Flash Flooding and High Surf in Hawaii, October 18 to 20, 2014

Name: Flash Flooding and High Surf in Hawaii, October 18 to 20, 2014
Start: 2014-10-18T00:51
End: 2014-10-20T14:00
Location: Hawaii

October 18 to 20, 2014 · NWS HFO · 27 events in 20 counties and zones

As Hurricane Ana moved to the south of the island chain, it brought heavy precipitation from the Big Island westward to Niihau. The system also generated isolated thunderstorms as it headed west.

Where it happened

Every event with a place to put it; 7 filed by county or forecast zone are drawn at its center, in a lighter ring. 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

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 27

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.

As Hurricane Ana moved to the south of the island chain, it brought heavy precipitation from the Big Island westward to Niihau. The system also generated isolated thunderstorms as it headed west.

The swell from Ana produced high surf, mainly along south shores of the islands and in the range of 8 to 15 feet. Overall, there were no reports of significant property damage or injuries from either the rain or the surf.

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 Oct 17, 11:40 PM HST, 1 hour 11 minutes earlier.

Area forecast discussion, Oct 17, 11:40 PM HST, 1 hour 11 minutes before

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HONOLULU HI
1140 PM HST FRI OCT 17 2014

.UPDATE...
INFORMATION ABOUT THE PROGRESS OF HURRICANE ANA HAS BEEN UPDATED
WITH THE 11 PM HST BULLETIN.

&&

.SYNOPSIS...
HURRICANE ANA WILL BRING POTENTIAL FOR HEAVY RAIN...WINDY
CONDITIONS...AND A CHANCE FOR THUNDERSTORMS DURING THE WEEKEND.
STAY WELL INFORMED WITH THE LATEST FORECASTS AND BULLETINS FROM THE
CENTRAL PACIFIC HURRICANE CENTER AND THE NATIONAL WEATHER SERVICE IN
HONOLULU. A MORE STABLE AND DRIER TREND WILL BEGIN ESTABLISHING IN
THE WAKE OF ANA EARLY NEXT WEEK.

&&

.DISCUSSION...
LATEST FORECAST FOR HURRICANE ANA SHOWS THE CYCLONE MOVING
WNW...PASSING TO THE S AND W OF THE ISLAND CHAIN DURING THE NEXT
COUPLE OF DAYS. AT 11 PM HST THE CENTER OF ANA WAS LOCATED AT 17.8N
157.4W...OR ABOUT 155 MILES SSW OF KAILUA-KONA ON THE BIG ISLAND. A
TROPICAL STORM WATCH REMAINS IN EFFECT FOR ALL THE MAIN HAWAIIAN
ISLANDS.

PEOPLE IN HAWAII SHOULD REMAIN WELL INFORMED WITH THE LATEST
BULLETINS AND FORECASTS WHICH ARE AVAILABLE AT
WWW.WEATHER.GOV/HAWAII UNDER HEADERS WTPA25 PHFO AND TCMCP5. PUBLIC
ADVISORIES UNDER HEADERS WTPA35 PHFO AND TCPCP5...AND DISCUSSIONS
UNDER HEADERS WTPA45 PHFO AND TCDCP5. MORE DETAILED INFORMATION CAN
ALSO BE FOUND IN THE TROPICAL STORM ANA LOCAL STATEMENT UNDER
HEADERS WTHW80 PHFO AND HLSHFO.

A FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE BIG ISLAND UNTIL NOON
SAT. RADAR DATA SHOWS SEVERAL BANDS OF SHOWERS MOVING FROM THE SE
ACROSS THE BIG ISLAND WITH LOCALLY HEAVY RAIN AND THUNDERSTORMS BEEN
OBSERVED DURING THE EVENING HOURS...AND WILL CONTINUE THROUGH THE
REST OF TONIGHT. SIMILAR CONDITIONS WILL GRADUALLY SPREAD ACROSS THE
REST OF THE ISLAND CHAIN DURING THE WEEKEND. WINDWARD AND MAUKA
AREAS OF MAUI AND OAHU ARE ALREADY EXPERIENCING INCREASING SHOWERS
AND PERIODS OF GUSTY WINDS.

