High Surf in Hawaii, June 7 to 9, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 AM HST SAT JUN 7 2008

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.SYNOPSIS...
HIGH PRESSURE FAR NORTHEAST OF THE STATE WILL MAINTAIN MODERATE TO
LOCALLY FRESH TRADE WINDS THIS WEEKEND AND MONDAY...WITH A DECREASE
IN WIND SPEED EXPECTED BY TUESDAY. A DEPARTING UPPER LEVEL LOW WILL
PRODUCE A BIT MORE CLOUDS AND SHOWERS ACROSS KAUAI AND OAHU THIS
MORNING...WITH CLEARING EXPECTED BY AFTERNOON. OTHERWISE...SHOWERS
WILL FAVOR WINDWARD AND MAUKA AREAS...AS WELL AS LEEWARD SECTIONS OF
THE BIG ISLAND DURING THE AFTERNOON HOURS.

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.DISCUSSION...
A MID AND UPPER LEVEL LOW CENTERED ABOUT 260 MILES WEST NORTHWEST OF
KAUAI WILL MOVE OFF TO THE WEST TODAY...ALLOWING AN INCREASINGLY
STABLE TRADE WIND FLOW TO BUILD IN FROM THE EAST. WHILE NEARLY ALL
GAGES ON THE BIG ISLAND...MAUI...AND MOLOKAI HAVE BEEN DRY
OVERNIGHT...MODEST RAINFALL HAS BEEN OCCURRING ON KAUAI AND OAHU
WITH ISOLATED HEAVY SHOWERS ACROSS KAUAI WATERS. THE MID AND UPPER
LOW WEST OF THE ISLANDS ENHANCED A PLUME OF CLOUDS OFF MOLOKAI...
CAUSING MOST OF OAHU AND WINDWARD PORTIONS OF KAUAI TO BE COVERED BY
BROKEN LOW CLOUDS. AS A RESULT...THE MODESTLY UNSTABLE 12Z LIHUE
SOUNDING DETECTED 0.4 INCHES MORE PRECIPITABLE WATER THAN THE HILO
SOUNDING...WHICH ALSO REVEALED A LOW LEVEL INVERSION. AS THE UPPER
LOW CONTINUES TO MOVE OFF TO THE WEST...STABLE MID LEVEL RIDGING
OVER THE EASTERN END OF THE STATE WILL SPREAD WESTWARD. HEAVY SHOWER
WORDING HAS BEEN REMOVED FROM THE FORECAST TODAY...AND THE LOW
CLOUDS OVER KAUAI AND OAHU WILL DISSIPATE DURING THE MORNING. A
TYPICAL SHOWER PATTERN WILL THEN FOCUS RAINFALL ACROSS WINDWARD
AREAS AND THE LEEWARD BIG ISLAND SLOPES THROUGH THE UPCOMING WEEK.
IN ADDITION...A WEAK UPPER TROUGH SETTING UP WEST OF THE ISLANDS
WILL DRAW THE SWATH OF HIGH CLOUDS SOUTHEAST OF THE BIG ISLAND OVER
THE STATE TONIGHT THROUGH MONDAY.

MODERATE...EASTERLY TRADE WINDS WILL INCREASE AND BACK OUT OF A MORE
TYPICAL EAST NORTHEAST DIRECTION THIS AFTERNOON AND TONIGHT. THE
UPPER LOW WEST NORTHWEST OF KAUAI IS WEAKENING THE PRESSURE GRADIENT
OVER THE ISLANDS...CAUSING THE TRADE WINDS TO BE OUT OF THE EAST AND
SLIGHTLY WEAKER THAN THEY WOULD USUALLY BE WITH A 1032 MB HIGH
PARKED 1200 MILES NORTHEAST OF THE STATE. AS THE UPPER LOW DEPARTS
TODAY...THE PRESSURE GRADIENT WILL STRENGTHEN...CAUSING TRADES TO
INCREASE TO MODERATE TO LOCALLY FRESH LEVELS WHERE THEY WILL PERSIST
THROUGH MONDAY.

TRADE WINDS WILL EASE ON TUESDAY AND REMAIN LIGHT THROUGH MUCH NEXT
WEEK. THE GFS AND ECMWF SHOW ANOTHER UPPER LOW WEAKENING THE
PRESSURE GRADIENT OVER THE STATE AS IT PASSING NORTH OF THE ISLANDS.
AT THIS TIME...IT APPEARS THAT THIS FEATURE WILL BE TOO FAR NORTH
TO DESTABILIZE THE ATMOSPHERE. THUS...A TYPICAL PATTERN OF MAINLY
WINDWARD AND MAUKA SHOWERS IS EXPECTED.

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.MARINE...
SEAS AT THE LANAI BUOY HAVE BEEN HOLDING AROUND 3.5 FEET OVERNIGHT
WITH AN INCREASE IN THE SWELL PERIOD TO AS MUCH AS 20 SECONDS.
WAVEWATCH III INDICATES THAT THE LONG-PERIOD SWELL OF AT LEAST 3
FEET WILL HOLD INTO SUNDAY...AND A HIGH SURF ADVISORY REMAINS FOR
SOUTH FACING SHORES THROUGH SUNDAY AFTERNOON.

WITH THE TRADE WINDS INCREASING TODAY...A SMALL CRAFT ADVISORY HAS
BEEN POSTED EFFECTIVE AT NOON FOR WATERS AROUND THE BIG ISLAND. THE
ADVISORY WILL LIKELY NEED TO BE EXPANDED TO COVER MAALAEA BAY AND
THE PAILOLO CHANNEL TONIGHT.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY THROUGH 6 PM HST SUNDAY FOR NIIHAU-KAUAI
WINDWARD-KAUAI LEEWARD-OAHU SOUTH SHORE-WAIANAE COAST-MOLOKAI
LEEWARD-LANAI MAKAI-KAHOOLAWE-MAUI LEEWARD WEST-MAUI CENTRAL
VALLEY-LEEWARD HALEAKALA-KONA-SOUTH BIG ISLAND-BIG ISLAND NORTH AND
EAST.

SMALL CRAFT ADVISORY FROM NOON TODAY THROUGH 6 AM SUNDAY FOR BIG
ISLAND SOUTHEAST WATERS-BIG ISLAND LEEWARD WATERS-ALENUIHAHA CHANNEL.

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WROE