Flash Flood Warning 28, NWS Honolulu, HI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST WED MAR 1 2006

.SYNOPSIS...
A TROUGH WEST OF THE ISLANDS IS CREATING MOIST SOUTHEAST FLOW AND
UNSTABLE CONDITIONS. THE TROUGH IS CREATING A THREAT OF HEAVY RAIN
OVER OAHU AND KAUAI COUNTY AND PRODUCING CLOUDY SKIES OVER ALL THE
ISLANDS. UNSETTLED WEATHER WILL CONTINUE THROUGH THURSDAY NIGHT. THE
TROUGH WILL SLOWLY MOVE WEST AND WEAKEN ALLOWING TRADE WINDS AND
DRIER WEATHER TO SPREAD WEST OVER THE ISLANDS ON FRIDAY.

&&

.DISCUSSION...
A DEEP TROUGH IS CENTERED 1100 MILES WEST NORTHWEST OF KAUAI WITH A
LOW 1100 MILES NORTHWEST OF KAUAI AT 35N 173W. THE TROUGH IS
PRODUCING UNSTABLE CONDITIONS OVER THE KAUAI END OF THE CHAIN. THE
TROUGH IS ALSO PRODUCING SOUTHEAST FLOW OVER THE ISLANDS. THE
SOUTHEAST FLOW IS BRINGING LOTS OF MOISTURE OVER THE ISLANDS. WITH
THE SOUTHEAST FLOW CLOUD PLUMES ARE EXTENDING WEST NORTHWEST FROM
THE ISLANDS AND MOVING OVER ISLANDS FARTHER DOWNSTREAM. SOME OF THE
HEAVIEST RAINFALL HAS BEEN OCCURRING OVER KAUAI AND OAHU IN THESE
PLUMES. A FLASH FLOOD WATCH IS IN EFFECT FOR KAUAI COUNTY AND OAHU.

FOR THE PAST TWO DAYS THE COMPUTER MODELS HAVE BEEN CONSISTENT IN
SHOWING THE TROUGH WEAKENING AND MOVING OFF TO THE WEST.
MEANWHILE...A SURFACE HIGH FAR NORTH OF THE ISLANDS WILL MOVE
SOUTHEAST. AS THE TROUGH MOVES AWAY AND THE HIGH MOVES SOUTHEAST...
THE ATMOSPHERE WILL BECOME DRIER AND MORE STABLE AND THE LOW LEVEL
FLOW WILL BACK TO A TYPICAL EAST NORTHEAST TRADE-WIND DIRECTION. THE
THREAT OF HEAVY RAIN WILL END FRIDAY MORNING.

TRADE WIND WEATHER WILL CONTINUE THROUGH EARLY NEXT WEEK. A SHOWER
BAND ALONG A SHEARLINE MAY MOVE SOUTH OVER THE ISLANDS MONDAY AND
INCREASE WINDWARD SHOWERS. BY THE MIDDLE OF NEXT WEEK...THE COMPUTER
MODELS SHOW A TROUGH REDEVELOPING WEST OF KAUAI. THE WIND MAY
BRIEFLY VEER TO EAST SOUTHEAST NEAR KAUAI AND OAHU BUT IT LOOKS LIKE
TRADE WINDS WILL SPREAD BACK OVER THE ISLANDS BY THE END OF THE WEEK.

&&

.MARINE...
A HIGH SURF ADVISORY...A SMALL CRAFT ADVISORY AND A MARINE WEATHER
STATEMENT ARE ALL UP TILL 6 AM THURSDAY MORNING DUE TO A LARGE NORTH
NORTHEAST SWELL. MODEL GUIDANCE SHOWS E NORTH-NORTHEAST SWELL
GRADUALLY DECREASING SO WE MAY ABLE TO DROP ALL THREE PRODUCTS
THURSDAY MORNING. .

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY UNTIL 6 AM HST THURSDAY FOR EAST FACING SHORES
OF ALL ISLANDS EXCEPT LANAI AND KAHOOLAWE.

SMALL CRAFT ADVISORY MOST HAWAIIAN WATERS UNTIL 6 AM HST THURSDAY
FOR SEAS GREATER THAN 10 FT.

FLASH FLOOD WATCH FOR NIIHAU KAUAI AND OAHU THROUGH 4 PM THURSDAY.

&&

DONALDSON