Area Forecast Discussion
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FXAK67 PAJK 291321
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
521 AM AKDT FRI AUG 29 2014

.SHORT TERM...EARLY MORNING WATER VAPOR SATELLITE IMAGE SHOWS A
WEAKENING UPPER LEVEL SHORTWAVE TROUGH OVER THE CENTRAL GULF
SLOWLY MOVES EAST TOWARD THE PANHANDLE. INFRA RED SATELLITE LOOP
REVEALS AN ASSOCIATED SURFACE LOW PRESSURE SYSTEM...ABOUT 991
MB...OVER THE EAST CENTRAL GULF WITH ITS ASSOCIATED OCCLUDED FRONT
STRETCHING SOUTHEASTWARD ACROSS THE EASTERN GULF. A TRIPLE POINT
FORMS NORTH OF BUOY 46184...NORTH NOMAD BUOY...AND PRODUCE 25 TO
30 KNOTS EAST TO SOUTHEAST WINDS ACROSS THE OUTER WATERS AND 15 TO
25 KNOT SOUTHEAST WINDS OVER THE SOUTHERN INNER CHANNELS. MULTIPLE
SHOWER BANDS WRAP AROUND THE LOW AND OUTSKIRT TO THE NORTHERN
PANHANDLE...PRODUCING OCCASIONAL MODERATE RAINFALL...ESPECIALLY
ACROSS THE SOUTHERN AREAS. OVERNIGHT TEMPERATURES REMAIN IN THE
LOWER TO MID 50S...EXCEPT UPPER 40S AT YAKUTAT.

MODELS REMAIN IN GENERAL AGREEMENT WITH THE UPPER LEVEL SHORTWAVE
TROUGH CONTINUES TO WEAKEN AND MOVE OVER THE PANHANDLE...FOLLOWED
BY A NEAR ZONAL UPPER LEVEL FLOW ACROSS THE GULF. THE SURFACE LOW
IN THE EAST CENTRAL GULF WILL CONSEQUENTLY WEAKEN TO 1000 MB OVER
THE EASTERN GULF THIS MORNING. THE SURFACE LOW WILL CONTINUE TO
SLOWLY WEAKEN AND DRIFT EAST TO SOUTHEAST ACROSS THE PANHANDLE
THROUGH LATE TONIGHT. THE ASSOCIATED FRONTAL PASSAGE WILL MOVE
SOUTHEASTWARD ACROSS THE PANHANDLE THROUGH LATE TONIGHT. REFRESHED
THE INHERITED FORECAST PACKAGE WITH THE 06Z RUN NAM12 AND MADE A
FEW FINE TUNES FOR THE POP/QPF FIELDS. MAINTAINED WIND FIELDS IN
WEAKENING TREND THIS AFTERNOON INTO TONIGHT AS THE LOW WEAKENS.
DAYTIME HIGH TEMPERATURES WILL BE IN THE MID TO UPPER 50S OVER THE
NORTHERN AND CENTRAL PANHANDLE. THE SOUTHERN AREAS WILL BE A BIT
WARMER TO THE LOWER 60S. CONTINUED MOSTLY CLOUDY SKIES WILL KEEP
THE DIURNAL TEMPERATURE RANGE WITHIN ABOUT 10 DEGREES FOR TONIGHT.

SMALL CRAFT LEVEL WINDS/SEAS WILL CONTINUE TO AFFECT THE OUTSIDE
WATERS TODAY...INCLUDING CROSS SOUND...AND GRADUALLY DIMINISH
SOUTHEASTWARD THROUGH LATE TONIGHT. AS THE FRONTAL BOUNDARY
INITIALLY TOUCHES THE SOUTHERN INNER CHANNELS...EXPECT SMALL CRAFT
LEVEL SOUTHEAST WINDS PREVAIL OVER FREDERICK SOUND SOUTH TO
CLARENCE STRAIT THIS MORNING. CATEGORICAL POPS OVER THE MAIN
PANHANDLE WILL SLOWLY DRIFT SOUTHEASTWARD THROUGH TONIGHT AND GIVE
LOWERED POPS OVER THE NORTHERN AND NORTH CENTRAL PANHANDLE BY
EARLY EVENING HOURS. COOLER TEMPERATURES ALOFT WILL CONTINUE TO
ENHANCE INSTABILITY OVER THE SOUTHERN OUTER WATERS AND SOUTHERN
PANHANDLE AREAS FOR POTENTIAL THUNDERSTORMS TODAY INTO THIS EVENING.

.LONG TERM...WET WEATHER IN STORE FOR THE WEEKEND INTO EARLY NEXT
WEEK. POTENTIAL DRYING MIDDLE OF NEXT WEEK.

 THE WEATHER PATTERN REMAINS VERY ACTIVE FOR THE START OF THE
FORECAST PERIOD. THERE WILL BE A 110-KT JET BRINGING SYSTEMS FROM
WEST TO EAST ACROSS THE GULF OF ALASKA. WITH ONSHORE FLOW ACROSS
THE PANHANDLE, DO EXPECT SHOWERS ACROSS THE CWA. THERE IS A SHORT
WAVE EMBEDDED IN THE JET STREAM, AND THIS SHORT WAVE WILL BRING
ENHANCED STRATIFORM PRECIPITATION TO THE PANHANDLE ON SUNDAY.
RIGHT NOW, MODELS ARE PROJECTING THIS SHORT WAVE DISTURBANCE TO
BRING CATEGORICAL PRECIPITATION TO THE SOUTHERN PANHANDLE, WHILE
THE REST OF THE PANHANDLE SHOULD SEE LIKELY POP.

 A STRONGER SHORTWAVE WILL FOLLOW RIGHT BEHIND THE FOOTSTEP OF
THE FIRST SHORT WAVE. THIS SHORTWAVE WILL ONCE AGAIN ENHANCE THE
STRATIFORM PRECIPITATION ACROSS THE PANHANDLE SUNDAY NIGHT INTO
MONDAY NIGHT. BEHIND THE SHORT WAVE, RIDGING WILL REBUILD ACROSS
THE GULF OF ALASKA. MODELS ARE HINTING ON A DRYING TREND MIDDLE OF
NEXT WEEK. HOWEVER, MOISTURE WILL BE RETURNING ON THE WEST SIDE OF
THE RIDGE.

 FORECAST CONFIDENCE NEAR AVERAGE FOR THE START OF THE WEEKEND,
THEN DECREASES TO BELOW AVERAGE FOR THE MIDDLE OF NEXT WEEK AND
BEYOND. UTILIZE A BLEND OF ECMWF/GFS/WPC GUIDANCE IN UPDATING THE
FORECAST PACKAGE.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ022-034>036-041>043-051-052.

&&

$$

AHN/RCL

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