High Surf Advisory 19, NWS Honolulu, HI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
900 AM HST THU MAR 8 2012

.SYNOPSIS...
A PASSING TROUGH IS FORECAST TO KEEP THE WEATHER UNSETTLED THROUGH
SATURDAY...WHILE A STRONG HIGH PRESSURE SYSTEM FAR NORTHWEST OF THE
STATE MAINTAIN STRONG AND GUSTY TRADES INTO EARLY NEXT WEEK.
THE SHOWERS WILL BE FOCUSED OVER THE WINDWARD AND MOUNTAIN AREAS.

&&

.DISCUSSION...
THE ECMWF /EC/ AND GFS MODELS DISAGREE ON SOME WEATHER ELEMENTS SUCH
AS THE WINDS BUT BOTH AGREE ON THE LETTING UP OF THE WET WEATHER
THIS SATURDAY.

FOR NOW...THERE IS A BOUNDARY OR TROUGH IN THE VICINITY OF MAUI...
WHERE MOST OF THE WEATHER IS OCCURRING NOW. THUNDERSTORM ACTIVITY IS
DETECTED BY BOTH SATELLITE AND RADAR RIGHT OFF THE NORTH COAST OF
MAUI AND THREATENS TO SPREAD ONSHORE. WIND WISE...IT APPEARS FROM
WIND DATA STATEWIDE...THE STRONG GUSTY TRADES ARE ON THE WEST SIDE
OF TROUGH...AND LIGHTER EASTERLY WINDS TO THE EAST. THE EC APPEARS
TO PICK THIS UP WELL AND MAINTAIN THIS IDENTITY AS THE TROUGH MOVES
WESTWARD. THE GFS ON THE OTHER HAND HAS THE TROUGH WEAKENING OR
DISSIPATING WITH STRONG AND GUSTY TRADES SPREADING TO ALL AREAS. WE
HAVE SIDED WITH THE WINDIER GFS SOLUTION.

WITH THIS THREATENING WEATHER...A FLASH FLOOD WATCH HAS BEEN ISSUED
FOR MAUI MOLOKAI LANAI OAHU AND KAUAI. THE THREAT OF HEAVY RAINS IS
NOT IMMEDIATE FOR KAUAI NOW...BUT IS EXPECTED FROM THIS EVENING ON.

WE ARE ALSO MONITORING CLOSELY THE WINDS ACROSS OAHU AND KAUAI...
WHERE IT IS RATHER BLUSTERY. A WIND ADVISORY MAY BE NECESSARY THIS
AFTERNOON FOR THESE TO ISLANDS IN PARTICULARLY

THE UNSETTLED WEATHER IS SLATED TO CLEAR KAUAI BY LATE SATURDAY
AFTERNOON WHERE THE TROUGH WILL BE WELL WEST OF KAUAI. THE STRONG
TRADES...HOWEVER...ARE EXPECTED TO LAST THROUGH THE WEEKEND.

&&

.AVIATION...
CONVECTION IS ONGOING OVER THE MAUI COUNTY ALONG WITH STRONG LLVL NE
WINDS. EXPECT WIDESPREAD MVFR WITH ISOLATED IFR CONDITIONS ACROSS
THE CENTRAL ISLANDS AND ADJ WTRS. CB TOPS ARE REACHING FL400-FL500.
A DEVELOPING UPPER LOW OVER THE WESTERN PORTION OF THE STATE WILL
LEAD TO DETERIORATING CONDITIONS OVERNIGHT.

AIRMETS ARE IN PLACE ACROSS THE BOARD FOR LLVL TURB...MT
OBSCURATION AND ICING IN THE CONVECTIVE AREAS OVER MAUI COUNTY.
THESE WILL LIKELY PERSIST WITH SOME ADJUSTMENTS THROUGH THE PD.

SIGMET ROMEO IS IN EFFECT FOR TS FROM MAUI COUNTY NEWD FOR 800
MILES. THE AREA OF TS STATIONARY.

&&

.MARINE...
A HIGH SURF ADVISORY IS LIKELY FOR THE EAST FACING SHORES FOR
ISLANDS EXPOSED TO A SHORT PERIOD NORTH NORTHEAST SWELL SLATED TO
ARRIVE TONIGHT. THE ADVISORY WILL BE POSTED THIS AFTERNOON.

THE SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT FOR ALL HAWAIIAN
WATERS FOR WINDS AND/OR COMBINED SEAS...WITH THESE CONDITIONS
EXPECTED THROUGH AT LEAST SATURDAY MORNING.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FOR MAUI MOLOKAI LANAI OAHU KAUAI UNTIL 4 PM HST
FRIDAY.

SMALL CRAFT ADVISORY UNTIL 6 AM HST SATURDAY FOR ALL HAWAIIAN WATERS.

&&

LAU