Alert archive / Hawaii / Flash Flood Warnings in 2004

Flash Flood Warning 59, NWS Honolulu, HI

August 4, 2004Honolulu County, Hawaii

NWS Honolulu, HI issued this flash flood warning at Aug 4, 2004, 9:32 AM HST for Honolulu County, Hawaii. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 4, 2004, 9:32 AM HST (19:32 UTC)
Expired
Aug 4, 2004, 12:45 PM HST
In force
3 hr
Issued by
NWS Honolulu, HI
Area
Counties, with a storm outline in the text

County Honolulu County, HI

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Lihue, (PHLI), launched 12:00Z, 7.5 hours before the alert went out and 161 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Lihue, at 12:00Z on 2004-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1527 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lihue, at 12:00Z on 2004-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1527 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
476 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
43 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WGHW50 PHFO 041933
FFWHFO
HIC003-042245-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HONOLULU HI
932 AM HST WED AUG 4 2004

THE NATIONAL WEATHER SERVICE IN HONOLULU HAS CONTINUED A

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

* UNTIL 1245 PM HST

* AT 932 AM HST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
  HEAVY RAINFALL CONTINUING OVER OAHU.

* LOCATIONS IMPACTED INCLUDE...
  ALL LOCATIONS ON OAHU.

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF
STREAMS...HIGHWAYS...UNDERPASSES AND LOW LYING AREAS. AREAS NEAR 
STEEP TERRAIN WILL ALSO BE VULNERABLE TO ROCK AND MUD SLIDES.

STREAMS AND ROADS ALONG WINDWARD OAHU FROM PUNALUU TO WAIMANALO ARE 
ESPECIALLY VULNERABLE DUE TO SATURATED GROUND CONDITIONS FROM 
OVERNIGHT RAINFALL.

MOTORISTS SHOULD BE ALERT FOR FLOODING AND SHOULD NOT ATTEMPT TO
CROSS FAST FLOWING OR RISING WATER...MANY FLASH FLOOD DEATHS OCCUR
WHEN MOTORISTS TRY CROSSING FLOODED ROADWAYS. TURN AROUND...DON/T
DROWN

STAY TUNED TO NOAA WEATHER RADIO OR OTHER LOCAL MEDIA SOURCES FOR THE
LATEST SEVERE WEATHER INFORMATION. REPORT FLOODING TO THE POLICE FOR
IMMEDIATE RELAY TO THE NATIONAL WEATHER SERVICE.

LAT...LON 2124 15756 2180 15796 2159 15839 2120 15810

$$
WROE
1 follow-up statement
000 
WGHW70 PHFO 042245
FFSHFO
HIC003-042300-

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
1245 PM HST WED AUG 4 2004

...THE FLASH FLOOD WARNING FOR OAHU HAS EXPIRED...

THE BAND OF HEAVY RAIN AND ISOLATED THUNDERSTORMS HAS SHIFTED WEST 
TO OVER KAUAI...AND THE THREAT FOR ADDITIONAL HEAVY RAINS HAS ENDED 
ON OAHU. THUS THE FLASH FLOOD WARNING FOR OAHU HAS BEEN ALLOWED TO 
EXPIRE. 

WITH GENERALLY 2 TO 5 INCHES OF RAIN HAVING OCCURRED ACROSS 
THE ISLAND...STREAMS WILL STILL BE RUNNING HIGH THROUGH THE 
AFTERNOON AND SOME RESIDUAL PONDING ON ROADWAYS IS POSSIBLE.

LAT...LON 2124 15756 2180 15796 2159 15839 2120 15810

$$
NASH

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Honolulu, HI wrote its last area forecast discussion before this flash flood warning went out at Aug 4, 4:00 AM HST, 5 hours 32 minutes earlier.

Area forecast discussion, Aug 4, 4:00 AM HST, 5 hours 32 minutes before
HAWAIIAN ISLANDS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 AM HST WED AUG 4 2004

.SYNOPSIS...
THE REMNANT TROPICAL MOISTURE FROM TROPICAL STORM DARBY REMAINS OVER
THE MAIN HAWAIIAN ISLANDS THIS MORNING. HEAVY SHOWERS AND
THUNDERSTORMS WILL BE MOVING OVER THE ISLANDS TODAY...AND
CONTINUING OVER KAUAI TONIGHT. TRADE WINDS...WITH THEIR MORE NORMAL
PATTERN OF WINDWARD AND MAUKA...NIGHT AND MORNING SHOWERS...WILL
RETURN ON THURSDAY.

&&

.DISCUSSION...
HEAVY SHOWERS CONTINUE TO MOVE UP OVER OAHU...MOLOKAI AND LANAI
FROM THE SOUTH THIS MORNING...WHILE KAUAI IS SEEING HEAVY SHOWERS
AND THUNDERSTORMS MOVING IN FROM THE EAST. THE DIVIDING LINE BETWEEN
SOUTH OR SOUTHEAST WINDS AND EAST OR NORTHEAST WINDS IS A SURFACE
TROUGH OF LOW PRESSURE...NOW LOCATED IN THE KAUAI CHANNEL. A TROUGH
OF LOW PRESSURE IN THE UPPER ATMOSPHERE TO THE WEST OF KAUAI IS
KEEPING THE ATMOSPHERE OVER THE HAWAIIAN ISLANDS AND THE REMNANT
TROPICAL MOISTURE UNSTABLE...AND THIS IS PROMPTING THE CONVECTION
OVER THE STATE. THE TROUGH AND SHOWERS ARE MOVING WESTWARD AT ABOUT
7 MPH...AND WILL CONTINUE TO AFFECT THE ISLANDS FROM KAUAI TO
MOLOKAI THROUGH THE DAY. BY THURSDAY AND FRIDAY MORE TYPICAL TRADE
WIND WEATHER IS EXPECTED THANKS TO HIGH PRESSURE FAR NORTH OF THE
STATE. TRADE WINDS WILL BE IN THE 10 TO 20 MPH RANGE WITH SHOWERS
MAINLY CONFINED TO WINDWARD AND MAUKA AREAS.

&&

.LONG TERM...
WE ARE ALSO WATCHING ANOTHER AREA OF SHOWERY WEATHER THAT MAY
APPROACH THE ISLANDS OVER THE WEEKEND. TROPICAL DEPRESSION SIX-E IS
LOCATED ABOUT 1500 MILES EAST SOUTHEAST OF HONOLULU. THE NATIONAL
HURRICANE CENTER IN MIAMI HAS ISSUED ITS LAST ADVISORY ON THIS SYSTEM
BUT THE GFS AND NOGAPS MODELS STILL BRING A LARGE AREA OF REMNANT
TROPICAL MOISTURE OVER THE STATE LATE FRIDAY INTO SATURDAY BRINGING
THE THREAT OF HEAVY RAINFALL ONCE AGAIN TO THE STATE.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH ALL ISLANDS.
HIGH SURF ADVISORY EAST SHORES OF KAUAI OAHU MOLOKAI MAUI AND THE
BIG ISLAND.

&&

FARRELL

The office that day

Everything else NWS Honolulu, HI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 3, 2:20 PM HSTFlash Flood WarningHFOKalawao3 hr
Aug 3, 7:11 PM HSTFlash Flood WarningHFOKalawao3 hr
Aug 4, 3:45 AM HSTFlash Flood WarningHFOHonolulu3 hr
Aug 4, 6:45 AM HSTFlash Flood WarningHFOHonolulu3 hr
Aug 4, 10:45 AM HSTFlash Flood WarningHFOKauai3 hr

Nearby

Flash Flood Warnings in Hawaii, 2004Every flash flood warning in 2004

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive.