High Surf in Hawaii, April 1 to 5, 2010

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST WED MAR 31 2010

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN NORTH OF THE ISLANDS THROUGH NEXT
WEEK...RESULTING IN BREEZY TO STRONG AND GUSTY TRADES. THE
ATMOSPHERE WILL REMAIN DRY...WITH ONLY LIGHT RAINFALL ACCUMULATIONS
THROUGH FRIDAY. SHOWER ACTIVITY WILL INCREASE SATURDAY THROUGH NEXT
WEEK DUE TO SLIGHT ATMOSPHERIC INSTABILITY. SHOWERS WILL FOCUS OVER
WINDWARD AND MOUNTAIN AREAS...WITH A FEW SHOWERS BEING BLOWN OVER TO
LEEWARD SECTIONS.

&&

.DISCUSSION...
A 1030 MB HIGH IS 735 MILES NORTHEAST OF THE ISLANDS THIS
EVENING...WHICH WILL CONTINUE TO BRING STRONG AND GUSTY TRADE WINDS
THROUGH THURSDAY AFTERNOON. A WIND ADVISORY REMAINS IN EFFECT FOR
THE STATE THROUGH THAT TIME. WINDS WILL START TO DECREASE SLIGHTLY
THURSDAY EVENING AS THE HIGH IS WEAKENED BY A FRONT FAR TO THE
NORTH. TRADES WILL STRENGTHEN AGAIN FRIDAY EVENING AS ANOTHER STRONG
HIGH MOVES IN. ANOTHER FRONT WILL START TO WEAKEN THIS HIGH LATE
SATURDAY...LOWERING WIND SPEEDS ONCE AGAIN. YET ANOTHER STRONG HIGH
WILL MOVE IN BEHIND THE FRONT...BOOSTING WIND SPEEDS. THUS...TRADES
WILL REMAIN BREEZY THROUGH NEXT THURSDAY.

THE ATMOSPHERE HAS BEEN RATHER DRY AND STABLE TODAY. RAIN GAGE
REPORTS HAVE SHOWN ALMOST NO RAINFALL ACCUMULATIONS EARLIER THIS
AFTERNOON. THE 00Z SOUNDINGS AT LIHUE AND HILO SHOW STRONG LOW LEVEL
INVERSIONS AT 4500 AND 6400 FT RESPECTIVELY...WITH PRECIPITABLE
WATER VALUES 1 INCH OR LESS. CURRENTLY...THERE ARE SCATTERED LOW
CLOUDS OVER THE NORTHEAST COASTAL AND OFFSHORE WATERS THAT ARE BEING
CARRIED ALONG WITH THE TRADE FLOW. EXPECT THESE CLOUDS TO THICKEN UP
AS THE NIGHT PROGRESSES...DUE TO CLOUD TOP COOLING. INFRARED
SATELLITE SHOWS SOME THICKENING ALREADY OCCURRING. SOME SHOWERS MAY
DEVELOP WITH STACKING CLOUDS ALONG NORTHEAST FACING SLOPES
TONIGHT...ALTHOUGH LITTLE ACCUMULATION IS FORESEEN. DRY AND STABLE
CONDITIONS ARE EXPECTED TO PERSIST THROUGH SATURDAY AFTERNOON.
SATURDAY EVENING...UPPER LEVEL TROUGHING OVER THE STATE WILL LIFT
THE INVERSION...ALLOWING FOR AN INCREASE IN SHOWER ACTIVITY...WITH A
POSSIBILITY FOR HEAVIER SHOWERS. THE WET WEATHER PATTERN WILL
CONTINUE THROUGH THE END OF THE WORK WEEK AS THE UPPER LEVEL TROUGH
WILL REMAIN OVER THE STATE...WITH PRECIPITABLE WATER VALUES ALSO
INCREASING. SHOWERS WILL FOCUS OVER WINDWARD AND MOUNTAIN AREAS
THROUGHOUT THE FORECAST PERIOD...WITH SOME SHOWERS BEING BLOWN OVER
TO LEEWARD AREAS.

&&

.FIRE WEATHER...
A RED FLAG WARNING HAS BEEN EXTENDED THROUGH THURSDAY AFTERNOON.
STRONG TRADES WILL PERSIST...KBDI VALUES WILL REMAIN ABOVE THE
CRITICAL THRESHOLD OF 600...AND THE AIRMASS OVER THE STATE WILL
REMAIN DRY AS THERE IS LITTLE MOISTURE UPSTREAM OF HAWAII. IN OTHER
WORDS...CONDITIONS SIMILAR TO THIS PAST AFTERNOON WILL EXIST
THURSDAY. THUS...IT IS LIKELY THAT RED FLAG CRITERIA WILL BE REACHED.

&&

.MARINE...
CHOPPY WIND GENERATED WAVES ALONG EAST FACING SHORES AND STRONG
TRADES WILL CONTINUE THROUGH THURSDAY AFTERNOON. THE HIGH SURF
ADVISORY FOR MOST EAST FACING SHORES IS IN EFFECT THROUGH THURSDAY
AFTERNOON.

STRONG AND GUSTY TRADES ARE PRODUCING GALES FOR THE PAILOLO AND
ALENUIHAHA CHANNELS AND WATERS SOUTH AND WEST OF THE BIG ISLAND. A
GALE WARNING REMAINS IN EFFECT FOR THESE WATERS THROUGH THURSDAY
AFTERNOON. REMAINING COASTAL ZONES ARE UNDER A SMALL CRAFT ADVISORY
DUE TO THE WINDS AND HIGH COMBINED SEAS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 6 PM HST THURSDAY FOR LEEWARD AREAS OF
KAUAI...OAHU...MOLOKAI...MAUI AND THE BIG ISLAND.

WIND ADVISORY UNTIL 6 PM HST THURSDAY FOR ALL HAWAIIAN ISLANDS.

HIGH SURF ADVISORY UNTIL 6 PM HST THURSDAY FOR EAST FACING SHORES OF
NIIHAU...KAUAI...OAHU...MOLOKAI...MAUI AND THE BIG ISLAND.

GALE WARNING UNTIL 6 PM HST THURSDAY FOR THE PAILOLO
CHANNEL...ALENUIHAHA CHANNEL...BIG ISLAND LEEWARD WATERS AND BIG
ISLAND SOUTHEAST WATERS.

SMALL CRAFT ADVISORY UNTIL 6 PM HST THURSDAY FOR ALL OTHER COASTAL
WATERS.

&&

HARRISON/HOUSTON