Alert archive / Hawaii / Flash Flood Warnings in 2005

Flash Flood Warning 35, NWS Honolulu, HI

October 1, 2005Honolulu County, Hawaii

NWS Honolulu, HI issued this flash flood warning at Oct 1, 2005, 10:20 PM HST for Honolulu County, Hawaii. It was in force for 3 hr. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Oct 1, 2005, 10:20 PM HST (08:20 UTC)
Expired: Oct 2, 2005, 1:15 AM HST
In force: 3 hr
Issued by: NWS Honolulu, HI
Area: Counties, with a storm outline in the text

County Honolulu County, HI

What was reported inside it

Time	Report	Where	Remark
Oct 1, 10:28 PM HST	FLASH FLOOD	5 Ne Honolulu, HI	6-12 INCHES OF RUNNING WATER ON PALI HIGHWAY.
Oct 1, 10:28 PM HST	FLASH FLOOD	Waialua, HI	CIVIL DEFENSE CURRENTLY EVACUATING OTAKE CAMP. LAKE WILSON MEASURING 84.8FT.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 2 storm reports to this flash flood warning; the first came 8 minutes after it went out.

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, 8.3 hours before the alert went out and 159 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1190 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 746 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 11 m²/s²
0-3 km storm-relative helicity: 25 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

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

000
WGHW50 PHFO 020822
FFWHFO
HIC003-021115-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HONOLULU HI
1020 PM HST SAT OCT 1 2005

THE NATIONAL WEATHER SERVICE IN HONOLULU HAS ISSUED A

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

* UNTIL 115 AM HST

* AT 1013 PM HST...HEAVY RAINFALL HAS SPREAD ALONG THE KOOLAU RANGE 
  TO THE NUUANU AND KANEOHE AREAS. OAHU CIVIL DEFENSE HAS DETERMINED 
  THAT RUNOFF FROM LAKE WILSON WILL THREATEN OTAKE CAMP IN WAIALUA.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  WAHIAWA...MILILANI TOWN...HONOLULU...MAUNAWILI...KAILUA...KAHALUU 
  AND HALEIWA.

MOVE TO HIGHER GROUND NOW. STAY AWAY FROM STREAMS AND LOW LYING AREAS
PRONE TO FLOODING.

THIS FLASH FLOOD WARNING REPLACES THE PRE-EXISTING WARNING THAT WAS
IN EFFECT FOR THE ISLAND OF OAHU.

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

DO NOT TRY TO CROSS FAST FLOWING OR RISING WATER IN YOUR VEHICLE OR
ON FOOT. THE WATER MAY BE TOO DEEP TO CROSS SAFELY. TURN AROUND...
DON/T DROWN.

REPORT FLOODING TO POLICE OR CIVIL DEFENSE OFFICIALS FOR RELAY TO THE
NATIONAL WEATHER SERVICE.

THIS FLASH FLOOD WARNING MAY NEED TO BE EXTENDED BEYOND 115 AM HST IF
FLASH FLOODING CONDITIONS PERSIST.

LAT...LON 2130 15784 2133 15767 2165 15807 2160 15815
      2143 15802

$$

2 follow-up statements

000
WGHW70 PHFO 020940
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
1133 PM HST SAT OCT 1 2005

HIC003-021115-
HONOLULU-
1133 PM HST SAT OCT 1 2005

...A FLASH FLOOD WARNING CONTINUES UNTIL 115 AM HST FOR THE ISLAND OF
OAHU IN HONOLULU COUNTY...

AS OF 1130 PM HST...HEAVY SHOWERS HAVE DECREASED IN THE PAST HALF 
HOUR...BUT MODERATE RAINFALL PERSISTS ALONG THE KOOLAU RANGE. RUNOFF 
FROM LAKE WILSON CONTINUES TO THREATEN OTAKE CAMP IN WAIALUA...AND 
THE POTENTIAL FOR ADDITIONAL HEAVY RAINFALL REMAINS HIGH.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WAHIAWA...
MILILANI TOWN...HONOLULU...MAUNAWILI...KAILUA...KAHALUU AND WAIALUA.

