Flash Flood Warning 5, NWS Honolulu, HI

001 
WGHW70 PHFO 180142
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
342 PM HST MON AUG 17 2015

HIC009-180148-
/O.CAN.PHFO.FF.W.0005.000000T0000Z-150818T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MAUI HI-
342 PM HST MON AUG 17 2015

...THE FLASH FLOOD WARNING IS CANCELLED FOR THE ISLAND OF MAUI IN
MAUI COUNTY...

THE HEAVIEST RAINFALL HAS SUBSIDED BUT POCKETS OF MODERATE RAIN ARE 
STILL OCCURRING OVER WINDWARD WEST MAUI AND THE SOUTH-FACING SLOPES 
OF HALEAKALA. 

THIS WARNING WILL BE REPLACED BY A FLOOD ADVISORY FOR THE ISLAND OF 
MAUI IN MAUI COUNTY.

LAT...LON 2099 15677 2086 15645 2089 15599 2060 15594
      2054 15648

$$

KODAMA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1019 AM HST MON AUG 17 2015

.SYNOPSIS...
A TROUGH OF LOW PRESSURE NEAR THE ISLANDS WILL KEEP WINDS RATHER
LIGHT THE NEXT FEW DAYS. TROPICAL HUMIDITY AND DAYTIME SEA BREEZES
WILL GIVE WAY TO LOCALLY HEAVY AFTERNOON SHOWERS OR THUNDERSHOWERS.
THERE WILL ALSO BE THE POSSIBILITY FOR VOG OVER THE SMALLER
ISLANDS THROUGH THE MIDDLE PART OF THE WEEK. THE AIRMASS WILL
STABILIZE AND TRADE WINDS WILL RETURN LATER IN THE WEEK AS THE
TROUGH MOVES AWAY.

&&

.DISCUSSION...
A BROAD AND SLOW MOVING TROUGH OF LOW PRESSURE OVER THE ISLANDS...
COMBINED WITH AN UPPER LOW NEAR 30N 155W...AND DEEP TROPICAL
MOISTURE IN PLACE WILL ALL WORK TOGETHER TO BRING AFTERNOON AND
EVENING SHOWERS OVER THE ISLANDS BOTH TODAY AND TUESDAY. VARIOUS
SENSORS ARE DEPICTING PRECIPITABLE WATER RANGING FROM ABOUT 1.6
INCHES NEAR KAUAI AND OAHU TO NEARLY 2.0 INCHES NEAR THE BIG
ISLAND. MID-LEVEL TEMPERATURES ARE NOT PARTICULARLY COOL...BUT
WITH THAT MUCH MOISTURE THEY ARE SUFFICIENT TO GENERATE SOME
HEFTY BUILDUPS DURING THE DAY TODAY. IN FACT...MID LEVEL HEIGHTS
AND TEMPS ACTUALLY DROP A LITTLE ON TUESDAY AS THE UPPER LOW DRAWS
A LITTLE CLOSER. HAVE ISSUED AN SPS FOR THE LIKLIHOOD OF SOME
AFTERNOON DOWNPOURS AND EVEN A FEW THUNDERSHOWERS AGAIN TODAY AND
ON TUESDAY.

THE LOW LEVEL TROUGH WILL BE WEST OF THE ISLANDS BY WED... AND
THE AXIS OF DEEPEST MOISTURE IS EXPECTED TO SLIDE WESTWARD OVER THE
SMALLER ISLANDS. THE LOW LEVEL FLOW WILL SWITCH TO THE SE AND
S...LEAVING THE SMALLER ISLANDS OPEN TO LOCALLY HEAVY SHOWERS
THAT COULD DEVELOP IN THE LOW LEVEL DOWNWIND CONVERGENCE ZONES.
MAY NEED TO MAKE SOME ADJUSTMENTS TO ADD HEAVY SHOWERS OR THUNDER
TO SOME AREAS AFTER TAKING A CLOSER LOOK AT THE NEWER GUIDANCE.
THIS TRAJECTORY ALSO COMMONLY BRINGS THE KILAUEA VOG PLUME UP OVER
THE SMALLER ISLANDS AS WELL.

THE LOW LEVEL FLOW WILL FINALLY START TO TURN BACK TOWARD EASTERLY
TRADES BY FRIDAY...AND THE AIRMASS MAY DRY OUT SOMEWHAT...THOUGH
GUIDANCE IS NOT EXACTLY OPTIMISTIC WITH THAT.

