Alert archive / Nebraska / Flash Flood Watches in 2011

Flash Flood Watch 1, NWS Omaha, NE

May 24, 201128 counties in Nebraska; 7 counties in Iowa

NWS Omaha, NE issued this flash flood watch at May 24, 2011, 1:10 PM CDT for 28 counties in Nebraska; 7 counties in Iowa. It took effect at May 24, 2011, 6:00 PM CDT. It was in force for 11 hr.

The area

The counties it named.

The facts

Issued: May 24, 2011, 1:10 PM CDT (18:10 UTC)
In effect from: May 24, 2011, 6:00 PM CDT
Expired: May 25, 2011, 5:03 AM CDT
In force: 11 hr
Issued by: NWS Omaha, NE
Flood severity: None

All 35 counties

Fremont County, IA, Harrison County, IA, Mills County, IA, Monona County, IA, Montgomery County, IA, Page County, IA, Pottawattamie County, IA, Antelope County, NE, Boone County, NE, Burt County, NE, Butler County, NE, Cass County, NE, Colfax County, NE, Cuming County, NE, Dodge County, NE, Douglas County, NE, Gage County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Madison County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Pierce County, NE, Platte County, NE, Richardson County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Stanton County, NE, Thurston County, NE, Washington County, NE, Wayne County, NE

The radar

The Omaha radar (KOAX), 17 km from the middle of the area, began a volume at 18:12 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 12:00Z, 6.2 hours before the alert went out and 17 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: 83 J/kg
Mixed-layer CIN: -113 J/kg
Mixed-layer LCL: 1073 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 40 m²/s²
0-3 km storm-relative helicity: 112 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

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 Omaha, NE wrote its last area forecast discussion before this flash flood watch went out at May 24, 3:13 AM CDT, 9 hours 57 minutes earlier.

Area forecast discussion, May 24, 3:13 AM CDT, 9 hours 57 minutes before

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Hazardous weather outlook, May 24, 12:22 PM CDT, 48 minutes before

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In the hours before

Local storm report, May 24, 10:30 AM CDT, 2 hours 40 minutes before

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Special weather statement, May 24, 12:50 PM CDT, 20 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
May 24, 9:28 AM CDT	River Flood Warning	OAX	Butler	23 hr
May 24, 9:28 AM CDT	River Flood Warning	OAX	Saline	23 hr
May 24, 9:28 AM CDT	River Flood Warning	OAX	Gage	23 hr
May 24, 9:28 AM CDT	River Flood Warning	OAX	Seward	23 hr
May 24, 9:28 AM CDT	River Flood Warning	OAX	Saline	23 hr
May 24, 1:58 PM CDT	River Flood Advisory	OAX	Douglas, Sarpy	4 days

Nearby

Flash Flood Watches in Nebraska, 2011 Flash Flood Watches in Iowa, 2011 Every flash flood watch in 2011

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.