Alert archive / Hawaii / Flash Flood Warnings in 2021

Flash Flood Warning 23, NWS Honolulu, HI

March 10, 2021Kauai County, Hawaii

NWS Honolulu, HI issued this flash flood warning at Mar 10, 2021, 6:26 PM HST for Kauai County, Hawaii. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Mar 10, 2021, 6:26 PM HST (04:26 UTC)
Expired
Mar 10, 2021, 9:30 PM HST
In force
3 hr
Issued by
NWS Honolulu, HI
Area
Storm-based polygon
Flood severity
None

County Kauai County, HI

The radar

The South Kauai radar (PHKI), 22 km from the middle of the area, began a volume at 04:27 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Lihue, (PHLI), launched 00:00Z, 4.4 hours before the alert went out and 18 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 00:00Z on 2021-03-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 858 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lihue, at 00:00Z on 2021-03-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 square meters per square second.1939Sfc1 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
858 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
769 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
51 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

096 
WGHW50 PHFO 110426
FFWHFO
HIC007-110730-
/O.NEW.PHFO.FF.W.0023.210311T0426Z-210311T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
626 PM HST Wed Mar 10 2021

The National Weather Service in Honolulu has issued a

* Flash Flood Warning for...
  The island of Kauai in Kauai County

* Until 930 PM HST.

* At 626 PM HST, radar showed heavy showers and a few embedded 
  thunderstorms lifting northward over Kauai. Rainfall rates up to 2 
  to 3 inches per hour with locally higher amounts can be expected. 
  Saturated grounds and rising water levels in streams are expected 
  to lead to flash flooding.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Radar indicated.

  IMPACT...Flooding in drainages, streams, rivers, roads,
           properties, and other low-lying areas. Public road
           closures possible in some areas. Landslides are
           possible in steep terrain.

* Some locations that will experience flash flooding include...
  Lihue, Kapaa, Kalaheo, Kekaha, Princeville, Kilauea, North Fork 
  Wailua Trails, Alakai Swamp Trails, Lawai, Omao, Kokee State Park, 
  Wailua Homesteads, Hanalei, Hanapepe, Wainiha, Na Pali State Park, 
  Koloa, Haena, Waimea and Wailua.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Stay away from streams, rivers, drainage ditches, and culverts, even 
if they are currently dry.

Do not cross fast flowing or rising water in your vehicle, or on 
foot. Turn around, don't drown.

Excessive runoff from heavy rainfall will cause flooding of drainage 
ditches and streams, streets, highways, properties, and other low 
lying spots.

The heavy rains may cause rock and mudslides in steep terrain areas.

&&

This warning may need to be extended beyond 930 PM HST if flooding 
persists.

LAT...LON 2225 15940 2222 15933 2216 15930 2215 15928
      2205 15932 2196 15932 2195 15934 2193 15934
      2190 15938 2186 15944 2188 15962 2194 15968
      2198 15978 2206 15980 2207 15980 2216 15974
      2224 15958 2222 15952 2225 15949 2224 15943

FLASH FLOOD...RADAR INDICATED

$$

GIBBS
2 follow-up statements
146 
WGHW70 PHFO 110606
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
806 PM HST Wed Mar 10 2021

HIC007-110730-
/O.CON.PHFO.FF.W.0023.000000T0000Z-210311T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kauai HI-
806 PM HST Wed Mar 10 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 930 PM HST THIS 
EVENING FOR THE ISLAND OF KAUAI IN KAUAI COUNTY...

At 806 PM HST, radar indicated moderate to heavy rain over east and 
southeast facing slopes of Kauai, from Poipu to Lihue to Anahola. 
Rain was falling at a rate of around 1 inch per hour, and area 
streams remain elevated.

HAZARD...Flash flooding caused by heavy rain.

SOURCE...Radar indicated.

IMPACT...Flooding in drainages, streams, rivers, roads,
         properties, and other low-lying areas. Public road
         closures possible in some areas. Landslides are possible
         in steep terrain.

