FXHW60 PHFO 110651
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST THU DEC 10 2009
.SYNOPSIS...
MOSTLY DRY WEATHER IS EXPECTED TO CONTINUE INTO THE WEEKEND SINCE
THE SURFACE RIDGE...PRESENTLY JUST NORTH OF THE ISLANDS...WILL MOVE
BACK OVER US. TRADE WINDS WILL BE MODERATE OM STRENGTH ON FRIDAY
BUT WILL WEAKEN AND BECOME LIGHT AND VARIABLE THROUGH THE WEEKEND.
A WEAKENING COLD FRONT MAY REACH KAUAI MONDAY AND STALL.
&&
.DISCUSSION...
SATELLITE IMAGERY REVEALS ALMOST NO CLOUDS OVER THE LAND AREAS OF
THE MAIN HAWAIIAN ISLANDS. DESPITE SCATTERED CLOUD COVER OVER THE
OCEAN THESE ARE ONLY SHALLOW FAIR WEATHER CUMULUS WITH LITTLE
VERTICAL DEVELOPMENT. IN THIS RELATIVELY DRY AIR MASS ALMOST NO
SHOWER ACTIVITY WILL OCCUR. THERE IS A VERY LOW LEVEL TEMPERATURE
INVERSION...NEAR 3000 FEET...AND PRECIPITABLE WATER IS STILL NEAR 1
INCH. A FEW WEAK SHOWERS MAY AFFECT THE WINDWARD BIG ISLAND TONIGHT
BUT ANOTHER MOSTLY SUNNY IS EXPECTED THERE FRIDAY.
A FRONT ABOUT 300 MILES NORTH WILL SHIFT FARTHER NORTH AS IT IS
DRAWN INTO THE CIRCULATION OF A DEVELOPING LOW THAT IS MOVING INTO
THE NORTHEAST PACIFIC. THE MODERATE TRADE WINDS WILL END SATURDAY
WHEN THE SURFACE RIDGE MOVES BACK JUST NORTH OF THE ISLANDS ON
SATURDAY AND THEN OVER THE ISLANDS SUNDAY. THIS SPELLS THE RETURN
OF VARIABLE WINDS AND THE ALTERNATION OF DAYTIME SEA BREEZES AND
NIGHTTIME LAND BREEZES. PLEASANT SUNNY WEATHER IS EXPECTED.
AFTERNOON SHOWERS WILL BE INSIGNIFICANT DESPITE SOME AFTERNOON CLOUD
FORMATION FROM SEA BREEZE CONVERGENCE AND AFTERNOON HEATING OF THE
LAND.
COMPUTER MODELS AGREE ON DEVELOPING A SIGNIFICANT LOW OVER THE
NORTHEAST PACIFIC THIS WEEKEND BUT STILL HAVE DIFFERENCES IN THE
TIMING OF TWO COLD FRONTS. THERE IS SOME MOISTURE EXPECTED FROM THE
FIRST FRONT STALLING JUST AS IT REACHES KAUAI MONDAY...ALTHOUGH THE
EUROPEAN MODEL SUGGESTS SLIGHTLY MORE MOISTURE AS IT STALLS.
THE MORE SIGNIFICANT FRONT IS THE SECOND ONE. THE PREVIOUS EUROPEAN
MODEL AND THE GFS BOTH BRING IT UP TO THE ISLANDS WEDNESDAY BUT THE
EUROPEAN MODEL PUSHES IT THROUGH MORE RAPIDLY WHEREAS THE NEW GFS
DEVELOPS A LOW WEDNESDAY JUST NORTHWEST OF THE ISLANDS AND
DEPICTS A WETTER FRONTAL EVENT.
&&
.HFO WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
HOAG
