Funnel Cloud in Hawaii, May 31, 2005

HAWAIIAN ISLANDS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 PM HST TUE MAY 31 2005

.SYNOPSIS...
A RIDGE OF HIGH PRESSURE NORTH OF THE STATE...WILL KEEP TRADE WINDS
IN THE LIGHT TO MODERATE RANGE INTO THE FORESEEABLE FUTURE. CLOUDS
AND SHOWERS WILL FAVOR WINDWARD AND MAUKA AREAS...WITH MOST LEEWARD
AREAS EXPERIENCING PLENTY OF SUNSHINE...AND MOSTLY CLEAR SKIES.
LEEWARD AREAS OF THE BIG ISLAND...WILL EXPERIENCE AFTERNOON AND
EVENING CLOUDS...WITH SOME SHOWERS ACCOMPANYING THEM.

&&

.DISCUSSION...
AT THE SURFACE...A 1029 MILLIBAR HIGH IS PRESENTLY LOCATED FAR TO
THE NORTHEAST OF THE ISLANDS. ITS ASSOCIATED SURFACE RIDGE EXTENDS
SOUTHEASTWARD FROM THE HIGH WITH ITS AXIS LOCATED ABOUT 425 MILES
NORTH OF THE ISLANDS. THIS HIGH IS FORECAST TO DRIFT TOWARD THE
NORTH NORTHWEST OVER THE NEXT SEVERAL DAYS AND STRENGTHEN TO A 1032
MILLIBAR HIGH OVER THE WEEKEND. AT THAT TIME THE HIGH WILL BE
LOCATED FAR TO OUR NORTH NORTHEAST WITH LITTLE CHANGE IN THE
PRESSURE GRADIENT IN THE VICINITY OF THE THE ISLANDS. THUS OUR TRADE
WINDS WILL REMAIN IN THE LIGHT TO MODERATE RANGE THROUGH THE
FORECAST PERIOD.

IN THE UPPER LEVELS OF THE ATMOSPHERE...AN UPPER LOW IS PRESENTLY
LOCATED NORTH OF KAUAI. THIS UPPER LOW IS MOVING TOWARD THE NORTH
NORTHEAST AT ABOUT 35 MPH AND IS FORECAST TO EXIT OUR VICINITY LATER
TODAY. ITS ASSOCIATED SWATH OF HIGH CIRRUS CLOUDS...THAT HAVE BEEN
RIDING UP ON THE EASTERN SIDE OF THE LOW ARE SLOWLY LEAVING THE
ISLANDS SKIES. THE WESTERN EDGE OF THE HIGH CLOUDS IS PRESENTLY OVER
THE BIG ISLAND BUT ON THERE CURRENT TRAJECTORY...THEY SHOULD BE GONE
BY LATER TODAY AS WELL. JUST AS THIS UPPER LOW DEPARTS...ANOTHER
UPPER LOW WILL DROP DOWN FROM THE NORTHWEST AND TAKE UP A POSITION
NORTHWEST OF THE STATE. IT SHOULD REMAIN FAR ENOUGH AWAY FROM THE
STATE TO NOT HAVE MUCH OF A DESTABILIZING EFFECT. THE GFS MODEL
SHOWS THE LOW REMAINING FAR ENOUGH NORTH THAT IT WILL NOT BE ABLE TO
TAP INTO UPPER LEVEL MOISTURE ORIGINATING DOWN IN THE ITCZ. SO THERE
SHOULD NOT BE MUCH IN THE WAY OF HIGH CLOUDS OVER THE ISLANDS.

AS FAR AS RAINFALL GOES...THE SHOWERS THAT AFFECTED SOUTH AND WEST
OAHU TODAY WERE THE RESULT OF THE SURFACE FLOW BEING SLIGHTLY SOUTH
OF DUE EAST ALLOWING THE MOLOKAI PLUME TO MOVE OVER PARTS OF OAHU
CAUSING BRIEF SCATTERED SHOWERS FOR VARIES LOCATIONS. UPWIND OF THE
ISLANDS LIES A BROAD FIELD OF BROKEN STRATOCUMULUS CLOUDS THAT ARE
MOVING TOWARD THE ISLANDS IN THE TRADE WIND FLOW. THUS A CONTINUANCE
OF SCATTERED WINDWARD AND MAUKA SHOWERS IS EXPECTED LIKELY FAVORING
CLIMATOLOGICAL NIGHT AND EARLY MORNING SHOWERS. SHOWERS SHOULD BE
LIGHT AND BRIEF WITH JUST ISOLATED MODERATE SHOWERS EXPECTED.
DAYTIME HEATING OF THE LEEWARD SLOPES ON THE BIG ISLAND WILL CAUSE
AFTERNOON AND EVENING CLOUDINESS WITH ISOLATED SHOWERS EXPECTED
THERE AS WELL.

&&

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

&&

BURKE