Alert archive / Hawaii / Flash Flood Warnings in 2026

Flash Flood Warning 22, NWS Honolulu, HI

March 21, 2026Kalawao County, Hawaii

NWS Honolulu, HI issued this flash flood warning at Mar 21, 2026, 9:34 AM HST for Kalawao County, Hawaii. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Mar 21, 2026, 9:34 AM HST (19:34 UTC)
Expired
Mar 21, 2026, 3:14 PM HST
In force
6 hr
Issued by
NWS Honolulu, HI
Area
Storm-based polygon
Flood severity
None

County Kalawao County, HI

The nearest sounding before it

Lihue, (PHLI), launched 12:00Z, 7.6 hours before the alert went out and 263 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Lihue, at 12:00Z on 2026-03-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 276 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lihue, at 12:00Z on 2026-03-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
276 J/kg
Mixed-layer CIN
-133 J/kg
Mixed-layer LCL
829 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
24 m²/s²
0-3 km storm-relative helicity
107 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning went out, 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 this flash flood warning went out at Mar 21, 9:18 AM HST, 16 minutes earlier.

Area forecast discussion, Mar 21, 9:18 AM HST, 16 minutes before
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In the hours before

Special weather statement, Mar 21, 3:42 AM HST, 5 hours 52 minutes before
Special Weather Statement
National Weather Service Honolulu HI
342 AM HST Sat Mar 21 2026

HIZ007-010-011-034>036-211415-
Oahu North Shore HI-Ewa Plain HI-Koolau Windward HI-
Koolau Leeward HI-Waianae Mountains HI-Central Oahu HI-
342 AM HST Sat Mar 21 2026

...A STRONG THUNDERSTORM WILL IMPACT OAHU IN HONOLULU COUNTY THROUGH
415 AM HST...

At 341 AM HST, Doppler radar was tracking a strong thunderstorm
tracking over central Oahu, moving northeast at 35 mph.

HAZARD...Wind gusts up to 50 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Whitmore Village, Waimea Bay, Hauula, Mililani, Waipio, Wahiawa,
Kahana Valley State Park, Schofield Barracks, Turtle Bay, Laie,
Sunset Beach, Kahaluu, Helemano Housing, Kualoa, Kaaawa, Punaluu,
Waimalu, Pupukea, Kunia, and Wheeler Field.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 2166 15792 2163 15793 2155 15784 2152 15784
      2149 15785 2145 15783 2136 15799 2149 15815
      2167 15806 2171 15800 2171 15797
TIME...MOT...LOC 1341Z 236DEG 32KT 2150 15795

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

Gibbs
Special weather statement, Mar 21, 7:29 AM HST, 2 hours 5 minutes before
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<body>
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The office that day

Everything else NWS Honolulu, HI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 20, 2:03 PM HSTAreal Flood AdvisoryHFOKalawao3 hr
Mar 20, 3:41 PM HSTWinter Storm WatchHFOHawaii17 hr
Mar 20, 6:25 PM HSTSpecial Marine WarningHFO2 hr
Mar 20, 8:22 PM HSTSpecial Marine WarningHFO113 min
Mar 20, 9:32 PM HSTSpecial Marine WarningHFO29 min
Mar 20, 9:35 PM HSTAreal Flood AdvisoryHFOKalawao3 hr
Mar 20, 10:50 PM HSTSmall Craft AdvisoryHFO29 hr
Mar 20, 10:51 PM HSTHigh Surf AdvisoryHFOHonolulu, Kauai29 hr
Mar 20, 11:34 PM HSTFlash Flood Warning Considerable damage threatHFOKalawao3 hr
Mar 21, 2:13 AM HSTAreal Flood AdvisoryHFOKalawao8 hr
Mar 21, 3:42 AM HSTSpecial Marine WarningHFO2 hr
Mar 21, 3:42 AM HSTSpecial Weather StatementHFOHonolulu33 min
Mar 21, 4:55 AM HSTFlash Flood WarningHFOHonolulu5 hr
Mar 21, 4:59 AM HSTAreal Flood AdvisoryHFOKalawao9 hr
Mar 21, 5:39 AM HSTSpecial Marine WarningHFO2 hr
Mar 21, 6:28 AM HSTSpecial Marine WarningHFO62 min
Mar 21, 7:24 AM HSTSpecial Marine WarningHFO51 min
Mar 21, 7:29 AM HSTSpecial Weather StatementHFO46 min
Mar 21, 8:11 AM HSTSpecial Marine WarningHFO64 min
Mar 21, 8:49 AM HSTWinter Storm WarningHFOHawaii42 hr
Mar 21, 9:09 AM HSTSpecial Marine WarningHFO66 min
Mar 21, 9:49 AM HSTAreal Flood AdvisoryHFOKalawao3 hr
Mar 21, 10:53 AM HSTSpecial Marine WarningHFO97 min
Mar 21, 11:32 AM HSTFlash Flood WarningHFOKalawao5 hr
Mar 21, 11:45 AM HSTSpecial Weather StatementHFOKalawao30 min
Mar 21, 11:57 AM HSTFlash Flood WarningHFOKalawao12 hr
Mar 21, 12:23 PM HSTSpecial Marine WarningHFO97 min

Nearby

Flash Flood Warnings in Hawaii, 2026Every flash flood warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive.