Flash Flood Warning 9, NWS Honolulu, HI

821 
WGHW70 PHFO 251042
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
1242 AM HST SUN MAY 25 2014

HIC003-251245-
/O.CON.PHFO.FF.W.0009.000000T0000Z-140525T1245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HONOLULU HI-
1242 AM HST SUN MAY 25 2014

...A FLASH FLOOD WARNING REMAINS IN EFFECT FOR THE ISLAND OF OAHU IN
HONOLULU COUNTY UNTIL 245 AM HST...

RADAR DATA SHOW THAT THE HEAVIEST SHOWERS HAVE MOVED OFF OF WINDWARD 
OAHU. GAUGES AT PUNALUU AND KAHANA HAVE BEGUN TO REPORT DECREASING 
STREAM LEVELS...WHILE THE WAIKANE STREAM HAS RECENTLY SHOWN A VERY 
RAPID RISE.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WAIKANE AND
PUNALUU.

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 245 AM HST IF FLASH
FLOODING PERSISTS.

LAT...LON 2158 15799 2164 15786 2140 15775 2134 15782
      2141 15797

$$

WROE

293 
WGHW70 PHFO 251131
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
131 AM HST SUN MAY 25 2014

HIC003-251141-
/O.CAN.PHFO.FF.W.0009.000000T0000Z-140525T1245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HONOLULU HI-
131 AM HST SUN MAY 25 2014

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

WEATHER RADAR SHOWED THAT HEAVY RAINFALL HAS DIMINISHED. THUS THE
FLASH FLOOD WARNING IS CANCELLED.

THE HEAVY RAINS AND FLOODING HAVE SUBSIDED...BUT RUNOFF IS STILL
OCCURRING AND STREAMS WILL REMAIN HIGH FOR SEVERAL HOURS.

LAT...LON 2158 15799 2164 15786 2140 15775 2134 15782
      2141 15797

$$
WROE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST SAT MAY 24 2014

.SYNOPSIS...
HEAVY SHOWERS AND THUNDERSTORMS WILL CONTINUE ACROSS THE WESTERN
HALF OF THE STATE THROUGH SUNDAY...AS LIGHT WINDS AND HUMID
CONDITIONS CONTINUE STATE-WIDE. THE THUNDERSTORM AND HEAVY SHOWER
THREAT WILL DIMINISH ON MEMORIAL DAY AS TRADE WINDS BUILD OVER THE
ISLANDS. TRADE WINDS WILL FOCUS SHOWERS ACROSS WINDWARD AND MAUKA
AREAS THROUGH THE NEW WORK WEEK.

&&

.DISCUSSION...
SHOWERS AND THUNDERSTORMS AROUND KAUAI AND OAHU HAVE DIMINISHED
SOMEWHAT IN THE PAST COUPLE OF HOURS...BUT EXPECT THUNDERSTORM
ACTIVITY TO INCREASE AGAIN FROM THE WEST OVERNIGHT. A SURFACE
TROUGH CURRENTLY SITS ABOUT 125 MILES NORTHWEST OF KAUAI WHILE A
POTENT UPPER LEVEL TROUGH IS DIGGING SOUTHEASTWARD TO THE WEST OF
THE ISLANDS. A MOIST AND UNSTABLE SOUTHERLY FLOW TO THE EAST OF
THE TROUGH OVER KAUAI AND OAHU HAS TRIGGERED PERIODS OF HEAVY
SHOWERS AND THUNDERSTORMS TODAY...WITH A DOWNWARD TREND IN ACTIVITY
OCCURRING AT PRESENT. AN IMPRESSIVE BLOWUP OF THUNDERSTORMS IS
UNDERWAY 100 TO 250 MILES WEST OF KAUAI ALONG THE BASE OF THE UPPER
LEVEL TROUGH. AS THE UPPER LEVEL TROUGH MOVES CLOSER TONIGHT...
EXPECT HEAVY SHOWERS AND THUNDERSTORMS TO INCREASE. MEANWHILE...
RATHER DRY AND STABLE CONDITIONS WILL PERSIST OVER THE EASTERN END
OF THE STATE.

VERY UNSTABLE CONDITIONS WILL DEVELOP OVER THE WESTERN HALF OF THE
STATE ON SUNDAY...MAINTAINING THE HEAVY SHOWER AND THUNDERSTORM
THREAT. THE UPPER TROUGH CURRENTLY WEST OF THE ISLANDS WILL PINCH
OFF AN UPPER LEVEL LOW THAT WILL DRIFT NEAR KAUAI AND OAHU ON
SUNDAY. THE AFTERNOON LIHUE SOUNDING SHOWED 500 MB TEMPERATURES OF
-9C...BUT AS THE UPPER LOW MOVES OVERHEAD...THESE TEMPS ALOFT WILL
DROP DOWN TO -12C...CREATING VERY UNSTABLE CONDITIONS BY LATE MAY
STANDARDS. SINCE THE LOW LEVELS WILL REMAIN MOIST OVER KAUAI AND
OAHU...EXPECT MORE HEAVY SHOWERS AND THUNDERSTORMS. IT/S IMPORTANT
TO NOTE THAT THUNDERSTORMS WILL BE STRONGER THAN THEY WERE TODAY AND
WILL BE CAPABLE OF PRODUCING FREQUENT LIGHTNING. THE EASTERN PORTION
OF THE STATE WILL CONTINUE TO BE HUMID AND SOMEWHAT DRY...BUT AN
ISOLATED AFTERNOON HEAVY SHOWER WILL BE POSSIBLE.

