Wildfire in Hawaii, September 6 to 7, 2004

HAWAIIAN ISLANDS FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HONOLULU HI
100 PM HST MON SEP 6 2004

.SYNOPSIS...
SHOWERS WILL CONTINUE TO AFFECT PORTIONS OF KAUAI THIS AFTERNOOON.
SEA BREEZES AND INTERIOR CLOUDS AND SHOWERS CAN BE EXPECTED FOR THE
REMAINING ISLANDS. FURTHER OUT...AN UNSETTLED WEATHER PATTERN IS
DEVELOPING OVER THE MAIN HAWAIIAN ISLANDS...AS A SURFACE TROUGH AND
UPPER LEVEL LOW COMBINE FORCES TO PRODUCE THE THREAT OF
THUNDERSTORMS AROUND KAUAI AND OAHU LATE TONIGHT AND TUESDAY.
SCATTERED SHOWERS WILL LIKELY STRETCH AS FAR SOUTH AS MAUI
COUNTY...BUT IT APPEARS THE BIG ISLAND WILL BE UNAFFECTED BY THIS
EVENT. TRADES WILL START TO SHOW UP ON WEDNESDAY AS HIGH PRESSURE
BUILDS BACK IN...WITH TRADEWIND WEATHER FIRMLY IN PLACE FROM
THURSDAY ON.

&&

.UPDATE...
HAVE UPDATED THE ZONES TO ACCOUNT FOR THE CURRENT CLEARING TREND ON
OAHU. WITH ABUNDANT LOW LEVEL MOISTURE DUE TO MORNING SHOWERS AND
STILL A LOT OF DAYLIGHT LEFT...BELIEVE CONVECTIVE TYPE SHOWERS WILL
WILL FORM OVER INTERIOR SECTIONS. THESE SHOWERS WILL BE CONCENTRATED
OVER THE MOUNTAINS AND CENTRAL OAHU...BUT OTHER LOCATIONS MAY SEE A
SHOWER OR TWO DRIFT OVERHEAD. HAVE OTHERWISE UPDATED OTHER ZONES TO
DECREASE THE POPS A BIT AND FRESHEN UP THE WORDING.

&&

.PREV DISCUSSION...
THERE IS QUITE A DIFFERENCE IN WEATHER FROM ONE END OF THE STATE TO
THE OTHER THIS MORNING...WITH THE BIG ISLAND AND MAUI COUNTY UNDER
MOSTLY SUNNY SKIES WHILE SHOWERS AND MOSTLY CLOUDY SKIES COVER OAHU
AND KAUAI. SOUNDINGS ARE ALSO MARKEDLY DIFFERENT...WITH THE LIHUE
SOUNDING BEING MODERATELY UNSTABLE WHILE THE HILO SOUNDING SHOWS A
DECENT TEMPERATURE INVERSION STARTING AROUND 7500 FEET. WIND
WISE...LIGHT SOUTHEAST WINDS SURROUND THE BIG ISLAND AND MAUI
COUNTY...WHILE TRADES REMAIN OVER KAUAI. A SURFACE ANALYSIS SHOWS
WEAK RIDGING OVER THE BIG ISLAND...WHICH EXPLAINS THE
INVERSION...AND THE AXIS OF A WEAK SURFACE TROUGH OVER MAUI COUNTY.
BOTH FEATURES ARE ORIENTED FROM THE SOUTHWEST TO NORTHEAST. JUST
NORTH OF THE TROUGH AXIS AND UNFORTUNATELY FOR OAHU...DIRECTLY
OVERHEAD AND UPSTREAM OF THE ISLAND...A SHEARLINE LIKE BOUNDARY
FORMED LAST NIGHT AND PUT A DAMPER ON THINGS. GAGES ON OAHU RECORDED
AT THE VERY LEAST CLOSE TO A TENTH OF AN INCH WHILE A FEW SPOTS
APPROACHED THREE QUARTERS OF A INCH. DOPPLER VELOCITY IMAGES THIS
MORNING FROM THE MOLOKAI RADAR PLACE THE BOUNDARY RIGHT ACROSS
KAHUKU POINT ON THE NORTHERN TIP OF OAHU...MOVING SLOWLY TOWARD THE
NORTHWEST. SATELLITE AND RADAR SHOW SHOWERS CONTINUE TO FORM ALONG
THE BOUNDARY UPSTREAM...SO WHILE WHILE THE CLOUDS APPEAR TO BE
THINNING OUT AT THE MOMENT...OAHU MAY STILL RECEIVE A FEW BOUTS OF
SHOWERS. THE EARLY MORNING SHOWERS HAS COMPLICATED THE OAHU
FORECAST...SINCE INTERIOR AFTERNOON CONVECTION WILL RELY ON HOW MUCH
SUN IS ABLE TO REACH THE GROUND TO HEAT THINGS UP. AS THE SURFACE
TROUGH MAKING ITS WAY OVER THE ISLANDS CONTINUES TO MOVE
WESTWARD...IT WILL PUSH THE BOUNDARY ALONG WITH IT...SO KAUAI IS
LIKELY TO FEEL SOME EFFECTS LATER TODAY. FOR MAUI COUNTY AND THE BIG
ISLAND...WHICH ENJOYED NEARLY CLOUD FREE SKIES OVERNIGHT...THE
FORECAST IS A BIT MORE STRAIGHT FORWARD...LIGHT WINDS AND MOSTLY
SUNNY SKIES SHOULD YIELD TO SEA BREEZES AND INTERIOR CLOUDS AND
SHOWERS BY THE AFTERNOON. WHILE SOME LOCALLY HEAVY SHOWERS ARE
POSSIBLE...THE WEAK RIDGING OVER THE EASTERN HALF OF THE CHAIN
SHOULD PREVENT ANY CONVECTION FROM GETTING OUT OF HAND.

