Area Forecast Discussion
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FXAK67 PAJK 232346
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
346 PM AKDT TUE SEP 23 2014

.SHORT TERM...VERTICALLY STACKED CYCLONE SLOWLY APPROACHING S
PANHANDLE WILL INDUCE SOME RAIN AND MODERATE WINDS TO SOUTHERN
SECTIONS LATE TONIGHT AND TOMORROW BUT WILL WEAKEN WITH TIME, THUS
LIMITING IMPACTS. MEANWHILE SHORTWAVE TO NORTH WILL TIGHTEN
SURFACE GRADIENT ON THE NORTH END ON WED AND PRODUCE WIND
INCREASES IN LYNN...ICY STRAIT AND GLACIER BAY. SCA FOR NORTHERN
LYNN AND SOUTHERN LYNN. SOME DRYING NORTHEASTERLY FLOW PROGGED TO
ACCOMPANY THIS GRADIENT AND BIG QUESTION IS FOG FOR SOME ZONES
TONIGHT WITH RESIDUAL MOISTURE. WILL LIKELY HAVE PATCHY FOG IN
MANY AREAS IN THE CENTRAL PORTION BUT SOME EXPOSED SPOTS WILL NOT
SATURATE DUE TO DRY NORTHEASTERLY LOW LEVEL FLOW, ESPECIALLY OVER
THE NORTH...AND CLOUDS/SOME INCREASING WIND IN SOUTHERN AREAS DUE
TO SOUTHERN LOW WILL PREVENT SIGNIFICANT FOG THERE. THUS HAVE
CHOSEN PATCHY FOG FOR SOME CENTRAL AREAS TONIGHT. SCA OUT FOR
NORTHERN LYNN BEGINNING TONIGHT AND FOR SOUTHERN LYNN TOMORROW.
ALSO ZONE 41 WILL LIKELY HAVE SCA WINDS TONIGHT THROUGH
TOMORROW...AND 42/43 FOR TOMORROW DUE TO SWELL.

.LONG TERM...LEADING OCCLUDED FRONT WILL DISSIPATE ALOFT OVER THE
CENTRAL PANHANDLE WED EVENING. SECOND WRAP OF FRONT WILL MOVE INTO
THE SRN AREA WED NIGHT BUT BE SOMEWHAT WEAKENED AS IT REACHES OUR
AREA. THIS FEATURE WILL DRIFT N INTO THE CENTRAL AREA FOR THU AND
THU NIGHT...AND REACH THE NRN AREA FRI BUT LIKELY DISSIPATE THERE.
A STRONGER OCCLUDED FRONT WILL MOVE IN FROM THE W FRI INTO SAT. PARENT
LOW OF THIS FRONT WILL LIKELY DRIFT E ACROSS THE SRN GULF AND WEAKEN
OVER THE WEEKEND. MODELS HAD SOME DIFFERENCES WITH ALL THE ABOVE
FEATURES BUT SEEM TO BE GETTING CLOSER. GENERALLY USED GFS/EC
BLEND FOR THU NIGHT AND FRI...THEN WENT WITH MAINLY WPC FOR FRI
NIGHT ONWARD. FOR WED NIGHT AND THU...MADE TWEAKS (MAINLY TO
WINDS) BASED ON CURRENT PRESSURE FORECAST.

FOR WED NIGHT AND THU...AS LEADING OCCLUDED FRONT DISSIPATES OVER
THE CENTRAL AREA...THE CLOUDS AND PRECIP WITH IT ON THE NRN SIDE
WILL LIKELY THIN OUT. HOWEVER...MORE CLOUDS/PRECIP WILL MOVE IN
FROM THE S WITH WEAKENING SECOND WRAP FEATURE...WITH MOST OF THE
PRECIP OVER THE SRN HALF DURING THIS TIME. THE N-NE FLOW IN LOWER
LEVELS WILL TEND TO KEEP THE NRN AREA DRY BUT CANNOT RULE OUT
SPOTTY LIGHT RAIN IN THE N-CENTRAL AREA ESPECIALLY THU.

FOR THU NIGHT AND FRI...AS WEAK SECOND WRAP OCCLUSION MOVES
FURTHER N...RAIN CHANCES WILL PICK UP OVER THE N AND DECREASE OVER
THE S. MODELS DIFFER ON HOW MUCH PRECIP IS LEFT BY TIME IT GETS TO
THE NRN AREA. LIMITED POPS ON HIGH END TO LIKELY WITH THIS PRECIP
AREA ON FRI. NEXT SYSTEM MOVING IN FROM THE W SHOULD INCREASE
WINDS OVER THE GULF AND PRECIP SHOULD REACH THE CENTRAL GULF WATERS
BY LATE FRI AFTERNOON.

FOR FRI NIGHT AND SAT...SHOULD SEE LARGER PRECIP SHIELD MOVING
INTO THE AREA FROM THE W WITH THE NEXT SYSTEM...BUT MODELS DIFFER
SOMEWHAT ON TIMING SO LIMITED HIGH END POPS TO LIKELY. POTENTIAL
WAVE DEVELOPMENT ON THE FRONTAL BAND SEEMS TO BE WHERE MODELS
DIFFER THE MOST.

FOR THE REMAINING PERIOD...LOOKS LIKE LOW SHOULD SLOWLY MOVE E OR SE
AND WEAKEN SOMEWHAT FOR SUN-MON. MODELS DIFFER ON TRACK OF LOW
ENOUGH TO MAKE FOR IMPORTANT SENSIBLE WEATHER DIFFERENCES...SO
KEPT IN THE HIGHEST POPS OVER THE S WHERE PROXIMITY OF THE LOW
WILL HAVE BETTER CHANCE TO KEEP SOME PRECIP OVER THE AREA. COULD
BE A DRIER SPELL FOR AT LEAST TUE AS SOME RIDGING MOVES IN...BUT
ANOTHER SYSTEM IS LIKELY TO MOVE IN AROUND MIDWEEK.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-013-041.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ042-043.

&&

$$

WESLEY/RWT

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