Alert archive / Minnesota / Mesoscale Discussions in 2021
Mesoscale Discussion 1569
The Storm Prediction Center issued this mesoscale discussion at Aug 20, 2021, 5:51 PM CDT for 26 counties in Minnesota. It was in force for 84 min.
The area
The outline as issued.
The facts
- Issued
- Aug 20, 2021, 5:51 PM CDT (22:51 UTC)
- Expired
- Aug 20, 2021, 7:15 PM CDT
- In force
- 84 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 451...452
All 26 counties
Becker County, MN, Beltrami County, MN, Cass County, MN, Chippewa County, MN, Clearwater County, MN, Douglas County, MN, Grant County, MN, Hubbard County, MN, Kandiyohi County, MN, Kittson County, MN, Mahnomen County, MN, Marshall County, MN, Meeker County, MN, Norman County, MN, Otter Tail County, MN, Pennington County, MN, Polk County, MN, Pope County, MN, Red Lake County, MN, Renville County, MN, Roseau County, MN, Stearns County, MN, Stevens County, MN, Swift County, MN, Todd County, MN, Wadena County, MN
The radar
The Fargo/Grand Forks radar (KMVX), 127 km from the middle of the area, began a volume at 22:54 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 nearest sounding before it
International Fa, MN (KINL), launched 12:00Z, 10.9 hours before the alert went out and 263 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
- 347 J/kg
- Mixed-layer CIN
- -74 J/kg
- Mixed-layer LCL
- 1086 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 22 m²/s²
- 0-3 km storm-relative helicity
- 13 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
736
ACUS11 KWNS 202251
SWOMCD
SPC MCD 202251
MNZ000-NDZ000-210015-
Mesoscale Discussion 1569
NWS Storm Prediction Center Norman OK
0551 PM CDT Fri Aug 20 2021
Areas affected...Eastern ND...Western MN...Northwestern IA
Concerning...Severe Thunderstorm Watch 451...452...
Valid 202251Z - 210015Z
The severe weather threat for Severe Thunderstorm Watch 451, 452
continues.
SUMMARY...Severe threat will shift east across ww451 this evening.
DISCUSSION...Strong short-wave trough is ejecting northeast across
the Dakotas this evening. Extensive corridor of convection has
evolved ahead of this feature from northeast ND, arcing across
western MN into northwest IA. Strengthening LLJ across MN this
evening should encourage a slow propagation east over the next
several hours. While some hail threat is expected with the strongest
storms, damaging wind may be the primary concern as storms migrate
across the instability axis over the next few hours.
..Darrow.. 08/20/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DLH...MPX...FGF...
LAT...LON 44659581 47289646 47629737 48429748 48949647 48679483
47599427 44739431 44659581SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 20, 1:41 PM CDT | Mesoscale Discussion | SPC | Clay, Kittson, Marshall, Norman, Pennington, Polk and 4 more | 3 hr |
| Aug 20, 2:24 PM CDT | Severe Thunderstorm Watch | SPC | Becker, Beltrami, Cass, Clay, Clearwater, Crow Wing and 16 more | 8 hr |
| Aug 20, 3:58 PM CDT | Severe Thunderstorm Watch | SPC | Big Stone, Blue Earth, Brown, Chippewa, Cottonwood, Douglas and 26 more | 6 hr |
Nearby
Mesoscale Discussions in Minnesota, 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.