Small Craft Advisory 376, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
609 AM AKDT THU JUN 21 2012

.SHORT TERM...UPPER LEVEL LOW OVER THE SOUTHEAST GULF IS
FORECAST TO SLOWLY MOVE OFF TO THE SE AND BE SOUTH OF HAIDA GWAII
BY FRIDAY MORNING. A BAND OF PRECIP ROTATING AROUND THE LOW
EXTENDS FROM JUST SOUTH OF SITKA TO NEAR WRANGELL AND WILL
CONTINUE TO WRAP NORTHWARD TODAY. AS IT DOES IT BECOMES LESS
ORGANIZED AND SHEARS APART OVER THE NORTHERN PANHANDLE THIS
EVENING. SHOWERS ACROSS THE SOUTHERN PANHANDLE DIMINISH THIS
AFTERNOON WITH SCATTED SHOWERS SPREADING INTO THE CENTRAL
PANHANDLE THIS AFTERNOON GOING TO ISOLATED SHOWERS ACROSS THE FAR
NORTH THIS EVENING.

 AHEAD OF THIS BAND BROKEN MID AND HIGH CLOUDS IN EASTERLY FLOW
WILL ALLOW FOR SOME SUNSHINE IN THE MORNING BUT EXPECT THICKER
MID LEVELS CLOUDS BY THIS AFTERNOON. ALONG THE IMMEDIATE COAST
STILL HAVE AREAS OF LOW STRATUS THAT COULD AFFECT COASTAL AREAS
THIS MORNING. CLOUDS DECREASE ACROSS THE NORTH LATE TONIGHT. A
SECOND BAND MOVES INTO DIXON ENTRANCE LATE TONIGHT WITH A CHANCE
OF SHOWERS RETURNING FOR FAR SOUTH.

 OVERALL PRESSURE GRADIENTS REMAINS WEAK TODAY WITH MAINLY LOCAL
SEA BREEZE WINDS. GRADIENT WILL START TO STRENGTHEN TONIGHT WITH
NORTHERLY WINDS INCREASING INTO 15-20 KT RANGE AS RIDGE BUILDS
INTO WESTERN GULF AND INVERTED TROUGH STARTS TO DEVELOP OVER
SOUTHEAST ALASKA.

 ATMO CONTINUES TO WARM AND COULD SEE UPPER 60S IN THE FAR NORTH
WITH SUNNY BREAKS. CLOUDS AND PRECIP WILL KEEP COASTAL AND
SOUTHERN HALF IN THE 50S FOR MOST OF THE DAY AND INCREASING TO
LOW 60S LATE AFTERNOON WITH BREAKS IN CLOUD COVER.

.LONG TERM...OVERALL THE WEATHER PATTERN IN THE MID RANGE IS
STABLE WITH NOT MUCH CHANGE IN THE FORECAST FROM PREVIOUS SHIFT.
THE VERY WARM AND NICE WEATHER IS STILL IN STORE WITH ABOVE NORMAL
TEMPS OVER THE NORTHERN AREAS ON FROM FRIDAY THROUGH SUNDAY. THE
NICE WEATHER WILL NOT LAST LONG A UPPER LEVEL TROF WILL LIFT OVER
THE GULF SUN NIGHT TO INCREASE THE ONSHORE FLOW AND THREAT OF
PRECIP. THE ONSHORE FLOW WILL CONTINUE INTO NEXT WEEK WITH LIKELY
TO CHANCE POPS. THERE IS ABOVE AVERAGE FORECASTER CONFIDENCE FROM
FRIDAY THROUGH SUNDAY THEN ABOUT AVERAGE THROUGH EARLY NEXT WEEK
AS THERE IS DIFFERENCES IN THE DETAILS. USED A BLEND OF THE
EC/NAM/GFS IN THE MID TERM AND HPC FOR THE EXTENDED PORTIONS.

AT THE START OF THE LONG TERM PERIOD PARTLY CLOUDS OVER THE NORTHERN
HALF WILL SLOWLY DECREASE THROUGH THE AFTERNOON AND MOSTLY CLEAR
WILL PERSIST INTO SAT NIGHT. THE SOUTHERN AREAS WILL SEE THE
CLOUDS THROUGH FRIDAY WITH SOME ISOLATED SHOWERS BUT THROUGH THE
FRIDAY THE CLOUDS WILL DECREASE. 850MB TEMPS WILL WARM THROUGH SAT
PEAKING IN THE MID TO UPPER TEENS. THIS ALONG WITH A INVERTED TROF
STRENGTHENING THROUGH FRIDAY AND SAT THIS WILL PRODUCE NE WINDS
AND THE ADIABATIC WARMING WILL INCREASE THE HIGH TEMPS INTO THE
MID TO UPPER 70S ON FRIDAY AND NEAR 80 OVER THE NORTHERN AREAS ON
SAT. LOW TEMPS WILL REMAIN ON THE WARMER SIDE ON FRIDAY AND SAT
AND MAY REMAIN IN THE 50S.

WINDS THROUGH SAT NIGHT WILL MAINLY LESS THAN 20KT FROM THE NORTH
BUT DUE TO THERMAL HEATING SMALL CRAFT WINDS WILL DEVELOP OVER THE
EASTERN AREAS OF ICY STRAIT LATE FRIDAY AFTERNOON IN THE THE
EVENING AND THEN AGAIN ON SAT AFTERNOON. OVER LAND DURING THE DAY
SEA BREEZES WILL DEVELOP THROUGH THE DAY AND THEN DIMINISH OVER
NIGHT.

CLOUDS WILL SLOWLY INCREASE OVER THE SOUTHERN AREAS SAT NIGHT AS A
WEATHER FRONT MOVES OVER CENTRAL BC. THIS FRONT WILL INCREASE THE
THREAT OF SHOWERS SAT NIGHT AND CONTINUE INTO SUN. THE CLOUDS WILL
SLOWLY MAKE ITS WAY OVER THE NORTHERN AREAS THROUGH LATE SUN
AFTERNOON INTO SUN NIGHT BUT HIGH TEMPS WILL AGAIN CLIMB INTO THE
MID 70S. A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE INNER
CHANNELS SUN AFTERNOON INTO SUN NIGHT AND SOUTHERLY WINDS WILL
INCREASE TO 15 TO 25 KT WITH THE STRONGEST WINDS OVER NORTH LYNN.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.

&&

MM/ABJ