Flash Flood Warning 15, NWS Honolulu, HI

993 
WGHW70 PHFO 040853
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
1053 PM HST THU MAR 3 2011

HIC007-040901-
/O.CAN.PHFO.FF.W.0015.000000T0000Z-110304T1030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KAUAI IN KAUAI COUNTY-
1053 PM HST THU MAR 3 2011

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

WEATHER RADAR SHOWS THAT HEAVY RAINFALL HAS MOVED OFFSHORE. 
EMERGENCY OFFICIALS REPORT THAT THE WATER LEVEL AT THE HANALEI 
BRIDGE PEAKED BELOW THE BRIDGE AND HAS CONTINUED TO DROP.

A FLASH FLOOD WATCH CONTINUES FOR KAUAI COUNTY AND OAHU THROUGH 
FRIDAY AFTERNOON.

LAT...LON 2203 15979 2218 15968 2223 15938 2196 15934
      2188 15943 2189 15964

$$
DONALDSON

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
900 PM HST THU MAR 3 2011

.SYNOPSIS...
EXPECT WINDY AND WET CONDITIONS ACROSS THE WESTERN END OF THE STATE
TONIGHT AND FRIDAY AS A DEVELOPING LOW PRESSURE SYSTEM PASSES NORTH
OF KAUAI. THIS LOW WILL BRING LOCALLY HEAVY RAINFALL WITH
THUNDERSTORMS AND STRONG...GUSTY SOUTHWEST WINDS...ESPECIALLY ACROSS
KAUAI AND OAHU. A FRONT WILL MOVE OVER KAUAI AND OAHU ON FRIDAY...
AND THEN ACROSS MAUI COUNTY ON SATURDAY...AND THE BIG ISLAND ON
SUNDAY. BREEZY NORTHEAST WINDS WILL FOLLOW THE FRONT...WITH TRADE
WINDS RETURNING BY SUNDAY...AND CONTINUING THROUGH MOST OF NEXT
WEEK.

&&

.DISCUSSION...
A SURFACE LOW PRESSURE SYSTEM CONTINUES TO BECOME BETTER ORGANIZED
THIS EVENING WEST OF KAUAI. THIS LOW HAS A WARM FRONT EXTENDING EAST
NORTHEAST OF THE LOW...WHILE A COLD FRONT TRAILS WEST SOUTHWEST OF
THE LOW. THE LOW APPEARS TO BE MOVING TOWARD THE EAST NORTHEAST AT
10 TO 15 MPH...WHILE THE WARM FRONT IS MOVING SLOWLY NORTH. ALSO...A
SHARP UPPER TROPOSPHERIC TROUGH...WHICH IS EVIDENT IN WATER VAPOR
IMAGERY LESS THAN 400 MILES WEST OF KAUAI...IS PROPAGATING EASTWARD
AT 15 TO 20 MPH. THE SURFACE LOW IS A REFLECTION OF THIS TROUGH
ALOFT.

THIS CLOSE PROXIMITY OF THE SURFACE LOW HAS LED TO INCREASING
SOUTHERLY WINDS AND WETTER CONDITIONS ACROSS KAUAI COUNTY AND OAHU.
SATELLITE IMAGERY AND RADAR REFLECTIVITY DATA CONTINUE TO INDICATE
NUMEROUS SHOWERS WITH EMBEDDED THUNDERSTORMS OVER KAUAI AND THE
SURROUNDING COASTAL WATERS. HAVE ISSUED SEVERE THUNDERSTORM WATCH 2
FOR KAUAI COUNTY...OAHU WINDWARD WATERS AND THE WATERS SURROUNDING
KAUAI...SINCE STRONG WINDS ARE EVIDENT IN SOME OF THE THUNDERSTORMS
FAR WEST OF KAUAI. HAVE ALSO ISSUED A FLOOD ADVISORY FOR KAUAI...AS
THESE HEAVY SHOWERS CONTINUE TO MOVE ACROSS AREAS ON THAT ISLAND
THAT ARE ALREADY SATURATED FROM EARLIER HEAVY RAINFALL. SHOWERS
REMAIN SCATTERED OVER AND IN THE VICINITY OF OAHU EARLY THIS EVENING.

IN ADDITION TO INCREASING SURFACE WINDS OVER THE WESTERN END OF THE
ISLAND CHAIN...THE APPROACHING UPPER LEVEL TROUGH IS ALSO CAUSING
STRONG WINDS OVER THE SUMMITS AND UPPER ELEVATIONS OF THE BIG ISLAND
AND THE SUMMIT OF MOUNT HALEAKALA ON MAUI...WHERE A HIGH WIND
WARNING REMAINS IN EFFECT.

THE FORECAST CALLS FOR THE DEVELOPING SURFACE LOW...WITH SIGNIFICANT
SUPPORT ALOFT...TO PASS TO THE NORTH OF KAUAI LATER TONIGHT AND
EARLY FRIDAY MORNING. AS THE SURFACE LOW CONTINUES TO DEVELOP AND
MOVE TO A POSITION NORTH OF THE ISLANDS LATER TONIGHT AND FRIDAY...
IT WILL CAUSE INCREASING SOUTHWESTERLY LOW-LEVEL WINDS. THESE STRONG
WINDS WILL ACCELERATE OVER DOWNSLOPE SECTIONS OF KAUAI AND OAHU...
PARTICULARLY TO THE NORTH AND EAST OF MOUNTAIN RANGES. THE
ANTICIPATION OF THESE WINDS HAS LED TO THE ISSUANCE OF A WIND
ADVISORY FOR KAUAI COUNTY AND MOST OF OAHU.

