Flash Flood Warning 47, NWS Honolulu, HI

936 
WGHW70 PHFO 120915
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU
1115 PM HST FRI SEP 11 2015

HIC001-120924-
/O.CAN.PHFO.FF.W.0047.000000T0000Z-150912T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HAWAII HI-
1115 PM HST FRI SEP 11 2015

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

RAINFALL HAS STOPPED AND RUNOFF FROM EARLIER DOWNPOURS HAS 
DIMINISHED...THUS THE FLASH FLOOD WARNING IS CANCELLED.

LAT...LON 1936 15589 1959 15597 1965 15603 1973 15606
      1978 15605 1985 15597 1986 15592 2003 15582
      2013 15590 2022 15590 2021 15578 1917 15571
      1915 15592

$$

BIRCHARD

AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 800 PM
HST FRI SEP 11 2015

.SYNOPSIS... A MOIST AIR MASS WILL MAINTAIN THE RISK OF LOCALLY
HEAVY SHOWERS AND THUNDERSTORMS THROUGH SATURDAY. TRADE WINDS WILL
REPLACE THE CURRENT LIGHT AND VARIABLE WINDS BY MONDAY. CLOUDS AND
SHOWERS WILL DIMINISH OVERALL DURING MID-WEEK...BUT ALSO WILL BECOME
MORE FOCUSED ALONG WINDWARD SLOPES. UNSETTLED WEATHER MAY RETURN FOR
NEXT WEEKEND.

&&

.DISCUSSION... AN EXTREMELY MOIST AIR MASS LINGERED OVER THE MAIN
HAWAIIAN ISLANDS...WHILE WEAK TROUGHING ALOFT EXTENDING TOWARD THE
STATE FROM THE NORTHWEST HELPED TO DESTABILIZE THE ATMOSPHERE.
THUNDERSTORMS DEVELOPING SIGNIFICANTLY OVER THE NORTHWEST HALF OF
THE STATE AGREED WELL WITH THIS COMBINATION...BUT THE DEEP
CONVECTION EXTENDED WELL TO THE SOUTH ALONG 160W...SUGGESTING THAT A
PASSING ATMOSPHERIC GRAVITY WAVE ALSO CONTRIBUTED. IF SO...THEN
CONVECTION MAY DIMINISH FAIRLY RAPIDLY OVERNIGHT ONCE THE SUBSIDING
PHASE OF THE WAVE ARRIVES. HOWEVER...THE POTENTIAL FOR HEAVY RAIN
WILL REMAIN AS LONG AS PRECIPITABLE WATER STAYS HIGH.

FROM SUNDAY INTO THE MIDDLE OF THE FORECAST PERIOD...GUIDANCE AGREED
WELL IN PREDICTING THE MID-LEVEL LOW TO DEEPEN SIGNIFICANTLY...BUT
ALSO TO MOVE WEST...LEAVING ROOM FOR A RIDGE ALOFT TO DEVELOP
LOCALLY. THE RIDGE WILL HELP TO SUPPRESS CONVECTION SOMEWHAT...BUT
MORE SIGNIFICANTLY IT WILL SUPPORT THE DEVELOPMENT OF THE
SUBTROPICAL RIDGE AT THE SURFACE...WHICH IN TURN WILL BRING BACK THE
TRADE WINDS. EASTERLIES MAY REACH SOME LOCATIONS AS EARLY AS SUNDAY
EVENING...BUT MOST SOLUTIONS AGREED THAT TRUE NORTHEASTERLY TRADE
WINDS WILL NOT ARRIVE STATEWIDE UNTIL ABOUT NOON ON MONDAY. IN ANY
CASE...A SOMEWHAT DRIER AIR MASS MAY ADVECT IN ON THE TRADES...
ALTHOUGH MODEL SPREAD WAS PRETTY WIDE ON THIS POINT.

SHOWER DEVELOPMENT WILL DIMINISH IN THE MORE STABLE ENVIRONMENT...
THOUGH IT IS UNLIKELY TO DROP BELOW CLIMATOLOGY. WINDWARD SLOPES IN
PARTICULAR WILL CONTINUE TO RECEIVE ACCUMULATION.

A LOW APPROACHING FROM THE WEST MAY BRING ANOTHER PERIOD OF
SOUTHEAST WINDS AND UNSETTLED WEATHER BY NEXT WEEKEND. UNTIL
THEN...TRADE WINDS WILL PERSIST.

&&

.MARINE...STRENGTHENING TRADE WINDS EARLY NEXT WEEK WILL INCREASE
SHORT-PERIOD CHOPPY SURF ALONG EAST-FACING SHORES. BY MONDAY...THE
WINDS ARE EXPECTED TO REACH THE CRITERION FOR A SMALL CRAFT ADVISORY
OVER TYPICALLY WINDY WATERS AROUND MAUI COUNTY AND THE BIG ISLAND. A
SERIES OF SMALL SOUTH SWELLS WILL ARRIVE THROUGH THE FORECAST
PERIOD...BUT SURF HEIGHTS SHOULD REMAIN BELOW ADVISORY LEVELS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH SATURDAY AFTERNOON FOR NIIHAU-KAUAI-OAHU.

&&

RYSHKO

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HONOLULU HI
641 PM HST FRI SEP 11 2015

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0640 PM     FLASH FLOOD      WAIKANE                 21.50N 157.88W
09/11/2015                   HONOLULU           HI   EMERGENCY MNGR

            WAIKANE BRIDGE IS CLOSED DUE TO FLOODING.

&&

HFO