Flash Flood Warning 24, NWS Honolulu, HI

540 
WGHW70 PHFO 241325
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
325 AM HST MON AUG 24 2015

HIC003-241545-
/O.CON.PHFO.FF.W.0024.000000T0000Z-150824T1545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HONOLULU HI-
325 AM HST MON AUG 24 2015

...A FLASH FLOOD WARNING REMAINS IN EFFECT FOR THE ISLAND OF OAHU IN
HONOLULU COUNTY UNTIL 545 AM HST...

VERY INTENSE RAIN CONTINUES OVER EAST OAHU...INCLUDING THE HONOLULU 
METRO AREA. RADAR ESTIMATES INDICATE TOTALS RANGING FROM 4 TO 6 
INCHES FROM KAHALA TO ALA MOANA OVER THE PAST HOUR. CIVIL DEFENSE IS 
REPORTING STANDING WATER UP TO VEHICLE DOORS FROM ALA MOANA TO 
KAIMUKI. ADDITIONAL ACCUMULATIONS UP TO 1 TO 3 INCHES WILL REMAIN 
POSSIBLE IN THE WARNED AREA OVER THE NEXT COUPLE OF HOURS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS FLASH FLOODING IS IMMINENT OR OCCURRING
IN STREAMS...ROADS AND LOW LYING AREAS. MOVE TO HIGHER GROUND NOW.

DO NOT CROSS FAST FLOWING OR RISING WATER IN YOUR VEHICLE OR ON FOOT.
TURN AROUND...DON/T DROWN.

&&

THIS WARNING MAY NEED TO BE EXTENDED BEYOND 545 AM HST IF FLASH
FLOODING PERSISTS.

LAT...LON 2142 15774 2130 15764 2126 15770 2125 15782
      2132 15796

$$

85-GIBBS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1015 AM HST MON AUG 24 2015

.UPDATE...FORECAST UPDATED FOR SEVERE THUNDERSTORM WATCH 1 FOR OAHU
AND MAUI COUNTY. A LARGE MCS WAS ABOUT TO ENTER THE NORTHEAST
COASTAL WATERS FROM THE OFFSHORE WATERS. THIS RAPIDLY MOVING MASS OF
THUNDERSTORMS WAS TOO FAR AWAY FOR RADAR TO ANALYZE IT IDEALLY...BUT
SHOWED SIGNS OF MERGING CELLS IN SATELLITE IMAGES...AND TREMENDOUS
AMOUNTS OF ELECTRICAL ACTIVITY IN LIGHTNING DETECTION DATA.

&&

.SYNOPSIS...
AN EXTREMELY MOIST AIR MASS OVER THE STATE...TOGETHER WITH LOW
PRESSURE IN THE MIDDLE ATMOSPHERE TO THE NORTH...RAISED THE THREAT
OF HEAVY RAIN AND THUNDERSTORMS ACROSS THE MAIN HAWAIIAN ISLANDS
THROUGH THE EARLY PART OF THE WEEK. LIGHT SOUTHEAST WINDS WILL
STRENGTHEN AND BECOME MORE EASTERLY SLOWLY THROUGH THE WEEK. ANOTHER
PERIOD OF UNSETTLED WEATHER MAY OCCUR NEXT WEEKEND. ALTHOUGH THE
LATEST FORECAST FROM THE CENTRAL PACIFIC HURRICANE CENTER KEEPS THE
CENTER OF KILO SEVERAL HUNDRED MILES WEST OF KAUAI LATER THIS
WEEK...YOU SHOULD CONTINUE TO MONITOR THE LATEST FORECASTS FOR
POTENTIAL CHANGES.

&&

.PREV DISCUSSION 830 PM...
ALTHOUGH TROPICAL CYCLONE KILO REMAINED WELL TO THE SOUTHWEST OF THE
MAIN HAWAIIAN ISLANDS...SOUTH TO SOUTHEAST WINDS TO ITS NORTHEAST
CONTINUED TO SPREAD AN EXTREMELY MOIST AIR MASS OVER THEM. AT THE
SAME TIME...BROAD BUT SHALLOW TROUGHING ALOFT TO THE NORTH OF THE
STATE HELPED TO DESTABILIZE THE LOCAL ATMOSPHERE. SOUNDING DATA
RECORDED TEMPERATURES AT 500 MB NOT MUCH COLDER THAN USUAL...BUT THE
AIR MASS AT LOWER LEVELS WAS SO MOIST THAT LITTLE FURTHER STEEPENING
OF THE ENVIRONMENTAL LAPSE RATE WAS NEEDED TO SUPPORT DEEP
CONVECTION. MOST SOLUTIONS PREDICTED A WAVE ON THE TROUGH ALOFT TO
PASS NORTH OF THE ISLANDS TONIGHT...AND THE ADDITIONAL DYNAMIC
SUPPORT EXPECTED IN SUCH A SITUATION APPEARED TO MATCH WELL WITH
SATELLITE AND RADAR OBSERVATIONS OF STRONG CONVECTION OVER...AND
ESPECIALLY NORTH OF...THE ISLANDS.

