High Surf, Niihau
- When
- September 24, 11:00 AM HST to September 26, 10:00 AM 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 in Hawaii, September 24 to 26, 2009
A swell from a strong low far northwest of the Hawaiian Islands produced surf of 12 to 20 feet along the north-facing shores of Niihau, Kauai, Oahu, Molokai, and Maui; and 8 to 14 feet along the west-facing shores of Niihau, Kauai, Oahu, and Molokai. No significant property damage or injuries were reported.
Where it happened
Every event with a place to put it; 5 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
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 11
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 swell from a strong low far northwest of the Hawaiian Islands produced surf of 12 to 20 feet along the north-facing shores of Niihau, Kauai, Oahu, Molokai, and Maui; and 8 to 14 feet along the west-facing shores of Niihau, Kauai, Oahu, and Molokai. No significant 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 Sep 24, 10:00 AM HST, 1 hour earlier.
Area forecast discussion, Sep 24, 10:00 AM HST, 1 hour before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 1000 AM HST THU SEP 24 2009 .SYNOPSIS... TRADE WINDS WILL STRENGTHEN ACROSS THE STATE TODAY AS HIGH PRESSURE STRENGTHENS NORTHEAST AND NORTHWEST OF THE HAWAIIAN ISLANDS. EXPECT TO SEE TYPICAL TRADE WIND WEATHER ACROSS THE ISLANDS THROUGH NEXT WEEK WITH MOSTLY WINDWARD AND MOUNTAIN SHOWERS...ALTHOUGH HEAVIER AND MORE WIDESPREAD SHOWERS ARE LIKELY TOMORROW INTO SATURDAY MORNING AS MOISTURE MOVES INTO THE STATE. && .DISCUSSION... SURFACE HIGH PRESSURE SYSTEMS CURRENTLY IN PLACE TO THE NORTHWEST AND NORTHEAST OF THE STATE ARE STRENGTHENING...THIS WILL RESULT IN STRONGER TRADE WINDS TODAY...REACHING MODERATE TO FRESH STRENGTH. THE HIGH FAR NORTHWEST OF THE STATE WILL MIGRATE TOWARDS THE EAST THIS WEEKEND AND NEXT WEEK...THIS WILL KEEP MODERATE TRADE WINDS IN PLACE THROUGH THE REST OF THE FORECAST PERIOD. THERE IS THE LIKELIHOOD OF AN INCREASE IN SHOWER ACTIVITY TOMORROW AS THE MODELS SHOW AN UPPER LEVEL LOW JUST SOUTHEAST OF THE ISLANDS...WHICH CAN BE SEEN ON WATER VAPOR IMAGERY...BRINGING SOME MOISTURE OVER THE STATE INTO SATURDAY MORNING. AS THE MOISTURE MOVES IN...THE LOW WILL MOVE TO THE NORTHWEST OVER THE STATE. MODEL SOUNDINGS SHOW HIGHER LOW LEVEL INVERSIONS AND LOWER LIFTED INDEX VALUES WITH THIS LOW WHICH SHOULD ALLOW FOR MORE VERTICALLY DEVELOPED SHOWERS...RESULTING IN LARGER ACCUMULATIONS...MAINLY FOR WINDWARD AND MOUNTAIN SLOPES...ALTHOUGH A FEW SHOWERS ARE POSSIBLE IN LEEWARD SECTIONS. AFTER THE MOISTURE MOVES OUT OF THE STATE ON SATURDAY...WE EXPECT TO SEE TYPICAL TRADE WIND WEATHER THROUGH NEXT WEEK. && .MARINE... READINGS FROM THE WAIMEA BUOY HAVE SHOWN ELEVATED WAVE HEIGHTS THIS MORNING...THOUGH CORRESPONDING SURF HEIGHTS ARE STILL BELOW ADVISORY LEVEL FOR NORTH FACING SHORES AT THIS TIME. MEANWHILE... DATA FROM THE BUOY FAR NORTHWEST OF THE ISLANDS INDICATED A HIGHER PEAK IN THE PAST HOUR. THUS EXPECT THE WEST NORTHWEST SWELL TO BUILD GRADUALLY THROUGH TODAY AND SLOWLY SHIFTING NORTHWEST. STILL EXPECT THE SURF TO REACH THE ADVISORY LEVEL THRESHOLD FOR NORTH AND WEST FACING SHORES BY TONIGHT. THUS...HAVE ISSUED A HIGH SURF ADVISORY FOR TONIGHT THROUGH SATURDAY MORNING. THE SWELL WILL BE DECLINING ON SATURDAY AND SUNDAY. && .HFO WATCHES/WARNINGS/ADVISORIES... HIGH SURF ADVISORY TONIGHT THROUGH SATURDAY MORNING FOR NORTH AND WEST FACING SHORES OF NIIHAU...KAUAI...OAHU AND MOLOKAI...AND NORTH FACING SHORES OF MAUI. && HARRISON/WROE
The radar
The national radar mosaic for the moment the first event began.
Event by event
11 high surf. Local standard time, as filed.
High Surf, Kauai Windward
- When
- September 24, 11:00 AM HST to September 26, 10:00 AM HST
- Where
- Kauai Windward forecast zone
- Reported by
- Trained Spotter
High Surf, Kauai Leeward
- When
- September 24, 11:00 AM HST to September 26, 10:00 AM 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
- September 24, 11:00 AM HST to September 26, 10:00 AM 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
- September 24, 11:00 AM HST to September 26, 10:00 AM 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
- September 24, 11:00 AM HST to September 26, 10:00 AM HST
- Where
- Oahu Koolau forecast zone
- Reported by
- Trained Spotter
High Surf, Molokai Windward
- When
- September 24, 11:00 AM HST to September 26, 10:00 AM HST
- Where
- Molokai Windward forecast zone
- Reported by
- Trained Spotter
High Surf, Molokai Leeward
- When
- September 24, 11:00 AM HST to September 26, 10:00 AM HST
- Where
- Molokai Leeward forecast zone
- Reported by
- Trained Spotter
High Surf, Maui Windward West
- When
- September 24, 11:00 AM HST to September 26, 10:00 AM 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
- September 24, 11:00 AM HST to September 26, 10:00 AM HST
- Where
- Maui Central Valley forecast zone
- Reported by
- Trained Spotter
High Surf, Windward Haleakala
- When
- September 24, 11:00 AM HST to September 26, 10:00 AM HST
- Where
- Windward Haleakala 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
More
Every storm in Hawaii in 2009Every state in 2009This day in weather historyWarnings in Hawaii, September 2009
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: 192344, 192345, 192346, 192347, 192348, 192349, 192350, 192351, 192352, 192353, 192354.