Some locations that will experience flash flooding include...
  Lihue, Kapaa, Kalaheo, Kekaha, Princeville, Kilauea, North Fork 
  Wailua Trails, Alakai Swamp Trails, Lawai, Omao, Kokee State Park, 
  Wailua Homesteads, Hanalei, Hanapepe, Wainiha, Na Pali State Park, 
  Koloa, Haena, Waimea and Wailua.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Stay away from streams, rivers, drainage ditches, and culverts, even 
if they are currently dry.

Do not cross fast flowing or rising water in your vehicle, or on 
foot. Turn around, don't drown.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

The heavy rains may cause rock and mudslides in steep terrain areas.

&&

This warning may need to be extended beyond 930 PM HST if flooding 
persists.

LAT...LON 2225 15940 2222 15933 2216 15930 2215 15928
      2205 15932 2196 15932 2195 15934 2193 15934
      2190 15938 2186 15944 2188 15962 2194 15968
      2198 15978 2206 15980 2207 15980 2216 15974
      2224 15958 2222 15952 2225 15949 2224 15943

FLASH FLOOD...RADAR INDICATED

$$

JELSEMA
442 
WGHW70 PHFO 110721
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
921 PM HST Wed Mar 10 2021

HIC007-110731-
/O.EXP.PHFO.FF.W.0023.000000T0000Z-210311T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kauai HI-
921 PM HST Wed Mar 10 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 930 PM HST THIS EVENING FOR 
THE ISLAND OF KAUAI IN KAUAI COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

A Flash Flood Watch remains in effect until 600 PM HST Friday.

LAT...LON 2225 15940 2222 15933 2216 15930 2215 15928
      2205 15932 2196 15932 2195 15934 2193 15934
      2190 15938 2186 15944 2188 15962 2194 15968
      2198 15978 2206 15980 2207 15980 2216 15974
      2224 15958 2222 15952 2225 15949 2224 15943

$$

JELSEMA

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 10, 2:36 PM HSTFlash Flood WarningHFOHonolulu97 min
Mar 10, 3:00 PM HSTSpecial Marine WarningHFO2 hr
Mar 10, 3:11 PM HSTSmall Craft AdvisoryHFO13 hr
Mar 10, 3:45 PM HSTAreal Flood AdvisoryHFOKalawao3 hr
Mar 10, 4:13 PM HSTAreal Flood AdvisoryHFOHonolulu2 hr
Mar 10, 4:30 PM HSTAreal Flood AdvisoryHFOHawaii2 hr
Mar 10, 4:36 PM HSTSpecial Weather StatementHFOKauai24 min
Mar 10, 4:37 PM HSTSpecial Marine WarningHFO113 min
Mar 10, 4:58 PM HSTAreal Flood AdvisoryHFOHonolulu3 hr
Mar 10, 6:22 PM HSTFlash Flood WarningHFOHonolulu5 hr
Mar 10, 6:34 PM HSTSpecial Marine WarningHFO25 min
Mar 10, 8:05 PM HSTSpecial Marine WarningHFO46 min
Mar 10, 8:12 PM HSTSpecial Marine WarningHFO2 hr
Mar 10, 9:18 PM HSTSpecial Marine WarningHFO76 min
Mar 10, 9:27 PM HSTAreal Flood AdvisoryHFOHonolulu86 min
Mar 10, 11:04 PM HSTSpecial Marine WarningHFO116 min
Mar 11, 2:23 AM HSTAreal Flood AdvisoryHFOHonolulu7 hr
Mar 11, 2:39 AM HSTSpecial Marine WarningHFO2 hr
Mar 11, 3:21 AM HSTAreal Flood AdvisoryHFOKauai9 hr
Mar 11, 3:47 AM HSTSpecial Weather StatementHFOKauai43 min
Mar 11, 1:39 PM HSTAreal Flood AdvisoryHFOHonolulu43 min

Nearby

Flash Flood Warnings in Hawaii, 2021Every flash flood warning in 2021

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; radar from the NEXRAD Level II archive.