Alert archive / Nebraska / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 228
The Storm Prediction Center issued this severe thunderstorm watch at May 3, 2012, 12:50 AM CDT for 8 counties in Iowa; Atchison County, Holt County, Nodaway County, Missouri; 10 counties in Nebraska. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- May 3, 2012, 12:50 AM CDT (05:50 UTC)
- Expired
- May 3, 2012, 5:00 AM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 21 counties
Adams County, IA, Cass County, IA, Fremont County, IA, Mills County, IA, Montgomery County, IA, Page County, IA, Pottawattamie County, IA, Taylor County, IA, Atchison County, MO, Holt County, MO, Nodaway County, MO, Cass County, NE, Douglas County, NE, Gage County, NE, Jefferson County, NE, Johnson County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Richardson County, NE, Sarpy County, NE
The radar
The Omaha radar (KOAX), 90 km from the middle of the area, began a volume at 05:50 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
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
3 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 3, 1:15 AM CDT | Severe Thunderstorm Warning | OAX | Cass, Douglas, Sarpy | 30 min |
| May 3, 2:11 AM CDT | Severe Thunderstorm Warning | OAX | Fremont, Mills | 34 min |
| May 3, 2:29 AM CDT | Severe Thunderstorm Warning | OAX | Fremont, Page | 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 00:00Z, 5.8 hours before the alert went out and 90 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.
- Mixed-layer CAPE
- 2533 J/kg
- Mixed-layer CIN
- -7 J/kg
- Mixed-layer LCL
- 1223 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 46 m²/s²
- 0-3 km storm-relative helicity
- 102 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 1.4
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 2, 10:43 PM CDT | Mesoscale Discussion | SPC | Harrison, Monona, Plymouth, Sioux, Woodbury | 62 min |
| May 3, 3:05 AM CDT | Mesoscale Discussion | SPC | Adair, Adams, Cass, Clarke, Decatur, Montgomery and 4 more | 85 min |
| May 3, 2:12 PM CDT | Mesoscale Discussion | SPC | Buena Vista, Calhoun, Cerro Gordo, Cherokee, Clay, Dickinson and 18 more | 2 hr |
| May 3, 3:41 PM CDT | Mesoscale Discussion | SPC | Adair, Adams, Cass, Clarke, Fremont, Madison and 7 more | 2 hr |
| May 3, 6:42 PM CDT | Mesoscale Discussion | SPC | Appanoose, Davis, Decatur, Des Moines, Henry, Lee and 5 more | 63 min |
| May 2, 7:32 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Antelope, Boone, Buffalo, Burt, Butler and 36 more | 6 hr |
Nearby
Severe Thunderstorm Watches in Nebraska, 2012Severe Thunderstorm Watches in Iowa, 2012Severe Thunderstorm Watches in Missouri, 2012Every severe thunderstorm watch in 2012
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.