High Surf in Hawaii, March 1 to 2, 2013

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST THU FEB 28 2013

.SYNOPSIS...
A MOSTLY DRY WEATHER PATTERN WILL CONTINUE TONIGHT AND THROUGH
FRIDAY...THEN SHOWERS GRADUALLY INCREASE DURING THE REST OF THE
WEEKEND WITH RAINFALL FAVORING WINDWARD AND MAUKA AREAS AS A WEAK
UPPER LEVEL TROUGH REACHES THE AREA. TRADE WINDS REMAIN IN PLACE
THROUGH THE FORECAST PERIOD...WITH A MORE ACTIVE WEATHER PATTERN
EXPECTED EARLY NEXT WEEK WHEN A STRONGER TROUGH ALOFT APPROACHES
FROM THE NORTHWEST.

&&

.DISCUSSION...
A STRONG SFC HIGH FAR NW OF THE ALOHA STATE CONTINUES TO GRADUALLY
MIGRATE EASTWARD AND BRINGING INCREASING TRADE WINDS ACROSS THE AREA
THROUGH THE WEEKEND. PRESSURE GRADIENTS WILL BECOME TIGHTER OVER
THE EASTERN HALF OF THE ISLAND CHAIN AS THE HIGH SLIDES TO THE
NORTH...FOR WHICH A WIND ADVISORY WILL BE IN EFFECT STARTING AT
MIDNIGHT TONIGHT AND THROUGH FRI AFTERNOON FOR MUCH OF MAUI COUNTY
AND THE BIG ISLAND.

WEATHERWISE...CONDITIONS WILL REMAIN RELATIVELY DRY UNTIL LATE FRI
WHEN AN UPPER LVL SHORTWAVE TROUGH WILL APPROACH FROM THE NW AND
SETTLE JUST TO THE EAST OF THE MAIN HAWAIIAN ISLANDS. MOST
SIGNIFICANT IMPACTS WITH THIS FEATURE WILL BE A SLIGHT INCREASE IN
SHOWERS...MAINLY WINDWARD AND MAUKA...THROUGH THE WEEKEND.

FOR EARLY NEXT WEEK...AN EVEN STRONGER UPPER LVL TROUGH COULD BRING
A GREATER INCREASE IN WINDWARD SHOWERS THROUGH MID WEEK.
MEANWHILE...AT THE SFC...ANOTHER HIGH WILL MOVE TO THE NORTH OF THE
ISLANDS AND ENSURE ONLY A GRADUAL SLOW DOWN IN THE TRADE WINDS.
LATEST MODEL GUIDANCE SUGGESTS A WEAKENING AND VEERING OF THE TRADES
BY THE END OF NEXT WEEK AS ANOTHER FRONTAL BOUNDARY APPROACHES THE
ISLAND CHAIN FROM THE NORTHWEST.

&&

.AVIATION...
VFR CONDITIONS ARE EXPECTED TO CONTINUE AT ALL TAF SITES THROUGH THE
REST OF TONIGHT. LOCAL MVFR CONDITIONS ARE POSSIBLE ALONG WINDWARD
SLOPES DUE MAINLY TO LOW CLOUDS AND ISOLATED SHOWERS.

AIRMET TANGO REMAINS UP FOR BELOW 8000 FEET SOUTH AND WEST OF THE
MOUNTAINS ON ALL ISLANDS DUE TO MODERATE LOW LEVEL TURBULENCE.

&&

.MARINE...
A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR ALL HAWAIIAN
COASTAL WATERS THROUGH SATURDAY DUE TO A COMBINATION OF A NW SWELL
AND LOCAL WIND DRIVEN WAVES. WINDS SHOULD DECREASE AROUND
SATURDAY WITH THE SCA SET TO EXPIRE FOR MOST ZONES EXCEPT THE TYPICAL
WINDY AREAS AROUND MAUI AND HAWAII COUNTIES...AND ALSO EXPIRE THE
HIGH SURF ADVISORY FOR NORTH AND WEST SHORES.

AS THE TRADES BECOMES STRONGER...THERE IS A SMALL CHANCE OF WINDS
REACHING GALE FORCE IN THE WINDY CHANNELS AND SOUTH OF THE BIG
ISLAND OVER THE NEXT 36 HOURS...BUT CONFIDENCE IS TOO LOW TO WARRANT
A GALE WATCH. THE INCREASING TRADE WINDS COULD ALSO TRIGGER A HIGH
SURF ADVISORY FOR ROUGH SEAS ALONG EAST SHORES FRIDAY NIGHT AND
SATURDAY. A MODERATE NORTHWEST SWELL IS DUE IN EARLY NEXT WEEK.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY UNTIL 6 AM HST SATURDAY FOR NORTH AND WEST FACING
SHORES OF KAUAI OAHU MOLOKAI AND NIIHAU AND FOR NORTH FACING SHORES
OF MAUI.

WIND ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM HST FRIDAY FOR LANAI-
KAHOOLAWE-MAUI WINDWARD WEST-MAUI LEEWARD WEST-MAUI CENTRAL
VALLEY-LEEWARD HALEAKALA-HALEAKALA SUMMIT-SOUTH BIG ISLAND-BIG
ISLAND NORTH AND EAST-KOHALA-BIG ISLAND INTERIOR.

SMALL CRAFT ADVISORY UNTIL 6 PM HST SATURDAY FOR ALL HAWAIIAN
WATERS-

&&

DISCUSSION/MARINE...REYNES
AVIATION...HUI