Alert archive / Nebraska / Mesoscale Discussions in 2022
Mesoscale Discussion 721
The Storm Prediction Center issued this mesoscale discussion at May 11, 2022, 12:50 PM CDT for 4 states. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- May 11, 2022, 12:50 PM CDT (17:50 UTC)
- Expired
- May 11, 2022, 3:15 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch likely
- Chance of a watch
- 80%
All 54 counties
Cherokee County, IA, Clay County, IA, Dickinson County, IA, Emmet County, IA, Ida County, IA, Lyon County, IA, Monona County, IA, O'Brien County, IA, Osceola County, IA, Plymouth County, IA, Sioux County, IA, Woodbury County, IA, Brown County, MN, Cottonwood County, MN, Jackson County, MN, Lincoln County, MN, Lyon County, MN, Martin County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Redwood County, MN, Rock County, MN, Watonwan County, MN, Antelope County, NE, Boone County, NE, Burt County, NE, Cedar County, NE, Colfax County, NE, Cuming County, NE, Dakota County, NE, Dixon County, NE, Dodge County, NE, Knox County, NE, Madison County, NE, Pierce County, NE, Platte County, NE, Stanton County, NE, Thurston County, NE, Wayne County, NE, Bon Homme County, SD, Brookings County, SD, Clay County, SD, Hanson County, SD, Hutchinson County, SD, Lake County, SD, Lincoln County, SD, McCook County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Turner County, SD, Union County, SD, Yankton County, SD
The radar
The Sioux Falls radar (KFSD), 80 km from the middle of the area, began a volume at 17:51 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, 5.8 hours before the alert went out and 193 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
- 3772 J/kg
- Mixed-layer CIN
- -76 J/kg
- Mixed-layer LCL
- 654 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 116 m²/s²
- 0-3 km storm-relative helicity
- 129 m²/s²
- Significant tornado parameter
- 1.4
- Supercell composite
- 6.0
The text
As transmitted.
620
ACUS11 KWNS 111751
SWOMCD
SPC MCD 111750
MNZ000-IAZ000-NEZ000-SDZ000-112015-
Mesoscale Discussion 0721
NWS Storm Prediction Center Norman OK
1250 PM CDT Wed May 11 2022
Areas affected...eastern Nebraska...western Iowa...southeast South
Dakota...southwest Minnesota
Concerning...Severe potential...Watch likely
Valid 111750Z - 112015Z
Probability of Watch Issuance...80 percent
SUMMARY...Storms are expected to form over northeastern Nebraska by
18 or 19Z, and will spread northward into South Dakota and Minnesota
later this afternoon. Damaging hail, wind, and few tornadoes will be
possible.
DISCUSSION...A prominent MCV continues to move north/northeast
across central NE, and is currently enhancing wind fields with
southerly midlevel winds of 40-50 kt. Meanwhile, a warm front
remains in place across far southeast SD into southern MN, with 70s
F dewpoints and heating to the south. Aiding instability are
relatively cool midlevel temperatures and steep lapse rates.
A few showers have developed recently near and north of the MCV,
where theta-e advection is occurring in the low levels. This feature
should cause a northward acceleration of the warm front later this
afternoon across SD and MN, and capping will be less at that time,
resulting in increased storm coverage. A 17Z OAX sounding shows
drying has occurred in the boundary layer, with MLCAPE values around
half what they were at 12Z.
Although favorable SRH near the warm front will tend to lift north
throughout the day, enhanced winds and shear associated with the MCV
may remain undersampled. Given the robust instability, it is likely
that zone of supercell potential will exist near and ahead of the
MCV, with damaging hail and wind likely. A few tornadoes will also
be possible, and a strong tornado cannot be ruled out as storms
approach the warm front, and assuming low-level shear remains
sufficient.
..Jewell/Mosier.. 05/11/2022
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MPX...DMX...FSD...OAX...LBF...
LAT...LON 44329447 43819419 43409438 43139477 42889514 42169558
41869590 41539639 41449714 41749829 42189846 43029825
43839803 44539655 44579528 44329447SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 11, 7:44 AM CDT | Mesoscale Discussion | SPC | Lyon, Sioux | 91 min |
| May 11, 1:15 PM CDT | Tornado Watch | SPC | Buena Vista, Calhoun, Cherokee, Clay, Crawford, Dickinson and 17 more | 8 hr |
| May 11, 3:52 PM CDT | Mesoscale Discussion | SPC | Buena Vista, Cherokee, Clay, Dickinson, Emmet, Lyon and 4 more | 113 min |
| May 11, 5:50 PM CDT | Mesoscale Discussion | SPC | Dickinson, Emmet, Osceola | 85 min |
| May 11, 6:32 AM CDT | Mesoscale Discussion | SPC | Dakota, Goodhue, Hennepin, Le Sueur, Ramsey, Rice and 3 more | 88 min |
| May 11, 5:27 PM CDT | Tornado Watch | SPC | Anoka, Benton, Blue Earth, Brown, Carver, Chippewa and 34 more | 7 hr |
Nearby
Mesoscale Discussions in Nebraska, 2022Mesoscale Discussions in South Dakota, 2022Mesoscale Discussions in Iowa, 2022Every mesoscale discussion in 2022
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.