Drought in Hawaii, February 1 to 28, 2013

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST THU JAN 31 2013

.SYNOPSIS...
WINDWARD SHOWERS WILL PERSIST OVER MAUI AND THE BIG ISLAND
OVERNIGHT...BUT SHOWER INTENSITY SHOULD DECREASE. TRADES WILL SPREAD
ACROSS THE ISLANDS FRIDAY...AND REMAIN IN PLACE FOR MUCH OF
SATURDAY. EXPECT THE WINDS TO WEAKEN AGAIN LATE SATURDAY...ALLOWING
LAND AND SEA BREEZES TO FINISH THE WEEKEND. TRADES ARE EXPECTED TO
BUILD BACK IN ON MONDAY...WITH TYPICAL TRADE WINDS SHOWERS FAVORING
WINDWARD AND MAUKA AREAS.

&&

.DISCUSSION...
SHOWERS PERSIST OVER THE WINDWARD AREAS OF MAUI...AND THE WINDWARD
SLOPES OF THE KOHALA MOUNTAINS ON THE BIG ISLAND. THESE SHOWERS ARE
CONTINUING TO MOVE AT A BRISK PACE OVER THE AREA. WITH LIMITED
MOISTURE UPSTREAM OF THE ISLANDS...ANTICIPATE THE SHOWER INTENSITIES
TO DECREASE AS THE NIGHT WEARS ON.

LOW CLOUD MOTION NEAR THE ISLANDS AND THE OBSERVATIONS FROM AROUND
THE STATE SHOW TRADE WINDS HAVE SET UP ACROSS THE ISLAND...AND THE
TRADES SHOULD PERSIST THROUGH MUCH OF SATURDAY AS THE HIGH PRESSURE
NORTH OF THE ISLANDS MOVES TO THE EAST. BY SATURDAY AFTERNOON...THE
HIGH PRESSURE RIDGE WILL BECOME DISRUPTED BY A COLD FRONT NORTHWEST
OF THE ISLANDS. THE MODELS ARE IN GOOD AGREEMENT THAT THE FRONT WILL
REMAIN NORTH OF THE ISLANDS...AND BE QUICKLY REPLACED BY THE NEXT
HIGH PRESSURE BUILDING IN NORTHWEST OF THE ISLANDS. AS SUCH...WINDS
WILL BRIEFLY WEAKEN LATE SATURDAY AND SUNDAY. THIS WILL LEAD TO SOME
LOCAL LAND AND SEA BREEZES TO END THE WEEKEND.

LIMITED TRADE WINDS SHOWERS ARE ANTICIPATED FRIDAY AND SATURDAY AS
THERE IS LIMITED LOW LEVEL MOISTURE UPSTREAM OF THE MAIN HAWAIIAN
ISLANDS. SOME LEFT OVER MOISTURE FROM THE TROUGH THAT PASSED THROUGH
THE ISLANDS EARLIER IN THE WEEK IS EXPECTED TO PASS SOUTH OF THE BIG
ISLAND THROUGH THE WEEKEND.

AS THE TRADES BRIEFLY SHUT DOWN...LOOK FOR CLOUDS TO FORM OVER THE
INTERIOR OF THE ISLANDS SUNDAY AFTERNOON...BUT CLEAR OUT SUNDAY
NIGHT. BY MONDAY MORNING...THE GFS AND ECMWF HAVE THE NEW 1030 MB
HIGH NEAR 30 NORTH...NORTH OF THE ISLANDS...AND SLOWS ITS EASTWARD
MOVEMENT. WITH THE SLOWING OF THE EASTWARD MOVEMENT...THE HIGH WILL
REMAIN THE DOMINANT FEATURE FOR MOST OF THE WEEK.

THE GFS BRINGS THE SOUTHERN END OF ANOTHER COLD FRONT NEAR THE
ISLANDS NEXT FRIDAY...AND THIS IS WHERE THE ECMWF AND GFS START TO
DIVERGE IN THEIR HANDLING OF THE WEATHER SITUATION. STILL HAVE
SEVERAL RUNS TO SEE HOW THE SITUATION PANS OUT.