MEANWHILE...PRESSURE GRADIENTS BETWEEN A HIGH PRESSURE SYSTEM
LOCATED FAR NE OF THE ISLANDS AND ANA ARE BECOMING TIGHTER.
THEREFORE...EXPECT STRONGER E/NE WINDS OVER THE ISLAND CHAIN
ESPECIALLY ACROSS OAHU AND KAUAI SAT THROUGH SUN.

FOR EARLY NEXT WEEK...AS ANA MOVES W AND NW OF THE AREA WINDS WILL
GRADUALLY SWITCH TO THE SE WITH A GENERAL DRYING TREND AND
INCREASINGLY STABLE CONDITIONS EXPECTED ACROSS THE ISLANDS.

&&

.AVIATION...
ANA PASSING SOUTH OF THE ISLANDS WILL BRING INCREASING LOW CLOUD
CEILINGS AND SHOWERS...AND POSSIBLY ISOLATED THUNDERSTORMS...ACROSS
THE ALOHA STATE.  THE CLOUDINESS AND PRECIPITATION...INCLUDING MVFR
AND IFR CONDITIONS...WILL MOVE FROM EAST TO WEST ACROSS THE ISLAND
CHAIN IN CADENCE WITH ANA/S MOVEMENT SOUTH OF THE STATE.

THE BIG ISLAND WILL SEE THE MOST ACTIVITY TONIGHT...ESPECIALLY
WINDWARD SECTIONS.  THE INCLEMENT WEATHER WILL MOVE TO MAUI COUNTY
LATER TONIGHT AND SATURDAY...AND LATER SATURDAY FOR OAHU. KAUAI WILL
LIKELY SEE WORSENING CONDITIONS SATURDAY NIGHT AND SUNDAY.

&&

.MARINE...
FROM EAST TO WEST...HURRICANE ANA WILL BE AFFECTING THE COASTAL
WATERS...ESPECIALLY SOUTH THROUGH WEST...THIS WEEKEND. OCEAN
CONDITIONS WILL CONTINUE TO DETERIORATE DUE TO STRONG WINDS...
COMBINED WITH ELEVATED SWELLS AND VERY ROUGH SEAS OVER AREAS
EXPOSED TO THE FETCH FROM ANA. LOCALLY HEAVY SHOWERS AND
THUNDERSTORMS CAN ALSO BE EXPECTED. ALL PEOPLE IN HAWAII SHOULD
CLOSELY FOLLOW THE LATEST BULLETINS AND FORECASTS ISSUED BY
THE CENTRAL PACIFIC HURRICANE CENTER AND THE NATIONAL WEATHER
FORECAST OFFICE IN HONOLULU.

FOR MORE DETAILED INFORMATION ON MARINE AND SURF CONDITIONS...PLEASE
REFER TO THE HURRICANE ANA LOCAL STATEMENT AVAILABLE AT
WWW.WEATHER.GOV/HAWAII UNDER HEADERS WTHW80 PHFO AND HLSHFO.

OTHERWISE...A MODERATE NORTHWEST SWELL IS EXPECTED TO FILL IN ON
SATURDAY...PEAK ON SUNDAY...THEN LOWER SLOWLY EARLY NEXT WEEK.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
TROPICAL STORM WATCH FOR ALL THE MAIN HAWAIIAN ISLANDS.

FLASH FLOOD WATCH THROUGH NOON SATURDAY FOR THE BIG ISLAND.

TROPICAL STORM WATCH 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-MAALAEA BAY-PAILOLO CHANNEL-
ALENUIHAHA CHANNEL-BIG ISLAND WINDWARD WATERS.

TROPICAL STORM WARNING FOR BIG ISLAND LEEWARD WATERS-BIG ISLAND
SOUTHEAST WATERS.

