Alert archive / Nebraska / Mesoscale Discussions in 2021
Mesoscale Discussion 1237
The Storm Prediction Center issued this mesoscale discussion at Jul 10, 2021, 1:20 PM CDT for 4 states. It was in force for 115 min.
The area
The outline as issued.
The facts
- Issued
- Jul 10, 2021, 1:20 PM CDT (18:20 UTC)
- Expired
- Jul 10, 2021, 3:15 PM CDT
- In force
- 115 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch possible
- Chance of a watch
- 40%
All 32 counties
Fremont County, IA, Mills County, IA, Montgomery County, IA, Page County, IA, Atchison County, KS, Brown County, KS, Doniphan County, KS, Marshall County, KS, Nemaha County, KS, Washington County, KS, Andrew County, MO, Atchison County, MO, Holt County, MO, Nodaway County, MO, Butler County, NE, Cass County, NE, Douglas County, NE, Fillmore County, NE, Gage County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Richardson County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Thayer County, NE, York County, NE
The radar
The Omaha radar (KOAX), 96 km from the middle of the area, began a volume at 18:23 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Omaha, NE (KOAX), launched 12:00Z, 6.3 hours before the alert went out and 96 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 976 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- -6 m²/s²
- 0-3 km storm-relative helicity
- 53 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
044
ACUS11 KWNS 101821
SWOMCD
SPC MCD 101820
MOZ000-IAZ000-KSZ000-NEZ000-102015-
Mesoscale Discussion 1237
NWS Storm Prediction Center Norman OK
0120 PM CDT Sat Jul 10 2021
Areas affected...Southeastern Nebraska...Southwestern
Iowa...Northwestern Missouri...and Northeastern Kansas
Concerning...Severe potential...Watch possible
Valid 101820Z - 102015Z
Probability of Watch Issuance...40 percent
SUMMARY...Thunderstorms are expected to increase in intensity and
organization this afternoon as they move south-southeastward across
the area. Convective trends will be monitored for the possibility
of a watch.
DISCUSSION...Disorganized convection, associated with a midlevel
shortwave trough, has moved into northeastern Nebraska and
northwestern Iowa this afternoon. Relatively cool midlevel
temperatures (<-10C) and surface dewpoints in the mid-to-upper 60s F
are contributing to moderate instability around 1500 J/kg in the
presence of effective bulk shear less than 25 knots. As the storms
move south-southeastward, they should encounter better shear
(despite shear weakening overall with time as the trough also shifts
southward), which may promote better updraft organization. These
storms will primarily pose a threat for severe hail, but a damaging
wind gust may also be possible if multicell clusters evolve.
..Jirak/Bunting.. 07/10/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DMX...EAX...OAX...TOP...GID...
LAT...LON 40799806 41089779 41339712 41469660 41459616 41289538
40979485 40459457 40039464 39709483 39539509 39419552
39429638 39629725 40039777 40799806SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 9, 7:08 PM CDT | Severe Thunderstorm Watch | SPC | Des Moines, Henry, Iowa, Jefferson, Johnson, Keokuk and 4 more | 3 hr |
| Jul 9, 9:12 PM CDT | Mesoscale Discussion | SPC | Adair, Adams, Cass, Fremont, Harrison, Mills and 7 more | 2 hr |
| Jul 9, 9:58 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Adams, Audubon, Carroll, Cass, Clarke and 16 more | 7 hr |
| Jul 10, 2:18 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Audubon, Cass, Fremont, Harrison, Mills and 5 more | 7 hr |
