High Surf Advisory 9, NWS Honolulu, HI

AREA FORECAST DISCUSSION...COR
NATIONAL WEATHER SERVICE HONOLULU HI
455 AM HST THU JAN 31 2013

.SYNOPSIS...
THE CLOUDINESS OVER THE BIG ISLAND WILL CONTINUE TO LESSEN THIS
MORNING AS THE TROUGH FINALLY DISSIPATES. MEANWHILE...THE TRADE
WINDS HAVE RETURNED. THEY WILL BE GAINING STRENGTH...REACHING
MODERATE SPEEDS BY FRIDAY. THE TRADES EASES OFF OVER THE
WEEKEND...BUT WILL RESUME PICKING UP STEAM AGAIN SUNDAY NIGHT.
SHOWERS RIDING IN WITH THE TRADE WILL FAVOR THE WINDWARD AND
MOUNTAIN AREAS.

&&

.DISCUSSION...
THE FORECAST REMAINS ON TRACK FOR CONTINUED THINNING OUT OF THE
CLOUD COVER OVER THE BIG ISLAND THIS MORNING. THE TRADES HAVE
RETURNED...AND WILL BE STRENGTHENING TO MODERATE SPEEDS TONIGHT.

THE FREQUENCY OF THE TRADE SHOWERS FOR TONIGHT AND FRIDAY NIGHT IS
SLATED TO BE LESS FOR ISLANDS WEST OF MOLOKAI AND A TAD MORE FOR
THE REMAINING ISLANDS. THIS IS DUE TO THE MOISTURE BEING BLOWN BACK
BY THE TRADES AFTER HAVING LEFT THE BIG ISLAND AND MAUI.

THE TRADES WILL WEAKEN SATURDAY...LIGHT ENOUGH TO PROMOTE THE
DEVELOPMENT OF LOCAL DAYTIME SEA BREEZES...WITH THE END RESULT OF
LOCAL INTERIOR AND LEEWARD CLOUDINESS. SHOWERS FROM THESE CONVECTIVE
CLOUDS WILL BE MINIMAL THANKS TO A STRONG MID LEVEL RIDGE SETTLING
OVER THE AREA. THE RIDGE WILL LIMIT THE VERTICAL GROWTH OF THESE
CLOUDS TO NO HIGHER THAN 8000 FEET ACROSS THE SMALLER ISLANDS.
DURING THE NIGHTTIME HOURS...THE TRADES WILL BE STRONG ENOUGH TO
CARRY A COUPLE OF SHOWERS ONTO THE ISLAND/S WINDWARD AND MOUNTAIN
AREAS.

THIS BRIEF LET DOWN IN THE TRADES IS THE RESULT OF AN APPROACHING
FRONT... CAUSING THE SURFACE RIDGE TO MOVE CLOSE TO KAUAI. THE FRONT
FALLS APART NORTH OF THE ISLANDS...BUT THE REMNANTS WILL LIKELY BE
BLOWN IN WITH THE TRADE WINDS...STARTING TUESDAY NIGHT.

THE RESUMPTION OF THE STRONGER TRADES SUNDAY NIGHT WILL LIKELY HAVE
A LOW FREQUENCY OF SHOWERS AS THE STRONG MID LEVEL RIDGE MAKE ITS
PRESENCE KNOWN. THE UPTICK IN TRADE SHOWERS...AS NOTED ABOVE...WILL
COME TUESDAY NIGHT...WHEN THE REMNANTS TO AN OLD FRONT REACHES THE
ISLANDS.

SHOULD ALSO NOTE THAT WE WILL BE WITHOUT THE SERVICE OF THE BIG
ISLAND WEATHER RADAR UNIT NEAR PAHALA AND NAALEHU...WITH THE CALL
SIGN PHWA. PHWA...COVERING EASTERN BIG ISLAND INCLUDING HILO...IS
DOWN FOR UPGRADE FOR THE NEXT TWO WEEKS. IT IS SLATED TO RETURN TO
SERVICE ON FEBRUARY 8 2013.

&&

.MARINE...
BUOY 51101 NORTHWEST OF KAUAI...IS NOW PICKING UP THE 15 SEC
NORTHWEST SWELL. THIS 15 SEC BELONGS TO THE FIRST TO TWO NORTHWEST
SWELLS WHICH IS RUNNING A FEW HOURS LATE. THE MORE SIGNIFICANT
NORTHWEST SWELL...SLATED TO REACH THIS BUOY AT 3 AM HST...WITH 20
SEC...HAS NOT YET.

WE HAVE GONE AHEAD IN ISSUING A HIGH SURF ADVISORY...EFFECTIVE AT
12 NOON TODAY. THE ADVISORY COVER THE NORTH AND WEST SHORES OF
NIIHAU KAUAI OAHU MOLOKAI AND THE NORTH FACING SHORES OF MAUI. THIS
ADVISORY WILL BE UPGRADED TO A WARNING IF NECESSARY.

ANOTHER HIGH SURF ADVISORY IS LIKELY FOR THE WEST FACING SHORES OF
THE BIG ISLAND SHOULD THE LARGE NW SWELL PANS OUT. THIS SWELL IS
SLATED TO REACH THE BIG ISLAND FRIDAY.

A SMALL CRAFT ADVISORY...DUE TO COMBINED SEAS OF 10 FEET OR
HIGHER...WILL LIKELY BE ISSUED SOMETIME TODAY...AS THE CONDITION
WILL NOT BE MET UNTIL TONIGHT.

THE TRADE WINDS FRIDAY WILL CUT CLOSE TO SMALL CRAFT CRITERIA OF 25
KNOTS SO WE WILL BE MONITORING THIS CLOSELY.

&&

.AVIATION...
VFR CONDS WILL PREVAIL ACROSS THE ISLANDS TODAY EXCEPT FOR MVFR
CEILINGS AND VIS ASSOCIATED WITH THE TRADE WIND SHOWERS. THESE
SHOWERS WILL FAVOR THE WINDWARD AND MOUNTAIN AREAS...ESPECIALLY
ISLANDS EAST OF OAHU.

WE ARE NOT EXPECTING LO LVL MOD TURB BUT WILL BE MONITORED CLOSELY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY IN EFFECT AT 12 NOON HST TODAY TO 6 PM HST FRIDAY
FOR THE NORTH AND WEST FACING SHORES OF NIIHAU KAUAI OAHU AND
MOLOKAI...AND THE NORTH FACING SHORES OF MAUI.

&&

LAU