Drought in Hawaii, September 21 to 30, 2010

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
340 AM HST TUE SEP 21 2010

.SYNOPSIS...
WEAK HIGH PRESSURE TO THE NORTH OF THE MAIN HAWAIIAN ISLANDS WILL
CONTINUE TO PROVIDE THE AREA WITH LIGHT TO MODERATE TRADE WINDS
THROUGH THE WEEKEND. THE MOISTURE FROM AN OLD FRONT THAT AFFECTED
THE ISLANDS SUNDAY WILL REVISIT ISLANDS TONIGHT AND WEDNESDAY.
OTHERWISE...THE SECOND HALF OF THE WEEK INVOLVES SOME SCATTERED
SHOWERS FAVORING THE WINDWARD AND MOUNTAIN AREAS ESPECIALLY NIGHTS
AND MORNINGS. RAINFALL AMOUNTS FROM THESE SHOWERS WILL BE LOW.

&&

.DISCUSSION...
THE RAGGED BAND OF LOW CLOUDS EXTENDING FROM THE WATERS OF EASTERN
BIG ISLAND NORTHEASTWARD...IS SLATED BY MANY OF THE FORECAST MODELS
TO START EASING WESTWARD THIS AFTERNOON. THIS COMES ABOUT AS THE
NORTHEAST WINDS WE ARE HAVING...TURNS SLIGHTLY MORE EAST.

WEDNESDAY MORNING IS SHAPING UP TO BE DAMP ESPECIALLY FOR THE
WINDWARD AND MOUNTAIN ZONES OF THE SMALLER ISLANDS. THE STRENGTH OF
THE TRADE WINDS ARE ALSO EXPECTED TO BECOME LIGHTER BY WEDNESDAY.
THIS ACTION WILL PROMOTE DAY TIME SEA BREEZES OVER THE LEEWARD
SECTIONS. AIDED BY THE REMNANT MOISTURE...THERE IS A GOOD BET THAT
THE LEEWARD COMMUNITIES SUCH AS THE WAIANAE COAST ON OAHU...WILL
BENEFIT FROM A COUPLE OF AFTERNOON SHOWERS WEDNESDAY. THE INTENSITY
OF THESE SHOWERS WILL BE LIMITED BY A STRONG MID LEVEL RIDGE
POSITIONED OVER THE AREA.

THE MODELS EASE THE LEFT-OVER MOISTURE TO THE WEST AND NORTH OF THE
ISLANDS WEDNESDAY NIGHT...LEAVING BEHIND A DRYING TREND. THE MODELS
SUGGEST A LOW RAINFALL...STABLE TYPE AIR MASS FOR THE WEEKEND AND
INTO EARLY NEXT WEEK.

THE LIGHT TO MODERATE TRADES WILL STAY PUT INTO SATURDAY...AND MAY
EVEN TURN LIGHT SUNDAY AS THE SURFACE RIDGE IS PUSHED SOUTH AND
CLOSER TO THE HAWAIIAN ISLANDS. THIS IS BROUGHT UPON BY A SERIES OF
LOW PRESSURE SYSTEMS PASSING FAR NORTH OF THE NORTHERN PACIFIC
OCEAN. THE DISTANCE OF THE SURFACE RIDGE FROM KAUAI ON THURSDAY IS
350 MILES NORTH AND 120 MILES ON SUNDAY.

&&

.MARINE...
THE PASSING LOWS NORTH OF THE ISLANDS WILL GENERATE A NICE SIZE
NORTHWEST SWELL TOWARDS THE MAIN HAWAIIAN ISLANDS THAT IS SLATED TO
ARRIVE THURSDAY AND FRIDAY. LOOK FOR MODERATE SIZE SURF FROM THIS
SWELL. ALSO...A 3 FOOT SOUTHWEST SWELL IS DUE TO ARRIVE WEDNESDAY.
SURF HEIGHTS FROM THIS SOUTHWEST SWELL WILL APPROACH HIGH SURF
ADVISORY CRITERIA.

&&

.AVIATION...
WE WILL BE MONITORING CLOSELY THE RETURN OF THE OLD FRONTAL BAND
CURRENTLY OFF EASTERN BIG ISLAND FOR IT MAY USHER IN SOME IFR
CONDITIONS SUCH AS CEILINGS AND VIS.

ANTICIPATE AN INCREASE IN TRADE WIND SHOWERS
DURING THE OVERNIGHT
HOURS. THESE SHOWERS WILL HAVE SOME BRIEF MVFR CONDITIONS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

LAU