Alert archive / Nebraska / Tornado Watches in 2023

Tornado Watch 215

May 12, 202311 counties in Iowa; 48 counties in Nebraska; 11 counties in South Dakota

The Storm Prediction Center issued this tornado watch at May 12, 2023, 1:09 PM CDT for 11 counties in Iowa; 48 counties in Nebraska; 11 counties in South Dakota. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued: May 12, 2023, 1:09 PM CDT (18:09 UTC)
Expired: May 12, 2023, 9:00 PM CDT
In force: 8 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 60 kt

All 70 counties

Fremont County, IA, Harrison County, IA, Ida County, IA, Mills County, IA, Monona County, IA, Montgomery County, IA, Page County, IA, Plymouth County, IA, Pottawattamie County, IA, Shelby County, IA, Woodbury County, IA, Antelope County, NE, Blaine County, NE, Boone County, NE, Boyd County, NE, Brown County, NE, Burt County, NE, Butler County, NE, Cass County, NE, Cedar County, NE, Colfax County, NE, Cuming County, NE, Custer County, NE, Dakota County, NE, Dixon County, NE, Dodge County, NE, Douglas County, NE, Gage County, NE, Garfield County, NE, Greeley County, NE, Holt County, NE, Howard County, NE, Johnson County, NE, Keya Paha County, NE, Knox County, NE, Lancaster County, NE, Loup County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Pierce County, NE, Platte County, NE, Polk County, NE, Richardson County, NE, Rock County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Sherman County, NE, Stanton County, NE, Thurston County, NE, Valley County, NE, Washington County, NE, Wayne County, NE, Wheeler County, NE, York County, NE, Bon Homme County, SD, Brule County, SD, Charles Mix County, SD, Clay County, SD, Douglas County, SD, Gregory County, SD, Hutchinson County, SD, Lyman County, SD, Tripp County, SD, Union County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 163 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes: 40%
One or more EF2 to EF5 tornadoes: 20%
Ten or more severe wind reports: 40%
One or more gusts of 65 knots or more: 20%
Ten or more severe hail reports: 60%
One or more hailstones of 2 inches or more: 60%
Six or more combined severe hail and wind reports: 90%

