High Surf in Hawaii, May 7 to 9, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 AM HST SAT MAY 7 2011

.SYNOPSIS...
HIGH PRESSURE TO THE NORTH WILL PROVIDE BREEZY TRADE WINDS TODAY.
THE WINDS WILL DECREASE AND TURN MORE SOUTHEASTERLY FROM
SUNDAY THROUGH MIDDLE OF NEXT WEEK. UNSETTLED WET WEATHER
IS EXPECTED TO LINGER INTO NEXT WEEK AS AN UPPER LEVEL TROUGH
MOVES NEAR THE ISLANDS.

&&

.DISCUSSION...
BREEZY TRADE WINDS CONTINUE OVER THE ISLANDS THIS MORNING AS A
STRONG HIGH REMAINS NORTH OF THE STATE. AIR MASS CONTINUES TO BE
QUITE UNSTABLE OVER THE AREA AS WELL...AS AN UPPER LEVEL LOW HOVERS
IN THE ISLAND VICINITY. COUPLED WITH ABUNDANT DEEP LOW LEVEL
MOISTURE...PASSING HEAVY SHOWERS AND ISOLATED THUNDERSTORMS WILL
CONTINUE TO AFFECT THE STATE TODAY. HEAVIER RAIN OVER OAHU IN THE
PAST HOUR HAS PROMPTED THE ISSUANCE OF A FLOOD ADVISORY...WHILE
POSSIBLE SNOW SHOWERS OVER THE SUMMITS OF THE BIG ISLAND TODAY ALSO
WARRANT THE CONTINUATION OF A WINTER WEATHER ADVISORY THROUGH THIS
EVENING.

THE STRONGER TRADE WINDS WILL PREVAIL TODAY...THEN SLOWLY WEAKEN BY
SUNDAY AS A SURFACE TROUGH DEVELOPS JUST WEST OF THE ISLANDS. THE
CURRENT UPPER LEVEL LOW IS EXPECTED TO LINGER NEAR THE STATE TODAY
ALSO...THEN LIFT NORTHWEST ON SUNDAY. EXPECT UNSETTLED WEATHER TO
CONTINUE OVER THE ISLANDS SUNDAY...THOUGH THE WINDS WILL SLOWLY
DECREASE AND TURNING MORE SOUTHEASTERLY BY SUNDAY NIGHT. WINDS WILL
REMAIN SOUTHEASTERLY OVER THE ISLANDS THROUGH THE MIDDLE OF NEXT
WEEK IN RESPONSE TO THE DEVELOPING SURFACE TROUGH JUST WEST OF THE
STATE. IN THE MEAN TIME...AN UPPER LEVEL TROUGH IS FORECAST TO
DEEPEN JUST NORTHWEST OF THE ISLANDS. THE CLOSE PROXIMITY OF THIS
DEVELOPING TROUGH WILL KEEP AIR MASS UNSTABLE OVER THE
STATE...ESPECIALLY FOR THE WESTERN ISLANDS. THUS UNSETTLED WEATHER
MAY LINGER THROUGH THE MIDDLE OF NEXT WEEK WITH MORE POSSIBLE HEAVY
RAIN AS WELL AS A THREAT OF OF THUNDERSTORMS OVER THE ISLANDS.

TRADE WINDS WITH IMPROVING WEATHER MAY STAGE A COMEBACK TOWARDS THE
NEXT WEEKEND AS THE SURFACE TROUGH IS FORECAST TO SHIFT WEST...AWAY
FROM THE ISLANDS WHILE A WEAK UPPER LEVEL RIDGE BUILDS OVER THE
STATE.

&&

.AVIATION...
CLOUDS AND SHOWERS CARRIED BY THE STRONG TRADE WINDS WILL BRING
PERSISTENT MVFR CONDITIONS TO THE WINDWARD SITES. THESE CLOUDS AND
SHOWERS WILL AFFECT THE SITES OVER THE LEE AREAS AT TIMES WITH MVFR
CONDITIONS. AIR MASS IS UNSTABLE ENOUGH FOR POSSIBLE ISOLATED TS
WITH CB TOPS TO 30 TO 35 THOUSAND FEET OVER THE ENTIRE FA AREA.

AIRMETS REMAIN POSTED FOR TURB DUE TO THE STRONG WINDS WHILE AIRMETS
FOR MTN OBSC AS WELL AS ICING CONTINUE WITH THE ABUNDANT CLOUDS AND
SHOWERS IN THE ISLAND VICINITY.

&&

.MARINE...
SMALL CRAFT CONDITIONS WITH ELEVATED CHOPPY SURF FOR EAST FACING
SHORES CONTINUE TODAY UNDER THE BREEZY TRADE WINDS. A SMALL CRAFT
ADVISORY REMAINS IN EFFECT FOR ALL WATERS THROUGH THIS EVENING WHILE
A HIGH SURF ADVISORY FOR EAST FACING SHORES OF MOST ISLANDS
CONTINUES. WINDS MAY DECREASE BY SUNDAY WITH IMPROVING WIND AND SEA
CONDITIONS OVER THE COASTAL WATERS.

A SMALL SOUTH SWELL WILL PERSIST THROUGH THE WEEKEND...FOLLOWED
BY A SLIGHTLY LARGER SOUTH SWELL EARLY NEXT WEEK. A SMALL NORTHWEST
SWELL MAY BOOST SURF INTO THE HEAD HIGH RANGE SUNDAY...THEN DECLINE
MONDAY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY UNTIL 6 PM HST THIS EVENING FOR KAUAI
WINDWARD-OAHU KOOLAU-OLOMANA-MOLOKAI WINDWARD-MAUI WINDWARD
WEST-WINDWARD HALEAKALA-SOUTH BIG ISLAND-BIG ISLAND NORTH AND EAST.

WINTER WEATHER ADVISORY UNTIL 6 PM HST THIS EVENING FOR BIG ISLAND
SUMMITS.

SMALL CRAFT ADVISORY UNTIL 6 PM HST THIS EVENING FOR ALL HAWAIIAN
WATERS.

&&

HUI