FXHW60 PHFO 272022
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1005 AM HST FRI NOV 27 2009

.SYNOPSIS...
SEVERAL HIGH PRESSURE SYSTEM PASSING FAR NORTH OF THE STATE WILL 
MAINTAIN TRADE WINDS THROUGH THE FIRST HALF OF NEXT WEEK. THE TRADE 
WINDS WILL TAIL OFF BRIEFLY SATURDAY THEN RAMPING UP SUNDAY AND 
PERSIST THROUGH MONDAY. THE STATE MAY ENDURE A SPAT OF UNSETTLE 
WEATHER SUNDAY INTO MONDAY AS A STRONG UPPER LEVEL DISTURBANCE 
PUSHES THROUGH THE AREA. A MORE NORMAL TYPICAL TRADE WIND REGIME 
RETURNS TUESDAY WITH LIGHTER TRADES.

&&

.DISCUSSION...
THE UPPER LEVEL TROUGH THAT PRODUCED THE ENHANCED TRADE SHOWERS OVER 
SELECTED PARTS OF THE STATE DURING THE PAST 36 HOURS HAS MOVED EAST 
OF THE BIG ISLAND. THERE IS STILL SOME REMNANT INSTABILITY AS NOTED 
BY SOME SCATTERED SHOWERS OVER WINDWARD BIG ISLAND AND TO THE 
NORTHEAST...BUT IT SHOULD BE GOING AWAY AS THE DAY PROGRESSES AS 
MID LEVEL RIDGING BUILDS EASTWARD.

SATURDAY IS SHAPING UP TO BE A NICE QUIET DAY BEFORE THE WEATHER 
STARTS TURNING SOUR SATURDAY NIGHT AS A VIGOROUS UPPER LEVEL 
DISTURBANCE DROPS TOWARD THE ISLANDS. THE TROUGH WILL BE ACCOMPANIED 
BY A POOL OF COLD AIR OF MINUS 12 TO 14 C AT 500 MILLIBARS. THE 
RESULT WILL BE ELEVATED...ENHANCED TRADE SHOWERS WITH AT LEAST A
SLIGHT CHANCE OF THUNDERSTORMS AREA WIDE FOR SUNDAY INTO MONDAY. 
PERHAPS THE ONLY DIFFERENCE WITH THE MODELS IS THAT ECMWF CLEAR THE 
WEATHER OUT BY MONDAY AFTERNOON. THE GFS SOLUTION IS MUCH SLOWER... 
NOT UNTIL TUESDAY. THE PREDICTED PRECIPITABLE WATER IS EXPECTED TO 
BE MODERATE WITH GFS SUGGESTING MAX OF 1.62 INCHES. IT IS DIFFICULT 
WHO WILL GET THE BRUNT OF THE WEATHER BUT THE WINDWARD SECTIONS IS A 
PRIME AREA. COMPLICATING THE SITUATION IS A SHEAR LINE OR THE TAIL 
END OF THE COLD FRONT WHICH WILL LIKELY BLEND IN WITH THE ALREADY 
PRESENT TRADES. FROM THE GFS MODEL...THE COLDEST 500 MILLIBAR TEMP 
OF MINUS 14 IS SLATED TO BE OVER THE WESTERN HALF OF THE STATE 
SUNDAY NIGHT WITH STRONG GUSTY TRADES PRESENT.

WE WILL KEEP A CLOSE TAB ON THIS AS THE SITUATION UNFOLDS.

&&

.MARINE...
THE ABOVE NORMAL NORTHWEST SWELL HAS TURNED MORE NORTHERLY. SO THE 
DAY...THE HIGH SURF ADVISORY HAS BEEN SHIFTED TO THE EAST FACING 
SHORES OF MOST ISLANDS. EXPECT THIS SWELL TO LAST TO AT LEAST EARLY 
SUNDAY. WE WILL ALSO BE MONITORING A NEW NORTHWEST SWELL THAT IS 
SLATED TO WILL ARRIVE EARLY SATURDAY WITH SURF HEIGHTS NEARING THE 
ADVISORY LEVEL ALONG NORTH SHORES.

A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR ALL COASTAL WATERS FOR 
A COMBINATION OF HIGH SEAS AND STRONG TRADE WINDS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY UNTIL 6 AM HST SUNDAY FOR NIIHAU-KAUAI 
WINDWARD-OAHU KOOLAU-OLOMANA-MOLOKAI-MAUI WINDWARD WEST-WINDWARD 
HALEAKALA-BIG ISLAND NORTH AND EAST.

SMALL CRAFT ADVISORY UNTIL 6 PM HST THIS EVENING FOR KAUAI 
WINDWARD WATERS-KAUAI LEEWARD WATERS-OAHU WINDWARD WATERS-OAHU 
LEEWARD WATERS-MAUI COUNTY WINDWARD WATERS-MAUI COUNTY LEEWARD 
WATERS-MAALAEA BAY-BIG ISLAND WINDWARD WATERS-BIG ISLAND LEEWARD 
WATERS.

SMALL CRAFT ADVISORY UNTIL 6 AM HST SATURDAY FOR KAUAI NORTHWEST 
WATERS-KAUAI CHANNEL-KAIWI CHANNEL-PAILOLO CHANNEL-ALENUIHAHA 
CHANNEL-BIG ISLAND SOUTHEAST WATERS.

&&

$$

H LAU