Alert archive / Hawaii / Flash Flood Watches in 2009

Flash Flood Watch 8, NWS Honolulu, HI

December 19, 2009Hawaii County, Honolulu County, Kalawao County, Hawaii

NWS Honolulu, HI issued this flash flood watch at Dec 19, 2009, 11:30 PM HST for Hawaii County, Honolulu County, Kalawao County, Hawaii. It took effect at Dec 20, 2009, 12:00 AM HST. It was in force for 16 hr.

The area

The counties it named.

The facts

Issued: Dec 19, 2009, 11:30 PM HST (09:30 UTC)
In effect from: Dec 20, 2009, 12:00 AM HST
Expired: Dec 20, 2009, 3:35 PM HST
In force: 16 hr
Issued by: NWS Honolulu, HI
Flood severity: None

Counties Hawaii County, HI, Honolulu County, HI, Kalawao County, HI

The nearest sounding before it

Hilo, (PITO), launched 00:00Z, 9.5 hours before the alert went out and 221 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: 759 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 812 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: -2 m²/s²
0-3 km storm-relative helicity: 110 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.3

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood watch 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 watch went out at Dec 19, 8:35 PM HST, 2 hours 55 minutes earlier.

Area forecast discussion, Dec 19, 8:35 PM HST, 2 hours 55 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 19, 2:28 PM HST	Areal Flood Advisory	HFO	Hawaii	3 hr
Dec 19, 5:15 PM HST	Areal Flood Advisory	HFO	Hawaii	3 hr
Dec 19, 5:37 PM HST	Flash Flood Warning	HFO	Hawaii	6 hr
Dec 19, 11:04 PM HST	Wind Advisory	HFO	Hawaii	4 hr
Dec 20, 3:12 AM HST	Areal Flood Advisory	HFO	Kalawao	5 hr
Dec 20, 4:51 AM HST	Areal Flood Advisory	HFO	Kalawao	4 hr
Dec 20, 6:04 AM HST	Special Marine Warning	HFO		116 min
Dec 20, 7:09 AM HST	Severe Thunderstorm Warning	HFO	Kalawao	23 min
Dec 20, 7:23 AM HST	Special Marine Warning	HFO		98 min
Dec 20, 7:59 AM HST	Special Marine Warning	HFO		77 min
Dec 20, 8:11 AM HST	Severe Thunderstorm Warning	HFO	Hawaii	68 min
Dec 20, 9:46 AM HST	Winter Weather Advisory	HFO	Hawaii	6 hr
Dec 20, 10:07 AM HST	Areal Flood Advisory	HFO	Hawaii	2 hr

Nearby

Flash Flood Watches in Hawaii, 2009 Every flash flood watch in 2009

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.