&&

DISCUSSION...REYNES
MARINE...HOUSTON
AVIATION...KINEL

The radar

The Molokai radar (PHMO), 83 km away, was scanning. The volume nearest the first event began at 10:48 UTC.

Open the radar archive at this moment

Event by event

16 high surf, 9 heavy rain, 2 flash flood. Local standard time, as filed.

Heavy Rain, Honolulu

When: October 18, 12:51 AM HST to 3:25 AM HST
Where: Honolulu County, 1.53 mi SSE of Kaaawa to 0.44 mi NW of Ala Moana Beach Park
Reported by: Official NWS Observations
Coordinates: 21.530, -157.860

Heavy Rain, Honolulu

When: October 18, 3:58 AM HST to 7:48 AM HST
Where: Honolulu County, 0.74 mi WSW of Waialua to 0.97 mi SSW of Kailua
Reported by: Official NWS Observations
Coordinates: 21.575, -158.140

Flash Flood, Hawaii

When: October 18, 7:00 AM HST to 5:41 PM HST
Where: Hawaii County, 5.04 mi NNE of Naalehu to 4.92 mi NNE of Naalehu
Cause: Heavy Rain / Tropical System
Reported by: Emergency Manager
Coordinates: 19.132, -155.530

Hawaii County Civil Defense and NWS Skywarn spotters reported road closures due to flash flooding near Kawa Flats between the 57 and 58 mile markers on Mamalahoa Highway (Highway 11).

High Surf, Niihau

When: October 18, 8:00 AM HST to October 20, 2:00 PM HST
Where: Niihau forecast zone
Reported by: Trained Spotter
Coordinates: 22.011, -159.705 (the zone’s center; the record gives no point)

High Surf, Kauai Windward

When: October 18, 8:00 AM HST to October 20, 2:00 PM HST
Where: Kauai Windward forecast zone
Reported by: Trained Spotter

High Surf, Kauai Leeward

When: October 18, 8:00 AM HST to October 20, 2:00 PM HST
Where: Kauai Leeward forecast zone
Reported by: Trained Spotter
Coordinates: 22.011, -159.705 (the zone’s center; the record gives no point)

High Surf, Waianae Coast

When: October 18, 8:00 AM HST to October 20, 2:00 PM HST
Where: Waianae Coast forecast zone
Reported by: Trained Spotter
Coordinates: 21.455, -157.961 (the zone’s center; the record gives no point)

High Surf, Oahu South Shore

When: October 18, 8:00 AM HST to October 20, 2:00 PM HST
Where: Oahu South Shore forecast zone
Reported by: Trained Spotter

High Surf, Olomana

When: October 18, 8:00 AM HST to October 20, 2:00 PM HST
Where: Olomana forecast zone
Reported by: Trained Spotter
Coordinates: 21.455, -157.961 (the zone’s center; the record gives no point)

High Surf, Molokai Leeward

When: October 18, 8:00 AM HST to October 20, 2:00 PM HST
Where: Molokai Leeward forecast zone
Reported by: Trained Spotter

High Surf, Lanai Makai

When: October 18, 8:00 AM HST to October 20, 2:00 PM HST
Where: Lanai Makai forecast zone
Reported by: Trained Spotter

High Surf, Kahoolawe

When: October 18, 8:00 AM HST to October 20, 2:00 PM HST
Where: Kahoolawe forecast zone
Reported by: Trained Spotter
Coordinates: 21.027, -156.788 (the zone’s center; the record gives no point)

High Surf, Maui Leeward West

When: October 18, 8:00 AM HST to October 20, 2:00 PM HST
Where: Maui Leeward West forecast zone
Reported by: Trained Spotter
Coordinates: 21.027, -156.788 (the zone’s center; the record gives no point)

High Surf, Maui Central Valley

When: October 18, 8:00 AM HST to October 20, 2:00 PM HST
Where: Maui Central Valley forecast zone
Reported by: Trained Spotter

High Surf, Windward Haleakala

When: October 18, 8:00 AM HST to October 20, 2:00 PM HST
Where: Windward Haleakala forecast zone
Reported by: Trained Spotter

