Alert archive / Hawaii / Flash Flood Warnings in 2004

Flash Flood Warning 64, NWS Honolulu, HI

October 27, 2004Honolulu County, Hawaii

NWS Honolulu, HI issued this flash flood warning at Oct 27, 2004, 12:00 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
Oct 27, 2004, 12:00 AM HST (10:00 UTC)
Expired
Oct 27, 2004, 3:00 AM 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 00:00Z, 10.0 hours before the alert went out and 152 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 00:00Z on 2004-10-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 739 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 00:00Z on 2004-10-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 21 square meters per square second.1939Sfc1 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
739 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
1125 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
21 m²/s²
0-3 km storm-relative helicity
32 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000
WGHW50 PHFO 271001
FFWHFO
HIC003-271300-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HONOLULU HI
1200 AM HST WED OCT 27 2004

THE NATIONAL WEATHER SERVICE IN HONOLULU HAS CONTINUED A

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

* UNTIL 300 AM HST

* AT 1153 PM HST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  FLASH FLOODING FROM A STORM OVER HAUULA...OR 21 MILES NORTH OF
  HONOLULU. THE STORM PRODUCING FLASH FLOODING WAS NEARLY STATIONARY.

* LOCATIONS IMPACTED INCLUDE...
   WAIKANE...KAAAWA...HAUULA...LAIE...KAHUKU AND PUPUKEA.

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF STREAMS
AND COULD ALSO TRIGGER ROCK AND MUDSLIDES IN STEEP TERRAIN.

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF
STREAMS...HIGHWAYS...UNDERPASSES AND LOW LYING AREAS.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODS AND FLASH FLOODS.

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

ESCAPE RISING WATER BY CLIMBING DIRECTLY TO HIGHER GROUND. NEVER TRY
TO OUTRACE A FLOOD...EITHER ON FOOT OR IN YOUR VEHICLE. DO NOT CAMP
NEAR STREAMS OR OTHER AREAS SUBJECT TO FLOODING.

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 2147 15793 2152 15779 2176 15796 2169 15809

$$
1 follow-up statement
000
WGHW70 PHFO 271255
FFSHFO
HIC003-271300-

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
252 AM HST WED OCT 27 2004

...THE FLASH FLOOD WARNING FOR NORTH CENTRAL HONOLULU COUNTY IS
CANCELLED...

MODERATE TO OCCASIONAL HEAVY RAINFALL IS STILL OBSERVED ON 
RADAR...BUT THE IMMEDIATE THREAT OF FLASH FLOODING ON OAHU HAS 
ENDED. HOWEVER...ADVISORIES AND WARNINGS MAY BE REISSUED FOR OAHU ON 
SHORT NOTICE...SO STAY ALERT.

A FLASH FLOOD WATCH REMAINS IN EFFECT FOR ALL HAWAIIAN ISLANDS 
UNTIL 4 AM HST.

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 2147 15793 2152 15779 2176 15796 2169 15809

$$

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 Oct 26, 8:30 PM HST, 3 hours 30 minutes earlier.

Area forecast discussion, Oct 26, 8:30 PM HST, 3 hours 30 minutes before
HAWAIIAN ISLANDS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST TUE OCT 26 2004

.SYNOPSIS...
THUNDERSTORMS CONTINUE TO FLARE OVER OAHU THIS EVENING...BUT THE
UPPER LOW RESPONSIBLE FOR OUR UNSTABLE WEATHER IS WEAKENING. BOUTS
OF HEAVY SHOWERS AND THUNDERSTORMS REMAIN POSSIBLE OVERNIGHT. TRADE
WINDS ARE EXPECTED TO MOVE INTO THE AREA ON WEDNESDAY...BRINGING
LIGHTER TRADE WIND SHOWERS TO WINDWARD AND MAUKA AREAS.

&&

.DISCUSSION...
WHILE DEEP CONVECTION ACROSS HAWAIIAN WATERS IS GENERALLY ON THE
DECREASE THIS EVENING...RADAR SHOWS A FLAREUP OF THUNDERSTORMS ALONG
NORTHEAST OAHU SLOPES...WITH 4 INCH PER HOUR RAINFALL RATES NOTED
NEAR PUNALUU. THIS TYPE OF ACTIVITY IS POSSIBLE ANYWHERE ACROSS THE
MAIN ISLANDS OVERNIGHT...GIVEN LINGERING INSTABILITY ASSOCIATED WITH
AN UPPER LOW NEAR MOLOKAI. AFTERNOON SOUNDINGS SHOW MINUS 9
TEMPERATURES AT 500 MB LEVEL AT BOTH HILO AND LIHUE. SHOWERS AND
THUNDERSTORMS TONIGHT WILL NOT BE AS WIDESPREAD AS THEY HAVE BEEN
THE LAST COUPLE OF NIGHTS. HOWEVER RAINFALL AMOUNTS IN THE HEAVIER
SHOWERS AND THUNDERSTORMS COULD STILL CAUSE LOCALIZED FLOODING. FOR
THIS REASON...A FLASH FLOOD WATCH REMAINS IN EFFECT FOR ALL HAWAIIAN
ISLANDS UNTIL WEDNESDAY MORNING.

WEDNESDAY WILL BE A DAY OF WEATHER TRANSITION AS THE UPPER LOW
WEAKENS AND MOVES AWAY AND WE SEE A CHANGE TO DRIER AND CLEARER
WEATHER. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH THE WEATHER
SCENARIO FOR THE NEXT SEVERAL DAYS. THE NORTH TO SOUTH ORIENTED
TROUGH TO THE WEST OF THE ISLANDS IS EXPECTED TO WEAKEN AS IT MOVES
TO THE WEST. DURING THIS TIME THE HIGH PRESSURE RIDGE TO THE NORTH
WILL BUILD BACK IN...RETURNING TRADES TO THE ISLANDS.

THE MOIST REMNANTS OF AN OLD FRONTAL BOUNDARY EMBEDDED IN THE TRADES
MAY REACH THE ISLANDS OVER THE WEEKEND. IT IS UNCLEAR IF THIS
FEATURE WILL IMPACT OUR WEATHER GIVEN THAT IT IS EXPECTED TO BREAK
UP AS IT APPROACHES.

&&

.MARINE...
A SOUTH SWELL IS STILL ANTICIPATED TO ARRIVE ON THURSDAY WHICH COULD
BRING SURF NEAR ADVISORY LEVELS OF 8 FEET FOR THE SOUTH SHORES.
&&

.HFO WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FOR ALL HAWAIIAN ISLANDS THROUGH 4 AM WEDNESDAY
&&

POWELL

In the hours before

Local storm report, Oct 26, 11:19 PM HST, 41 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HONOLULU HI
1119 PM HST TUE OCT 26 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0702 PM     FLASH FLOOD      KAHUKU                  21.68N 157.95W
10/26/2004                   HONOLULU           HI   LAW ENFORCEMENT

            POLICE OFFICER REPORTS ANKLE DEEP WATER FLOWING ACROSS
            KAMEHAMEHA HIGHWAY.

0800 PM     FLASH FLOOD      WAIKANE                 21.50N 157.88W
10/26/2004                   HONOLULU           HI   EMERGENCY MNGR

            OAHU CIVIL DEFENSE REPORTS CLOSURE OF KAMEHAMEHA HIGHWAY
            BRIDGE IN WAIKANE SHORTLY BEFORE 8 PM.

&&

POWELL

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 26, 6:49 PM HSTFlash Flood WarningHFOHonolulu3 hr
Oct 27, 6:47 AM HSTFlash Flood WarningHFOKauai3 hr
Oct 27, 9:37 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.