Alert archive / Minnesota / Mesoscale Discussions in 2021
Mesoscale Discussion 1626
The Storm Prediction Center issued this mesoscale discussion at Aug 28, 2021, 5:42 AM CDT for 17 counties in Minnesota; 14 counties in South Dakota. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 28, 2021, 5:42 AM CDT (10:42 UTC)
- Expired
- Aug 28, 2021, 7:45 AM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 466
All 31 counties
Benton County, MN, Big Stone County, MN, Chippewa County, MN, Douglas County, MN, Grant County, MN, Kandiyohi County, MN, Lac qui Parle County, MN, McLeod County, MN, Meeker County, MN, Pope County, MN, Renville County, MN, Stearns County, MN, Stevens County, MN, Swift County, MN, Traverse County, MN, Wright County, MN, Yellow Medicine County, MN, Brown County, SD, Clark County, SD, Codington County, SD, Day County, SD, Deuel County, SD, Edmunds County, SD, Faulk County, SD, Grant County, SD, Marshall County, SD, McPherson County, SD, Potter County, SD, Roberts County, SD, Spink County, SD, Walworth County, SD
The radar
The Aberdeen radar (KABR), 144 km from the middle of the area, began a volume at 10:42 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
Aberdeen, SD (KABR), launched 00:00Z, 10.7 hours before the alert went out and 148 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
- 650 J/kg
- Mixed-layer CIN
- -128 J/kg
- Mixed-layer LCL
- 1212 m above ground
- 0-6 km bulk shear
- 54 kt
- 0-1 km storm-relative helicity
- 74 m²/s²
- 0-3 km storm-relative helicity
- 186 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 4.1
The text
As transmitted.
420
ACUS11 KWNS 281042
SWOMCD
SPC MCD 281042
MNZ000-SDZ000-281245-
Mesoscale Discussion 1626
NWS Storm Prediction Center Norman OK
0542 AM CDT Sat Aug 28 2021
Areas affected...Northeast South Dakota and western/central
Minnesota
Concerning...Severe Thunderstorm Watch 466...
Valid 281042Z - 281245Z
The severe weather threat for Severe Thunderstorm Watch 466
continues.
SUMMARY...An isolated severe threat will likely continue across
northeast South Dakota over the next couple of hours. Strong to
severe storms will likely approach the Minnesota state line
necessitating the issuance of a new weather watch.
DISCUSSION...The latest radar imagery from Aberdeen shows a
well-developed supercell just to the southeast of Aberdeen. The
storm is located on the western end of an east-to-west corridor of
moderate instability. The RAP is estimating MLCAPE around 2500 J/kg
along this corridor with effective shear near 50 kt. This combined
with 700-500 mb lapse rates approaching 8.0 C/km will continue to be
favorable for supercells with large hail. In spite of a low-level
temperature inversion, a few strong to severe wind gusts will also
be possible.
Further to the west, a short line segment with embedded rotating
storms is located near Mobridge. The storms will move eastward along
a gradient of moderate instability with the RAP estimating MLCAPE
near 1500 J/kg. This combined with strong effective shear will be
favorable for continued hail threat. A potential for isolated strong
gusts will also be possible.
The storms and the associated severe threat will likely continue
beyond the current watch expiration time. A new weather will likely
be needed beyond 13Z.
..Broyles.. 08/28/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MPX...FGF...FSD...ABR...
LAT...LON 44989389 45419387 45769402 45969446 46049500 45989565
45889662 45839863 45839961 45580019 45240024 44960006
44769943 44829772 44729672 44499576 44449520 44579433
44989389SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 27, 9:57 PM CDT | Mesoscale Discussion | SPC | Fillmore, Houston | 93 min |
| Aug 28, 2:17 AM CDT | Mesoscale Discussion | SPC | Big Stone, Stevens, Swift, Traverse | 2 hr |
| Aug 28, 2:32 AM CDT | Severe Thunderstorm Watch | SPC | Big Stone, Traverse | 5 hr |
| Aug 28, 7:08 AM CDT | Severe Thunderstorm Watch | SPC | Big Stone, Chippewa, Douglas, Grant, Kandiyohi, Lac qui Parle and 13 more | 5 hr |
| Aug 28, 9:39 AM CDT | Mesoscale Discussion | SPC | Anoka, Benton, Chisago, Douglas, Grant, Isanti and 12 more | 2 hr |
| Aug 28, 10:34 AM CDT | Tornado Watch | SPC | Aitkin, Anoka, Benton, Carlton, Carver, Chisago and 14 more | 4 hr |
| Aug 28, 1:13 PM CDT | Mesoscale Discussion | SPC | Anoka, Chisago, Isanti, Kanabec, Pine | 2 hr |
| Aug 28, 2:43 PM CDT | Mesoscale Discussion | SPC | Murray, Nobles, Pipestone, Rock | 3 hr |
| Aug 28, 3:44 PM CDT | Tornado Watch | SPC | Cottonwood, Jackson, Lincoln, Lyon, Murray, Nobles and 2 more | 5 hr |
| Aug 28, 3:57 PM CDT | Severe Thunderstorm Watch | SPC | Cottonwood, Jackson, Murray, Nobles, Rock | 7 hr |
| Aug 28, 5:27 PM CDT | Mesoscale Discussion | SPC | Blue Earth, Brown, Carver, Cottonwood, Dakota, Dodge and 22 more | 63 min |
| Aug 28, 5:59 PM CDT | Severe Thunderstorm Watch | SPC | Blue Earth, Brown, Carver, Faribault, Freeborn, Le Sueur and 11 more | 6 hr |
| Aug 28, 6:09 PM CDT | Mesoscale Discussion | SPC | Blue Earth, Brown, Cottonwood, Nicollet, Watonwan | 66 min |
Nearby
Mesoscale Discussions in Minnesota, 2021Mesoscale Discussions in South Dakota, 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.