Gale Warning 281, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
407 PM AKDT FRI OCT 11 2013

.SHORT TERM...WET DAY ACROSS THE AREA AS A WEAK OCCLUDED FRONT
MOVES THROUGH THE PANHANDLE. BACK END OF THE STEADIER RAIN HAS
REACHED SITKA, ANGOON, AND HOONAH WITH POINTS EAST STILL HAVING
SOME PERIODS OF LIGHT RAIN. WHILE POINTS TO THE WEST HAVE
TRANSITIONED TO MORE SCATTERED SHOWERS. RAINFALL AMOUNTS HAVE
BEEN LOW WITH ABOUT A HALF OF AN INCH OR LESS OVER THE LAST
12 HOURS. HIGHEST AMOUNTS HAVE BEEN IN THE NORTHERN PANHANDLE
PARTICULARLY AROUND JUNEAU, YAKUTAT, AND HOONAH. WINDS HAVE NOT
BEEN A PROBLEM EITHER WITH MOST PLACES STAYING BELOW 15 KT. THE
EXCEPTION IS LYNN CANAL, HAINES, AND SKAGWAY WHERE A PERSISTENT
SOUTHERLY PRESSURE GRADIENT CONTINUES TO KEEP SOUTHERLY WINDS OF
15 TO 25 KT BLOWING TODAY.

 THE PANHANDLE WILL DRY OUT A BIT TONIGHT AS A RIDGE BUILDS OVER
THE AREA OVERNIGHT. THE EXCEPTION WILL BE YAKUTAT WHERE ANOTHER
WEAK WAVE WILL MOVE IN FROM THE SW OVERNIGHT BRINGING MORE RAIN
TO THAT AREA. THIS WAVE MAY ALSO KEEP THE CHANCE OF SHOWERS FOR
AREAS WEST OF LYNN CANAL AND CHATHAM STRAIT OVERNIGHT AS THOSE
AREAS WILL STILL BE IN THE SW FLOW TO THE WEST OF THE BUILDING
RIDGE AXIS.

 MEANWHILE TO THE EAST OF THE BUILDING RIDGE AXIS, THINGS WILL BE
DRYING OUT AND SOME BREAKS WILL BE FORMING IN THE CLOUDS OVER
MOST OF THE SOUTHERN PANHANDLE OVERNIGHT. WINDS WILL BE LIGHT AS
WELL SO SOME PATCHY FOG MAY MAKE AN APPEARANCE LATE TONIGHT.
OTHERWISE MOSTLY DRY CONDITIONS WILL REMAIN INTO TOMORROW.

 AS FOR WINDS, LYNN CANAL WILL STILL BE WINDY THIS EVENING BUT
WILL START TO DIMINISH TONIGHT AS THE SW FLOW, KEEPING THE
SOUTHERLY PRESSURE GRADIENT STRONG, WEAKENS. THE WINDS ARE
EXPECTED TO REMAIN LOW THROUGH TOMORROW THERE. ELSEWHERE LIGHT
WINDS ARE THE NORM WITH THE EXCEPTION OF THE GULF. THERE SE WINDS
WILL BE INCREASING IN THE CENTRAL GULF AS THE NEXT FRONT STARTS
TO MAKE ITS WAY ACROSS THE GULF. WINDS WILL BE INCREASING TO
35 MPH IN THE CENTRAL GULF BY TOMORROW AFTERNOON.

 MODELS WERE IN DECENT AGREEMENT WITH THE NAM AND ECMWF HAVING
THE BEST REPRESENTATION OF CURRENT FEATURES. DECIDED TO USE BOTH
FOR OVERALL UPDATES TODAY.

 &&

.LONG TERM...HEAVY RAIN EVENT REMAINS IN THE FORECAST FOR SUNDAY
THROUGH MONDAY NIGHT FOR SOUTHEAST ALASKA. THIS PARTICULAR EVENT
HAS BEEN MODELED CONSISTENTLY BY ECMWF, GEM, AND GFS FOR SEVERAL
DAYS NOW WITH VERY LITTLE DRIFT IN FORECAST TRACK OF THE HEAVIEST
RAINFALL, SO CONFIDENCE IS ABOVE AVERAGE. 48 HOUR RAINFALL TOTALS
RANGING FROM AROUND 0.75 INCHES IN THE KETCHIKAN AREA TO OVER 3
INCHES ALONG THE CENTRAL OUTER COAST. FAR NORTHERN INNER CHANNELS
WILL SEE BETWEEN 1 AND 1.5 INCHES. LIKEWISE FOR THE SOUTHERN OUTER
COAST. REMAINING LOCATIONS WILL RECEIVE BETWEEN 2.25 INCHES TO
SLIGHTLY LESS THAN 3 INCHES BETWEEN SUNDAY MORNING AND LATE MONDAY
NIGHT.

WINDS ASSOCIATED WITH THE FRONT HAVE ALSO BEEN CONSISTENTLY
MODELED FOR SEVERAL MODEL CYCLES NOW AND CONFIDENCE IS ABOVE
AVERAGE FOR THIS PORTION OF THE FORECAST AS WELL. EXPECT 40 KT
GALE FORCE WINDS TO ARRIVE OVER THE WESTERN COASTAL MARINE ZONES
LATE SATURDAY NIGHT AND INCREASE DOWN THE COAST THROUGH SUNDAY
MORNING BEFORE BEGINNING TO WEAKEN. FRONTAL WIND SHIFT TO THE
WEST/SOUTHWEST SHOULD OCCUR OVER THE COASTAL MARINE ZONES
BEGINNING SUNDAY AFTERNOON AND WORKING DOWN THE OUTER COAST
THROUGH THE NIGHT. GUSTY CONDITIONS ASSOCIATED WITH FRONTAL
PASSAGE ARE POSSIBLE OVER THE INNER CHANNELS DURING THE DAY
MONDAY BUT WILL BE COMPLICATED IN TERMS OF TIMING DUE TO THE
EXTREME TOPOGRAPHY ASSOCIATED WITH SOUTHEAST ALASKA.

TEMPERATURES ACROSS THE PANHANDLE FOR THE UPCOMING WEEK WILL BE
AS MUCH AS 10 DEGREES WARMER THAN NORMAL FOR THIS TIME OF THE
YEAR. THIS IS THE RESULT OF A VERY AMPLIFIED UPPER LEVEL PATTERN
INCLUDING A STRONG RIDGE OVER WESTERN NORTH AMERICA AND THE
EASTERN PACIFIC COUPLED WITH A EQUALLY DEEP TROUGH SOUTH OF THE
ALEUTIANS. WHILE BOTH HIGHS AND LOWS WILL BE ABOVE NORMAL,
TEMPERATURE DEPARTURES FROM NORMAL WILL BE GREATER DURING THE
DAYTIME AND OVER THE CENTRAL INNER CHANNELS AWAY FROM THE OUTER
COAST.

BLENDED NAM AND ECMWF FOR PRESSURE AND WIND EARLY ON WITH WPC
ADDED TO THE BLEND BEYOND TUESDAY. CONTINUED TO USED A COMBINATION
OF GFS, GEM, AND ECMWF FOR POP AND QPF GRIDS. TEMPS ADJUSTED PER
GFS AND ENSEMBLE MEAN MOS GUIDANCE.

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

&&

EAL/FRITSCH