High Surf, Leeward Haleakala

When: October 18, 8:00 AM HST to October 20, 2:00 PM HST
Where: Leeward Haleakala forecast zone
Reported by: Trained Spotter

High Surf, Kona

When: October 18, 8:00 AM HST to October 20, 2:00 PM HST
Where: Kona forecast zone
Reported by: Trained Spotter
Coordinates: 19.602, -155.523 (the zone’s center; the record gives no point)

High Surf, South Big Island

When: October 18, 8:00 AM HST to October 20, 2:00 PM HST
Where: South Big Island forecast zone
Reported by: Trained Spotter

High Surf, Big Island North and East

When: October 18, 8:00 AM HST to October 20, 2:00 PM HST
Where: Big Island North and East forecast zone
Reported by: Trained Spotter

Heavy Rain, Hawaii

When: October 18, 4:38 PM HST to 7:16 PM HST
Where: Hawaii County, 4.7 mi SW of Kona Village Resort to 0.56 mi NNW of Kainaliu
Reported by: Official NWS Observations
Coordinates: 19.776, -156.024

Heavy Rain, Maui

When: October 18, 9:58 PM HST to October 19, 12:45 AM HST
Where: Maui County, 6.54 mi W of Shipwreck Beach to 1.95 mi ENE of Manele Harbor
Reported by: Official NWS Observations
Coordinates: 20.910, -157.021

Heavy Rain, Maui

When: October 18, 10:46 PM HST to October 19, 1:38 AM HST
Where: Maui County, 2.8 mi S of Papohaku Beach Park to 1.51 mi SSE of Halawa Valley
Reported by: Official NWS Observations
Coordinates: 21.130, -157.268

Heavy Rain, Maui

When: October 19, 1:36 AM HST to 5:28 AM HST
Where: Maui County, 2.42 mi SSE of Paia to 1.61 mi NE of Kaupo
Reported by: Official NWS Observations
Coordinates: 20.867, -156.368

Heavy Rain, Hawaii

When: October 19, 7:22 AM HST to 10:07 AM HST
Where: Hawaii County, 3.74 mi NW of Akaka Falls St Park to 2.43 mi NNE of Pahoa
Reported by: Official NWS Observations
Coordinates: 19.886, -155.193

Heavy Rain, Honolulu

When: October 19, 8:34 AM HST to 7:43 PM HST
Where: Honolulu County, 1.75 mi SSW of Mokuleia to 1.48 mi NNW of Niu Valley
Reported by: Official NWS Observations
Coordinates: 21.557, -158.191

Flash Flood, Honolulu

When: October 19, 1:15 PM HST to 7:43 PM HST
Where: Honolulu County, 0.53 mi SSE of Ala Moana Beach Park to 0.61 mi SSE of Ala Moana Beach Park
Cause: Heavy Rain / Tropical System
Reported by: Broadcast Media
Coordinates: 21.294, -157.845

Heavy rain from Hurricane Ana flooded a portion of Kona Street near the Ala Moana Mall. The water was knee-high in some areas.

Heavy Rain, Kauai

When: October 19, 4:42 PM HST to 7:41 PM HST
Where: Kauai County, 2.7 mi WNW of Anahola to 4.27 mi SSW of Puuwai
Reported by: Official NWS Observations
Coordinates: 22.132, -159.340

What these are

Heavy Rain: Rainfall totals unusual for the place and season that did not produce a flood.
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.
High Surf: Large waves breaking on the shore that caused damage, erosion or casualties.

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

The same day elsewhere

Every storm in Hawaii in 2014 Every state in 2014 This day in weather history Warnings in Hawaii, October 2014

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 2026-10-01. Each event’s entry at NCEI: 542467, 542468, 542466, 542469, 542470, 542471, 542472, 542473, 542474, 542475, 542476, 542477, 542478, 542479, 542480, 542481, 542482, 542483, 542484, 542485, 542486, 542487, 542488, 542489, 542490, 543045, 542491.