Weather Service Report


869 
FXAK67 PAJK 162300
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
300 PM AKDT TUE SEP 16 2014

.SHORT TERM...REMNANTS OF A FRONT THAT PRODUCED RAIN OVER THE
PANHANDLE LATE MONDAY NIGHT INTO TUESDAY MORNING IS NOW MOVING
SOUTHEASTWARD AS THE HIGH PRESSURE RIDGE OVER THE AK GULF BEGIN TO
TRACK OVER THE PANHANDLE TONIGHT. A GALE FORCE LOW CURRENTLY OVER
THE AK PENINSULA WILL TRACK SOUTHWEST OF KODIAK BY WEDNESDAY WITH
ASSOCIATED FRONT REACHING THE CENTRAL GULF BY WEDNESDAY AFTERNOON.

AS THE FRONTAL REMNANTS MOVE TO THE SOUTHEAST IT WILL STILL HAVE
POTENTIAL TO PRODUCE SOME RAIN FALL OVER THE SOUTHERN HALF OF THE
PANHANDLE TONIGHT INTO EARLY WEDNESDAY MORNING. SATELLITE IMAGERY
SHOWING CLOUD COVER BEGINNING TO BREAK APART OVER THE WESTERN
PORTIONS OF THE PANHANDLE BUT WITH AN AREA OF MARINE STRATUS UNDER
THE AK GULF RIDGE AND SOME HIGHER CLOUDS TRACKING UP FROM THE
SOUTHWEST AND THERE IS A LARGE SPREAD AMONG MODELS ON CLEAR BREAKS
DEVELOPING TONIGHT INTO WEDNESDAY. THAT SAID GOING TO KEEP MOSTLY
CLOUDY SKIES FOR THE PANHANDLE INTO WEDNESDAY BUT EXPECT CEILINGS
TO BE MUCH HIGHER THAN THIS MORNING FOR MOST OF WEDNESDAY. ALSO
NOT RULING OUT A NUMBER OF SUCKER HOLES DEVELOPING. MODEL SOUNDING
BEGIN TO SHOW THE ATMOSPHERE BECOMING UNSTABLE LATER TONIGHT BUT
SOON A STABLE INVERSION FORMS AGAIN SO GOING WITH PERSISTENCE AND
EXPECTING ANOTHER ROUND OF FOG TO FORM OVERNIGHT. THE FOG SHOULD
BURN OFF A BIT QUICKER DUE TO IMPROVING SKY CONDITIONS BUT STILL
MAY SEE DENSE FOG DEVELOPMENT OVER THE SOUTHERN PANHANDLE LATE
TONIGHT. AS THE NEXT FRONT MOVES IN WILL JUST BEGIN TO SEE RAIN
INTO THE WESTERN PORTIONS OF YAKUTAT WEDNESDAY AFTERNOON WITH
CLOUD COVER INCREASING FROM THE WEST AND ADVANCING OVER THE
PANHANDLE.

MINOR DIFFERENCES WITH MODELS OVER THE SHORT TERM FOR WINDS AND
PRESSURE. BLENDED IN SOME GFS/NAM WITH INHERITED GRIDS WITH LITTLE
CHANGE TO THE INHERITED FORECAST BUT DID MOVE IN WINDS FROM THE
WEDNESDAY AFTERNOON FRONT A BIT FASTER. MODELS SHOWING LARGER
SPREAD WITH CLOUD COVER AND AS A RESULT DAY TIME TEMPERATURES.
WENT THE MORE PESSIMISTIC ROUTE WITH CLOUD COVER. FORECAST
CONFIDENCE IS AVERAGE.

.LONG TERM...LOOKS LIKE A COMPLEX LOW PRESSURE SYSTEM WILL MOVE
INTO THE GULF FOR WED NIGHT AND THU. MODELS SUGGEST MULTIPLE LOW
CENTERS...WITH TRIPLE POINT FEATURE POSSIBLE OVER THE E-CENTRAL
GULF. THIS COMPLICATES TIMING AND STRENGTH OF WINDS OVER THE GULF
AND SE AK WED NIGHT INTO THU. AFTER COORD WITH WFO PAFC...DECIDED
TO USE A BLEND OF THE 12Z ECMWF/GFS/GEM THRU FRI...WHICH GIVES A 
MORE MIDDLE GROUND IDEA ON THE COMPLEX LOW STRUCTURE AND TIMING OF
OCCLUDED FRONT. LATER SHIFTS MAY NEED TO ADJUST AS NEWER MODELS COME
IN AND SATELLITE PRESENTATION SHOWS WHERE POTENTIAL LOWS ARE
DEVELOPING. IF ANY TRIPLE POINT FEATURES ARE STRONGER THAN
CURRENTLY SHOWN...MAY NEED TO BUMP WINDS UP FURTHER OVER THE AREA.

FOR THE WEEKEND INTO NEXT WEEK...UPPER TROF WILL DOMINATE THE AREA
BUT DETAILS ON INDIVIDUAL SYSTEMS REMAIN DIFFICULT TO FORECAST.
USED WPC FOR FRI NIGHT ONWARD AS THEY USED BLEND OF
ENSEMBLES...WHICH SEEMS LIKE A GOOD IDEA GIVEN THE MODEL
DIFFERENCES. STILL LOOKS FAIRLY WET BUT THERE MAY BE BREAKS IN
BETWEEN SYSTEMS...SO DUE TO LOW CONFIDENCE IN TIMING OF SYSTEMS
LIMITED POPS ON HIGH END TO LIKELY.

&&

.MARINE...SOUTHWEST SWELL WILL SUBSIDE OVERNIGHT WITH SEAS OVER
THE COASTAL WATERS NOW BELOW SMALL CRAFT LEVELS. AS THE NEXT FRONT
APPROACHES THE AREA THROUGH WEDNESDAY WINDS WILL INCREASE TO GALE
FORCE OVER THE WESTERN PORTIONS OF THE GULF WITH SEAS BUILDING
INTO THE 12 FOOT RANGE. INNER CHANNEL WINDS WILL REMAIN AT 10 KTS
OR LESS THROUGH WEDNESDAY WHILE THE HIGH PRESSURE RIDGE MOVES
OVER THE AREA.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ052. 
         SMALL CRAFT ADVISORY FOR PKZ051. 
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041. 

&&

$$

PRB/RWT

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