Warnings issued inside it

92 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
May 12, 1:35 PM CDT	Severe Thunderstorm Warning	GID	Sherman, Valley	25 min
May 12, 1:49 PM CDT	Severe Thunderstorm Warning	GID	Greeley, Valley	41 min
May 12, 2:17 PM CDT	Severe Thunderstorm Warning	GID	Valley	43 min
May 12, 2:28 PM CDT	Tornado Warning Tornado observed	GID	Greeley	17 min
May 12, 2:30 PM CDT	Tornado Warning Tornado observed	LBF	Garfield, Wheeler	45 min
May 12, 2:33 PM CDT	Tornado Warning	GID	Merrick, Nance	27 min
May 12, 2:33 PM CDT	Tornado Warning	LBF	Garfield, Loup	42 min
May 12, 2:41 PM CDT	Severe Thunderstorm Warning	OAX	Boone	34 min
May 12, 2:47 PM CDT	Tornado Warning	OAX	Antelope, Boone	32 min
May 12, 2:48 PM CDT	Flash Flood Warning	LBF	Garfield, Loup	3 hr
May 12, 2:54 PM CDT	Tornado Warning	GID	Merrick, Polk	36 min
May 12, 2:55 PM CDT	Severe Thunderstorm Warning	LBF	Garfield, Loup, Wheeler	50 min
May 12, 3:00 PM CDT	Severe Thunderstorm Warning	OAX	Boone, Platte	45 min
May 12, 3:04 PM CDT	Tornado Warning	OAX	Platte	41 min
May 12, 3:09 PM CDT	Severe Thunderstorm Warning	OAX	Butler, Lancaster, Saunders, Seward	51 min
May 12, 3:17 PM CDT	Tornado Warning	GID	Nance	28 min
May 12, 3:21 PM CDT	Severe Thunderstorm Warning	GID	Merrick, Polk	24 min
May 12, 3:25 PM CDT	Tornado Warning Tornado observed	LBF	Garfield, Wheeler	50 min
May 12, 3:26 PM CDT	Tornado Warning	GID	Merrick, Nance, Polk	34 min
May 12, 3:27 PM CDT	Severe Thunderstorm Warning	OAX	Boone, Platte	48 min
May 12, 3:29 PM CDT	Tornado Warning	OAX	Butler, Colfax, Platte	23 min
May 12, 3:29 PM CDT	Tornado Warning	OAX	Boone, Madison, Platte	46 min
May 12, 3:41 PM CDT	Tornado Warning	OAX	Boone, Madison, Platte	49 min
May 12, 3:42 PM CDT	Severe Thunderstorm Warning	OAX	Butler, Colfax, Lancaster, Saunders, Seward	39 min
May 12, 3:56 PM CDT	Tornado Warning	LBF	Custer, Logan	34 min
May 12, 3:58 PM CDT	Tornado Warning	OAX	Antelope, Boone, Madison	47 min
May 12, 4:01 PM CDT	Tornado Warning	LBF	Garfield, Holt, Wheeler	44 min
May 12, 4:03 PM CDT	Severe Thunderstorm Warning	OAX	Johnson, Nemaha, Pawnee, Richardson	42 min
May 12, 4:15 PM CDT	Severe Thunderstorm Warning	OAX	Butler, Colfax, Platte	30 min
May 12, 4:18 PM CDT	Tornado Warning	OAX	Platte	42 min
May 12, 4:20 PM CDT	Tornado Warning	OAX	Madison, Platte	40 min
May 12, 4:24 PM CDT	Tornado Warning	OAX	Butler, Colfax, Platte	51 min
May 12, 4:26 PM CDT	Tornado Warning	OAX	Johnson, Nemaha, Pawnee	49 min
May 12, 4:36 PM CDT	Severe Thunderstorm Warning	OAX	Butler, Colfax	39 min
May 12, 4:43 PM CDT	Tornado Warning Tornado observed	LBF	Garfield, Holt, Wheeler	47 min
May 12, 4:44 PM CDT	Tornado Warning	OAX	Madison, Pierce	28 min
May 12, 4:47 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Colfax, Madison, Platte, Stanton	43 min
May 12, 4:50 PM CDT	Tornado Warning Tornado observed	OAX	Johnson, Nemaha, Pawnee, Richardson	40 min
May 12, 4:58 PM CDT	Severe Thunderstorm Warning	OAX	Butler, Lancaster, Saunders, Seward	62 min
May 12, 5:00 PM CDT	Tornado Warning	OAX	Stanton	45 min
May 12, 5:02 PM CDT	Tornado Warning	OAX	Dodge, Saunders	43 min
May 12, 5:07 PM CDT	Tornado Warning	OAX	Colfax, Platte, Stanton	38 min
May 12, 5:08 PM CDT	Tornado Warning	OAX	Butler, Colfax, Dodge	15 min
May 12, 5:11 PM CDT	Tornado Warning	OAX	Madison, Pierce	11 min
May 12, 5:22 PM CDT	Tornado Warning	OAX	Nemaha, Pawnee, Richardson	38 min
May 12, 5:24 PM CDT	Tornado Warning	OAX	Dodge, Saunders	51 min
May 12, 5:25 PM CDT	Tornado Warning	LBF	Holt	50 min
May 12, 5:26 PM CDT	Tornado Warning Tornado observed	OAX	Dodge	49 min
May 12, 5:31 PM CDT	Tornado Warning Tornado observed	OAX	Colfax, Platte, Stanton	30 min
May 12, 5:42 PM CDT	Tornado Warning	OAX	Nemaha, Richardson	48 min
May 12, 5:46 PM CDT	Tornado Warning	OAX	Cuming, Stanton, Wayne	44 min
May 12, 5:54 PM CDT	Tornado Warning Tornado observed	OAX	Burt, Cuming, Dodge	66 min
