Wildfire in Hawaii, June 4 to 6, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
825 AM HST MON JUN 4 2007

.SYNOPSIS...CLOUDS AND SHOWERS ASSOCIATED WITH A SHEAR LINE ARE
AFFECTING KAUAI AND OAHU...AND ARE EXPECTED TO DO SO INTO TUESDAY.
MOST OF THE LIGHT RAIN WILL FALL OVER WINDWARD AREAS...BUT SOME
SPRINKLES WILL SPREAD LEEWARD AS WELL. DRY CONDITIONS WILL PREVAIL
OVER THE BIG ISLAND...WHILE A FEW SHOWERS WILL MOVE OVER WINDWARD
MAUI. CLOUDS ASSOCIATED WITH THE SHEAR LINE WILL MOVE AWAY FROM THE
ISLANDS BY TUESDAY NIGHT...AND MODERATE TRADE WINDS WILL CONTINUE
THROUGH THE WEEK.

&&

.UPDATE...HAVE UPDATED TODAY FORECASTS TO INCREASE POPS AND SKY
COVER OVER KAUAI AND OAHU...AS SHOWERY LOW CLOUDS ASSOCIATED WITH A
SHEAR LINE ARE MOVING OVER THESE ISLANDS FROM THE EAST. HAVE ALSO
REMOVED MENTION OF RAIN FOR THE WINDWARD SIDE OF THE BIG
ISLAND...BUT STILL MAINTAIN A CHANCE OF AFTERNOON SHOWERS ON THE
KONA SLOPES.

&&
.DISCUSSION...SHOWERY LOW CLOUDS ASSOCIATED WITH A SHEAR LINE ARE
MOVING OVER KAUAI OAHU AND LIMITED PORTIONS OF MAUI COUNTY THIS
MORNING...WHILE THE PARCHED BIG ISLAND REMAINS SOUTH OF THE MOISTURE
AXIS. THE SHEAR LINE WAS PUSHED SOUTHWARD BY A HIGH THAT HAD BEEN
BUILDING TO THE NORTHWEST OF THE ISLANDS YESTERDAY...BUT IS NOW
PASSING NORTH OF THE ISLANDS...ON ITS WAY TO THE NORTHEAST PACIFIC.

THE HIGH/S CURRENT POSITION AND MOVEMENT MEAN THAT THE MOISTURE
ASSOCIATED WITH THE SHEAR LINE WILL MAKE VERY LITTLE FURTHER
PROGRESS TO THE SOUTH...AS THE LOW-LEVEL FLOW BECOMES INCREASINGLY
PARALLEL TO THE ORIENTATION OF THE SHEAR LINE. THIS WOULD LEAD TO
DECREASING SHEAR ACROSS THE BOUNDARY...INHIBITING ITS ABILITY TO
MAINTAIN ITS IDENTITY...BUT NUMERICAL GUIDANCE HAS BEEN FAIRLY
CONSISTENT IN SAYING THAT MOISTURE ASSOCIATED WITH THIS BOUNDARY
WILL LINGER NEAR KAUAI AND OAHU THROUGH THE EARLY MORNING ON
TUESDAY...BEFORE THE BULK OF IT LIFTS NORTH OF KAUAI TUESDAY
AFTERNOON. INTERESTINGLY...BUT MAYBE NOT BELIEVABLY...THE GFS BRINGS
ANOTHER ROUND OF LOW LEVEL MOISTURE OVER THE ISLANDS FROM THE EAST
ON THURSDAY AND THURSDAY NIGHT.

THE CENTER OF THE SURFACE HIGH NOW NORTH OF THE ISLANDS WILL MOVE
SLOWLY EASTWARD TO A POSITION FAR NORTHEAST OF THE ISLANDS FROM
TUESDAY THROUGH FRIDAY...MAINTAINING MODERATE TRADE WINDS. THE HIGH
STRENGTHENS NEXT WEEKEND...BUT DEEP LAYER TROUGHING FAR TO OUR
NORTHWEST IS EXPECTED TO RESULT IN A SOUTHWARD DISPLACED RIDGE...
WITH A SOUTHEAST COMPONENT TO THE LOW LEVEL FLOW NEAR THE ISLANDS.
THIS WOULD KEEP FRESH ESE TRADES OVER WINDWARD WATERS...BUT LIGHTER
ESE WINDS OVER THE ISLANDS AND LEEWARD WATERS AS THE BIG ISLAND
DISRUPTS THE FLOW TO ITS LEE.

RIDGING ALOFT IS FORECAST TO WEAKEN AS THE UPPER LEVEL FLOW SHIFTS
LATER IN THE WEEK. A TROPICAL UPPER TROPOSPHERIC TROUGH /TUTT/ IS
FORECAST TO DEVELOP WITH ITS TYPICAL EAST-NORTHEAST TO WEST-
SOUTHWEST ORIENTATION BETWEEN HAWAII AND THE U.S. WEST COAST BY MID
WEEK. A TUTT LOW...OR A COLD-CORE LOW ALOFT...IS FORECAST TO
DEVELOP NEAR THE BIG ISLAND ON THURSDAY...AND THEN LINGER IN THE
AREA THROUGH NEXT WEEKEND. A MID LEVEL REFLECTION IS INDICATED NEAR
THE ISLANDS BY THE GFS ON THURSDAY...AND HENCE THE SECOND ROUND OF
MOISTURE MENTIONED ABOVE. WILL NOT MAKE BIG CHANGES TO POP FORECASTS
AT THIS TIME...BUT IT SEEMS SAFE TO SAY THAT OUR RECENT BOUT OF
STRONG SUBSIDENCE WILL END...WHICH SHOULD ALLOW FOR A RETURN TO AT
LEAST NORMAL TRADE WIND SHOWER COVERAGE TO ALL ISLANDS.

THE BUILDING HIGH TO OUR NORTH WILL BRING BREEZY CONDITIONS TO THE
HALEAKALA SUMMIT...BUT NOT THE BIG ISLAND SUMMITS...TUESDAY THROUGH
WEDNESDAY. WHETHER OR NOT ADVISORY CRITERIA WILL BE EXCEEDED REMAINS
TO BE SEEN...BUT CURRENT FORECAST HAS WINDS NEAR ADVISORY LEVELS.

&&

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

&&

BIRCHARD