Alert archive / Nebraska / Severe Thunderstorm Watches in 2018
Severe Thunderstorm Watch 82
The Storm Prediction Center issued this severe thunderstorm watch at May 11, 2018, 1:50 AM CDT for 12 counties in Nebraska. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- May 11, 2018, 1:50 AM CDT (06:50 UTC)
- Expired
- May 11, 2018, 5:00 AM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 65 kt
Counties Butler County, NE, Cass County, NE, Gage County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Saline County, NE, Saunders County, NE, Seward County, NE
The radar
The Omaha radar (KOAX), 74 km from the middle of the area, began a volume at 06:53 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 5%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 11, 1:57 AM CDT | Severe Thunderstorm Warning | OAX | Butler, Gage, Jefferson, Lancaster, Saline, Saunders and 1 more | 33 min |
| May 11, 3:34 AM CDT | Severe Thunderstorm Warning | OAX | Gage, Jefferson, Lancaster, Saline, Seward | 26 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
Topeka, KS (KFOE), launched 00:00Z, 6.8 hours before the alert went out and 216 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
- 577 J/kg
- Mixed-layer CIN
- -121 J/kg
- Mixed-layer LCL
- 2178 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 7 m²/s²
- 0-3 km storm-relative helicity
- 118 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.3
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 10, 7:06 PM CDT | Mesoscale Discussion | SPC | Dundy | 114 min |
| May 10, 7:39 PM CDT | Mesoscale Discussion | SPC | Adams, Arthur, Blaine, Buffalo, Chase, Custer and 25 more | 2 hr |
| May 10, 7:59 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Arthur, Blaine, Brown, Buffalo, Chase and 40 more | 9 hr |
| May 10, 11:16 PM CDT | Mesoscale Discussion | SPC | Adams, Antelope, Boone, Buffalo, Chase, Custer and 19 more | 89 min |
| May 11, 1:13 AM CDT | Mesoscale Discussion | SPC | Butler, Cass, Douglas, Gage, Jefferson, Johnson and 7 more | 92 min |
| May 11, 4:24 AM CDT | Mesoscale Discussion | SPC | Adams, Butler, Cass, Clay, Colfax, Douglas and 22 more | 66 min |
| May 11, 3:02 PM CDT | Severe Thunderstorm Watch | SPC | Banner, Kimball, Scotts Bluff, Sioux | 7 hr |
| May 11, 6:39 PM CDT | Mesoscale Discussion | SPC | Banner, Kimball, Scotts Bluff, Sioux | 96 min |
Nearby
Severe Thunderstorm Watches in Nebraska, 2018Every severe thunderstorm watch in 2018
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.