High Surf in Hawaii, April 17 to 20, 2007

Name: High Surf in Hawaii, April 17 to 20, 2007
Start: 2007-04-17T07:00
End: 2007-04-20T12:00
Location: Hawaii

April 17 to 20, 2007 · NWS HFO · 7 events in 7 counties and zones

A trade wind swell caused surf of 6 to 10 feet along the east-facing shores of Kauai, Oahu, Molokai, Maui, and the Big Island of Hawaii. No serious property damage or injuries were reported.

Where it happened

Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

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The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 7

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.

A trade wind swell caused surf of 6 to 10 feet along the east-facing shores of Kauai, Oahu, Molokai, Maui, and the Big Island of Hawaii. No serious property damage or injuries were reported.

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 17, 4:15 AM HST, 2 hours 45 minutes earlier.

Area forecast discussion, Apr 17, 4:15 AM HST, 2 hours 45 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
415 AM HST TUE APR 17 2007

.SYNOPSIS...
STRONG HIGH PRESSURE TO THE NORTHEAST OF THE ISLANDS WILL KEEP IT
QUITE BREEZY FOR THE NEXT FEW DAYS.

&&

.DISCUSSION...A BAND OF LOW CLOUDS AND SHOWERS HAS BEEN MOVING
ACROSS THE ISLANDS OVERNIGHT. THIS BAND WILL CLEAR THE SMALLER
ISLANDS EARLY THIS MORNING. ALTHOUGH BOTH BIG ISLAND RADARS ARE OUT
OF SERVICE...SATELLITE SHOWS THERE ARE SHOWERY BROKEN TO OVERCAST
LOW CLOUDS EXTENDING TO ABOUT 415 MILES EAST OF THE BIG ISLAND. SOME
OF THESE SHOWERS MAY BE BEING ENHANCED BY A DIGGING UPPER TROUGH
OVER THE ISLANDS. THE CLOUDS AND SHOWERS WILL PROBABLY BREAK UP A
LITTLE DURING THE DAY...BUT QUITE A FEW SHOWERS CAN BE EXPECTED
THERE UNTIL THEN.

WINDS TODAY WILL PROBABLY BE A LITTLE BIT LOWER THAN YESTERDAY...
BUT IT WILL STILL BE ON THE BREEZY SIDE THANKS TO A STRONG 1041 MB
HIGH NEAR 40N 150W. OVER THE NEXT FEW DAYS...THIS HIGH WILL SHIFT
SOUTH...WEAKEN...AND EVENTUALLY ELONGATE TO A RIDGE. THE PRESSURE
GRADIENT OVER THE ISLANDS WILL CONTINUE TO MAINTAIN FRESH TO LOCALLY
STRONG TRADES THROUGH THE REST OF THE WORK WEEK.

MODELS DO NOT SHOW ANY PARTICULARLY WELL ORGANIZED SHOWER AREAS IN
THE MOISTURE FIELDS THE NEXT FEW DAYS. THUS...EXCEPT FOR THE BIG
ISLAND TODAY...EXPECTING JUST A FEW MAINLY NIGHT AND MORNING SHOWERS
OVER WINDWARD AND MAUKA SECTIONS. THERE IS SURPRISINGLY GOOD
AGREEMENT IN THE WRF-NMM AND GFS LOW LEVEL MOISTURE FIELDS...SHOWING
FRONTAL REMNANTS CAUGHT UP IN THE TRADES COMING ACROSS THE NORTHERN
MAIN ISLANDS THURSDAY NIGHT...AND HAVE ADJUSTED THE POPS A BIT TO
REFLECT THIS. THE MODELS SHOW MUCH DRIER AIR FOLLOWS THIS FEATURE
FOR FRIDAY AND FRIDAY NIGHT...SO EVEN WINDWARD AND MAUKA SHOWERS MAY
BE RATHER LIMITED BY THEN.

THE SUBTROPICAL RIDGE WILL SETTLE SOUTH OF 30N BY THE END OF THE
WORK WEEK...AND THE TRADES WILL DROP OFF TO MORE MODERATE LEVELS
NEXT WEEKEND.

&&

.MARINE...
THE LONG FETCH OF STRONG TRADES OVER AND UPWIND OF THE ISLANDS WILL
MAINTAIN HAZARDOUS SEAS THROUGH THE NEXT COUPLE DAYS...AT LEAST.
THUS WE WILL CONTINUE THE HIGH SURF ADVISORY FOR EAST SHORES AS WELL
AS THE SMALL CRAFT ADVISORY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY FOR EAST FACING SHORES THROUGH 6 PM WEDNESDAY.

SMALL CRAFT ADVISORY FOR ALL REMAINING HAWAIIAN WATERS TODAY AND
TONIGHT.

&&

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

7 high surf. Local standard time, as filed.

High Surf, Kauai Windward

When: April 17, 7:00 AM HST to April 20, 12:00 PM HST
Where: Kauai Windward forecast zone
Reported by: Trained Spotter

High Surf, Oahu Koolau

When: April 17, 7:00 AM HST to April 20, 12:00 PM HST
Where: Oahu Koolau forecast zone
Reported by: Trained Spotter

High Surf, Olomana

When: April 17, 7:00 AM HST to April 20, 12:00 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 Windward

When: April 17, 7:00 AM HST to April 20, 12:00 PM HST
Where: Molokai Windward forecast zone
Reported by: Trained Spotter

High Surf, Maui Windward West

When: April 17, 7:00 AM HST to April 20, 12:00 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, Windward Haleakala

When: April 17, 7:00 AM HST to April 20, 12:00 PM HST
Where: Windward Haleakala forecast zone
Reported by: Trained Spotter

High Surf, Big Island North and East

When: April 17, 7:00 AM HST to April 20, 12:00 PM HST
Where: Big Island North and East forecast zone
Reported by: Trained Spotter

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: 22179, 22180, 22181, 22182, 22183, 22184, 22185.