THE COMPUTER MODELS REMAIN FAIRLY BULLISH ABOUT DEVELOPING A
TROPICAL CYCLONE IN THE MONSOON TROUGH FAR TO THE SE OF THE
ISLANDS. SEE THE LATEST TROPICAL WEATHER OUTLOOKS FROM THE CENTRAL
PACIFIC HURRICANE CENTER FOR THE LATEST ON THIS DISTURBANCE. AS
FAR AS LOCAL EFFECTS GO...THIS IS CLIMATOLOGICALLY AN AREA OF
SOME CONCERN FOR THE ALOHA STATE. HOWEVER...BY THE WEEKEND...THERE
IS A SPREAD OF OVER 600 MILES AMONG THE VARIOUS MODELS IN WHERE
THIS FUTURE SYSTEM WOULD BE IF IT DEVELOPS. ALSO...THE MODELS
HAVE AN ESPECIALLY DIFFICULT TIME WITH THE TRACKS OF TROPICAL
CYCLONES THAT HAVE NOT YET DEVELOPED...AS WELL AS WITH THE VARIOUS
FACTORS THAT STEER THEM IN THE LONG RANGE. WE WILL KEEP A CLOSE
EYE ON THIS AREA IN THE COMING DAYS AND SHOULD GET A BETTER IDEA
OF WHAT WILL ACTUALLY HAPPEN AS TIME GOES ON.

&&

.AVIATION...
A TROUGH OF LOW PRESSURE WILL REMAIN IN PLACE OVER THE ISLANDS
THROUGH TONIGHT. THIS WILL KEEP A LIGHT WIND REGIME IN PLACE...WITH
DAYTIME SEA BREEZES AND OVERNIGHT LAND BREEZES EXPECTED IN MOST
AREAS. SHOWERS WILL DEVELOP OVER THE ISLANDS BY LATE MORNING/EARLY
AFTERNOON...WITH LOCALIZED +SHRA AND EVEN A FEW TSRA POSSIBLE.
WILL HANDLE WITH VCSH IN THE TAFS FOR NOW AND AMEND AS IT BECOMES
MORE CLEAR THAT CONDITIONS COULD IMPACT A PARTICULAR TERMINAL.
SHRA/TSRA ARE EXPECTED TO END IN THE EVENING...WITH VFR CONDITIONS
PREVAILING OVERNIGHT.

NO AIRMETS ARE CURRENTLY IN EFFECT. AIRMET SIERRA MAY BE NEEDED AT
SOME POINT THIS AFTERNOON AS SHRA/TSRA DEVELOP OVER THE ISLANDS.

&&

.MARINE...
WITH WINDS REMAINING LIGHT...RELATIVELY QUIET MARINE CONDITIONS
ARE EXPECTED FOR THE NEXT SEVERAL DAYS. THE GUIDANCE ALSO DOES NOT
SHOW ANY SIGNIFICANT SWELLS. THERE MAY BE SOME HEAVIER SHOWERS OR
THUNDERSHOWERS OVER SOME OF THE COASTAL WATERS ZONES STARTING
LATE TODAY OR TONIGHT...AND CONTINUING THROUGH WED.

&&

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

&&

DISCUSSION/MARINE...R BALLARD
AVIATION...JELSEMA/R BALLARD

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
902 AM HST MON AUG 17 2015

HIZ001>028-180215-
NIIHAU-KAUAI WINDWARD-KAUAI LEEWARD-KAUAI MOUNTAINS-
OAHU SOUTH SHORE-WAIANAE COAST-OAHU NORTH SHORE-OAHU KOOLAU-
OLOMANA-CENTRAL OAHU-WAIANAE MOUNTAINS-MOLOKAI WINDWARD-
MOLOKAI LEEWARD-LANAI MAKAI-LANAI MAUKA-KAHOOLAWE-
MAUI WINDWARD WEST-MAUI LEEWARD WEST-MAUI CENTRAL VALLEY-
WINDWARD HALEAKALA-LEEWARD HALEAKALA-HALEAKALA SUMMIT-KONA-
SOUTH BIG ISLAND-BIG ISLAND NORTH AND EAST-KOHALA-
BIG ISLAND INTERIOR-BIG ISLAND SUMMITS-
902 AM HST MON AUG 17 2015

...LOCALLY HEAVY DOWNPOURS EXPECTED BOTH MONDAY AND TUESDAY
AFTERNOONS OVER ISLAND INTERIORS...

SUNSHINE THIS MORNING HEATING THE VERY MOIST AIRMASS OVER THE
ISLANDS WILL CAUSE LOCALIZED HEAVY DOWNPOURS THAT WILL START OVER
THE INTERIORS EARLY THIS AFTERNOON.

THESE SHOWERS MAY AFFECT THE RUSH HOUR AS THEY START SPREADING
TOWARD THE SHORES DURING THE MID TO LATE AFTERNOON. RAINFALL RATES
OF 2 TO 3 INCHES PER HOUR AND LIGHTNING STRIKES WILL BE POSSIBLE
IN AND NEAR THE STRONGEST ACTIVITY. MOTORISTS MAY ENCOUNTER
SIGNIFICANT PONDING OF WATER IN LOW LYING AND POOR DRAINAGE
AREAS...AND AREAS OF LOW VISIBILITY IN HEAVY RAIN.

THE SHOWERS WILL TEND TO SPREAD OFFSHORE THIS EVENING BEFORE
DIMINISHING. A SIMILAR WEATHER CYCLE WITH LOCALIZED AFTERNOON
DOWNPOURS IS EXPECTED OCCUR OVER THE ISLANDS ON TUESDAY.

R BALLARD