May 12, 5:58 PM CDT	Flash Flood Warning	OAX	Nemaha	2 hr
May 12, 6:01 PM CDT	Tornado Warning	OAX	Dodge, Saunders, Washington	45 min
May 12, 6:07 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Cuming, Dodge, Saunders	38 min
May 12, 6:09 PM CDT	Flash Flood Warning	OAX	Dodge	80 min
May 12, 6:09 PM CDT	Tornado Warning	OAX	Knox	36 min
May 12, 6:21 PM CDT	Tornado Warning	OAX	Cedar, Wayne	39 min
May 12, 6:25 PM CDT	Tornado Warning	FSD	Dixon	35 min
May 12, 6:27 PM CDT	Severe Thunderstorm Warning	OAX	Nemaha, Otoe	48 min
May 12, 6:29 PM CDT	Tornado Warning	OAX	Nemaha	12 min
May 12, 6:45 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Burt, Cuming, Dodge, Saunders, Washington	45 min
May 12, 6:48 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Dixon	42 min
May 12, 6:49 PM CDT	Severe Thunderstorm Warning	OAX	Richardson	56 min
May 12, 6:51 PM CDT	Tornado Warning	OAX	Fremont	24 min
May 12, 6:56 PM CDT	Tornado Warning	OAX	Monona	36 min
May 12, 7:02 PM CDT	Severe Thunderstorm Warning	OAX	Cedar, Knox	43 min
May 12, 7:04 PM CDT	Tornado Warning Tornado observed	OAX	Richardson	41 min
May 12, 7:09 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Dixon	51 min
May 12, 7:10 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Cedar	35 min
May 12, 7:10 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Cedar	35 min
May 12, 7:10 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Bon Homme, Yankton	35 min
May 12, 7:20 PM CDT	Severe Thunderstorm Warning	OAX	Burt, Dodge, Saunders, Washington	40 min
May 12, 7:21 PM CDT	Tornado Warning	OAX	Fremont, Page	39 min
May 12, 7:23 PM CDT	Tornado Warning	OAX	Harrison, Monona	37 min
May 12, 7:27 PM CDT	Severe Thunderstorm Warning	FSD	Woodbury	33 min
May 12, 7:31 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Monona	59 min
May 12, 7:36 PM CDT	Severe Thunderstorm Warning	OAX	Richardson	37 min
May 12, 7:37 PM CDT	Severe Thunderstorm Warning	OAX	Cedar	23 min
May 12, 7:46 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth, Woodbury	44 min
May 12, 7:50 PM CDT	Severe Thunderstorm Warning	FSD	Woodbury	40 min
May 12, 7:51 PM CDT	Severe Thunderstorm Warning	OAX	Fremont, Page	8 min
May 12, 7:51 PM CDT	Severe Thunderstorm Warning	OAX	Monona	9 min
May 12, 7:55 PM CDT	Tornado Warning	FSD	Woodbury	35 min
May 12, 7:55 PM CDT	Flash Flood Warning	OAX	Monona	3 hr
May 12, 7:56 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Harrison, Monona	49 min
May 12, 8:16 PM CDT	Tornado Warning	FSD	Plymouth, Woodbury	29 min
May 12, 8:17 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth, Sioux	28 min
May 12, 8:18 PM CDT	Severe Thunderstorm Warning	OAX	Harrison	27 min
May 12, 8:27 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth, Woodbury	48 min
May 12, 8:58 PM CDT	Severe Thunderstorm Warning	OAX	Richardson	18 min
May 12, 8:59 PM CDT	Severe Thunderstorm Warning	OAX	Harrison	31 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 6.2 hours before the alert went out and 198 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: 413 J/kg
Mixed-layer CIN: -14 J/kg
Mixed-layer LCL: 616 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 52 m²/s²
0-3 km storm-relative helicity: 44 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 12, 12:17 PM CDT	Mesoscale Discussion	SPC	Fremont, Harrison, Mills, Monona, Pottawattamie, Woodbury	118 min
May 12, 6:00 PM CDT	Mesoscale Discussion	SPC	Fremont, Harrison, Mills, Pottawattamie	90 min
May 12, 5:06 PM CDT	Severe Thunderstorm Watch	SPC	Andrew, Atchison, Holt, Nodaway	8 hr
May 12, 3:23 PM CDT	Mesoscale Discussion	SPC	Antelope, Blaine, Boone, Boyd, Brown, Butler and 36 more	2 hr

Nearby

Tornado Watches in Nebraska, 2023 Tornado Watches in Iowa, 2023 Tornado Watches in South Dakota, 2023 Every tornado watch in 2023

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.