| Jul 10, 3:44 PM CDT | Mesoscale Discussion | SPC | Fremont, Page | 91 min |
| Jul 9, 8:45 PM CDT | Severe Thunderstorm Watch | SPC | Jewell, Mitchell, Osborne, Phillips, Rooks, Smith | 8 hr |
| Jul 9, 8:49 PM CDT | Mesoscale Discussion | SPC | Gove, Greeley, Hamilton, Kearny, Lane, Logan and 4 more | 86 min |
| Jul 9, 9:37 PM CDT | Severe Thunderstorm Watch | SPC | Finney, Gove, Greeley, Hamilton, Kearny, Lane and 8 more | 4 hr |
| Jul 9, 11:39 PM CDT | Mesoscale Discussion | SPC | Finney, Grant, Gray, Greeley, Hamilton, Kearny and 4 more | 66 min |
| Jul 10, 1:10 AM CDT | Mesoscale Discussion | SPC | Edwards, Finney, Ford, Grant, Gray, Hamilton and 10 more | 65 min |
| Jul 10, 1:21 AM CDT | Mesoscale Discussion | SPC | Atchison, Brown, Doniphan, Jackson, Jefferson, Leavenworth and 2 more | 84 min |
| Jul 10, 2:57 AM CDT | Mesoscale Discussion | SPC | Anderson, Clay, Cloud, Coffey, Dickinson, Douglas and 16 more | 93 min |
| Jul 10, 2:17 PM CDT | Mesoscale Discussion | SPC | Allen, Bourbon, Butler, Chautauqua, Cherokee, Cowley and 11 more | 118 min |
| Jul 10, 3:02 PM CDT | Severe Thunderstorm Watch | SPC | Allen, Bourbon, Butler, Chautauqua, Cherokee, Cowley and 9 more | 8 hr |
| Jul 10, 5:27 PM CDT | Mesoscale Discussion | SPC | Atchison, Brown, Doniphan, Douglas, Jackson, Jefferson and 9 more | 2 hr |
| Jul 9, 7:54 PM CDT | Mesoscale Discussion | SPC | Adair, Audrain, Chariton, Clark, Grundy, Knox and 18 more | 36 min |
| Jul 9, 8:18 PM CDT | Tornado Watch | SPC | Adair, Audrain, Boone, Callaway, Carroll, Chariton and 32 more | 6 hr |
| Jul 9, 10:26 PM CDT | Mesoscale Discussion | SPC | Adair, Audrain, Boone, Callaway, Chariton, Cole and 21 more | 64 min |
| Jul 10, 1:01 AM CDT | Mesoscale Discussion | SPC | Bollinger, Boone, Callaway, Cape Girardeau, Chariton, Cole and 23 more | 59 min |
| Jul 10, 1:36 AM CDT | Severe Thunderstorm Watch | SPC | Bollinger, Butler, Cape Girardeau, Carter, Perry, Ripley and 3 more | 4 hr |
| Jul 10, 3:09 AM CDT | Mesoscale Discussion | SPC | Bollinger, Butler, Cape Girardeau, Carter, Perry, Ripley and 3 more | 2 hr |
| Jul 10, 5:04 AM CDT | Mesoscale Discussion | SPC | Butler, Carter, Ripley, Stoddard | 56 min |
| Jul 10, 11:37 AM CDT | Mesoscale Discussion | SPC | Barry, Christian, Douglas, Howell, Laclede, McDonald and 9 more | 83 min |
| Jul 10, 1:25 PM CDT | Mesoscale Discussion | SPC | Bollinger, Butler, Camden, Cape Girardeau, Carter, Cedar and 34 more | 2 hr |
| Jul 10, 2:01 PM CDT | Severe Thunderstorm Watch | SPC | Bollinger, Butler, Cape Girardeau, Carter, Crawford, Franklin and 16 more | 8 hr |
| Jul 9, 8:21 PM CDT | Mesoscale Discussion | SPC | Adams, Antelope, Arthur, Blaine, Boone, Boyd and 44 more | 114 min |
| Jul 9, 9:06 PM CDT | Severe Thunderstorm Watch | SPC | Arthur, Blaine, Boyd, Brown, Cherry, Custer and 15 more | 6 hr |
| Jul 9, 10:20 PM CDT | Mesoscale Discussion | SPC | Butler, Clay, Fillmore, Gage, Hamilton, Jefferson and 7 more | 115 min |
| Jul 9, 10:44 PM CDT | Mesoscale Discussion | SPC | Box Butte, Garden, Grant, Sheridan | 91 min |
| Jul 10, 1:37 AM CDT | Mesoscale Discussion | SPC | Custer, Dawson, Lincoln, Logan, Thomas | 53 min |
| Jul 10, 1:45 AM CDT | Mesoscale Discussion | SPC | Custer, Dawson, Lincoln, Logan, Thomas | 60 min |
Nearby
Mesoscale Discussions in Nebraska, 2021Mesoscale Discussions in Kansas, 2021Mesoscale Discussions in Iowa, 2021Every mesoscale discussion in 2021
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.