THE PASSAGE OF THE SURFACE LOW AND TROUGH ALOFT WILL ALSO BRING THE
POTENTIAL FOR VERY WET WEATHER TO KAUAI AND OAHU...WHERE A FLASH
FLOOD WATCH REMAINS IN EFFECT THROUGH FRIDAY AFTERNOON. THE LOW WILL
PUSH THE COLD FRONT TOWARD KAUAI AND OAHU...WITH INCREASING MOISTURE
AND INSTABILITY AHEAD OF THE FRONT BRINGING THE THREAT OF
THUNDERSTORMS...SOME OF WHICH COULD PRODUCE STRONG AND GUSTY WINDS.

THE COLD FRONT...WHICH IS MARKED BY A WIND SHIFT FROM SOUTHWEST TO
NORTH...IS EXPECTED TO PASS ACROSS KAUAI FRIDAY MORNING...AND OAHU
FRIDAY AFTERNOON...BEFORE IT REACHES MAUI COUNTY FRIDAY NIGHT AND
SATURDAY. THE FRONT IS FORECAST TO BE GRADUALLY WEAKENING BY THAT
TIME...BUT A SECONDARY SHORT WAVE TROUGH ALOFT COULD POSSIBLY
RE-ACTIVATE THE BOUNDARY FROM SATURDAY NIGHT INTO SUNDAY. THE LATEST
GUIDANCE CONTINUES TO INDICATE LOW LEVEL MOISTURE ASSOCIATED WITH
THE FRONT WILL SPREAD TO THE WINDWARD BIG ISLAND ON SUNDAY...WITH
THE MOISTURE DIMINISHING BY MONDAY...AS THE LOW LEVEL CONVERGENCE
AND UPPER LEVEL SUPPORT WEAKEN.

AS THE FRONT PASSES ACROSS ANY PARTICULAR ISLAND...EXPECT A WIND
SHIFT TO THE NORTH AND NORTHEAST...ALONG WITH A GRADUAL DRYING
TREND. THESE BREEZY NORTHEASTERLY WINDS WILL BE SUPPORTED BY HIGH
PRESSURE PASSING NORTH OF THE ISLANDS...WITH THE HIGH TRACKING
STEADILY EAST INTO EARLY NEXT WEEK. THEREFORE...THE BREEZY NORTHEAST
WINDS BEHIND THE FRONT WILL VEER TO THE MORE TYPICAL EAST NORTHEAST
TRADE WIND DIRECTION AND WEAKEN BY EARLY NEXT WEEK. ALSO EXPECT
TYPICAL TRADE WIND WEATHER FOR THE START OF THE WORK WEEK...
FOLLOWED BY POTENTIALLY WETTER TRADE WIND WEATHER LATER NEXT WEEK.

&&

.MARINE...
A SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH FRIDAY FOR THE
COASTAL WATERS AROUND KAUAI OAHU AND MAUI...DUE TO THE INCREASING
SOUTH TO SOUTHWEST WINDS...AND COMBINED SEAS APPROACHING 10 FEET.

ALSO...A GALE WARNING REMAINS IN EFFECT TONIGHT AND FRIDAY FOR THE
OFFSHORE WATERS...AS GALE FORCE WINDS ARE EXPECTED IN ASSOCIATION
WITH THE DEVELOPING SURFACE LOW AND FRONT THAT TRACKS ACROSS A
PORTION OF THE OFFSHORE WATERS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SEVERE THUNDERSTORM WATCH 2 IN EFFECT UNTIL 100 AM HST FRIDAY FOR
KAUAI COUNTY...OAHU WINDWARD WATERS AND THE WATERS SURROUNDING KAUAI.

FLASH FLOOD WATCH THROUGH 600 PM HST FRIDAY AFTERNOON FOR
NIIHAU-KAUAI-OAHU.

WIND ADVISORY UNTIL NOON HST FRIDAY FOR NIIHAU-KAUAI-WAIANAE
COAST-OAHU NORTH SHORE-OAHU KOOLAU-OLOMANA-CENTRAL OAHU-WAIANAE
MOUNTAINS.

HIGH WIND WARNING UNTIL 600 PM HST FRIDAY FOR BIG ISLAND SUMMITS AND
FOR MOUNT HALEAKALA SUMMIT.

SMALL CRAFT ADVISORY UNTIL 600 PM HST FRIDAY FOR KAUAI NORTHWEST
WATERS-KAUAI WINDWARD WATERS-KAUAI LEEWARD WATERS-KAUAI CHANNEL-
OAHU WINDWARD WATERS-OAHU LEEWARD WATERS-KAIWI CHANNEL-MAUI
COUNTY WINDWARD WATERS-MAUI COUNTY LEEWARD WATERS-PAILOLO
CHANNEL-ALENUIHAHA CHANNEL.

&&

HOUSTON