Drought in Hawaii, December 1 to 31, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST FRI NOV 30 2012

.SYNOPSIS...
LIGHT SOUTHERLY WINDS WILL CONTINUE OVERNIGHT. A COLD FRONT
APPROACHING FROM THE NORTHWEST WILL BRING AN INCREASE IN SHOWERS
OVER KAUAI AND OAHU SATURDAY...WITH AN INCREASE IN SHOWER ACTIVITY
ALSO EXPECTED OVER THE REMAINING ISLANDS BY SUNDAY MORNING. THE
INCREASE SHOWER ACTIVITY WILL CARRY INTO THE MIDDLE PART OF THE WEEK.

&&

.DISCUSSION...
THE MODELS REMAIN IN GOOD AGREEMENT WITH THE HANDLING OF THE WEATHER
SYSTEMS INTO THE MIDDLE OF THE WEEK. THE ECMWF IS A TOUCH WETTER AND
MORE UNSTABLE THAN THE GFS.

THE COMPLEX LOW PRESSURE SYSTEMS FAR NORTHWEST OF THE ISLANDS ARE
EXPECTED TO MERGE INTO ONE MAIN AREA ON SUNDAY. A COLD FRONT
CURRENTLY ASSOCIATED WITH THE SYSTEM WILL BE EDGING CLOSER TO THE
MAIN HAWAIIAN ISLANDS SATURDAY NIGHT...AND WE ARE EXPECTING AN
INCREASE IN SHOWERS OVER KAUAI AND OAHU AS A RESULT. THESE AREAS ARE
ALSO THE MOST PRONE TO SOME LOCALLY HEAVY RAINFALL DURING SATURDAY
NIGHT AND SUNDAY. A BLENDING OF THE MODELS SHOW PRECIPITABLE WATER
/PW/ VALUES EXCEEDING 1.50 INCHES ACROSS THE STATE SATURDAY
NIGHT...WHICH IS WELL ABOVE NORMAL FOR THIS TIME OF YEAR. COMBINED
WITH NEAR NORMAL 500 MB TEMPERATURES AND IT WON/T TAKE MUCH FOR
HEAVY SHOWERS TO FORM. A LOOK AT THE LATEST MODEL RUNS SHOWS AN
INCREASE IN MOISTURE NEAR THE BIG ISLAND AS WELL. WE DON/T CURRENTLY
HAVE MAUI COUNTY OR THE BIG ISLAND SLATED FOR ANY HEAVY RAIN...BUT
WE DO HAVE INCREASED POPS IN PLACE. WILL NEED TO CONTINUE TO EXAMINE
THOSE AREAS FOR HEAVY RAIN POTENTIAL.

THE BLENDED MODEL PW SHOWS VALUES DROPPING A BIT ON MONDAY ACROSS
THE STATE. STILL PLENTY OF MOISTURE TO BRING SHOWERS TO STATE...BUT
IT LOOKS LIKE A BRIEF REPRIEVE FROM HEAVY SHOWER ACTIVITY FOR THE
DAY. PW VALUES GET ANOTHER UPTICK MONDAY NIGHT THROUGH TUESDAY
NIGHT...WITH INCREASED INSTABILITY. ONCE AGAIN HAVE HEAVY RAIN IN
THE FORECAST FOR KAUAI AND OAHU...BUT MIGHT NEED TO EXPAND IT TO THE
OTHER ISLANDS BASED ON FUTURE MODEL RUNS. THE INSTABILITY OVER THE
ISLANDS DURING THIS PERIOD DOES RAISE THE CHANCE FOR THUNDERSTORM
ACTIVITY. CURRENTLY WE HAVE THE SLIGHT CHANCE OVER KAUAI AND
OAHU...BUT AS WITH THE HEAVY RAIN CHANCE...IT MAY NEED TO BE
EXPANDED.

&&

.MARINE...
THE LONG PERIOD NORTH SWELL IS ON THE DECLINE...WITH SURF FALLING
BELOW ADVISORY LEVELS BY TOMORROW MORNING. THE IMPACT ON THE HARBORS
WITH A NORTH EXPOSURE BY THIS SWELL SHOULD BE ON THE DECREASE AS
WELL...WITH A RETURN TO MORE TYPICAL CONDITIONS BY MORNING.

&&

.AVIATION...
VFR CONDITIONS WILL PREVAIL ACROSS MOST OF THE AREA INTO SATURDAY.
THE EXCEPTION IS ACROSS INTERIOR SECTIONS OF THE ISLANDS SATURDAY
AFTERNOON...WHERE MVFR CEILINGS ARE POSSIBLE IN CLOUD BUILDUPS ALONG
SEA BREEZES. AN INCREASE IN CLOUDS AND SHOWER ACTIVITY SATURDAY
NIGHT WILL BRING SOME MVFR CONDITIONS PARTICULARLY TO KAUAI AND OAHU
SATURDAY NIGHT.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY UNTIL 6 AM HST SATURDAY FOR NIIHAU-KAUAI
WINDWARD-KAUAI LEEWARD-OAHU NORTH SHORE-OAHU KOOLAU-OLOMANA-MOLOKAI-
MAUI WINDWARD WEST-MAUI CENTRAL VALLEY-WINDWARD HALEAKALA-BIG
ISLAND NORTH AND EAST.
&&