Area Forecast Discussion
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000
FXAK67 PAJK 051317
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
517 AM AKDT THU MAY 5 2016

.SHORT TERM...A GALE FORCE FRONT MOVING INTO THE EASTERN GULF
WILL BE THE MAIN WEATHER MAKER OVER THE NEXT 24 HOURS. STEADY
LIGHT TO MODERATE RAIN HAS FALLEN OVERNIGHT FROM SITKA TO ANGOON
AND NORTHWARD. THE AREA OF STEADY RAIN WILL SLOWLY SHIFT TO THE
NORTH AND LESSEN IN INTENSITY ESPECIALLY OVER THE INNER CHANNELS
LATE THIS MORNING AND EARLY IN THE AFTERNOON IN RESPONSE TO
SHORTWAVE RIDGING. AS THE FRONT PROGRESSES EASTWARD, RAINFALL
RATES WILL AGAIN INTENSIFY AND BECOME HEAVY AT TIMES OVER THE
NORTHEAST GULF COAST LATE THIS AFTERNOON AND INTO TONIGHT. FOR THE
REMAINDER OF THE NORTHERN PANHANDLE, EXPECT RAINFALL RATES TO
INCREASE MID TO LATE EVENING OVER THE OUTER COAST AND LATE TONIGHT
OVER THE NORTHERN INNER CHANNELS. PRECIPITABLE WATER VALUES WITH
THIS SYSTEM ARE 3-4 STANDARD DEVIATIONS ABOVE NORMAL RESULTING IN
HIGH CONFIDENCE IN HEAVY RAINFALL. 24 HOUR RAINFALL AMOUNTS ARE
EXPECTED TO RANGE FROM 1-2 INCHES ACROSS THE NORTHERN PANHANDLE
WITH LOCALLY HIGHER AMOUNTS POSSIBLE. BY THE END OF THE SHORT TERM
PERIOD, STEADY RAIN WILL HAVE PROGRESSED AS FAR SOUTH AS SUMNER
STRAIT WITH THE FAR SOUTHERN PANHANDLE STILL REMAINING DRY. REFER
TO THE SPECIAL WEATHER STATEMENT FOR ADDITIONAL INFORMATION ON
EXPECTED RAINFALL.

STRONG SOUTHWESTERLY FLOW ALOFT WILL PERSIST THROUGH THE DAY WITH
CONTINUED SMALL CRAFT WINDS IN LYNN CANAL AND GUSTS TO 35 MPH IN
SKAGWAY. WINDS WILL PICK UP OVER THE OUTSIDE WATERS IN RESPONSE
THE APPROACHING FRONT WITH GALES OVER THE NORTHEAST GULF. THESE
WINDS WILL PUSH INTO THE NORTHERN PANHANDLE TONIGHT WITH SMALL
CRAFTS OVER MANY OF THE INNER CHANNELS AND INCREASING
SOUTHEASTERLY WIND OVER LAND.

THERE WILL BE LITTLE IN THE WAY OF DIURNAL CHANGE FROM HIGH
TEMPERATURES TODAY AND LOWS TONIGHT ACROSS THE NORTHERN HALF OF
THE PANHANDLE. TEMPERATURES WILL GENERALLY RANGE FROM THE MID TO
UPPER 40S. ACROSS THE SOUTHERN PANHANDLE, HIGHS THIS AFTERNOON
WILL CLIMB INTO THE UPPER 50S UNDER PARTLY CLOUDY SKIES.
INCREASING CLOUD COVER TONIGHT WILL INHIBIT TEMPERATURES FROM
FALLING BELOW THE MID TO UPPER 40S.

CHANGES TO THE FORECAST WERE MINIMAL AS MODELS REMAIN IN GOOD
AGREEMENT. RELIED ON THE HIRES ARW/NMM FOR MANY FIELDS.
FORECASTER CONFIDENCE IS ABOVE AVERAGE.

.LONG TERM...OCCLUDED FRONT WILL MOVE ACROSS THE AREA FRI INTO FRI
NIGHT. A WEAK LOW WILL MOVE ACROSS THE GULF AND DISSIPATE ALONG
THE CENTRAL OUTER COAST SAT EVENING. LOOKS LIKE A RIDGE WILL TRY
TO BUILD OVER THE AREA FOR AT LEAST PART OF NEXT WEEK...BUT MODELS
ARE STRUGGLING ON THIS. ENDED UP USING A BLEND OF THE 00Z
GEM/ECMWF FOR FRI-SAT NIGHT...THEN PRETTY MUCH LEFT REST OF
FORECAST AS IS.

STILL LOOKS LIKE LOCALLY HEAVY RAIN WILL FALL OVER THE AREA
THROUGH FRI EVENING AT LEAST. A GENERAL 2-4 INCHES OF RAIN IS
EXPECTED WITH HIGHEST AMOUNTS OVER THE N HALF OF THE AREA. LOOKING
LIKE FRONT WILL MOVE ACROSS THE AREA A LITTLE FASTER THAN
PREVIOUSLY THOUGHT SO LOOKING LESS LIKELY THAT THE SRN AREA WILL
SEE A PROLONGED HEAVY RAINFALL. PRECIP WILL TRANSITION TO SHOWERS
BEHIND THE FRONT AND CONTINUE INTO SAT NIGHT AS LOW MOVES ACROSS
THE GULF AND DISSIPATES ALONG THE OUTER COAST. SHOULD SEE
IMPROVING CONDITIONS SUN AS HIGH PRESSURE MOVES IN. WILL LIKELY
STILL HAVE DECENT AMOUNT OF CLOUD COVER BUT THE PRECIP THREAT WILL
DIMINISH.

NEXT WEEK...CONFIDENCE IN A LONGER DRY SPELL IS WAVERING AS MODELS
HINT THAT SYSTEMS MIGHT MAKE IT INTO THE AREA AT TIMES. COULD BE
ONE SYSTEM FOR MON NIGHT...AND POTENTIALLY ANOTHER FOR LATE WEEK.
UNTIL MODELS COME INTO BETTER AGREEMENT ABOUT THIS TIME PERIOD
THOUGH...FORECAST CONFIDENCE WILL REMAIN ON THE LOW SIDE.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ043-051-052.
     SMALL CRAFT ADVISORY FOR PKZ012-013-021-022-031>036-041-042-053.
&&

$$

TPS/RWT

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