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 2130 15784 2133 15767 2165 15807 2160 15815
      2143 15802

$$
WROE

000
WGHW70 PHFO 021113
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
111 AM HST SUN OCT 2 2005

HIC003-021141-
HONOLULU-
111 AM HST SUN OCT 2 2005

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

...A FLASH FLOOD WATCH REMAINS IN EFFECT FOR OAHU KAUAI AND NIIHAU 
UNTIL 6 PM HST SUNDAY...

HEAVY RAINFALL HAS SUBSIDED OVER MUCH OF OAHU...WHILE MODERATE 
SHOWERS CONTINUE ALONG PORTIONS OF THE KOOLAU RANGE. ALTHOUGH THE 
FLASH FLOOD WARNING HAS BEEN CANCELLED...RUNOFF FROM STREAMS... 
PARTICULARLY FROM LAKE WILSON INTO KAUKONAHUA STREAM THROUGH 
WAIALUA...WILL REMAIN ELEVATED FOR AT LEAST THE NEXT SEVERAL 
HOURS...AND ADDITIONAL HEAVY RAINS ARE POSSIBLE LATER.

LAT...LON 2130 15784 2133 15767 2165 15807 2160 15815
      2143 15802

$$
WROE

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 1, 8:30 PM HST, 1 hour 50 minutes earlier.

Area forecast discussion, Oct 1, 8:30 PM HST, 1 hour 50 minutes before

HAWAIIAN ISLANDS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST SAT OCT 1 2005

.SYNOPSIS...
TROPICAL MOISTURE AND A LOW ALOFT WILL PRODUCE MORE WET WEATHER OVER
THE ISLANDS THROUGH SUNDAY...ESPECIALLY OVER OAHU AND KAUAI. DRIER
WEATHER IS RETURNING AS THE TROPICAL MOISTURE AND THE LOW MOVE OFF
TO THE WEST. TRADE-WIND WEATHER WILL RETURN TO ALL THE ISLANDS BY
MONDAY AND CONTINUE THROUGH THE REST OF NEXT WEEK.
&&

.DISCUSSION...
THE UPPER LOW TO THE NORTH OF KAUAI IS KEEPING THE AIRMASS UNSTABLE
OVER THE REGION TONIGHT. CONVECTIVE PARAMETERS ARE ALL FAIRLY GOOD
FOR THUNDERSTORMS THIS EVENING. CURRENT ZONES HAVE ENHANCED WORDING
FOR HEAVY RAIN...WILL CONTINUE. PROBLEM AREA AS OF RIGHT NOW IS
CENTRAL OAHU...HOWEVER KAUAI IS SHOWING SOME HEAVIER RETURNS AND
SHOWERS ARE ONGOING OVER THE REMAINDER OF THE MAIN HAWAIIAN ISLANDS.

&&

.MARINE...
A NEW SOUTH SWELL WILL BE REACHING THE ISLANDS TUESDAY. THAT
SWELL IS LIKELY TO PRODUCE SURF ABOVE THE ADVISORY LEVEL OF 8 FEET
THROUGH FRIDAY.

&&

.HYDROLOGY...
HEAVY RAINS CONTINUE OVER CENTRAL KOOLAU ON OAHU WITH RATES 4 TO 6
INCHES WHICH HAS CONTINUED OVER THE REGION. ENHANCED AREAS OF
CONVECTION ARE SHOWING UP ON WATER VAPOR UPSTREAM OF THE WESTERN
ISLAND WHICH COULD KEEP THE HEAVY RAIN GOING INTO THE EARLY MORNING
HOURS.

&&

.PREV DISCUSSION...
ISSUED AT 400 PM
A WEAK SURFACE TROUGH...ALL THAT REMAINS OF TROPICAL DEPRESSION
KENNETH...IS SOUTHWEST OF KAUAI AND MOVING WEST. THIS SYSTEM IS NO
LONGER HAVING MUCH INFLUENCE ON THE MAIN HAWAIIAN ISLANDS BUT IT HAS
LEFT INCREASED MOISTURE AROUND THE ISLANDS. DESPITE ALL THE WEATHER
AFFECTING THE MAIN HAWAIIAN ISLANDS RECENTLY...TRADE WINDS HAVE
CONTINUED. A 1025 MB SURFACE HIGH ABOUT 800 MILES NORTH OF KAUAI
NEAR 31N 161W IS MAINTAINING THE TRADES. OVER THE NEXT TWO DAYS THE
HIGH WILL SHIFT EASTWARD ENDING UP NEAR 140W ON MONDAY MORNING.

