Flash Flood in Hawaii, January 31, 2005

Name: Flash Flood in Hawaii, January 31, 2005
Start: 2005-01-31T21:35
End: 2005-01-31T23:59
Location: Hawaii

January 31, 2005 · NWS HFO · 1 event in 1 county or zone

Heavy showers and isolated thunderstorms caused the Hanalei River to overflow its banks and force the closure of the Hanalei Bridge for a time on Kauai. Rainfall was heavy over much of the island, with deep ponding on roadways, road closures, and occasional landslides being the main problems affecting the Garden Isle.

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

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The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 1

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS HFO wrote it up.

What forecasters said that day

The local office's own words before the first event, 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 the first event at Jan 31, 8:30 PM HST, 1 hour 5 minutes earlier.

Area forecast discussion, Jan 31, 8:30 PM HST, 1 hour 5 minutes before

HAWAIIAN ISLANDS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST MON JAN 31 2005

.SYNOPSIS...
A COLD FRONT APPROACHING THE STATE WILL INTERACT WITH THE MOIST AND
UNSTABLE AIR ALREADY OVER THE ISLANDS. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO FORM ALONG...AND AHEAD OF THIS FRONT. EXCESSIVE RAINFALL
AND FLASH FLOODING IS POSSIBLE THROUGH MIDWEEK. THE RISK FOR FLASH
FLOODING WILL INITIALLY BE OVER THE WESTERN MAIN ISLANDS
TONIGHT...THEN SPREAD TOWARD MAUI AND THE BIG ISLAND LATER TUESDAY.
DRIER AIR WILL SLOWLY OVERSPREAD THE ISLANDS BEHIND THE FRONT...BUT
MAY NOT REACH THE BIG ISLAND UNTIL LATE IN THE WORK WEEK.

&&

.DISCUSSION..
HEAVY RAIN AND THUNDERSTORMS CONTINUE TO AFFECT KAUAI AND ARE
KNOCKING ON THE DOOR OF OAHU. THE COLD FRONT...JUST NORTHWEST OF
KAUAI AT 8 PM...IN COMBINATION WITH THE ALREADY UNSTABLE AIRMASS
OVER THE ISLANDS IS HAVING NO TROUBLE PRODUCING HEAVY RAIN AND
THUNDERSTORMS THIS EVENING. KAUAI HAS AND IS CURRENTLY EXPERIENCING
THE HIGHEST RAINFALL. WITHIN THE PAST TWO HOURS...BOTH RAIN AND
RIVER GAGES HAVE SHOWN MARKED INCREASES AND A FLASH FLOOD WARNING
WAS ISSUED JUST AFTER 8 PM COVERING THE ENTIRE ISLAND OF KAUAI. IT
APPEARS THE HEAVY RAIN WILL CONTINUE AT LEAST THROUGH THE EARLY
MORNING HOURS THERE BEFORE STARTING TO TAPER OFF. RAINFALL IN THE
VICINITY OF OAHU HAS SO FAR REMAINED OFFSHORE TO THE NORTH...BUT
SHOWERS FORMING IN THE KAUAI CHANNEL WILL MOVE ONSHORE WITHIN THE
NEXT HALF HOUR OR SO. A BIT TO EARLY TO DECIDE IF A WARNING HAS TO
BE ISSUED FOR OAHU...BUT THE INGREDIENTS ARE CERTAINLY IN PLACE.
WILL BE KEEPING A CLOSE WATCH OVER OAHU AS THE RAIN BEGINS TO FALL.
FOCUS WILL SHIFT TOWARD MAUI COUNTY AND THE BIG ISLAND TUESDAY.

.FROM PREVIOUS DISCUSSION...
THE COLD FRONT WILL PASS OVER KAUAI TONIGHT AND OAHU EARLY TUESDAY.
THE FRONT IS THEN PROGGED TO SLOW AND MOVE OVER MAUI COUNTY LATER
TUESDAY...STALLING NEAR THE BIG ISLAND BY WEDNESDAY. BEST RAIN
CHANCES WILL BE ALONG AND AHEAD OF THE FRONT. THE AIRMASS BEHIND THE
FRONT WILL BE DRIER...BUT STILL QUITE UNSTABLE. HAVE LEFT IN
ISOLATED THUNDERSTORMS BEHIND THE FRONT AS LONG AS THE VERY COLD
MID-LEVEL AIR IS OVER THE ISLANDS.

OUR EXPECTATION CONTINUES TO BE THAT THE FRONT WILL LIKELY GET HUNG
UP NEAR THE BIG ISLAND AS A WAVE OF LOW PRESSURE DEVELOPS NORTH OF
THE ISLANDS ON WEDNESDAY. THUS...ONLY GRADUALLY DECREASING CHANCES
OF RAIN FOR THE SOUTHERN END OF THE CHAIN AS UPPER LEVEL HEIGHTS
BEGIN TO RISE.

FORECAST SOUNDINGS INDICATE THAT THE SNOW LEVEL SHOULD LOWER TO NEAR
10000 FEET AS THE DEEP LAYERED MOISTURE APPROACHES THE BIG ISLAND.
WINTER STORM WATCH WILL CONTINUE FOR THE POSSIBILITY OF HEAVY
SNOWFALL FOR THE BIG ISLAND SUMMITS TUESDAY INTO WEDNESDAY.

&&

.MARINE...
BUOY 51001 SHOWS THAT THE NORTHWEST SWELL IS SLOWLY TRENDING DOWN AS
EXPECTED. WILL LEAVE HIGH SURF ADVISORY UP FOR TONIGHT...AND
EVALUATE WHETHER OR NOT TO DROP THE ADVISORY WITH THE 4 AM PACKAGE.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH...KAUAI OAHU AND MOLOKAI THROUGH WEDNESDAY.

FLASH FLOOD WATCH...LANAI MAUI AND BIG ISLAND TUESDAY AND WEDNESDAY.

WINTER STORM WATCH...BIG ISLAND SUMMITS TUESDAY AND WEDNESDAY.

HIGH SURF ADVISORY...N AND W FACING SHORES OF NIIHAU KAUAI OAHU
                             AND MOLOKAI.
                     N FACING SHORES OF MAUI.

&&

R BALLARD

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

1 flash flood. Local standard time, as filed.

Flash Flood, Kauai

When: January 31, 9:35 PM HST to 11:59 PM HST
Where: Kauai County, Hanalei
Reported by: LAW ENFORCEMENT
Coordinates: 22.200, -159.500

What these are

Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Hawaii in 2005 Every state in 2005 This day in weather history Warnings in Hawaii, January 2005

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5435702.