Alert archive / Hawaii / Flash Flood Warnings in 2021

Flash Flood Warning 8, NWS Honolulu, HI

February 17, 2021Kauai County, Hawaii

NWS Honolulu, HI issued this flash flood warning at Feb 17, 2021, 2:27 AM HST for Kauai 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 outline as issued.

The facts

Issued: Feb 17, 2021, 2:27 AM HST (12:27 UTC)
Expired: Feb 17, 2021, 8:05 AM HST
In force: 6 hr
Issued by: NWS Honolulu, HI
Area: Storm-based polygon
Flood severity: None

County Kauai County, HI

The radar

The South Kauai radar (PHKI), 30 km from the middle of the area, began a volume at 12:28 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 12:00Z, 0.5 hours before the alert went out and 27 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 403 J/kg
Mixed-layer CIN: -114 J/kg
Mixed-layer LCL: 910 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 11 m²/s²
0-3 km storm-relative helicity: 45 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

566 
WGHW50 PHFO 171227
FFWHFO
HIC007-171515-
/O.NEW.PHFO.FF.W.0008.210217T1227Z-210217T1515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
227 AM HST Wed Feb 17 2021

The National Weather Service in Honolulu has issued a

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

* Until 515 AM HST.

* At 227 AM HST, radar and automated rain gauges indicated 
  thunderstorms producing heavy rain falling over northern Kauai. 
  Rain was falling at a rate of up to 3 inches per hour. Flash 
  flooding is occurring or expected to begin shortly. The Hanalei 
  River gage has reached 7.6 feet. River rises have also been 
  observed on the Hanakapiai Stream and Wainiha Rivers.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Radar and automated gauges.

  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, Princeville, Kilauea, North Fork Wailua Trails, 
  Hanalei, Wainiha, Wailua Homesteads, Haena, Wailua, Na Pali State 
  Park, Moloaa, Kokee State Park, Anahola, Kalihiwai, Wailua River 
  State Park, Hanamaulu and Waimea Canyon State Park.

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.

&&

This warning may need to be extended beyond 515 AM HST if flooding 
persists.

This Flash Flood Warning replaces the previously issued Flood 
Advisory that was in effect for The island of Kauai in Kauai County.

LAT...LON 2211 15977 2223 15956 2222 15952 2225 15949
      2221 15932 2199 15932

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

M BALLARD

3 follow-up statements

743 
WGHW70 PHFO 171338
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
338 AM HST Wed Feb 17 2021

HIC007-171515-
/O.CON.PHFO.FF.W.0008.000000T0000Z-210217T1515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kauai HI-
338 AM HST Wed Feb 17 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 515 AM HST EARLY THIS 
MORNING FOR THE ISLAND OF KAUAI IN KAUAI COUNTY...

At 338 AM HST, radar and automated rain gauges continue to show 
thunderstorms and heavy rain over the northern half of Kauai. Rain 
was falling at a rate of 1 to 2 inches per hour. Flash flooding is 
occurring or expected to begin shortly. Emergency management reports 
that Kuhio Highway in the vicinity of the Hanalei Bridge is closed. 
Stream gages show elevated levels along the Hanalei, Wainiha, 
Hanakapiai and Wailua Rivers.

HAZARD...Flash flooding caused by heavy rain.

SOURCE...Radar and automated gauges.

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, Princeville, Kilauea, North Fork Wailua Trails, 
  Hanalei, Wainiha, Wailua Homesteads, Haena, Wailua, Na Pali State 
  Park, Moloaa, Kokee State Park, Anahola, Kalihiwai, Wailua River 
  State Park, Hanamaulu and Waimea Canyon State Park.

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.

&&

This warning may need to be extended beyond 515 AM HST if flooding 
persists.

LAT...LON 2211 15977 2223 15956 2222 15952 2225 15949
      2221 15932 2199 15932

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

M BALLARD

331 
WGHW50 PHFO 171501
FFWHFO
HIC007-171815-
/O.EXT.PHFO.FF.W.0008.000000T0000Z-210217T1815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
501 AM HST Wed Feb 17 2021

The National Weather Service in Honolulu has extended the

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

* Until 815 AM HST.

* At 501 AM HST, emergency management reported water remains over 
  Kuhio Highway in the vicinity of the Hanalei Bridge, so the road 
  remains closed. Rain has dissipated some, but some rain continues 
  falling at a rate of up to 1 inch per hour. Several stream gages 
  continue to be elevated, but are on the decline.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Emergency management.

  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, Princeville, Kilauea, North Fork Wailua Trails, 
  Hanalei, Wainiha, Wailua Homesteads, Haena, Wailua, Na Pali State 
  Park, Moloaa, Kokee State Park, Anahola, Kalihiwai, Wailua River 
  State Park, Hanamaulu and Waimea Canyon State Park.

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.

&&

This warning may need to be extended beyond 815 AM HST if flooding 
persists.

LAT...LON 2211 15977 2223 15956 2222 15952 2225 15949
      2221 15932 2199 15932

FLASH FLOOD...OBSERVED

$$

M BALLARD

336 
WGHW70 PHFO 171805
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
805 AM HST Wed Feb 17 2021

HIC007-171815-
/O.CAN.PHFO.FF.W.0008.000000T0000Z-210217T1815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kauai HI-
805 AM HST Wed Feb 17 2021

...FLASH FLOOD WARNING IS CANCELLED FOR THE ISLAND OF KAUAI IN KAUAI 
COUNTY...

Heavy showers and thunderstorms have moved offshore and stream 
levels are dropping. Kauai Emergency Management reports that Kuhio 
Highway remains closed at the Hanalei Bridge, though flood waters 
are receding.

A Flash Flood Watch remains in effect until 600 PM HST Thursday for 
Kauai.

LAT...LON 2211 15977 2223 15956 2222 15952 2225 15949
      2221 15932 2199 15932

$$

WROE

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 17, 12:53 AM HST	Areal Flood Advisory	HFO	Kauai	3 hr

Nearby

Flash Flood Warnings in Hawaii, 2021 Every 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.