Flash Flood Warning 42, NWS Honolulu, HI

936 
WGHW70 PHFO 190854
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
1054 PM HST SAT MAY 18 2013

HIC001-191000-
/O.CON.PHFO.FF.W.0042.000000T0000Z-130519T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HAWAII HI-
1054 PM HST SAT MAY 18 2013

...A FLASH FLOOD WARNING REMAINS IN EFFECT FOR THE ISLAND OF HAWAII
IN HAWAII COUNTY UNTIL MIDNIGHT HST...

RADAR SHOWS THAT MOST OF THE HEAVY RAIN OVER LEEWARD KOHALA HAS 
EITHER DIMINISHED...OR MOVED OFFSHORE. HOWEVER...RUNOFF FROM EARLIER 
HEAVY RAIN CONTINUES...AND BIG ISLAND CIVIL DEFENSE REPORTS SOME 
WATER ON HIGHWAY 270 BETWEEN KAWAIHAE AND MAHUKONA...AND ON THE 
KOHALA MOUNTAIN ROAD. HIGHWAY MAINTENANCE PERSONNEL ARE CLEARING 
DEBRIS FROM THE KOHALA MOUNTAIN ROAD...PRIMARILY BETWEEN MILE 
MARKERS 8 AND 10...BUT THE ROADWAY REMAINS OPEN. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS FLASH FLOODING IS IMMINENT OR OCCURRING
IN STREAMS...ROADS AND LOW LYING AREAS. DO NOT CROSS FAST FLOWING OR 
RISING WATER IN YOUR VEHICLE OR ON FOOT. USE CAUTION AND ALLOW EXTRA 
TIME IF DRIVING IN LEEWARD KOHALA TONIGHT. 

&&

LAT...LON 2024 15595 2024 15579 1998 15561 1998 15585

$$

BIRCHARD

533 
WGHW70 PHFO 190947
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
1147 PM HST SAT MAY 18 2013

HIC001-190956-
/O.CAN.PHFO.FF.W.0042.000000T0000Z-130519T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HAWAII HI-
1147 PM HST SAT MAY 18 2013

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

WEATHER RADAR SHOWS THAT THE HEAVY RAIN HAS ENDED...THUS THE FLASH 
FLOOD WARNING IS CANCELLED.

LAT...LON 2024 15595 2024 15579 1998 15561 1998 15585

$$

BIRCHARD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
835 PM HST SAT MAY 18 2013

.SYNOPSIS...
A LOW ALOFT WILL LINGER NORTHEAST OF THE AREA THROUGH MID-WEEK...
BEFORE WEAKENING AND MOVING OFF TO THE NORTH. THE LOW WILL PRODUCE
LIGHT SURFACE WINDS OVER MOST AREAS AND BRING A CHANCE OF LOCALLY
HEAVY SHOWERS. AS THE LOW ALOFT DEPARTS...TRADE WINDS WILL SPREAD
BACK OVER THE AREA BY NEXT WEEKEND. HIGH SURF WILL CONTINUE ALONG
THE SOUTH SHORES THROUGH SUNDAY...AND POSSIBLY INTO MONDAY.

&&

.DISCUSSION...
A COMPLICATED WEATHER PATTERN PERSISTS ACROSS THE STATE THIS
EVENING. WATER VAPOR IMAGERY SHOWS A COLD UPPER TROUGH NORTH OF
THE ISLANDS DIGGING SOUTH-SOUTHEAST THIS EVENING. MEANWHILE...AT
THE SURFACE...A SHARP INVERTED TROUGH HAS AN AXIS ACROSS MAUI AND
IS STATIONARY. TO THE NORTH...A COLD FRONT IS LOCATED ABOUT 175
MILES AWAY FROM KAUAI AND MOVING SOUTH AT 20 MPH. THE FRONT IS
OVERRUN BY BREEZY NORTHERLY WINDS ASSOCIATED WITH HIGH PRESSURE
NORTH AND WEST OF THE INVERTED TROUGH.

CURRENT RADAR AND INFRARED SATELLITE SHOWS A NORTH TO SOUTH
ORIENTED BAND OF CLOUDS AND SHOWERS LINED UP ALONG THE WINDWARD AND
SOUTHEASTERN COASTS OF THE BIG ISLAND. CLOUDS AND SCATTERED
SHOWERS COVER THE BIG ISLAND AND MAUI THIS EVENING. A FEW MODERATE
TO HEAVY SHOWERS REMAIN THIS EVENING FROM THE DAY/S SEA BREEZE
CONVERGENCE OVER THE KOHALA AND NORTH KONA AREAS.