WATER VAPOR IMAGERY SHOWS A LOW ALOFT AT 25N 158W...ABOUT 240 MILES
NORTH NORTHEAST OF KAUAI. A TROUGH EXTENDS FROM THE LOW TO 100 MILES
NORTHEAST OF OAHU. THIS TROUGH HELPED KICK OFF THUNDERSTORMS AND
HEAVY SHOWERS FROM KAUAI TO MAUI TODAY. THE TROUGH IS NOW ROTATING
NORTHEASTWARD AROUND THE EAST SIDE OF THE LOW. THE LOW CENTER IS
FORECAST TO MOVE TOWARDS THE WEST NORTHWEST OVER THE NEXT 24
HOURS...THEN LIFT OUT TO THE NORTH.

THE LOW ALOFT WILL KEEP THE ATMOSPHERE UNSTABLE OVER THE MAIN
HAWAIIAN ISLANDS THROUGH SUNDAY. THE MOST INSTABILITY WILL BE NEAR
KAUAI AND OAHU WITH MORE STABLE CONDITIONS SPREADING WESTWARD OVER
THE BIG ISLAND AND MAUI COUNTY. WE ARE CANCELLING THE FLASH WATCH
FOR THE BIG ISLAND AND MAUI COUNTY AT 400 PM AND EXTENDING THE WATCH
TILL 600 PM SUNDAY FOR OAHU AND KAUAI.

STARTING MONDAY...SURFACE HIGH PRESSURE NORTHEAST OF THE ISLANDS
WILL BUILD SOUTHWESTWARD. THE PRESSURE GRADIENT OVER THE ISLANDS
WILL INCREASE. TRADE WINDS WILL STRENGTHEN AND BECOME LOCALLY
BREEZY BY THE MIDDLE OF NEXT WEEK. TRADE WIND WEATHER WILL CONTINUE
THROUGH NEXT WEEK.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FOR KAUAI AND OAHU THROUGH 600 PM SUNDAY.
&&

PROTON

In the hours before

Local storm report, Oct 1, 8:48 PM HST, 1 hour 32 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HONOLULU HI
848 PM HST SAT OCT 01 2005

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

0840 PM     HEAVY RAIN       2 NE MILILANI TOWN      21.47N 157.99W
10/01/2005  0.00 INCH        HONOLULU           HI   TRAINED SPOTTER

            HEAVY RAIN WITH PONDING ON ROADWAYS.

0840 PM     HEAVY RAIN       N MILILANI TOWN         21.45N 158.02W
10/01/2005  0.00 INCH        HONOLULU           HI   TRAINED SPOTTER

            HEAVY RAIN FOR THE LAST HOUR. FLOODED SIDEWALK AND
            PONDING ON ROADWAY.

&&

HFO

Local storm report, Oct 1, 8:51 PM HST, 1 hour 29 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE HONOLULU HI
851 PM HST SAT OCT 01 2005

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

0840 PM     HEAVY RAIN       N MILILANI TOWN         21.45N 158.02W
10/01/2005  2.00 INCH        HONOLULU           HI   TRAINED SPOTTER

            -CORRECTION- HEAVY RAIN 2INCHES IN ONE HOUR. FLOODED
            SIDEWALK AND PONDING ON ROADWAY.

&&

HFO

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 1, 7:39 PM HST	Flash Flood Warning	HFO	Honolulu	3 hr
Oct 1, 8:38 PM HST	Flash Flood Warning	HFO	Honolulu	3 hr
Oct 1, 10:15 PM HST	Flash Flood Warning	HFO	Kauai	3 hr
Oct 1, 11:26 PM HST	Flash Flood Warning	HFO	Kauai	3 hr
Oct 2, 2:16 AM HST	Flash Flood Warning	HFO	Kauai	3 hr

Nearby

Flash Flood Warnings in Hawaii, 2005 Every flash flood warning in 2005

Sources

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