Flash Flood Warning 38, NWS Honolulu, HI

015 
WGHW70 PHFO 041512
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
512 AM HST FRI NOV 4 2011

HIC009-041715-
/O.CON.PHFO.FF.W.0038.000000T0000Z-111104T1715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MAUI HI-
512 AM HST FRI NOV 4 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT FOR THE ISLAND OF MAUI IN
MAUI COUNTY UNTIL 715 AM HST...

RADAR CONTINUES TO SHOW RAINFALL RATES IN THE 3 TO 5 INCH PER HOUR 
RANGE IN PORTIONS OF THE WARNING AREA. STEEP TERRAIN ALONG WINDWARD 
AND SOUTHEAST HALEAKALA SLOPES IS ACTING TO TRAP AND FOCUS THIS 
HEAVY RAINFALL...ENHANCING THE FLOOD THREAT IN THIS AREA.

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 715 AM HST IF FLASH
FLOODING PERSISTS.

LAT...LON 2095 15619 2082 15592 2062 15593 2054 15635

$$

POWELL

059 
WGHW70 PHFO 041707
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
707 AM HST FRI NOV 4 2011

HIC009-041715-
/O.CAN.PHFO.FF.W.0038.000000T0000Z-111104T1715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MAUI HI-
707 AM HST FRI NOV 4 2011

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

WEATHER RADAR AND RAIN GAGES SHOWED THAT THE HEAVY RAINS HAVE ENDED.
THUS THE FLASH FLOOD WARNING FOR EAST MAUI IS CANCELLED. WHILE THE 
HEAVY RAINS HAVE SUBSIDED...RUNOFF IS STILL OCCURRING AND STREAMS 
WILL REMAIN HIGH FOR SEVERAL HOURS.

A FLASH FLOOD WATCH FOR ALL ISLANDS REMAINS IN EFFECT THROUGH THIS 
AFTERNOON.

LAT...LON 2095 15619 2082 15592 2062 15593 2054 15635

$$

BRAVENDER

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HONOLULU HI
410 AM HST FRI NOV 4 2011

.UPDATE...
THE FORECAST IS UNCHANGED...BUT A FLASH FLOOD WATCH IS NOW IN
EFFECT FOR ALL MAIN HAWAIIAN ISLANDS THROUGH THIS AFTERNOON.

&&

.SYNOPSIS...
AN UPPER LOW ACROSS THE STATE WILL CONTINUE THE THREAT OF HEAVY
RAINFALL...ALONG WITH A SLIGHT CHANCE OF THUNDERSTORMS...INTO THE
WEEKEND. RAINFALL WILL FAVOR WINDWARD AND MAUKA AREAS. LEEWARD AREAS
WILL GET WET AS WELL ESPECIALLY DURING PERIODS OF STRONGER TRADE
WINDS. A WET TRADE WIND PATTERN WILL CONTINUE INTO NEXT WEEK.

&&

.DISCUSSION...
AN UPPER LOW OVER THE STATE CONTINUES TO DESTABILIZE OUR
AIRMASS...SUPPORTING THE THREAT OF HEAVY RAINFALL ALONG WITH A
SLIGHT CHANCE FOR THUNDERSTORMS. SATELLITE IMAGERY SHOWS
THUNDERSTORMS BEGINNING TO FLARE UP ONCE AGAIN EAST OF THE
ISLANDS...WITHIN A NORTHWEST TO SOUTHEAST BAND OF ENHANCED MOISTURE.
EXTENDING FROM JUST NORTHEAST OF THE BIG ISLAND TO A POINT 180 MILES
NORTHEAST OF KAUAI...THIS BAND OF HEAVY SHOWERS AND THUNDERSTORMS IS
EMBEDDED IN THE TRADES AND WILL AFFECT THE ISLANDS LATER THIS
MORNING. THE PROBABILITY OF HEAVY SHOWERS AND THUNDERSTORMS IS
GREATEST FOR THE BIG ISLAND AND MAUI BY DAYBREAK...BUT THIS THREAT
WILL SPREAD TO THE REMAINING ISLANDS THROUGH TODAY AS THE MOISTURE
BAND SLIDES WESTWARD BENEATH THE UPPER LOW. DEEP CONVECTION MAY
PRODUCE FROZEN PRECIPITATION ON THE BIG ISLAND SUMMITS THROUGH THIS
AFTERNOON. A WINTER WEATHER ADVISORY REMAINS IN EFFECT THERE THROUGH
6 PM HST. MODELS SHOW THE UPPER LOW WILL STILL AFFECT THE STATE OVER
THE WEEKEND. HOWEVER...THE DEEPEST MOISTURE SHOULD RESIDE MOSTLY
WEST OF THE AREA. TRAILING MOISTURE MAY STILL PRODUCE HEAVY RAIN FOR
WESTERN ISLANDS SATURDAY.

