Alert archive / Nebraska / Flash Flood Warnings in 2026

Flash Flood Warning 9, NWS Omaha, NE

May 17, 2026Johnson County, Nemaha County, Otoe County, Nebraska

NWS Omaha, NE issued this flash flood warning at May 17, 2026, 12:54 AM CDT for Johnson County, Nemaha County, Otoe County, Nebraska. It was in force for 93 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: May 17, 2026, 12:54 AM CDT (05:54 UTC)
Expired: May 17, 2026, 2:27 AM CDT
In force: 93 min
Issued by: NWS Omaha, NE
Area: Storm-based polygon
Flood severity: None

Counties Johnson County, NE, Nemaha County, NE, Otoe County, NE

The radar

The Omaha radar (KOAX), 97 km from the middle of the area, began a volume at 05:53 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, 5.9 hours before the alert went out and 97 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: 2743 J/kg
Mixed-layer CIN: -30 J/kg
Mixed-layer LCL: 1278 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 77 m²/s²
0-3 km storm-relative helicity: 253 m²/s²
Significant tornado parameter: 1.5
Supercell composite: 12.0

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 May 17, 12:38 AM CDT, 16 minutes earlier.

Area forecast discussion, May 17, 12:38 AM CDT, 16 minutes before

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Hazardous weather outlook, May 16, 8:21 PM CDT, 4 hours 33 minutes before

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In the hours before

Local storm report, May 16, 11:56 PM CDT, 58 minutes before

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Local storm report, May 16, 11:58 PM CDT, 56 minutes before

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Local storm report, May 17, 12:02 AM CDT, 52 minutes before

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Local storm report, May 17, 12:16 AM CDT, 38 minutes before

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Local storm report, May 17, 12:35 AM CDT, 19 minutes before