FOR TONIGHT...EXPECTING THE CLOUDS AND SHOWERS TO WEAKEN AND
DISSIPATE OVER THE ISLANDS AS THE LAND BREEZES SET IN. SOME SHOWER
ACTIVITY WILL LIKELY CONTINUE INTO OVERNIGHT ACROSS BOTH WINDWARD
AND LEEWARD SIDES OF THE BIG ISLAND GIVEN THE POOLED MOISTURE
AROUND THE AREA. THE POTENTIAL FOR HEAVY RAINS WILL CONTINUE
THROUGH THE NIGHT FOR THE BIG ISLAND.

FOR TOMORROW...THE LIGHT BACKGROUND FLOW RESULTING FROM THE PRESENCE
OF THE SURFACE TROUGH WILL ALLOW SEA BREEZES TO BUILD OVER THE
ISLANDS AGAIN. KAUAI WILL BE THE EXCEPTION WITH MODERATE NORTHERLY
WINDS. CLOUDS AND SHOWERS ASSOCIATED WITH THE APPROACHING FRONT
SHOULD ARRIVE SUNDAY AFTERNOON AND WILL PRIMARILY IMPACT THE
NORTHERN SLOPES AND MAUKA AREAS. ELSEWHERE...THE SEA BREEZES WILL
BRING CLOUDS AND SHOWERS TO THE ISLAND INTERIORS AND LEEWARD
SECTIONS SUNDAY AFTERNOON AND EVENING. THE INSTABILITY ALOFT FROM
THE UPPER LOW WILL CAUSE LOCALLY HEAVY RAIN ON ALL ISLANDS EXCEPT
KAUAI. THE BIG ISLAND SHOULD AGAIN BE THE FOCUS FOR THE HIGHEST
CHANCES OF HEAVY RAIN IN THE STATE. WILL BE ADDING A SLIGHT CHANCE
FOR THUNDERSTORMS FOR THE BIG ISLAND SHORTLY.

THE FRONT WILL WASH OUT NEAR OAHU SUNDAY NIGHT...AND WILL LIKELY
BRING LITTLE DIRECT RAINFALL AFTER THIS. LAND BREEZES WILL SET IN
SUNDAY NIGHT PUSHING MOST OF THE CLOUDS AND RAIN OFFSHORE. THE
SURFACE TROUGH WILL LINGER NEAR MAUI THROUGH MONDAY...THEN SLOWLY
WEAKEN AND MOVE OFF TO THE WEST. ALOFT...A LOW WILL PERSIST
NORTHEAST OF THE AREA THROUGH MIDWEEK. LIGHT WINDS ASSOCIATED
WITH THE SURFACE TROUGH AND INSTABILITY FROM THE LOW ALOFT WILL
CONTINUE THIS DIURNAL CONVECTIVE PATTERN OVER ALL THE ISLANDS
THROUGH WEDNESDAY OR THURSDAY.

LONG RANGE MODELS ARE IN GOOD AGREEMENT SHOWING THE TRADE WINDS
BECOMING WELL-ESTABLISHED BY FRIDAY...AND LOCALLY BREEZY NEXT
WEEKEND. THE CONVECTIVE PATTERN WILL END AND THE TRADES WILL BRING
FOCUS LIGHTER SHOWERS TO WINDWARD AND MAUKA AREAS. ANOTHER TROUGH
ALOFT MAY DIG DOWN OVER THE AREA NEXT WEEKEND AND MAY ENHANCE THE
WINDWARD SHOWERS.

&&

.AVIATION...
CLOUDS AND SHRA OVER WINDWARD AREAS WILL BRING ISOL MVFR
OVERNIGHT...BUT LINGERING +SHRA OVER LEEWARD BIG ISLAND WILL
PRODUCE TEMPO MVFR/ISOL IFR THRU THE EVENING BEFORE DIMINISHING BY
EARLY MORNING. LIGHT WINDS WILL ALLOW WIDESPREAD SEA BREEZES TO
DEVELOP IN THE AFTERNOON SUNDAY...WITH CLOUDS AND +SHRA FAVORING
INTERIOR AND LEEWARD SECTIONS.

&&

.MARINE...
WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS STATEWIDE THROUGH NEXT WEEK. A SERIES OF SWELLS WILL KEEP
ELEVATED SURF ALONG SOUTH SHORES THROUGH MOST OF THE UPCOMING
WEEK WITH SURF EXPECTED TO REMAIN ABOVE THE ADVISORY THRESHOLD
THROUGH AT LEAST SUNDAY EVENING AND LIKELY LONGER. A MARINE
WEATHER STATEMENT ALSO CONTINUES FOR WAVES BREAKING NEAR CHANNEL
ENTRANCES AND POSSIBLE HARBOR SURGES. SEE THE SURF ZONE FORECAST AND
COLLABORATIVE NEAR SHORE SWELL AND WIND FORECAST FOR OAHU.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY UNTIL 6 PM HST SUNDAY FOR SOUTH SHORES OF ALL
ISLANDS.

&&

DISCUSSION/MARINE...FOSTER
AVIATION...BIRCHARD