Alert archive / Nebraska / Flash Flood Warnings in 2019

Flash Flood Warning 38, NWS Omaha, NE

September 11, 2019Thurston County, Nebraska; Monona County, Iowa

NWS Omaha, NE issued this flash flood warning at Sep 11, 2019, 4:43 AM CDT for Thurston County, Nebraska; Monona County, Iowa. 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 counties it named.

The facts

Issued: Sep 11, 2019, 4:43 AM CDT (09:43 UTC)
Expired: Sep 11, 2019, 7:45 AM CDT
In force: 3 hr
Issued by: NWS Omaha, NE
Area: Storm-based polygon
Flood severity: None

Counties Monona County, IA, Thurston County, NE

The radar

The Omaha radar (KOAX), 88 km from the middle of the area, began a volume at 09:44 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

Omaha, NE (KOAX), launched 00:00Z, 9.7 hours before the alert went out and 88 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: 2988 J/kg
Mixed-layer CIN: -12 J/kg
Mixed-layer LCL: 1146 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 86 m²/s²
0-3 km storm-relative helicity: 108 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 6.1

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Omaha, NE wrote its last area forecast discussion before this flash flood warning went out at Sep 10, 6:09 PM CDT, 10 hours 34 minutes earlier.

Area forecast discussion, Sep 10, 6:09 PM CDT, 10 hours 34 minutes before

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Hazardous weather outlook, Sep 10, 3:20 PM CDT, 13 hours 23 minutes before

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The office that day

Everything else NWS Omaha, NE issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 10, 7:26 PM CDT	Severe Thunderstorm Warning	OAX	Knox	23 min
Sep 10, 11:42 PM CDT	Special Weather Statement	OAX	Knox	33 min
Sep 11, 4:13 AM CDT	Flash Flood Watch	OAX	Antelope, Cedar, Knox, Pierce, Thurston, Wayne	27 hr
Sep 11, 10:03 AM CDT	River Flood Warning	OAX	Washington	31 days
Sep 11, 10:03 AM CDT	River Flood Warning	OAX	Cass	58 days
Sep 11, 10:19 AM CDT	River Flood Advisory	OAX	Douglas, Sarpy	25 hr

Nearby

Flash Flood Warnings in Nebraska, 2019 Flash Flood Warnings in Iowa, 2019 Every flash flood warning in 2019

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.