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Local storm report, May 17, 12:53 AM CDT, 1 minute 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 16, 7:16 PM CDT	Severe Thunderstorm Warning	OAX	Boone	44 min
May 16, 7:17 PM CDT	Severe Thunderstorm Warning	OAX	Gage, Jefferson, Saline	43 min
May 16, 7:32 PM CDT	Severe Thunderstorm Warning	OAX	Butler	58 min
May 16, 7:43 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Gage, Jefferson, Lancaster, Saline	47 min
May 16, 8:06 PM CDT	Severe Thunderstorm Warning	OAX	Lancaster, Saline, Seward	54 min
May 16, 8:12 PM CDT	Tornado Warning	OAX	Gage	33 min
May 16, 8:17 PM CDT	Severe Thunderstorm Warning	OAX	Madison, Pierce, Stanton, Wayne	24 min
May 16, 8:19 PM CDT	Severe Thunderstorm Warning	OAX	Butler, Saunders	41 min
May 16, 8:25 PM CDT	Severe Thunderstorm Warning	OAX	Jefferson, Saline	50 min
May 16, 8:30 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Gage	45 min
May 16, 8:43 PM CDT	Flood Watch	OAX	Butler, Cass, Douglas, Gage, Jefferson, Johnson and 9 more	6 hr
May 16, 9:01 PM CDT	Severe Thunderstorm Warning Destructive damage threat	OAX	Gage, Lancaster, Saline	44 min
May 16, 9:04 PM CDT	Severe Thunderstorm Warning	OAX	Butler, Lancaster, Saunders, Seward	35 min
May 16, 9:09 PM CDT	Tornado Warning	OAX	Gage	36 min
May 16, 9:12 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Gage, Johnson, Pawnee	48 min
May 16, 9:19 PM CDT	Severe Thunderstorm Warning	OAX	Saline	56 min
May 16, 9:22 PM CDT	Flash Flood Warning	OAX	Gage	4 hr
May 16, 9:22 PM CDT	Tornado Warning	OAX	Gage	21 min
May 16, 9:28 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Saunders	16 min
May 16, 9:42 PM CDT	Severe Thunderstorm Warning	OAX	Douglas, Sarpy, Saunders	33 min
May 16, 9:51 PM CDT	Severe Thunderstorm Warning	OAX	Lancaster, Saunders	26 min
May 16, 9:56 PM CDT	Severe Thunderstorm Warning	OAX	Gage, Johnson	49 min
May 16, 10:12 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Butler, Jefferson, Saline, Seward	48 min
May 16, 10:16 PM CDT	Severe Thunderstorm Warning	OAX	Jefferson	13 min
May 16, 10:28 PM CDT	Severe Thunderstorm Warning	OAX	Johnson, Nemaha, Otoe	62 min
May 16, 10:42 PM CDT	Severe Thunderstorm Warning	OAX	Lancaster, Saunders	24 min
May 16, 10:52 PM CDT	Severe Thunderstorm Warning	OAX	Gage, Jefferson, Saline	53 min
May 16, 11:08 PM CDT	Flash Flood Warning	OAX	Gage, Johnson, Otoe	3 hr
May 16, 11:15 PM CDT	Severe Thunderstorm Warning	OAX	Saline, Seward	60 min
May 16, 11:17 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Gage, Jefferson	58 min
May 16, 11:30 PM CDT	Flash Flood Warning	OAX	Saline	3 hr
May 16, 11:43 PM CDT	Severe Thunderstorm Warning	OAX	Nemaha, Otoe	47 min
May 16, 11:46 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Gage, Jefferson, Johnson, Pawnee	59 min
May 16, 11:59 PM CDT	Severe Thunderstorm Warning Destructive damage threat	OAX	Gage, Jefferson, Johnson, Pawnee	46 min
May 17, 12:03 AM CDT	Severe Thunderstorm Warning	OAX	Gage, Jefferson, Johnson, Otoe, Saline	57 min
May 17, 12:09 AM CDT	Flash Flood Warning	OAX	Gage, Jefferson, Saline	114 min
May 17, 12:41 AM CDT	Severe Thunderstorm Warning	OAX	Gage, Johnson, Nemaha, Pawnee, Richardson	79 min
May 17, 11:52 AM CDT	Flood Watch	OAX	Cass, Gage, Jefferson, Johnson, Lancaster, Nemaha and 5 more	34 hr
May 17, 2:25 PM CDT	Severe Thunderstorm Warning	OAX	Knox	50 min
May 17, 5:34 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Boone, Platte	56 min
May 17, 5:47 PM CDT	Severe Thunderstorm Warning	OAX	Antelope, Boone, Madison, Platte	43 min
May 17, 6:01 PM CDT	Severe Thunderstorm Warning Destructive damage threat	OAX	Madison, Platte, Stanton	44 min
May 17, 6:15 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Madison, Stanton, Wayne	45 min
May 17, 6:18 PM CDT	Severe Thunderstorm Warning	OAX	Platte	42 min
May 17, 6:22 PM CDT	Severe Thunderstorm Warning	OAX	Saline, Seward	53 min
May 17, 6:23 PM CDT	Tornado Warning	OAX	Colfax, Platte, Stanton	25 min
May 17, 6:26 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Colfax, Cuming, Stanton	49 min
May 17, 6:30 PM CDT	Tornado Warning	OAX	Colfax, Platte	18 min
May 17, 6:39 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Burt, Cuming, Dodge, Stanton, Thurston, Wayne	66 min
May 17, 6:48 PM CDT	Severe Thunderstorm Warning	OAX	Lancaster, Saline, Saunders, Seward	42 min
May 17, 6:54 PM CDT	Severe Thunderstorm Warning	OAX	Butler, Colfax, Platte	51 min
May 16, 7:41 PM CDT	Severe Thunderstorm Warning	OAX	Fremont	34 min

Nearby

Flash Flood Warnings in Nebraska, 2026 Every flash flood warning in 2026

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.