High Surf in Hawaii, January 8 to 9, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 PM HST SAT JAN 8 2011

.SYNOPSIS...
LIGHT TO MODERATE SOUTHWEST WINDS WILL DEVELOP ON SUNDAY ACROSS THE
STATE. THE SOUTHWEST WINDS WILL INCREASE AND BECOME GUSTY SUNDAY
NIGHT AND MONDAY AHEAD OF AN APPROACHING COLD FRONT. THIS WEAKENING
COLD FRONT WILL CROSS THE ISLANDS MONDAY AFTERNOON AND NIGHT...THEN
STALL AND DISSIPATE NEAR THE BIG ISLAND. ANOTHER TROUGH WILL DEVELOP
NORTHWEST OF THE STATE WEDNESDAY...BRINGING GUSTY SOUTH WINDS TO
ISLANDS WEDNESDAY AND THURSDAY WITH THE THREAT OF HEAVY RAIN.

&&

.DISCUSSION...
A COOL AND STABLE AIRMASS WILL BE IN PLACE OVER THE STATE TONIGHT.
ISOLATED SHOWERS REMAINING OVER THE FORECAST AREA THIS AFTERNOON
ARE EXPECTED TO DISSIPATE WITH THE LOSS OF DAYTIME HEATING...THE
EXCEPTION BEING THE NORTHERN COASTAL WATERS WHERE ENOUGH LINGERING
MOISTURE CONVERGENCE ASSOCIATED WITH THE DEPARTING LOW TO THE NORTH
REMAINS. THE FEW HIGH CLOUDS CROSSING THE AREA THIS EVENING SHOULD
NOT BE PERSISTENT OVERNIGHT. OTHERWISE...LOW TEMPERATURES WILL BE
BELOW NORMAL AGAIN TONIGHT...EXPECTING SIMILAR LOWS TONIGHT AS WE
HAD THIS MORNING ACROSS THE ISLANDS LOW ELEVATIONS WITH LIGHT WINDS.
THE SUMMIT ELEVATIONS OF THE BIG ISLAND AND MAUI WILL BE A BIT
WARMER AS RIDGING ALOFT MOVES IN FROM THE WEST AND GUSTY WINDS
CONTINUE OVERNIGHT. THE MODELS CONTINUE TO SHOW THESE STRONG WEST
WINDS TO ABATE TO BREEZY LEVELS BY SUNDAY MORNING...SO THE WIND
ADVISORY IS SET TO EXPIRE THEN.

SOUTHWEST FLOW DEVELOPS SUNDAY AFTERNOON WHICH WILL MODIFY THE
AIRMASS QUICKLY...REPLACING THE DRY AIRMASS WITH A MORE WARM AND
HUMID ONE SUNDAY NIGHT AND EARLY MONDAY. GUSTY SOUTHWEST WINDS ARE
EXPECTED TO DEVELOP SUNDAY NIGHT AND MONDAY IN AREAS PRONE TO KONA
DOWNSLOPE WIND EVENTS...CURRENT 850 MB WIND GUIDANCE SUGGESTS GUSTS
AROUND 30 TO 40 MPH IN THE WINDIEST AREAS SUCH AS KANEOHE...KAILUA
AND SCHOFIELD BARRACKS.

THE INCOMING COLD FRONT WILL BE WEAKENING AS IT CROSSES THE STATE
WEST TO EAST MONDAY AFTERNOON AND NIGHT THEN STALLS AND RAPIDLY
DISSIPATES NEAR THE BIG ISLAND EARLY TUESDAY. SHOWERS WILL DEVELOP
IN THE PREFRONTAL ENVIRONMENT MONDAY AS LOW LEVEL CONVERGENCE
DEVELOPS IN THE INCREASINGLY MOIST AND UNSTABLE SOUTHWEST FLOW. THE
FRONT WILL BRING A WIND SHIFT TO NORTHWEST AND BAND OF
RAIN...FOLLOWED BY A SHORT PERIOD OF CLOUDS AND SHOWERS ON THE
NORTHERN SIDES OF THE ISLANDS AS LOW LEVEL COLD AIR ADVECTION KEEPS
GOING FOR A FEW HOURS BEHIND THE FRONT.

A RIDGE TRANSITIONS ACROSS THE AREA TUESDAY FOR THE DRIEST WEATHER
OF THE WORK WEEK...THEN THE FLOW QUICKLY SHIFTS BACK TO SOUTHERLY AS
ANOTHER TROUGH DEVELOPS NORTH OF THE STATE. THIS IS EXPECTED TO
BRING A TRAILING FRONT THAT STALLS JUST NORTH OF THE AREA THROUGH
THE END OF THE WEEK. THIS WILL BRING A LONGER PERIOD OF SHOWERS AND
GUSTY KONA WINDS ACROSS THE AREA THROUGH THE END OF THE WEEK. THE
POTENTIAL OF HEAVY RAINFALL IS HIGH AS AN AXIS OF NEAR 2.0 INCHES OF
PRECIPITABLE WATER LIES ACROSS THE STATE.

&&

.MARINE...
THE CURRENT NORTH SWELL IS SUBSIDING. A NEW NORTHWEST ARRIVING LATE
THIS AFTERNOON WILL SUBSIDE BY MONDAY. A LARGER NORTHWEST SWELL
WILL EXCEED ADVISORY LEVEL LATE TUESDAY...AND REMAIN ELEVATED
THROUGH NEXT WEEK.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 AM HST SUNDAY FOR BIG ISLAND SUMMITS AND
HALEAKALA SUMMIT.

&&

BRENCHLEY