Drought in Hawaii, December 1 to 7, 2010

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST TUE NOV 30 2010

.SYNOPSIS...
TRADE WINDS WILL INCREASE STEADILY INTO THE WEEKEND AS HIGH PRESSURE
BUILDS NORTH OF THE STATE. A FRONT APPROACHING FROM THE NORTH WILL
REACH THE ISLANDS THURSDAY...BRINGING WET WEATHER AND THE
POSSIBILITY OF HEAVY SHOWERS AND ISOLATED THUNDERSTORMS THURSDAY AND
FRIDAY. DRIER WEATHER WILL MOVE IN THIS WEEKEND AS THE FRONT PASSES
TO OUR SOUTH. WITH CONTINUED TRADE FLOW...SHOWERS WILL FAVOR
WINDWARD AND MAUKA AREAS. LEEWARD AREAS WILL ALSO GET WET FROM TIME
TO TIME DURING PERIODS OF STRONG TRADES.

&&

.DISCUSSION...
AN UPPER LOW FAR WEST OF THE ISLANDS CONTINUES TO PROVIDE A STEADY
SUPPLY OF HIGH CLOUDS TO THE 808 STATE THIS EVENING. THE UPPER LOW
WILL REMAIN NEARLY STATIONARY OVER THE NEXT FEW DAYS...WITH HIGH
CLOUDS LIKELY AFFECTING THE ISLANDS DURING THAT TIME...BEFORE
DISSIPATING EARLY FRIDAY.

A 1037 MB HIGH FAR NORTH OF THE STATE WILL DRIFT TO THE SOUTHEAST
TONIGHT AND INTO THE WEEKEND...GRADUALLY STEEPENING THE PRESSURE
GRADIENT ACROSS THE ISLANDS AND CAUSING TRADE WINDS TO INCREASE.
WINDS ARE ALREADY STRONGER THAN THEY WERE 24 HOURS AGO...AND RADAR
SHOWS AN UPTICK IN SHOWER ACTIVITY ACROSS WINDWARD WATERS AS
RESURGING TRADES BRING MORE MOISTURE TO THE AREA. THESE SHOWERS WILL
AFFECT MAINLY WINDWARD AND MAUKA AREAS OF THE ISLANDS AND LAST
THROUGH WEDNESDAY MORNING.

THE HIGH WILL MOVE CLOSER TO THE ISLANDS AS IT SLIDES SOUTHEASTWARD.
AS A RESULT...MODERATE TRADES THIS EVENING WILL CONTINUE TO
INCREASE...BECOMING MODERATE TO FRESH WEDNESDAY...THEN FRESH TO
LOCALLY STRONG BY THURSDAY MORNING. TRADES WILL REMAIN BREEZY
THROUGH THE WEEKEND.

A SURFACE FRONT ABOUT 500 MILES NORTH OF KAUAI WILL BE PUSHED SOUTH
BY THE HIGH AND WILL REACH THE ISLANDS THURSDAY AFTERNOON...BRINGING
ANOTHER ROUND OF WET WEATHER TO THE STATE. A DIGGING UPPER TROUGH
WILL MOVE SOUTHEAST OVER NORTHERN OFFSHORE WATERS LATE THURSDAY
NIGHT THROUGH SATURDAY NIGHT...BEFORE SLOWING EAST OF THE BIG
ISLAND. THIS FEATURE WILL BRING INSTABILITY WITH THE FRONTAL
PASSAGE...MAINLY ON THURSDAY NIGHT AND FRIDAY...AND HEAVY SHOWERS
AND ISOLATED THUNDERSTORMS ARE POSSIBLE. SHOWERS WILL CONTINUE TO
FOCUS OVER WINDWARD AND MOUNTAIN AREAS. SOME SHOWERS WILL BE BLOWN
TO LEEWARD AREAS WITHIN THE BREEZY TRADES.

MODELS SHOW AN UPPER LOW WILL FORM WITHIN THE UPPER TROUGH AS IT
SLOWS TO THE EAST OF THE BIG ISLAND...KEEPING SLIGHTLY UNSTABLE
CONDITIONS OVER THE EASTERN HALF OF THE STATE. HOWEVER...A RATHER
DRY ATMOSPHERE THIS WEEKEND AND INTO EARLY NEXT WEEK WILL KEEP THE
CHANCE OF HEAVY SHOWERS AND THUNDERSTORMS THIS WEEKEND LOW. THE
UPPER LOW MAY BRING WINDIER CONDITIONS TO THE SUMMITS OF
HALEAKALA...MAUNA KEA AND MAUNA LOA.

&&

.AVIATION...
AIRMET TANGO REMAINS POSTED FOR MODERATE TURBULENCE BETWEEN 33000
AND 37000 FEET FOR THE ENTIRE STATE. STRONG SPEED SHEAR AND
DIFFLUENCE ASSOCIATED WITH AN 80 TO 115 KT SUBTROPICAL JET MAX IS
CREATING SOME CHOP FOR HIGH LEVEL TRAFFIC OVER THE AREA. MODERATE
TURBULENCE IS EXPECTED TO DECREASE AFTER MIDNIGHT. LOW LEVEL
TURBULENCE WILL LIKELY OCCUR OVER THE NEXT FEW DAYS AS TRADE WINDS
INCREASE.

&&

.MARINE...
WIND DRIVEN SURF IS EXPECTED TO INCREASE ACROSS EAST FACING SHORES
OF THE ISLANDS STARTING THURSDAY NIGHT...AS FRESH TO LOCALLY STRONG
TRADES IMPACT THE REGION. THESE CONDITIONS WILL LAST THROUGH THE
WEEKEND AS THE BREEZY TRADES CONTINUE. A HIGH SURF ADVISORY FOR EAST
FACING SHORES WILL LIKELY NEED TO BE ISSUED IN THE COMING DAYS FOR
THIS EVENT.

A SMALL...SHORT PERIOD NORTH SWELL WILL ARRIVE TONIGHT. SWELL
HEIGHTS WILL BUILD THROUGH THURSDAY...BUT THE PERIODS WILL REMAIN ON
THE SHORT SIDE.

WITH THE INCREASE IN THE TRADES...A SMALL CRAFT ADVISORY WILL GO
INTO EFFECT TUESDAY MORNING FOR THE TYPICALLY WINDIER COASTAL WATERS
NEAR MAUI AND THE BIG ISLAND. THE OTHER COASTAL WATERS WILL THEN
NEED TO BE ADDED LATER IN THE WEEK AS WINDS CONTINUE TO STRENGTHEN.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FROM 6 AM HST WEDNESDAY UNTIL 6 PM HST THURSDAY
FOR PAILOLO CHANNEL...MAALAEA BAY...ALENUIHAHA CHANNEL AND WATERS
SOUTH OF THE BIG ISLAND.

&&

POWELL