High Surf in Hawaii, April 15 to 16, 2015

Name: High Surf in Hawaii, April 15 to 16, 2015
Start: 2015-04-15T10:00
End: 2015-04-16T13:00
Location: Hawaii

April 15 to 16, 2015 · NWS HFO · 11 events in 11 counties and zones

A late season swell from the northwest generated surf of 10 to 20 feet along the north-facing shores of Niihau, Kauai, Oahu, Molokai, and Maui; and 8 to 12 feet along the west-facing shores of Niihau, Kauai, Oahu, and Molokai. There were no reports of significant injuries or property damage.

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

Open the live radar over this ground

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.

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 15, 10:00 AM HST, 0 minutes earlier.

Area forecast discussion, Apr 15, 10:00 AM HST, 0 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST WED APR 15 2015

.SYNOPSIS...
A SURFACE RIDGE TO THE NORTH WILL MAINTAIN TRADE WINDS OVER THE
ISLANDS THROUGH NEXT WEEK. A TROUGH ALOFT WILL PASS NORTH OF THE
AREA THROUGH FRIDAY. THE TROUGH WILL MAKE SHOWERS MORE ACTIVE AND
WEAKEN THE TRADES AS IT PASSES. THE TRADE WINDS WILL STRENGTHEN AND
RAINFALL WILL DECREASE OVER THE WEEKEND AS THE TROUGH MOVES AWAY.

&&

.DISCUSSION...
A STRONG 1035 MB HIGH IS ABOUT 1900 MILES NORTHEAST OF OAHU WITH A
1031 MB HIGH ABOUT 1400 MILES TO THE NORTHWEST. THERE IS A FRONT...
SUPPORTED BY A TROUGH ALOFT...BETWEEN THE TWO HIGHS ABOUT 650 MILES
NORTHWEST OF OAHU. THE HIGH PRESSURE AT THE SURFACE IS MAINTAINING
TRADE WINDS OVER THE ISLANDS BUT THE WINDS HAVE WEAKENED SINCE
YESTERDAY DUE TO THE FRONT TO THE NORTHWEST. THE TRADE WINDS ARE
CARRYING LOW CLOUDS OVER THE WINDWARD SIDES OF THE ISLANDS. THE
ATMOSPHERE OVER THE AREA IS A BIT MOIST AND UNSTABLE THANKS TO THE
TROUGH ALOFT...SO THE CLOUDS MOVING OVER THE ISLANDS ARE RATHER
SHOWERY.

THE MODELS ARE IN PRETTY GOOD AGREEMENT SHOWING THE ATMOSPHERE
REMAINING MOIST AND UNSTABLE THROUGH FRIDAY AS THE TROUGH ALOFT
PASSES NORTH OF THE AREA. THE WEATHER WILL TURN DRIER BY THE WEEKEND
AND THE DRIER WEATHER IS EXPECTED TO CONTINUE THROUGH THE FIRST HALF
OF NEXT WEEK. MEANWHILE...HIGH PRESSURE NORTH OF THE ISLANDS WILL
STRENGTHEN AS THE TROUGH ALOFT MOVES AWAY. THAT WILL TIGHTEN THE
PRESSURE GRADIENT OVER THE ISLANDS AND THE TRADE WINDS WILL
STRENGTHEN. THE TRADES WILL BECOME QUITE BREEZY BY EARLY NEXT WEEK.

&&

.AVIATION...
AIRMET SIERRA FOR MTN OBSC IS IN EFFECT FOR THE WINDWARD SIDES OF
THE BIG ISLAND AND MAUI. VFR CONDITIONS WILL PREVAIL OVER MOST
LEEWARD AREAS...BUT AFTERNOON CONVECTION MAY PRODUCE MVFR CONDITIONS
OVER THE LEEWARD AREAS OF THE BIG ISLAND AND MAUI.

AIRMET TANGO IS IN EFFECT FOR MOD TURB BETWEEN FL280 AND FL350 DUE
TO A JET STREAM ALOFT AND FOR MOD TURB BLW 090 IN THE LEE OF THE
ISLANDS.

&&

.MARINE...
WIND SPEEDS AND SEAS ARE FORECAST TO REMAIN BELOW THE ADVISORY
THRESHOLDS TODAY. TRADE WINDS WILL STRENGTHEN AGAIN LATER THIS WEEK
AND SMALL CRAFT ADVISORIES...SCA...MAY BE REQUIRED AGAIN BY TOMORROW
NIGHT FOR THE WINDY AREAS AROUND THE BIG ISLAND AND MAUI. THE WINDS
WILL LIKELY STRENGTHEN FURTHER OVER THE WEEKEND AND THE SCA
CONDITIONS MAY BECOME MORE WIDESPREAD.

SURF IS BUILDING ALONG NORTH AND WEST FACING SHORES AS A NEW
NORTHWEST SWELL ROLLS IN...BUT THE SURF IS EXPECTED TO REMAIN BELOW
THE ADVISORY THRESHOLD. THIS SWELL WILL PEAK OVERNIGHT...THEN
GRADUALLY SUBSIDE THROUGH THE WEEKEND.

TRADE WINDS WILL CONTINUE TO PRODUCE ROUGH SURF ALONG EAST FACING
SHORES. SURF HEIGHTS WILL LIKELY INCREASE SLIGHTLY ALONG EAST FACING
SHORES THIS WEEKEND AS THE TRADE WINDS STRENGTHEN AGAIN. ONLY SMALL
SURF IS EXPECTED ALONG SOUTH FACING SHORES THROUGH THE WEEKEND. SURF
ALONG THE SOUTH FACING SHORES MAY BUILD TO MODERATE LEVELS NEXT WEEK.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

DONALDSON

The radar

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

Open the radar archive at this moment

Event by event

11 high surf. Local standard time, as filed.

High Surf, Niihau

When: April 15, 10:00 AM HST to April 16, 1:00 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 15, 10:00 AM HST to April 16, 1:00 PM HST
Where: Kauai Windward forecast zone
Reported by: Trained Spotter

High Surf, Kauai Leeward

When: April 15, 10:00 AM HST to April 16, 1:00 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 15, 10:00 AM HST to April 16, 1:00 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 15, 10:00 AM HST to April 16, 1:00 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 15, 10:00 AM HST to April 16, 1:00 PM HST
Where: Oahu Koolau forecast zone
Reported by: Trained Spotter

High Surf, Molokai Windward

When: April 15, 10:00 AM HST to April 16, 1:00 PM HST
Where: Molokai Windward forecast zone
Reported by: Trained Spotter

High Surf, Molokai Leeward

When: April 15, 10:00 AM HST to April 16, 1:00 PM HST
Where: Molokai Leeward forecast zone
Reported by: Trained Spotter

High Surf, Maui Windward West

When: April 15, 10:00 AM HST to April 16, 1:00 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 15, 10:00 AM HST to April 16, 1:00 PM HST
Where: Maui Central Valley forecast zone
Reported by: Trained Spotter

High Surf, Windward Haleakala

When: April 15, 10:00 AM HST to April 16, 1:00 PM 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

Every storm in Hawaii in 2015 Every state in 2015 This day in weather history Warnings in Hawaii, April 2015

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: 565949, 565950, 565951, 565952, 565953, 565954, 565955, 565956, 565957, 565958, 565959.