WHILE WE EXPECT THE THREAT OF HEAVY SHOWERS AND THUNDERSTORMS TO
FADE BY SUNDAY...MODELS SHOW THE UPPER LOW WILL NEVER STRAY FAR FROM
THE ISLANDS THROUGH THE FORECAST PERIOD. THIS FEATURE WILL DRIFT
BACK EASTWARD BEGINNING LATE SUNDAY...BECOMING STATIONARY ONCE AGAIN
JUST EAST OF THE BIG ISLAND BY MIDWEEK. ANY UNEXPECTED SURGE OF
MOISTURE MAY BE ENOUGH TO KICK OFF ANOTHER BOUT OF HEAVIER THAN
NORMAL SHOWERS. POPS/QPF WILL REMAIN SLIGHTLY ELEVATED IN THE GRIDS
INTO NEXT WEEK TO ACCOUNT FOR THIS POSSIBILITY.

AT THE SURFACE...EVER-PRESENT BUT FLUCTUATING HIGH PRESSURE NORTH OF
THE STATE MAY ALLOW FOR A SUBTLE DECREASE IN TRADE WIND SPEEDS EARLY
NEXT WEEK. HOWEVER...OVERALL TRADE WIND SPEEDS WILL REMAIN MODERATE
OR STRONGER. THIS FLOW WILL CONTINUE TO SUPPLY ABUNDANT MOISTURE TO
THE ISLANDS EVEN AFTER THE CURRENT BOUT OF INSTABILITY
RECEDES...FOCUSING SHOWERS ALONG WINDWARD AND MAUKA AREAS INTO
MIDWEEK. THUS WE EXPECT A WET TRADE WIND PATTERN TO CONTINUE THROUGH
THE FORECAST PERIOD.

&&

.AVIATION...
AIRMET TANGO CONTINUES FOR MODERATE TURBULENCE SOUTH THROUGH WEST OF
THE MOUNTAINS BELOW 10000 FEET DUE TO STRONG TRADE WINDS.

INSTABILITY ALOFT DUE TO AN UPPER LOW NEAR THE ISLANDS WILL BRING
HEAVY SHOWERS...REDUCED VISIBILITY AND LOCALLY MVFR/IFR FLYING
CONDITIONS ESPECIALLY FOR WINDWARD SLOPES WHERE THE TRADE WINDS ARE
DIRECTING THEM. A FEW THUNDERSTORMS ARE POSSIBLE OVER THE AREA DUE
TO THE INSTABILITY THROUGH TONIGHT.

&&

.MARINE...
MODELS SHOW THAT TRADE WINDS WILL REMAIN STRONG ENOUGH ACROSS WATERS
AROUND THE BIG ISLAND TO KEEP SMALL CRAFT ADVISORIES UP THROUGH THE
DAY SATURDAY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 6 PM HST TODAY FOR ALL MAIN HAWAIIAN ISLANDS.

WINTER WEATHER ADVISORY UNTIL 6 PM HST TODAY FOR BIG ISLAND
SUMMITS.

SMALL CRAFT ADVISORY UNTIL 6 PM HST SATURDAY FOR MAALAEA BAY-
PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND LEEWARD WATERS-BIG
ISLAND SOUTHEAST WATERS.

&&

PUBLIC/MARINE...POWELL
AVIATION...MBALLARD