THE TROUGHING ALOFT ALSO LIMITED SUPPORT FOR THE SUBTROPICAL RIDGE
AT THE SURFACE. THUS...THE WEST END OF THE RIDGE RETREATED GRADUALLY
TOWARD THE EAST...KEEPING WINDS SOUTHEASTERLY TO SOUTHERLY OVER THE
ISLANDS. GUIDANCE AGREED WELL IN MAINTAINING THIS SITUATION THROUGH
AT LEAST THE MIDDLE OF THE WEEK. INTERESTINGLY...SATELLITE ESTIMATES
DETECTED A SIGNIFICANTLY DRIER AIR MASS EAST OF 150W AT THE LATITUDE
OF THE STATE. HOWEVER...THE ORIENTATION OF THE PREVAILING FLOW WILL
KEEP PRECIPITABLE WATER AMOUNTS APPROACHING TWO AND A HALF INCHES IN
PLACE OVER THE ISLANDS.

BY THE END OF THE WEEK...GUIDANCE GENERALLY AGREED THAT THE MOSTLY
ZONAL MID-LEVEL TROUGH TO THE NORTH WILL SHIFT SOUTH IN SOME WAY...
ALTHOUGH SPECIFICS DIFFERED. SOME SOLUTIONS...SUCH AS THE ECMWF...
DEPICTED THE AXIS OF THE MERIDIONALLY DIGGING TROUGH TO REMAIN
MOSTLY EAST OF THE STATE. ON THE OTHER HAND...OTHER SOLUTIONS...LIKE
THE GFS...DEVELOPED THE TROUGH RIGHT OVER THE ISLANDS. DESPITE SOME
LIMITED DRYING NEAR THE SURFACE...THE COLDER AIR AND DYNAMIC SUPPORT
ALOFT STILL IMPLIED ANOTHER PERIOD OF POSSIBLE DEEP CONVECTION FOR
NEXT WEEKEND. IT WAS TOO EARLY TO TELL WHETHER THE POTENTIAL WOULD
BE AS GREAT AS TONIGHT...BUT THE LONG-TERM FORECAST MAY NEED A NUDGE
TOWARD HEAVY RAIN AND POSSIBLE THUNDERSTORMS.

FOR THE TIME BEING HOWEVER...KILO AND THE INDEPENDENT THUNDERSTORMS
OVER THE STATE THIS EVENING REPRESENTED THE BIGGEST CONCERNS IN THE
FORECAST. ALL INTERESTS IN THE STATE OF HAWAII SHOULD CONTINUE TO
FOLLOW THE LATEST BULLETINS AND PRODUCTS ISSUED BY THE CENTRAL
PACIFIC HURRICANE CENTER AND THE NATIONAL WEATHER SERVICE OFFICE IN
HONOLULU.

&&

.MARINE...
A SMALL TO MODERATE W SWELL WILL CONTINUE OVER THE ISLANDS THROUGH
THE MIDDLE OF THE WEEK. A SLIGHTLY LARGER VERY LONG-PERIOD WNW
SWELL FROM DISTANT TYPHOON ATSANI IS EXPECTED TO ARRIVE AROUND
WEDNESDAY...AND THEN TO PEAK THURSDAY INTO FRIDAY. THIS SWELL...MAY
BE LARGE ENOUGH TO PRODUCE ADVISORY-LEVEL SURF ALONG WEST-FACING
SHORES OF THE BIG ISLAND.

MARINERS MAY ENCOUNTER HEAVY SHOWERS OR THUNDERSTORMS AS A VERY
MOIST AND UNSTABLE AIR MASS LINGERS ACROSS THE AREA THROUGH THE NEXT
COUPLE OF DAYS. A MARINE WEATHER STATEMENT IS IN EFFECT TO HIGHLIGHT
THE THREAT TO MARINERS.

SMALL CHANGES IN THE TRACK OR INTENSITY OF TROPICAL CYCLONE KILO MAY
INTRODUCE BIG CHANGES IN FORECASTS FOR THE ISLANDS AND SURROUNDING
WATERS. MARINERS SHOULD MONITOR FORECASTS FOR THE LATEST UPDATES
BEFORE HEADING OUT...ESPECIALLY IF PLANNING TRIPS TO THE OFFSHORE
WATERS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR NIIHAU-KAUAI-OAHU-
MOLOKAI-LANAI-MAUI-BIG ISLAND.

SEVERE THUNDERSTORM WATCH 1 IN EFFECT UNTIL 4 AM HST MONDAY FOR
OAHU...MAUI COUNTY...AND ADJACENT WINDWARD WATERS.

&&

RYSHKO

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HONOLULU HI
945 PM HST SUN AUG 23 2015

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

0935 PM     FLASH FLOOD      HANA                    20.77N 155.99W
08/23/2015                   MAUI               HI   LAW ENFORCEMENT

            MAUI CIVIL DEFENSE REPORTED THE FOLLOWING -- ULAINO ROAD
            IN HANA AREA CLOSED DUE TO WATER ON ROAD.

&&

ITUU