Small Craft Advisory 332, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
316 PM AKDT SAT MAY 19 2012

.SHORT TERM...THE LATEST SATELLITE IMAGERY SHOWS THE PANHANDLE
UNDER CLOUDY TO MOSTLY CLOUDY SKIES WITH A WEATHER FRONT OVER THE
EASTERN GULF EXTENDING TO THE NW TOWARDS PWS. THERE IS SOME LIGHT
RAIN ALONG THE NORTHERN GULF AND SPOTTY PRECIP OVER THE EASTERN
GULF COAST. THE RAIN NEAR PAYA WILL DIMINISH THROUGH TONIGHT AS
THE FRONT WEAKENS AND DRIFTS TO THE WEST. WINDS OVER THE INNER
CHANNELS ARE RELATIVELY LESS THAN 15 MPH WITH MARINE WATERS OF
THE INNER CHANNELS LESS THEN 15 KT. THE WINDS WILL SLOWLY BACK
AROUND TO THE NORTH OVER THE MARINE WATERS AND WINDS OVER LAND
WILL BECOME LIGHT THROUGH TONIGHT. THE STRONGEST WINDS ARE OVER
THE NORTHERN GULF WITH MIN GALES OVER AREA 52 AND SMALL CRAFT
OVER THE REST OF THE EASTERN GULF. THESE WINDS WILL SLOWLY
DIMINISH THROUGH TONIGHT TO BE MAINLY 20 KT.

 A WEAK WAVE WILL LIFT NORTH OUT OF THE NORTH PACIFIC LATE
TONIGHT INTO SUN OVER THE SOUTHEAST GULF. AS THIS WAVE LIFTS
NORTH RAIN WILL DEVELOP OVER THE FAR SOUTHERN AREAS LATE TONIGHT
AND PERSIST INTO THE SUN MORNING. THIS BAND OF RAIN WILL TRACK
NORTH ALONG THE EASTERN GULF COAST THROUGH THE AFTERNOON WITH THE
RAIN TAPERING OFF OVER THE SOUTHERN INNER CHANNELS. THE REST OF
THE INNER CHANNELS WILL SEE MAINLY DRY CONDITIONS WITH JUST A
CHANCE OF LIGHT RAIN BY THE AFTERNOON AS FAR NORTH AS THE ICY
STRAIT CORRIDOR.

 THERE IS ABOUT AVERAGE FORECASTER CONFIDENCE FOR THE NEXT 24 HRS
AND USED A BLEND OF THE PREVIOUS FORECAST WITH THE 12Z EC.

&&

.LONG TERM...MODELS ARE IN GENERAL AGREEMENT THROUGH EARLY NEXT
WEEK WITH A VERTICALLY STACKED LOW DRIFTS NORTHEASTWARD FROM THE
NORTH PACIFIC INTO THE SOUTHEASTERN GULF FOR A GOOD CHANCE OF RAIN
AND A MODERATE WARMING TREND OVER THE PANHANDLE. THE LOW IS
EXPECTED TO WEAKEN AND DRIFT SOUTHEAST BY LATE MONDAY NIGHT INTO
EARLY TUESDAY MORNING. MODELS HANDLE THE LOW SOMEWHAT DIFFERENT
WAYS AND THE ECMWF SHOWED THE BEST RUN-TO-RUN CONSISTENCY.
REFRESHED THE INHERITED FORECAST PACKAGE WITH THE ECMWF THROUGH
TUESDAY TIME FRAME.

WITH THE INCOMING LOW...SMALL CRAFT WINDS/SEAS WILL REMAIN
OVER THE SOUTHERN OUTER WATERS THROUGH EARLY NEXT WEEK THEN SLOWLY
DIMINISH AS THE LOW WEAKENS AND DRIFTS SOUTHEASTWARD. NO
SIGNIFICANT WINDS/SEAS ARE EXPECTED ACROSS THE INNER CHANNELS
EXCEPT SOUTHERN MOST OCEAN ENTRANCES FOR SMALL CRAFT WINDS ON
SUNDAY NIGHT.

LIKELY POPS WILL SPREAD ACROSS SOUTHEAST ALASKA WITH HIGHER POPS
OVER THE SOUTHERN PANHANDLE BUT THE PROXIMITY OF THE LOW WILL
PRODUCE GENERAL OFFSHORE FLOW ACROSS THE NORTHERN AREAS FOR LOWER
POPS. NO SIGNIFICANT WINDS ARE EXPECTED OVER THE LAND AREAS DUE TO
RELATIVELY WEAK PRESSURE GRADIENT. RAIN WILL MOST LIKELY TO TAPER
OFF LATE MONDAY NIGHT INTO TUESDAY MORNING AS THE LOW WEAKENS AND
DRIFTS SOUTHEAST AWAY FROM THE PANHANDLE.

MODEL SPREAD BECOMES LARGER BY MID WEEK AND THUS LEANED OVER THE
HPC ENSEMBLE APPROACH OF THE ECMWF AND GFS BLEND. THE GENERAL
UPPER LEVEL PATTERN WILL BECOME AN OMEGA BLOCK BY LATE WEDNESDAY
NIGHT AND CONTINUE TOWARD THE NEXT WEEKEND FOR GENERALLY DRY
WEATHER AND CONTINUED WARMING TREND. SURFACE HIGH PRESSURE WILL
CONTINUE TO DOMINATE THE WEATHER ACROSS THE CENTRAL AND EASTERN
GULF AND A WEAK INVERTED TROUGH OF LOW PRESSURE WILL EXTEND NORTH
ACROSS THE PANHANDLE AND ALONG COAST MOUNTAINS.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ052.
         SMALL CRAFT ADVISORY FOR PKZ041>043-051.

&&

ABJ/AHN