High Surf in Hawaii, January 23 to 25, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST FRI JAN 23 2009

.SYNOPSIS...
A SURFACE RIDGE NORTH OF THE ISLANDS WILL MAINTAIN LOCALLY BREEZY
TRADE WINDS OVER THE AREA THROUGH SATURDAY NIGHT. CLOUDS AND SHOWERS
CARRIED BY THE WINDS WILL AFFECT MAINLY WINDWARD AND MOUNTAIN AREAS.
WINDS WILL GRADUALLY SHIFT TO SOUTHEAST LATE SUNDAY AS A FRONT
APPROACHES FROM THE NORTHWEST. THE FRONT WILL MOVE DOWN THE ISLAND
CHAIN EARLY NEXT WEEK BRINGING WIDESPREAD SHOWERS. REMNANTS OF THE
FRONT WILL LINGER THROUGH THURSDAY...WITH TRADE WINDS RETURNING BY
THE WEEKEND.

&&

.DISCUSSION...
PASSING CLOUDS AND SHOWERS CONTINUE TO AFFECT THE ISLANDS AT TIMES
THIS EVENING. SATELLITE IMAGERY SHOWED THERE IS A SLIGHT BREAK IN
THE CLOUD COVERAGE OVER THE ISLANDS...THOUGH THE NEXT BATCH OF LOW
CLOUDS ARE JUST A LITTLE FURTHER UPSTREAM EAST OF THE ISLANDS.
MAINLY WINDWARD AND MOUNTAIN STATIONS REPORTED RAINFALL SINCE THIS
AFTERNOON...THOUGH AMOUNTS ARE STILL ON THE LIGHTER SIDE.

WINDS AT THE SUMMITS OF MAUNA KEA AND MAUNA LOA HAVE FINALLY DROP
BELOW ADVISORY LEVEL OF 30 MPH THIS EVENING. THUS THE WIND ADVISORY
IS CANCELED.

A SURFACE RIDGE NORTH OF THE ISLANDS IS KEEPING A GOOD ENOUGH
PRESSURE GRADIENT OVER THE AREA...RESULTING IN THE CONTINUATION OF
LOCALLY BREEZY TRADE WINDS. DO EXPECT THE TRADES TO PERSIST FOR
ANOTHER DAY OR SO...THEN FINALLY WEAKEN AND SHIFT SOUTHERLY AS A
COLD FRONT APPROACHES THE ISLANDS FROM THE NORTHWEST SUNDAY. LOOK
FOR TRADE WIND WEATHER TO HOLD THROUGH SUNDAY...WITH PASSING CLOUDS
AND SHOWERS FAVORING WINDWARD AND MOUNTAIN AREAS.

FORECAST CHARTS CONTINUE TO BE IN GOOD AGREEMENT ON THE ARRIVAL OF
THE NEXT FRONT OVER THE ISLANDS. ON THE OTHER HAND...THERE IS
DISAGREEMENT UPON HOW STRONG THIS FRONT WILL BE...AS GFS HAS BEEN
PROGRESSIVELY DEPICTING A MORE RIGOROUS FRONT MOVING THROUGH THE
ISLANDS...WITH STRONGER WINDS...MORE WIDESPREAD PRECIPITATION AND
AIR MASS BECOMING MORE UNSTABLE...ALLOWING HEAVIER RAIN AND EVEN A
CHANCE OF THUNDERSTORMS TO DEVELOP. THE FRONT IS STILL EXPECTED TO
REACH KAUAI MONDAY...AND ADVANCE TO NEAR BIG ISLAND BY LATE TUESDAY
THEN STALL AND DISSIPATE. THIS EVOLVING SITUATION CERTAINLY BEARS A
CLOSER MONITOR AS THE THREAT OF SEVERE WEATHER MAY INCREASE OVER THE
ISLANDS IF THE STRONGER FRONT SCENARIO PANS OUT. SHALL AWAIT FUTURE
MODEL RUNS AT THIS TIME BEFORE ADJUSTING THE FORECAST ACCORDINGLY.
IT LOOKS LIKE THE REMNANT OF THE FRONT WILL LINGER OVER THE ISLANDS
THROUGH THURSDAY. THERE IS A SLIGHT DISAGREEMENT ON THE LONG RANGE
FORECAST...AS GFS SHOWS MORE A SOUTHEASTERLY FLOW OVER THE ISLANDS
AS ANOTHER TROUGH DEEPENS TO THE WEST WHILE THE OTHER MODEL HAS
TRADE WINDS RETURN. FORECAST CERTAINLY SUBJECTS TO CHANGE AT THIS
POINT.

.MARINE...
THE CURRENT NORTHWEST SWELL SEEMED TO HAVE PEAKED EARLIER TODAY AT
THE BUOY FAR NORTHWEST OF THE ISLANDS...THOUGH THERE IS STILL
ELEVATED READINGS WITH THE LONG PERIOD AT THIS TIME. THUS EXPECT THE
LARGE NORTHWEST SWELL TO CONTINUE TO AFFECT THE ISLANDS AT LEAST
THROUGH SATURDAY. SMALL CRAFT ADVISORIES FOR MOST WATERS WILL
CONTINUE AS WELL DUE TO THE LARGE SWELL AS WELL AS LOCALLY STRONGER
WINDS OVER THE COASTAL WATERS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY FOR NORTH AND WEST FACING SHORES OF NIIHAU KAUAI
AND OAHU AND NORTH FACING SHORES OF MOLOKAI AND MAUI.

SMALL CRAFT ADVISORY FOR MOST WATERS.

&&

HUI