High Surf in Hawaii, April 23 to 24, 2007

Name: High Surf in Hawaii, April 23 to 24, 2007
Start: 2007-04-23T04:00
End: 2007-04-24T14:00
Location: Hawaii

April 23 to 24, 2007 · NWS HFO · 14 events in 14 counties and zones

A strong low far northwest of the islands generated surf of 12 to 20 feet along the north-facing shores of Niihau, Kauai, Oahu, Molokai, and Maui; 8 to 15 feet along the west-facing shores of Niihau, Kauai, Oahu, and Molokai; and 6 to 8 feet along the west-facing shores of the Big Island of Hawaii. There were no reports of significant injuries or property damage.

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: 14

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 Apr 23, 4:00 AM HST, 0 minutes earlier.

Area forecast discussion, Apr 23, 4:00 AM HST, 0 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 AM HST MON APR 23 2007

.SYNOPSIS...
TRADE WINDS HAVE INCREASED AROUND THE STATE THIS MORNING AS A
STRONG HIGH PRESSURE SYSTEM MOVES TO THE NORTH OF THE ISLANDS.
TONIGHT AND TUESDAY TRADES WILL BE AT THEIR STRONGEST...IN THE 20 TO
25 MPH RANGE. TRADE WIND SHOWER ACTIVITY WILL ALSO PICK UP DURING
THIS BREEZY PERIOD THAT WILL LAST THROUGH WEDNESDAY. TRADES WILL
WEAKEN AFTER THURSDAY AND INTO THE WEEKEND.

&&

.DISCUSSION...
THE 1033 MB SURFACE HIGH TO THE NORTH-NORTHWEST WILL TIGHTEN THE
PRESSURE GRADIENT ACROSS THE MAIN HAWAIIAN ISLANDS. FRESH TO STRONG
TRADES WILL REMAIN UNTIL THE HIGH PROGRESSES FAR ENOUGH TO THE EAST
TO ALLOW A WEAKENING OF THE PRESSURE GRADIENT BEGINNING THURSDAY.
STRONGER TRADES ARE OFTEN ACCOMPANIED BY SOME INCREASE IN SHOWERS
OVER THE FAVORED WINDWARD AND MOUNTAIN AREAS WITH SOME LIGHT SHOWERS
BLOWING TO LEEWARD SECTIONS. MORNING BALLOON SOUNDINGS SHOW
TEMPERATURE INVERSION HAS RISEN TO AROUND 9 THOUSAND FEET.

MORNING SATELLITE IMAGERY SHOWS SCATTERED LIGHT TO MODERATE
SHOWERS...ENHANCED BY NIGHTTIME COOLING OF CLOUD TOPS... MOVING ONTO
ISLANDS IN THE TRADE FLOW. ALTHOUGH THIS AREA OF CLOUDS EXTEND
ALMOST 300 MILES UPWIND TO THE NORTHEAST IT IS EXPECTED THAT THEY
WILL THIN AND WEAKEN AS TEMPERATURES WARM THROUGH THE MORNING. THE
COLD FRONT ABOUT 350 MILES NORTH OF KAUAI WILL NOT REACH OUR AREA.

THE BRISK EASTERLY WINDS OVER THE STATE EXTEND NEARLY TO THE MID
ATMOSPHERE. WINDS HAVE INCREASED TO 30 TO 40 MPH ATOP HALEAKALA
VOLCANO ON MAUI...HENCE WIND ADVISORY IN EFFECT FOR SUMMIT AREA.
THIS BELT OF STRONG WINDS ALOFT IT EXPECTED TO SPREAD TO THE BIG
ISLAND SUMMITS TONIGHT...POSSIBLY REQUIRING A WIND ADVISORY THIS
AFTERNOON.

&&
.LONG TERM...THE UPPER TROUGH AND ACCOMPANYING SURFACE LOW PROGGED
TO DIP DOWN TO 20N EARLY FRIDAY THROUGH SATURDAY IS NOT QUITE AS
STRONG AS EARLIER DEPICTED. THEREFORE HAVE KEPT WEAK TRADES IN THE
FORECAST FOR THAT PERIOD.

&&

.MARINE...
THE LARGE NORTHWEST SWELL APPEARS TO HAVE PEAKED EARLIER THIS
MORNING AT 9 FEET AT THE BUOY NORTHWEST OF KAUAI. THE SWELL IS
EXPECTED TO REACH THE BIG ISLAND MIDDAY OR THIS AFTERNOON. STRONG
TRADE WINDS MAY REQUIRE ISSUANCE OF HIGH SURF ADVISORY FOR EAST
FACING SHORES BY TUESDAY MORNING DUE TO RESULTING ROUGH SHORT PERIOD
TRADE WIND SWELL.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY ALL COASTAL WATERS THROUGH EARLY WEDNESDAY
MORNING.

HIGH SURF ADVISORY NORTH AND WEST FACING SHORES OF NIIHAU KAUAI OAHU
MOLOKAI AND THE BIG ISLAND THROUGH EARLY TUESDAY MORNING.

HIGH SURF ADVISORY NORTH FACING SHORES OF MAUI THROUGH EARLY TUESDAY
MORNING.

&&

HOAG

The radar

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

Open the radar archive at this moment

Event by event

14 high surf. Local standard time, as filed.

High Surf, Niihau

When: April 23, 4:00 AM HST to April 24, 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: April 23, 4:00 AM HST to April 24, 2:00 PM HST
Where: Kauai Windward forecast zone
Reported by: Trained Spotter

High Surf, Kauai Leeward

When: April 23, 4:00 AM HST to April 24, 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: April 23, 4:00 AM HST to April 24, 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 North Shore

When: April 23, 4:00 AM HST to April 24, 2:00 PM HST
Where: Oahu North Shore forecast zone
Reported by: Trained Spotter
Coordinates: 21.455, -157.961 (the zone’s center; the record gives no point)

High Surf, Oahu Koolau

When: April 23, 4:00 AM HST to April 24, 2:00 PM HST
Where: Oahu Koolau forecast zone
Reported by: Trained Spotter

High Surf, Molokai Windward

When: April 23, 4:00 AM HST to April 24, 2:00 PM HST
Where: Molokai Windward forecast zone
Reported by: Trained Spotter

High Surf, Molokai Leeward

When: April 23, 4:00 AM HST to April 24, 2:00 PM HST
Where: Molokai Leeward forecast zone
Reported by: Trained Spotter

High Surf, Maui Windward West

When: April 23, 4:00 AM HST to April 24, 2:00 PM HST
Where: Maui Windward 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: April 23, 4:00 AM HST to April 24, 2:00 PM HST
Where: Maui Central Valley forecast zone
Reported by: Trained Spotter

High Surf, Windward Haleakala

When: April 23, 4:00 AM HST to April 24, 2:00 PM HST
Where: Windward Haleakala forecast zone
Reported by: Trained Spotter

High Surf, Kona

When: April 23, 4:00 AM HST to April 24, 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, Big Island North and East

When: April 23, 4:00 AM HST to April 24, 2:00 PM HST
Where: Big Island North and East forecast zone
Reported by: Trained Spotter

High Surf, Kohala

When: April 23, 4:00 AM HST to April 24, 2:00 PM HST
Where: Kohala forecast zone
Reported by: Trained Spotter
Coordinates: 19.602, -155.523 (the zone’s center; the record gives no point)

What these are

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 2007 Every state in 2007 This day in weather history Warnings in Hawaii, April 2007

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: 22186, 22187, 22188, 22189, 22190, 22191, 22192, 22193, 22194, 22195, 22196, 22197, 22198, 22199.