Alert archive / Hawaii / Flash Flood Warnings in 2018

Flash Flood Warning 49, NWS Honolulu, HI

August 27, 2018Hawaii County, Hawaii

NWS Honolulu, HI issued this flash flood warning at Aug 27, 2018, 1:24 PM HST for Hawaii 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: Aug 27, 2018, 1:24 PM HST (23:24 UTC)
Expired: Aug 27, 2018, 4:30 PM HST
In force: 3 hr
Issued by: NWS Honolulu, HI
Area: Storm-based polygon
Flood severity: None

County Hawaii County, HI

The radar

The Kamuela/Kohala Apt radar (PHKM), 28 km from the middle of the area, began a volume at 23:24 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, 11.4 hours before the alert went out and 70 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: 350 J/kg
Mixed-layer CIN: -9 J/kg
Mixed-layer LCL: 683 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: -48 m²/s²
0-3 km storm-relative helicity: -23 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

184 
WGHW50 PHFO 272324
FFWHFO
HIC001-280230-
/O.NEW.PHFO.FF.W.0049.180827T2324Z-180828T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
124 PM HST MON AUG 27 2018

The National Weather Service in Honolulu has issued a

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

* Until 430 PM HST.
    
* At 124 PM HST, radar indicated a thunderstorm producing heavy rain
  near Waikii, or near Pohakuloa Camp. The storm is nearly 
  stationary. Rain was falling at a rate of 3 to 4 inches per hour. 
  Flash flooding is expected to begin shortly.

* Locations in the warning include but are not limited to...
  Pohakuloa Camp, Kamuela, Pohakuloa Training Area and Waipio Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A flash flood warning means that flooding is imminent or occurring in
streams, roads, and low lying areas. Move to higher ground now.

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

&&

This warning may need to be extended beyond 430 PM HST if heavy rain
persists.

LAT...LON 2004 15555 1969 15545 1961 15576 1990 15573
      2016 15580

$$

Foster

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 26, 3:18 PM HST	Areal Flood Advisory	HFO	Hawaii	63 min
Aug 27, 7:34 AM HST	Areal Flood Advisory	HFO	Kauai	3 hr
Aug 27, 10:29 AM HST	Areal Flood Advisory	HFO	Kauai	3 hr
Aug 27, 11:44 AM HST	Flash Flood Warning	HFO	Kauai	9 hr

Nearby

Flash Flood Warnings in Hawaii, 2018 Every flash flood warning in 2018

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.