High Surf in Hawaii, May 3 to 4, 2010

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST MON MAY 3 2010

.SYNOPSIS...
A WEAKENING FRONT WILL PRODUCE CLOUDS AND SHOWERS OVER KAUAI AND
OAHU TODAY...WHILE LIGHT SOUTHEASTERLY WINDS CONTINUE TO BRING HAZE
TO THE SMALLER ISLANDS. THE FRONT WILL DRIFT TO THE NORTHWEST
TONIGHT AS TRADE WINDS GRADUALLY REBUILD OVER THE STATE. MODERATE
TRADE WINDS AND A STABLE REGIME OF WINDWARD AND MAUKA SHOWERS WILL
RETURN ON TUESDAY AND CONTINUE THROUGH THE WEEKEND.

&&

.DISCUSSION...
A STALLED FRONT LIES ACROSS THE WESTERN END OF THE STATE THIS
MORNING...BLANKETING KAUAI AND OAHU WITH BROKEN TO OVERCAST LOW
CLOUDS. EMBEDDED SHOWERS ALONG THE FRONT ARE CONCENTRATED NEAR
KAUAI...ALTHOUGH OAHU AND THE EXTREME WESTERN COAST OF MOLOKAI
SHOULD EXPERIENCE SOME ADDITIONAL FRONTAL SHOWERS MOVING UP FROM THE
SOUTH THIS MORNING. THE UPPER LEVEL TROUGH SUPPORTING THE FRONT IS
BROAD AND WILL BE LIFTING NORTHWARD TODAY...BUT WITH A BAND OF
PRECIPITABLE WATER IN EXCESS OF 1.5 INCHES EXPECTED TO PERSIST NEAR
KAUAI...A GREATER AMOUNT OF SHOWERS...SOME BRIEFLY HEAVY...CAN BE
EXPECTED ON THE GARDEN ISLE THROUGH THE AFTERNOON. AFTERNOON SEA
BREEZES ON OAHU ARE EXPECTED TO MAINTAIN CLOUDY CONDITIONS AND A
CHANCE OF SHOWERS.

DRIER AND MORE STABLE CONDITIONS ARE IN PLACE OVER THE EASTERN END
OF THE STATE THIS MORNING. SOUTHEASTERLY WINDS ARE PRODUCING
SCATTERED TO LOCALLY BROKEN LOW CLOUDS WITH LITTLE RAIN. THE
OVERNIGHT HILO SOUNDING SHOWED AN INVERSION IN PLACE AROUND 5500
FT...A BIG CONTRAST TO THE 12000 FT INVERSION BASE SEEN AT LIHUE.
AFTERNOON SEA BREEZES WILL OVERPOWER REBUILDING TRADE WINDS TODAY
ACROSS THE BIG ISLAND AND MAUI COUNTY TODAY...LEADING TO AN INCREASE
IN CLOUDS WITH LIMITED SHOWERS.

THE SOUTHEAST FLOW INDUCED BY THE FRONT HAS CAUSED VOLCANIC HAZE TO
BE BROUGHT UP FROM THE BIG ISLAND OVER THE REST OF THE STATE. THE
HAZY CONDITIONS WILL PERSIST TODAY AND INTO TONIGHT BEFORE
REBUILDING TRADE WINDS CLEAR THE HAZE FROM THE SMALLER ISLANDS.

TRADE WINDS WILL GRADUALLY REBUILD TONIGHT AND TUESDAY...REACHING
MODERATE LEVELS BY AFTERNOON. MOISTURE FROM THE FRONT MAY PRODUCE A
GREATER AMOUNT OF SHOWERS NEAR KAUAI DURING THE EVENING...BUT A
DRIER TRADE WIND FLOW WILL FILTER IN OVERNIGHT...FOCUSING SHOWERS
BACK TO TYPICAL WINDWARD AND MAUKA AREAS. THE GFS MODEL SHOWS
RIDGING ALOFT REBUILDING OVER THE STATE AND PRECIPITABLE WATER
VALUES DROPPING SHARPLY TO JUST OVER AN INCH BY TUESDAY AND
REMAINING AT SIMILAR LEVELS THROUGH THE WEEKEND. THIS SUGGESTS BELOW
NORMAL WINDWARD RAINFALL AND DRY LEEWARD CONDITIONS. HIGH PRESSURE
CENTERED FAR NORTHEAST OF THE ISLANDS WILL MAINTAIN MODERATE TRADE
WINDS...WITH AN INCREASE POSSIBLE DURING THE WEEKEND.

&&

.MARINE...
THE LOW ASSOCIATED WITH THE FRONT OVER THE STATE HAS BEEN SITTING
700 TO 900 MILES NORTH NORTHWEST OF THE STATE FOR THE PAST COUPLE OF
DAYS. THE BULK OF THE NORTH NORTHWEST SWELL ASSOCIATED WITH THE LOW
WILL PASS WEST OF THE ISLANDS...BUT KAUAI AND NIIHAU WILL EXPERIENCE
ENOUGH OF THE SWELL THIS AFTERNOON AND TONIGHT TO REQUIRE THE
ISSUANCE OF A HIGH SURF ADVISORY FOR NORTH FACING SHORES.

TRADE WINDS WILL LIKELY BE STRONG ENOUGH FOR A SMALL CRAFT ADVISORY
OVER THE TYPICALLY WINDY CHANNELS AND COASTAL WATERS AROUND THE BIG
ISLAND BY WEDNESDAY.

&&

.AVIATION...
EXTENSIVE MOUNTAIN OBSCURATION WILL CONTINUE ACROSS KAUAI AND OAHU
THROUGH THE REST OF THE DAY AS CLOUDS AND SHOWERS ASSOCIATED WITH A
STATIONARY FRONT REMAINS JUST TO THE WEST OF KAUAI. CEILINGS ARE
EXPECTED TO LIFT TONIGHT A RIDGE NORTHEAST OF THE STATE BEGINS TO
PUSH THE FRONT BACK TOWARDS THE WEST.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY FOR NORTH FACING SHORES OF KAUAI AND NIIHAU FROM
NOON TODAY THROUGH TONIGHT.

&&

WROE