TRADE WINDS WILL BUILD OVER THE SATE ON MEMORIAL DAY...BUT
INSTABILITY WILL LINGER AS THE WEAKENING UPPER LEVEL LOW MOVES OVER
THE ISLANDS. THIS WILL SHIFT THE RAINFALL FOCUS OVER TO WINDWARD
SLOPES AS FORECAST MODELS ARE HINTING AT DRIER AIR MOVING IN FROM
THE EAST AT MID LEVELS. THAT SAID...THERE WILL BE ENOUGH INSTABILITY
AROUND TO TRIGGER SOME AFTERNOON CONVECTION...PROBABLY ON THE HEATED
LEEWARD SLOPES.

BY MID WEEK...MODERATE TRADE WINDS WILL BE WELL ESTABLISHED. THE
UPPER LOW WILL LINGER NEAR THE BIG ISLAND ON TUESDAY AND
WEDNESDAY...BUT IT WILL LIKELY BE TOO WEAK TO HAVE AN IMPACT ON
ISLAND WEATHER. AS A RESULT...LOOK FOR A RETURN TO TYPICAL TRADE
WIND WEATHER.

&&

.AVIATION...
AIRMET SIERRA FOR MOUNTAIN OBSCURATION REMAINS POSTED FOR
KAUAI...OAHU...MOLOKAI AND LANAI DUE TO LOW CLOUDS AND SHOWERS. THE
MAIN BAND OF HEAVY SHOWERS AND THUNDERSTORMS ARE OVER THE KAUAI
CHANNEL THIS EVENING...BUT ANTICIPATING KAUAI AND OAHU TO REMAIN
ENTRENCHED IN THE MOUNTAIN OBSCURATION INTO SUNDAY. CLOUDS AND
SHOWERS OVER MOLOKAI AND LANAI ARE EXPECTED TO DISSIPATE SOME
OVERNIGHT...WHICH MAY ALLOW THE AIRMET TO BE DROPPED FOR THOSE
ISLANDS.

LOW CLOUDS...SHOWERS...AND THUNDERSTORMS ARE EXPECTED TO PERSIST
FROM OAHU TO THE NORTHWEST THROUGH SUNDAY...WITH MVFR CONDITIONS
LIKELY AND EMBEDDED IFR CONDITIONS. AROUND MAUI COUNTY...VFR
CONDITIONS ARE EXPECTED TO PREVAIL...WITH BRIEF MVFR CONDITIONS
POSSIBLE...ALONG WITH ISOLATED IFR CONDITIONS. THE BIG ISLAND SHOULD
REMAIN PREDOMINANTLY VFR.

&&

.MARINE...
MODERATE SOUTHEAST WINDS WILL CONTINUE OVER THE WINDWARD AND
SOUTHEAST WATERS OF THE BIG ISLAND...WITH LIGHT TO GENTLE SOUTHERLY
WINDS OVER THE REMAINING COASTAL WATERS ADJACENT TO THE SMALLER MAIN
HAWAIIAN ISLANDS. BASED ON THE LATEST FORECAST...THE WINDS ARE
EXPECTED TO SHIFT TO AN EASTERLY DIRECTION AND STRENGTHEN STARTING
SUNDAY EVENING. AS THE TRADE WINDS CONTINUE TO STRENGTHEN...WIND
SPEEDS MAY REACH THE SMALL CRAFT ADVISORY /SCA/ CRITERIA IN THE
TYPICALLY WINDY WATERS ADJACENT TO THE ISLANDS OF MAUI AND HAWAII
COUNTIES STARTING MONDAY NIGHT. NOTE THAT RECENT OUTPUT FROM SOME OF
THE GLOBAL MODELS HAVE BACKED OFF ON THE STRENGTH OF THE FORECAST
TRADE WINDS...SO THERE IS A POSSIBILITY WIND SPEEDS MAY NOT ACTUALLY
REACH SCA THRESHOLD EARLY NEXT WEEK.

THE NEW LONG-PERIOD SOUTH SWELL...WHICH ARRIVED LAST NIGHT...
CONTINUES TO BUILD SLOWLY THIS EVENING BASED ON OBSERVATIONS FROM
THE BUOYS NEAR THE SOUTH SHORES OF THE ISLANDS. WE WILL CONTINUE TO
MONITOR THESE BUOY OBSERVATIONS AS THIS SWELL CONTINUES TO FILL IN
OVERNIGHT...SINCE THE SURF RESULTING FROM THIS SWELL MAY APPROACH
THE HIGH SURF ADVISORY CRITERIA ALONG SOUTH FACING SHORES ON SUNDAY.
REGARDLESS OF WHETHER OR NOT A HIGH SURF ADVISORY IS ISSUED...THIS
SWELL IS EXPECTED TO PRODUCE ELEVATED SURF ALONG EXPOSED SOUTHERN
BEACHES AND REEFS OF THE ISLANDS THROUGH MONDAY. THIS SWELL WILL
SLOWLY SUBSIDE TUESDAY AND WEDNESDAY.

ELSEWHERE...AS THE TRADES INCREASE EARLY NEXT WEEK...EXPECT CHOPPY
SHORT-PERIOD WAVES TO GRADUALLY BUILD ALONG EAST FACING SHORES BY
THE MIDDLE OF NEXT WEEK. ALSO...A NEW RELATIVELY LONG-PERIOD WEST
NORTHWEST SWELL ARRIVING MONDAY NIGHT IS EXPECTED TO PRODUCE A
SLIGHT BUMP IN SURF HEIGHTS IN EXPOSED NORTH AND WEST FACING SHORES
OF THE ALOHA STATE FROM TUESDAY THROUGH THURSDAY.

&&

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

&&

DISCUSSION...WROE
AVIATION...MBALLARD
MARINE...HOUSTON