High Surf in Hawaii, March 5 to 10, 2005

HAWAIIAN ISLANDS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 PM HST SAT MAR 5 2005

.SYNOPSIS...
A COLD FRONT ACROSS THE KAUAI CHANNEL WILL CONTINUE TO MOVE
SOUTHEAST THROUGH THE AFTERNOON AND EVENING...REACHING WEST MAUI
TONIGHT BEFORE STALLING. CLOUDS AND SHOWERS MAY LINGER THROUGH
SUNDAY AS THE FRONT DISSIPATES...BUT TOTAL RAINFALL WILL BE LIGHT.
ANOTHER COLD FRONT IS EXPECTED TO REACH KAUAI LATE WEDNESDAY INTO
THURSDAY...BRINGING ANOTHER BRIEF PERIOD OF CLOUDS AND SHOWERS. THE
INTERVAL BETWEEN FRONTS WILL HAVE DRIER WEATHER AND LIGHT WINDS.

&&

.DISCUSSION...
THE LEADING EDGE OF A CLOUD BAND ASSOCIATED WITH A WEAK COLD FRONT
HAS REACHED OAHU...WHILE THE REST OF THE BAND EXTENDS WEST ACROSS
THE KAUAI CHANNEL AND THE ISLAND OF KAUAI. NIIHAU AND HAWAIIAN
WATERS JUST NORTHWEST OF KAUAI ARE JUST NOW BEGINNING TO SEE CLEARER
SKIES AS THE TRAILING EDGE OF THE CLOUD BAND SLOWLY MOVES BY. THE
PARENT LOW IS 1200 MILES NORTH OF THE MAIN ISLAND CHAIN AND LIFTING
OUT TO THE NORTHEAST...TAKING MOST SYSTEM DYNAMICS WITH IT AND
LEAVING THAT PORTION OF THE FRONT OVER THE ISLANDS RATHER
ATTENUATED. MOST OF THE SHOWERS WITHIN THE FRONTAL CLOUD BAND ARE
CONCENTRATED ALONG THE LEADING EDGE...WHERE CLOUD TOPS ARE COOLER
AND HIGHER. RADAR SHOWS A 10 MILE WIDE LINE OF MODERATE SHOWERS
ORIENTED NORTHEAST TO SOUTHWEST ACROSS THE KAUAI CHANNEL...POISED TO
CROSS OVER THE NORTH SHORE OF OAHU...MOVING EASTWARD AT ABOUT 15
MPH.

LATEST GFS75 HAS THE FRONT JUST GRAZING MAUI LATE TONIGHT AND EARLY
SUNDAY BEFORE THE LAST OF THE SYSTEM DYNAMICS IS LEACHED AWAY AND
THE FRONT STALLS. CLOUDS AND SHOWERS MAY LINGER THROUGH SUNDAY AS
THE REMNANT DEFORMATION ZONE IN THE WIND FIELD SLOWLY SHREDS THE OLD
FRONTAL CLOUD BAND. POST FRONTAL NORTHWESTERLIES WILL SWITCH BACK TO
SOUTHWESTERLIES BY EARLY NEXT WEEK AS THE SUBTROPICAL RIDGE REMAINS
SOUTH OF THE ISLANDS EVEN AFTER FRONTAL DISSIPATION. THE
SOUTHWESTERLIES WILL LIKELY BE LIGHT ENOUGH FOR LOCAL LAND AND SEA
BREEZES TO FORM.

ANOTHER COLD FRONT IS EXPECTED TO REACH THE MAIN ISLANDS LATE
WEDNESDAY AND THURSDAY. GFS WANTS TO MAINTAIN THE STRENGTH OF THIS
FRONT AS IT STALLS AND LINGERS OVER MAUI COUNTY LATE NEXT
WEEK...EVEN DEVELOPING A WEAK LOW ALONG THE LENGTH OF IT SOUTH OF
OAHU. THIS WOULD MAKE THE LAST OF THE NEXT WORK WEEK AND NEXT
WEEKEND A BIT WETTER THAN CURRENTLY FORECAST. HOWEVER...THIS IS A
WEEK AWAY AND WE WILL WAIT TO SEE IF SUBSEQUENT MODEL RUNS INSIST
THAT THIS WILL OCCUR BEFORE WE CHANGE ANYTHING.

ANYWAY...TROUGHING IN THE MIDLATITUDES WILL HAVE MOVED EAST BY
MIDWEEK...ALLOWING A POST FRONTAL HIGH TO MOVE IN NORTHWEST OF THE
STATE AND SWING POSTFRONTAL NORTHWESTERLIES OVER TO NORTHEAST TRADES
FROM LATE THURSDAY ONWARD.

&&

.MARINE...
OBSERVATIONS SHOW THE 320 DEGREE SWELL HAS ARRIVED...WITH 20 FEET
SURF LIKELY OCCURRING AT WAIMEA ON OAHU LATE THIS AFTERNOON. MODEL
GUIDANCE CONTINUES TO SHOW THIS SWELL WILL GRADUALLY RISE OVERNIGHT.
HIGH SURF WARNINGS ARE NOW IN EFFECT FOR NORTH AND WEST FACING
SHORES OF KAUAI AND NIIHAU...AND FOR NORTH FACING SHORES OF OAHU.
HIGH SURF ADVISORIES ARE IN EFFECT FOR WEST FACING SHORES OF OAHU
AND THE BIG ISLAND...AND FOR NORTH FACING SHORES OF MAUI AND
MOLOKAI. PEAK SURF SHOULD BE TONIGHT FOR KAUAI...EARLY SUNDAY FOR
OAHU...AND LATER SUNDAY FOR MAUI COUNTY AND THE BIG ISLAND. THE
WAVEWATCH MODEL CONTINUES TO SHOW A LARGER NW SWELL ARRIVING LATER
MONDAY. THE SMALL CRAFT ADVISORY REFLECTS THE HAZARD FROM SWELL
RATHER THAN WIND.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...

NIIHAU AND KAUAI -
HIGH SURF WARNING FOR N AND W FACING SHORES TONIGHT AND SUNDAY.

OAHU -
HIGH SURF WARNING FOR N FACING SHORES TONIGHT AND SUNDAY.
HIGH SURF ADVISORY FOR W FACING SHORES TONIGHT AND SUNDAY.

MAUI AND MOLOKAI -
HIGH SURF ADVISORY FOR N FACING SHORES TONIGHT AND SUNDAY.

BIG ISLAND OF HAWAII -
HIGH SURF ADVISORY FOR W FACING SHORES TONIGHT AND SUNDAY.

&&

POWELL