE. THE FIRST ONE IN A SERIES MOVING
INTO THE OFFSHORE WATERS WILL DISSIPATE OVER THE EASTERN GULF ON
THURSDAY...FOLLOWED BY ANOTHER FRONT MOVING INTO THE NORTHEASTERN
GULF FRIDAY AND SATURDAY. THIS WILL BRING CATEGORICAL POPS TO
YAKUTAT AND NORTHWESTERN PANHANDLE. THE FRONTAL PASSAGE WILL ALSO
PRODUCE SMALL CRAFT LEVEL SOUTHEASTERLY WINDS AND ROUGH SEAS OVER
THE OUTSIDE WATERS...INCLUDING OCEAN TRANSIT AREA OF CROSS SOUND.
THE SERIES OF WAVES PASSING OVER SOUTHEAST ALASKA WILL MAKE A
SLIGHT MODIFICATION FOR DIURNAL TEMPERATURE FLUCTUATION AND EXPECT
MOSTLY IN THE 50S AS DAYTIME HIGHS AND OVERNIGHT LOWS IN THE 40S.
YET ANOTHER UPPER LOW WILL MOVE INTO THE CENTRAL GULF ON FRIDAY
NIGHT FROM THE SOUTH...THEN PROGRESS NORTHWARD WITH INCREASING
UNCERTAINTIES. THIS LOW WILL PUSH THE RIDGE EASTWARD ACROSS THE
PANHANDLE THROUGH THE WEEKEND. MODEL DIFFERENCES BECOME LARGER
NEXT WEEK AND USED THE WPC ENSEMBLE SOLUTIONS...MAINTAINING FAIR
AMOUNT OF CLOUDINESS AND LOWER POPS AS A WEAK UPPER LEVEL
SHORTWAVE TROUGH MOVING ACROSS THE GULF.

&&

.AVIATION...ENJOY THE FLYING TODAY AFTER SOME MVFR CONDS DISSIPATE
AFTER THE PUSH. VFR CONDS WILL PERSIST THROUGH TONIGHT EXCEPT FOR
THE YAKUTAT AREA.

&&

.MARINE...SOME WESTERLY BREEZES THIS MORNING WITH THE PUSH BUT THE
TENDENCY SHOULD BE FOR LIGHTER WIND IN THE AFTERNOON. THERE WILL BE
A SIGNIFICANT DIRECTIONAL SHIFT LATER TONIGHT IN RESPONSE TO THE
FRONT. ANCHORAGE IS FORECASTING EASTERLY GALES TONIGHT WEST OF
SUCKLING AND 30KT LOOKS QUITE REASONABLE ON OUR SIDE. NO SWELL TO
SPEAK OF TODAY AND TONIGHT.

&&

.FIRE WEATHER...INCREASING LOW LEVEL MOISTURE THIS MORNING WITH THE
PUSH...BUT DRY CONDS WILL PERSIST FOR THE HAINES & SKAGWAY AREAS.
HOONAH HAD FULL RECOVERY. EXPECT ONE AND TEN HOUR FUELS TO REMAIN
DRY FOR SOME THREAT NORTHERN LYNN CANAL. FRONT THURSDAY WILL END
ALL CONCERNS.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-043-051-052.

&&

$$

JC/AHN

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