High Surf in Hawaii, December 8 to 9, 2010

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST TUE DEC 7 2010

.SYNOPSIS...
LIGHT WINDS WITH LAND AND SEA BREEZES WILL CONTINUE THROUGH
WEDNESDAY AS A WEAK HIGH PRESSURE RIDGE REMAINS OVER THE ISLANDS.
SOUTH TO SOUTHWEST WINDS WILL INCREASE THURSDAY AND FRIDAY AS A
FRONT MOVES NEAR THE STATE FROM THE WEST...BRINGING A THREAT OF
HEAVY RAIN AND THUNDERSTORMS FROM LATE THURSDAY INTO FRIDAY. THE
FRONT IS EXPECTED TO ADVANCE ACROSS THE ISLANDS LATE FRIDAY INTO
SATURDAY. LINGERING MOISTURE FROM THE FRONT MAY CONTINUE TO AFFECT
THE STATE SUNDAY.

&&

.DISCUSSION...
WINDS ARE LIGHT THROUGHOUT THE STATE THIS EVENING...AS A WEAK RIDGE
OF HIGH PRESSURE REMAINS IN THE ISLAND VICINITY. AFTERNOON CLOUDS
OVER THE ISLANDS ARE SLOWLY DISSIPATING AS SUBSIDENCE DEVELOPS UNDER
NIGHTTIME COOLING. THERE ARE SOME LOW CLOUDS IN THE SURROUNDING
COASTAL WATERS...THOUGH THESE CLOUDS ARE EXPECTED TO REMAIN
OFFSHORE THROUGH THE REST OF THIS EVENING THUS HAVE LITTLE EFFECT ON
THE ISLAND WEATHER. LOOK FOR FAIR WEATHER TO PREVAIL OVER THE STATE
REST OF THIS EVENING INTO EARLY WEDNESDAY MORNING. THE WEAK HIGH
PRESSURE RIDGE WILL HOLD ACROSS THE ISLANDS ONE MORE DAY...KEEPING
WINDS LIGHT WITH SEA BREEZES ON WEDNESDAY. STILL EXPECT ANOTHER
MAINLY FAIR WEATHER DAY FOR THE STATE WEDNESDAY...THOUGH LATEST
FORECAST CHARTS DO INDICATE AN INCREASE IN LOW LEVEL MOISTURE FOR
THE NORTHERN ISLANDS. EXPECT TO SEE A LITTLE MORE AFTERNOON CLOUDS
AND EVEN SOME AFTERNOON SHOWERS FOR KAUAI WEDNESDAY.

LATEST FORECAST CHARTS CONTINUE TO POINT TO THE SHARPENING OF AN
UPPER LEVEL TROUGH WEST OF THE ISLANDS WEDNESDAY NIGHT AND THURSDAY.
A SURFACE LOW IS STILL EXPECTED TO DEVELOP JUST NORTH OF THE
ISLANDS...WITH AN ASSOCIATED FRONT EXTENDING SOUTHWEST. A BAND OF
DEEP MOISTURE WILL MOVE OVER THE ISLANDS THURSDAY AND FRIDAY AHEAD
OF THE FRONT. SOUTH TO SOUTHWEST WINDS WILL ALSO INCREASE OVER THE
STATE...AND WILL BECOME LOCALLY GUSTY...ESPECIALLY ON THE NORTH AND
EAST SIDES OF THE ISLANDS THURSDAY AND FRIDAY AHEAD OF THE FRONT.
THE AIR MASS IN THE ISLAND VICINITY WILL BECOMING MORE UNSTABLE
UNDER THE INCREASED MOISTURE AS WELL AS THE DEEPENING UPPER LEVEL
TROUGH WEST OF THE ISLANDS. CONDITIONS WILL BECOME FAVORABLE FOR
LOCALLY HEAVY RAINFALL AND THUNDERSTORMS TO DEVELOP. THE UPPER
LEVEL TROUGH WILL ALSO BRING STRONG SOUTHWEST WINDS OVER THE SUMMITS
OF MAUI AND THE BIG ISLAND THURSDAY INTO SATURDAY. COMBINED WITH
INCREASING MOISTURE AHEAD OF THE FRONT...THERE LIES A THREAT OF
WINTER WEATHER FOR THE SUMMITS.

LATEST FORECAST CHARTS INDICATE THE FRONT WILL MOVE ACROSS THE STATE
LATE FRIDAY INTO SATURDAY. SOME CLEARING IS EXPECTED BEHIND THE
FRONTAL PASSAGE...THOUGH FORECAST CHARTS HINT LINGERING MOISTURE MAY
CONTINUE IN THE ISLAND VICINITY SATURDAY AND SUNDAY. LOOK FOR
PARTIAL CLEARING WITH SOME SHOWERS ACROSS THE STATE BY THE WEEKEND.
TRADE WINDS ARE EXPECTED TO RETURN BY LATE SUNDAY...AND MAY LAST
THROUGH EARLY NEXT WEEK.

&&

.MARINE...
A SIGNIFICANT BUILDING LONG-PERIOD NORTH SWELL PROMPTS THE ISSUANCE
OF HIGH SURF ADVISORY FOR NORTH AND EAST FACING SHORES. SURF IS
STILL EXPECTED TO PEAK WELL ABOVE ADVISORY LEVELS ALONG NORTH FACING
SHORES WEDNESDAY WHILE THE EAST FACING SHORES EXPOSED TO THE NORTH
SWELL WILL ALSO SEE ADVISORY LEVEL SURF. THE BUILDING NORTH SWELL
WILL BE LARGE ENOUGH TO CAUSE HARBOR SURGES IN BOTH KAHULUI AND HILO
HARBORS. THE SWELL WILL DIMINISH ON THURSDAY...BUT WILL LIKELY
REMAIN ABOVE ADVISORY LEVELS DURING THE DAY.

THE LONG-PERIOD NORTH SWELL IS ALSO LARGE ENOUGH TO WARRANT THE
ISSUANCE OF SMALL CRAFT ADVISORY /SCA/ FOR THE COASTAL WATERS. THE
SEAS AND SWELL WILL DIMINISH BELOW SCA CRITERION THURSDAY
NIGHT...THOUGH INCREASING SOUTH AND SOUTHWEST WINDS MAY BE STRONG
ENOUGH TO MAINTAIN THE SCA THROUGH FRIDAY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY FOR NORTH AND EAST FACING SHORES OF NIIHAU KAUAI
OAHU MOLOKAI MAUI AND THE BIG ISLAND TILL 6 PM HST THURSDAY.

SMALL CRAFT ADVISORY FOR ALL WATERS EXCEPT MAALAEA BAY AND LEEWARD
BIG ISLAND TILL 6 PM HST THURSDAY.

&&

HUI