Alert archive / Hawaii / Flash Flood Warnings in 2021

Flash Flood Warning 39, NWS Honolulu, HI

November 14, 2021Kalawao County, Hawaii

NWS Honolulu, HI issued this flash flood warning at Nov 14, 2021, 5:20 AM HST for Kalawao County, Hawaii. It was in force for 116 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Nov 14, 2021, 5:20 AM HST (15:20 UTC)
Expired: Nov 14, 2021, 7:16 AM HST
In force: 116 min
Issued by: NWS Honolulu, HI
Area: Storm-based polygon
Flood severity: None

County Kalawao County, HI

The radar

The Kamuela/Kohala Apt radar (PHKM), 77 km from the middle of the area, began a volume at 15:19 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

Hilo, (PITO), launched 12:00Z, 3.3 hours before the alert went out and 158 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: 257 J/kg
Mixed-layer CIN: -26 J/kg
Mixed-layer LCL: 645 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 17 m²/s²
0-3 km storm-relative helicity: 59 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

899 
WGHW50 PHFO 141520
FFWHFO
HIC009-141830-
/O.NEW.PHFO.FF.W.0039.211114T1520Z-211114T1830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
520 AM HST Sun Nov 14 2021

The National Weather Service in Honolulu has issued a

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

* Until 830 AM HST.

* At 520 AM HST, radar indicated heavy rain over East Maui. Rain was 
  falling at a rate of 1.5 to 2.5 inches per hour. Flash flooding is 
  ongoing or expected to begin shortly.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Radar.

  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...
  Hana.

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.

&&

This warning may need to be extended beyond 830 AM HST if flooding 
persists.

LAT...LON 2077 15605 2081 15603 2082 15602 2081 15601
      2080 15599 2078 15597 2077 15597 2076 15597
      2073 15603

FLASH FLOOD...RADAR INDICATED

$$

RCB

1 follow-up statement

617 
WGHW70 PHFO 141716
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
716 AM HST Sun Nov 14 2021

HIC009-141726-
/O.CAN.PHFO.FF.W.0039.000000T0000Z-211114T1830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maui HI-
716 AM HST Sun Nov 14 2021

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

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Light rain will continue to fall across the area through the 
rest of the day.

A Flood Watch remains in effect until 600 AM HST Monday for 
Kahoolawe, Kauai, Lanai, Maui, Molokai, Niihau, Oahu and the Big 
Island.

LAT...LON 2077 15605 2081 15603 2082 15602 2081 15601
      2080 15599 2078 15597 2077 15597 2076 15597
      2073 15603

$$

LAU

The office that day

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

Issued	Product	Office	Counties	Lasted
Nov 13, 8:38 PM HST	Areal Flood Advisory	HFO	Hawaii	105 min
Nov 14, 3:42 AM HST	Flood Watch	HFO	Hawaii, Honolulu, Kauai, Kalawao	23 hr
Nov 14, 4:28 AM HST	Areal Flood Advisory	HFO	Kalawao	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.