Flash Flood Warning 37, NWS Honolulu, HI

013 
WGHW70 PHFO 271727
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
727 AM HST WED MAR 27 2013

HIC007-271815-
/O.CON.PHFO.FF.W.0037.000000T0000Z-130327T1815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KAUAI HI-
727 AM HST WED MAR 27 2013

...A FLASH FLOOD WARNING REMAINS IN EFFECT FOR THE ISLAND OF KAUAI IN
KAUAI COUNTY UNTIL 815 AM HST...

AT 715 AM HST...RIVER GAGES ON THE HANALEI RIVER REMAIN VERY HIGH... 
AND COUNTY OFFICIALS REPORTED THAT THE BRIDGE AT THE HANALEI RIVER 
REMAINS CLOSED. HEAVY RAINFALL CONTINUES TO FALL AT RATES OF ONE TO 
TWO INCHES PER HOUR ACROSS NORTHERN AND WINDWARD KAUAI.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WAINIHA...
HANALEI...PRINCEVILLE...KILAUEA...ANAHOLA...KAPAA...WAILUA...AND 
LIHUE.

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 815 AM HST IF FLASH
FLOODING PERSISTS.

LAT...LON 2198 15950 2210 15957 2223 15955 2223 15938
      2217 15927 2195 15934

$$

WROE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
330 AM HST WED MAR 27 2013

.SYNOPSIS...
A PASSING UPPER LEVEL TROUGH WILL KEEP POTENTIAL FOR HEAVY RAIN AND
FLASH FLOODING...AND POSSIBLE THUNDERSTORMS FROM KAUAI THROUGH MAUI
COUNTY TODAY. A BRIEF PERIOD OF DRIER WEATHER WILL RETURN ON
THURSDAY...THEN AN APPROACHING TROUGH AND FRONTAL BOUNDARY SYSTEM
WILL BRING ANOTHER ROUND OF UNSETTLED WEATHER DURING THE WEEKEND.

&&

.DISCUSSION...
LATEST WV/IR SATELLITE IMAGERY SHOWS A LARGE UPPER LVL TROUGH
SLOWLY MOVING INTO THE ISLAND CHAIN FROM THE WEST. THE EASTERN EDGE
OF THIS TROUGH IS NOW MOVING OVER KAUAI...AND WILL KEEP MIGRATING E.
A SHORTWAVE DISTURBANCE WILL MOVE JUST TO THE N OF THE AREA TODAY.
MIMIC ANALYSIS DEPICTS THE AXIS OF BEST MOISTURE RIGHT OVER KAUAI
AND GRADUALLY PUSHING TOWARDS OAHU. ALTHOUGH THE CORE OF THE
SHORTWAVE IS EXPECTED TO REMAIN N OF THE ISLANDS...SOUNDING
DATA...MIMIC MOISTURE ANALYSES AND MODEL CAPE STILL DEPICT ENOUGH
INSTABILITY TO JUSTIFY CARRYING CHANCES OF THUNDERSTORMS TODAY FROM
KAUAI THROUGH MAUI COUNTY. A DRIER AIRMASS SHOULD KEEP LOWER CHANCES
OF RAIN OVER THE BIG ISLAND.

KAUAI HAS BEEN EXPERIENCING ALMOST CONTINUOUS RAIN OVER THE NORTHERN
AND EASTERN HALF OF THAT ISLAND...FOR WHICH SEVERAL FLASH FLOOD
WARNINGS HAVE BEEN ISSUED THROUGHOUT THE NIGHT. NATIONAL WEATHER
SERVICE DOPPLER RADAR STILL SHOWS RAINFALL RATES OF OVER 2 INCHES
AN HOUR ACROSS THE WARNED AREA...WITH THE HANALEI RIVER GAUGE
SHOWING LEVELS OF 8 FEET OR HIGHER SINCE LATE LAST NIGHT. A ROAD
CLOSURE AT THE HANALEI BRIDGE WAS ALSO REPORTED BY THE KAUAI CIVIL
DEFENSE AND KAUAI LAW ENFORCEMENT. ADDITIONAL WARNINGS FOR KAUAI ARE
POSSIBLE THROUGH THE MORNING HOURS.

