Alert archive / Minnesota / Mesoscale Discussions in 2021
Mesoscale Discussion 1627
The Storm Prediction Center issued this mesoscale discussion at Aug 28, 2021, 9:39 AM CDT for 18 counties in Minnesota; 11 counties in Wisconsin. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 28, 2021, 9:39 AM CDT (14:39 UTC)
- Expired
- Aug 28, 2021, 11:45 AM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 467
All 29 counties
Anoka County, MN, Benton County, MN, Chisago County, MN, Douglas County, MN, Grant County, MN, Isanti County, MN, Kanabec County, MN, Kandiyohi County, MN, Mille Lacs County, MN, Morrison County, MN, Pine County, MN, Pope County, MN, Sherburne County, MN, Stearns County, MN, Stevens County, MN, Swift County, MN, Todd County, MN, Wright County, MN, Ashland County, WI, Barron County, WI, Bayfield County, WI, Burnett County, WI, Douglas County, WI, Iron County, WI, Polk County, WI, Price County, WI, Rusk County, WI, Sawyer County, WI, Washburn County, WI
The radar
The Duluth radar (KDLH), 98 km from the middle of the area, began a volume at 14:42 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
Minneapolis, MN (KMPX), launched 12:00Z, 2.7 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
- 1550 J/kg
- Mixed-layer CIN
- -130 J/kg
- Mixed-layer LCL
- 676 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 139 m²/s²
- 0-3 km storm-relative helicity
- 193 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.3
The text
As transmitted.
839
ACUS11 KWNS 281439
SWOMCD
SPC MCD 281439
WIZ000-MIZ000-MNZ000-281645-
Mesoscale Discussion 1627
NWS Storm Prediction Center Norman OK
0939 AM CDT Sat Aug 28 2021
Areas affected...central Minnesota...northern Wisconsin and western
Upper Michigan
Concerning...Severe Thunderstorm Watch 467...
Valid 281439Z - 281645Z
The severe weather threat for Severe Thunderstorm Watch 467
continues.
SUMMARY...An MCS is expected to produce wind damage as it moves
across central Minnesota and into northwest Wisconsin today. A few
significant wind gusts are possible. Additional watches are expected
downstream of WW 467.
DISCUSSION...A small but intense MCS continues to become more
organized as it moves out of northeast SD and into west-central MN,
with impressive IR presentation. Surface temperatures are currently
cool ahead of this system, only in the upper 60s to lower 70s F
north of the warm front. However, significant elevated instability
is present as seen on the 12Z MPX sounding, and, a differential
heating zone currently exists around the latitude of the Twin
Cities.
SBCAPE is expected to increase with heating throughout the day, and
due to increasing low-level warm advection. Moderate southwest flow
aloft combined with backed/southeasterly surface winds ahead of this
system will maintain favorable shear and storm relative inflow. As
such, this system should at least maintain intensity, and perhaps
strengthen. While embedded areas of rotation or a brief tornado
cannot be ruled out with this system, the primary threat is expected
to be damaging winds.
..Jewell.. 08/28/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MQT...GRB...DLH...MPX...FGF...ABR...
LAT...LON 46029610 46679190 46959101 46959082 46799043 46569023
46328999 45899004 45499041 45299143 45199283 45109634
45279631 45669614 46029610SPC 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, 5:42 AM CDT | Mesoscale Discussion | SPC | Benton, Big Stone, Chippewa, Douglas, Grant, Kandiyohi and 11 more | 2 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, 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 |
| Aug 27, 7:59 PM CDT | Mesoscale Discussion | SPC | Crawford, Grant, Iowa, Lafayette | 2 hr |
Nearby
Mesoscale Discussions in Minnesota, 2021Mesoscale Discussions in Wisconsin, 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.