&&

.MARINE...
A LONG PERIOD NW SWELL IS CURRENTLY BUILDING ACROSS HAWAIIAN
WATERS...WITH THE RESULTANT SURF EXPECTED TO EXCEED WARNING LEVEL
HEIGHTS ALONG N AND W FACING SHORES OF MANY ISLANDS OVERNIGHT AND
FRIDAY. THE SWELL IS EXPECTED TO PEAK EARLY FRIDAY BEFORE DROPPING
RATHER QUICKLY BY LATE FRIDAY. THIS SWELL WILL ALSO RESULT IN SURF
EXCEEDING ADVISORY LEVELS ALONG W FACING SHORES OF THE BIG ISLAND.

THE SWELL WILL ALSO BRING SEAS IN EXCESS OF 10 FEET...WHICH HAS
PROMPTED THE ISSUANCE OF A SMALL CRAFT ADVISORY /SCA/ FOR ALL
HAWAIIAN WATERS EXCEPT MAALAEA BAY. TRADE WINDS INCREASING ON
FRIDAY WILL LEAD TO WIND SPEEDS NEAR 25 KT IN THE WINDIER ZONES
AROUND MAUI AND THE BIG ISLAND ON FRIDAY...AND MAALAEA BAY WILL JOIN
THE SCA EARLY FRIDAY. WITH WINDS AND SEAS EXPECTED TO DIMINISH OVER
THE WEEKEND...SCA CONDITIONS ARE NOT EXPECTED UNTIL EARLY NEXT
WEEK...WHEN TRADE WINDS ARE EXPECTED TO INCREASE.

&&

.AVIATION...
LOW CLOUDS AND SHOWERS CONTINUE TO AFFECT PORTIONS OF MAUI COUNTY
AND THE BIG ISLAND EARLY THIS EVENING. OCCASIONAL MVFR CEILINGS AND
VISIBILITIES IN SHOWERS WILL BE FOCUSED MAINLY ALONG WINDWARD FACING
SLOPES THIS EVENING. AS A RESULT...AIRMET SIERRA FOR MOUNTAIN
OBSCURATION ON MAUI AND MOLOKAI IS EXPECTED TO CONTINUE THROUGH THIS
EVENING. THE AIRMET FOR MOUNTAIN OBSCURATION ALONG THE WINDWARD BIG
ISLAND MAY ALSO NEED TO BE EXTENDED BEYOND 0800 UTC. CONDITIONS WILL
LIKELY IMPROVE LATER TONIGHT OR EARLY FRIDAY MORNING AS THESE LOW
CLOUDS AND SHOWERS EVENTUALLY PUSH WEST AND SOUTHWEST OF THE STATE.

HIGH PRESSURE BUILDING NORTH OF THE STATE HAS ALREADY INCREASED
WINDS ACROSS THE ISLANDS. SURFACE WIND OBSERVATIONS AND THE VAD WIND
PROFILES ARE ALREADY SHOWING STRONGER LOW-LEVEL NORTHEASTERLY
WINDS...SO AIRMET TANGO FOR TEMPO MODERATE TURBULENCE IN THE AIR
SPACE BELOW 8 KFT LEEWARD OF THE MOUNTAINS ON ALL ISLANDS WAS
ISSUED EARLIER THIS EVENING. THIS AIRMET WILL LIKELY CONTINUE
THROUGH THE DAY ON FRIDAY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING UNTIL 6 PM HST FRIDAY FOR THE NORTH AND WEST
FACING SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI...AND THE NORTH
FACING SHORES OF MAUI.

HIGH SURF ADVISORY UNTIL 6 PM FRIDAY FOR WEST FACING SHORES OF THE
BIG ISLAND.

SMALL CRAFT ADVISORY UNTIL 6 PM HST FRIDAY FOR ALL HAWAIIAN
WATERS...EXCEPT MAALAEA BAY.

SMALL CRAFT ADVISORY FROM 4 AM TO 6 PM HST FRIDAY FOR MAALAEA
BAY.

&&

DISCUSSION/MARINE...M BALLARD
AVIATION...HOUSTON
MBALLARD