High Surf in Hawaii, December 17 to 18, 2006

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST SUN DEC 17 2006

.SYNOPSIS...
THE STATE WILL ENJOY MOSTLY SUNNY WEATHER TODAY. AN OLD SHEAR LINE
MOVING IN FROM THE EAST TONIGHT WILL PRODUCE A SHOWERY MONDAY
MORNING FOR MUCH OF THE STATE. THE REMAINDER OF THE WEEK HOWEVER
PROMISES BRING PLEASANT MOSTLY SUNNY WEATHER WITH LIGHT TRADE WINDS.

&&

.DISCUSSION...
VERY STRONG JET STREAM LEVEL FLOW OVER THE NORTH PACIFIC MEANS
HAWAII WILL ENJOY LITTLE VARIATION FROM RATHER DRY TRADE WIND
WEATHER AFTER MONDAY. WITHOUT THE NORMAL SOUTHWARD DIPS IN THE JET
STREAM PUSHING COLD FRONTS ACROSS OUR ISLANDS...OR AT LEAST
UNSETTLED CONDITIONS ARISING FROM TROUGHS TO OUR WEST...WE ARE LEFT
WITH SURFACE HIGH PRESSURE NEAR US. STRONGER HIGH PRESSURE CELLS FAR
THE NORTH AT LEAST PROVIDE ENHANCED OROGRAPHIC...THAT IS WINDWARD
AND MOUNTAIN...PRECIPITATION. BUT THIS WEEK THE HIGH OR SUBTROPICAL
SURFACE RIDGE THAT EXTENDS FROM THE HIGH WILL AFTER MONDAY TAKE UP
RESIDENCE JUST TO THE NORTH OF HAWAII...HENCE MUCH DRIER THAN NORMAL
WEATHER WITH ONLY LIGHT TRADE WINDS.

MAIN WEATHER CONCERN AT PRESENT IS THE SHEAR LINE OR TAIL END OF THE
VERY LONG FRONT THAT SWEPT DOWN THE WEST COAST OVER THE PAST FEW
DAYS...READILY IDENTIFIABLE ON VISIBLE SATELLITE IMAGERY AS THE LONG
CLOUD BAND JUST EAST AND NORTHEAST OF THE MAIN HAWAIIAN ISLANDS.
THE SHOWERS MAY BE ENHANCED BY A SLIGHT BOOST IN TRADE WINDS FROM
THE RAPIDLY EASTWARD MOVING HIGH BEHIND ANOTHER FRONT MUCH FARTHER
NORTH...THIS FRONT WILL NOT REACH US. HOWEVER COMPUTER MODELS DO NOT
SUGGEST VERY SIGNIFICANT PRECIPITATION TOMORROW.

A WEAK UPPER TROUGH...PRESENTLY JUST EAST OF THE DATE
LINE...CONTINUES TO ADVECT RATHER SPARSE HIGH CLOUDS OVER THE STATE.
THIS UPPER TROUGH WILL CROSS OVER US MONDAY AFTER WHICH THE UPPER
FLOW WILL BECOME ANTICYCLONIC IMPLYING INCREASED ATMOSPHERIC
STABILITY.

&&

.MARINE...
STRONG TRADE WINDS IN THE FETCH SOUTH OF THE NORTHEAST PACIFIC HIGH
MEANS CONTINUATION THROUGH MONDAY OF SHORT PERIOD TRADE WIND SWELL
CAUSING HIGH SURF ON EASTERN SHORES AND SMALL CRAFT ADVISORY FOR
MOST AREAS DUE TO HAZARDOUS SEAS. UNSEASONABLE SOUTH SWELL EXPECTED
TO RISE TO HIGH SURF ADVISORY LEVEL OF 8 FEET BY EARLY MONDAY. THE
ADVISORY WILL BE ISSUED BY 4 PM TODAY. INITIAL FETCH AREA WAS JUST
SOUTHEAST OF NEW ZEALAND BUT THEN EVOLVED INTO STRONG LOW ABOUT 4000
MILES SOUTH OF HAWAII LAST MONDAY. THEREFORE PEAK OF THIS EPISODE
MAY NOT ARRIVE TIL LATE MONDAY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...

SMALL CRAFT ADVISORY UNTIL 2 PM MONDAY FOR ALL HAWAIIAN WATERS
EXCEPT MAALAEA BAY.

HIGH SURF ADVISORY UNTIL 6 PM MONDAY FOR EAST FACING SHORES OF KAUAI
OAHU MOLOKAI MAUI AND THE BIG ISLAND. HIGH SURF ADVISORY FOR SOUTH
SHORES TO BE ISSUED THIS AFTERNOON.
&&

HOAG