Small Craft Advisory 446, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
231 PM AKDT MON AUG 1 2011

.SHORT TERM...THE WEATHER OVER THE PANHANDLE REMAINS MOSTLY
QUIET FOR THE NEXT 24 HOURS. THE ONLY WEATHER OF ANY REAL NOTE IS
THE WINDS IN NORTHERN LYNN CANAL AND SKAGWAY. THE INTERACTION
BETWEEN A BUILDING SURFACE RIDGE ALONG THE PANHANDLE AND A
THERMAL TROUGH IN THE YUKON HAVE CREATED SMALL CRAFT WINDS TO
30 KT AT ELDRED ROCK AND WIND GUSTS TO 35 MPH AT SKAGWAY THIS
MORNING. OTHER WISE WINDS REMAIN MOSTLY LESS THEN 20 KT OVER MOST
OF THE PANHANDLE AND MARINE AREAS. AS FOR PRECIP, NORTHERN
PANHANDLE IS ONCE AGAIN IN THE FIRING LINE FOR PERIODS OF LIGHT
RAIN TODAY AS MID LEVEL ONSHORE FLOW CONTINUES. FARTHER SOUTH,
MID LEVEL FLOW HAS TURNED MORE WEST BRINGING MORE CLOUDS INTO
THAT AREA.

FOR TONIGHT AND TOMORROW, THE FORECAST WILL MAINLY BE DOMINATED
BY A MID LEVEL TROUGH THAT IS CURRENTLY MOVING INTO THE EASTERN
GULF. YAKUTAT IS JUST STARTING TO FEEL THE AFFECTS OF IT. THE
RESULTS OF THIS WILL BE LOT OF RAIN FOR THE YAKUTAT AREA TONIGHT
AS THE TROUGH MOVES BY. FARTHER EAST THE SURFACE RIDGE OVER THE
PANHANDLE IS GOING TO LIMIT THE RAIN MOSTLY TO THE NORTHERN
PANHANDLE. HOWEVER, ONCE THE TROUGH MOVES BY NW MID LEVEL FLOW
BEHIND IT IS GOING TO START DRYING PARTS OF THE PANHANDLE OUT.
THIS WILL PARTICULARLY BE TRUE FOR THE SOUTHERN PANHANDLE WHERE
POPS DROP BELOW SLIGHT CHANCE BY TOMORROW. IN THE NORTH, LIKELY
POPS HANG ON INTO TUES MORNING AS A SLIGHT ON SHORE FLOW STILL
LINGERS. HIGHEST POPS WILL MOST LIKELY REMAIN NEAR THE HIGH
TERRAIN IN PLACES LIKE JUNEAU, GUSTAVUS AND YAKUTAT.

WINDS WILL ALSO START BE BECOME A PROBLEM IN THE OUTSIDE WATERS
TONIGHT AND TOMORROW AS A WEAK FRONT STALLS OUT IN THE FAR WESTERN
PARTS OF THE FORECAST AREA. THE WESTERN PART OF THE OFFSHORE AND
MARINE ZONE 52 WILL HAVE SOME SMALL CRAFT WINDS TO 25 KT BY
TOMORROW. THE OTHER WINDY SPOT REMAINS NORTHERN LYNN CANAL AND
SKAGWAY WHERE SMALL CRAFT CONDITIONS WILL REMAIN PRESENT INTO
TOMORROW.

MODELS WERE IN GOOD AGREEMENT THROUGH THE SHORT TERM THROUGH THE
GFS WAS A BIT OFF WITH THE SURFACE RIDGE POSITION. DECIDED TO USE
A BLEND OF THE NAM AND EC FOR FORECAST UPDATES. FORECAST
CONFIDENCE IS A LITTLE ABOVE AVERAGE.

&&

.LONG TERM...UPPER LEVEL RIDGE MOVES OVER THE PANHANDLE TUESDAY
NIGHT....WEAKENS WEDNESDAY...AND SHIFTS EAST OF THE AREA FRIDAY
NIGHT. UPPER LEVEL LOW OVER BRISTOL BAY TUESDAY EVENING MOVES OVER
THE SOUTHWEST GULF WEDNESDAY THEN LIFTS NE AND OPENS UP INTO A
TROUGH ON THURSDAY. A 990 MB SURFACE LOW WILL BE AT ITS DEEPEST
NEAR KODIAK TUE EVENING...TRACKS NORTHEAST INTO NORTHERN GULF AND
OPENS UP INTO A TROUGH THROUGH THURSDAY. THE ASSOCIATED WEAKENING
OCCLUDED FRONT WILL BE IN THE CENTRAL GULF TRAILING BACK TO THE SW
TUESDAY EVENING. A WAVE ALONG THE TRAILING FRONT TAKES OVER ON
WEDNESDAY AS IT CURVES NE THROUGH THE CENTRAL GULF. FRONT MOVES
TO OUR COASTAL WATERS WEDNESDAY AFTERNOON AND THEN SLOWLY PUSHES
OVER SOUTHEAST ALASKA THROUGH THURSDAY.

CLOUDS WILL DECREASE FROM THE SOUTH TUESDAY NIGHT WITH SKIES
BECOMING PARTLY CLOUDY SOUTH OF A PAJN-PASI LINE WHILE NORTHERN
SOUTHEAST ALASKA KEEPS A CHANCE OF RAIN WITH LIKELY POPS
CONTINUING FOR PAYA INTO WEDNESDAY. TEMPS SHOULD BE A FEW DEGREES
WARMER FOR THE SOUTHERN TWO THIRDS WITH MORE SUNSHINE TUESDAY AND WEDNESDAY.

THE LEAD WEAKER FRONT WILL KEEP RAIN GOING FOR YAKUTAT TUESDAY
NIGHT AND WEDNESDAY. AS WAVE TAKES OVER GRADIENTS BETWEEN KODIAK
LOW AND SRN PNHDL RIDGE TIGHTEN UP GALE FORCE WIND DEVELOP IN THE
NORTH CENTRAL GULF TUE NIGHT AND CONTINUE THROUGH WEDNESDAY FOR ZONES
PKZ052 AND POSSIBLY PKZ051. FRONT WEAKENS AS IT MOVES ONSHORE
WEDNESDAY EVENING AND WINDS DROP OFF TO SMCR. RAIN SPREADS ACROSS
THE NORTHERN THIRD WED NIGHT AND ACROSS THE SOUTHERN TWO THIRDS ON
THURSDAY.

A FLAT RIDGE BUILDS BACK INTO PANHANDLE FRIDAY AND IS OVER SE
CORNER OF PANHANDLE SAT WHERE EXPECT PARTLY CLOUDY CONDITIONS
WHILE WEAK ONSHORE FLOW CONTINUES FOR NORTHERN AND WILL KEEP A
CHANCE OF SHOWERS.

DECENT AGREEMENT IN SHORT RANGE BUT DIFFERENCES IN TIMING AND
AMPLITUDE OF INDIVIDUAL SHORTWAVES LOWER CONFIDENCE FROM FRI ON.
USED A NAM BLEND THROUGH WED AND TRANSITIONED TO HPC BEYOND.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-052.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ051.

&&

EAL/MM