FOCUS CONTINUES ON AN UNSETTLED WEATHER PATTERN UNFOLDING
OVER THE ISLANDS TONIGHT AND TUESDAY AS AN UPPER LOW AND SURFACE
TROUGH COMBINE FORCES. GLOBAL MODELS REMAIN IN REMARKABLE AGREEMENT
IN FORECASTING THE EVOLUTION OF THIS DYNAMIC DUO. THE SURFACE LOW IS
CURRENTLY LOCATED NEAR 24N 156S...WITH A TROUGH EXTENDING TOWARD THE
SOUTHWEST AND OVER MAUI COUNTY. MODELS DO NOT CURRENTLY INDICATE A
CLOSED LOW...BUT SATELLITE ANALYSIS INDICATES A WEAK CIRCULATION
STILL EXISTS. EXPECT WHATEVER IS LEFT OF THIS CIRCULATION...FORMERLY
TROPICAL STORM GEORGETTE...TO WEAKEN FURTHER INTO A TROUGH LATER
TODAY.

AT MID AND UPPER LEVELS...WATER VAPOR IMAGERY SHOWS A LOW NORTHEAST
OF THE STATE WITH A BROAD TROUGH EXTENDING SOUTHWESTWARD OVER THE
EASTERN TIP OF THE BIG ISLAND. A SHORTWAVE NORTH OF KAUAI IS ALSO
EVIDENT SPEEDING DOWN THE WESTERN SIDE OF THE TROUGH. MODELS ARE IN
GOOD AGREEMENT FORMING A CUTOFF LOW OVER OR JUST NORTHWEST OF KAUAI
AS THE SHORTWAVE INTERACTS WITH THE TROUGH AXIS. ABOUT THE SAME TIME
THIS OCCURS...THE SURFACE TROUGH WILL BE RIGHT BELOW THE CUTOFF
LOW...PRODUCING THE THREAT OF THUNDERSTORMS AND PERIODS OF HEAVY
RAINFALL. AS FAR AS COVERAGE GOES...IT LOOKS LIKE KAUAI THEN OAHU
HAVE THE HIGHEST POTENTIAL FOR THUNDERSTORMS...BUT SCATTERED SHOWERS
SHOULD REACH AS FAR SOUTH AS MAUI COUNTY. TIMING WISE...LATE TONIGHT
AND TUESDAY ARE THE PERIODS OF CONCERN. IT APPEARS THAT THE BIG
ISLAND MAY GO UNSCATHED THROUGHOUT THIS EVENT.

WEDNESDAY IS STILL THE TRANSITION DAY...AS THE UPPER LOW AND
SURFACE TROUGH DRIFTS WEST OF THE ISLANDS. THE LATEST MODEL RUNS ARE
A BIT FASTER IN BRINGING BACK THE TRADES...PERHAPS BY WEDNESDAY
MORNING VERSUS THE AFTERNOON.

BIG BUBBLE NO TROUBLE FROM THURSDAY ON THROUGH THE WEEKEND AS HIGH
PRESSURE AT THE SURFACE AND ALOFT LOOKS TO USHER IN MORE ROUTINE
TRADEWIND WEATHER.

&&

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

&&

TANABE