MEANWHILE...A WEAKENING FRONTAL BOUNDARY REMAINS NEARLY STATIONARY
JUST NORTH OF THE ISLANDS...WITH A WEAK SFC TROUGH NEAR OAHU. THE
COMBINATION OF THESE FEATURES WILL KEEP VERY FAVORABLE CONDITIONS
FOR RAIN...POTENTIAL FOR LOCALIZED FLOODING AND SOME POSSIBLE
THUNDERSTORM ACTIVITY LATER TODAY FROM KAUAI TO MAUI COUNTY. THE
MORNING FORECAST PACKAGE WILL INCLUDE MAUI COUNTY IN THE ONGOING
FLASH FLOOD WATCH...VALID THROUGH 6 PM HST THIS EVENING.

IN ADDITION...PRESSURE GRADIENTS ALOFT ARE BECOMING TIGHTER AS THE
TROUGH MOVES CLOSER TO THE AREA. GFS 600-500 MB LAYER WINDS SHOW
SPEEDS AROUND 25 KT OVER THE BIG ISLAND THROUGH LATE THU. WINDS AT
THE BIG ISLAND SUMMITS ARE CURRENTLY INCREASING AND NEARING ADVISORY
LEVELS. THEREFORE...BASED ON THE UPWARD TREND OF THE SPEEDS...A
WIND ADVISORY HAS BEEN ISSUED FOR THE SUMMITS THROUGH THURSDAY
EVENING. THE SITUATION WILL BE CLOSELY MONITORED IN CASE AN UPGRADE
TO A WARNING BECOMES NECESSARY.

A BRIEF DRIER PERIOD WILL ESTABLISH FROM THURSDAY THROUGH EARLY
FRIDAY...THEN MODELS SHOW ANOTHER SHORTWAVE TROUGH APPROACHING THE
ALOHA STATE DURING THE WEEKEND WITH A COLD FRONT PASSAGE POSSIBLY
BRINGING ANOTHER ROUND OF UNSETTLED WEATHER.

&&

.AVIATION...
AIRMET SIERRA FOR MTN OBSCURATION FOR THE BIG ISLAND AND KAUAI WILL
REMAIN POSTED THROUGH THE FORECAST PERIOD. WILL MOST LIKELY EXTEND
THE AIRMET TO INCLUDE OTHER ISLANDS AS THE UPPER LEVEL TROUGH
MIGRATES EAST.

AIRMET TANGO IS ALSO IN EFFECT FOR MOD CHOP ALF OVER KAUAI AND ADJ
WATERS FOR LEVELS BETWEEN FL280 AND FL430. TEMPO LIGHT ICE IC IS
ALSO INCLUDED IN THE AIRMET FOR LYRS EXTENDING FROM 120 TO FL200.

FREQ MVFR FOR PHLI CONTINUES WITH SAME CONDITIONS ADVANCING E TO
OAHU AND MOLOKAI...AND THE POSSIBILITY OF SPREADING FURTHER TO LANAI
AND MAUI LATER TODAY.

SIGMET QUEBEC REMAINS POSTED FOR HIGH LVL MOD-SEV CAT CONTINUES IMT
NW OF KAUAI MOVING EWD.

&&

.MARINE...
A NORTHWEST SWELL WILL CONTINUE TO SLOWLY DIMINISH TODAY. A NEW LONG
PERIOD NORTHWEST SWELL ARRIVING LATE FRIDAY COULD BRING SURF
HEIGHTS NEAR ADVISORY LEVELS FOR NORTH AND WEST FACING SHORES OVER
THE WEEKEND.

ALTHOUGH WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS UNTIL THE WEEKEND...MARINERS SHOULD REMAIN ALERT FOR
THE POTENTIAL FOR HAZARDOUS MARINE WEATHER...PRIMARILY TONIGHT AND
WEDNESDAY AROUND KAUAI AND OAHU...WITH THE GREATEST THREATS BEING
THUNDERSTORMS AND GUSTY ERRATIC WINDS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR NIIHAU KAUAI
OAHU AND MAUI COUNTY.

WIND ADVISORY UNTIL 6 PM HST THURSDAY FOR BIG ISLAND SUMMITS.

&&

DISCUSSION/MARINE...REYNES
AVIATION...LUTU-MCMOORE