Alert archive / Minnesota / Mesoscale Discussions in 2021
Mesoscale Discussion 1818
The Storm Prediction Center issued this mesoscale discussion at Oct 9, 2021, 11:20 PM CDT for 13 counties in Minnesota. It was in force for 115 min.
The area
The outline as issued.
The facts
- Issued
- Oct 9, 2021, 11:20 PM CDT (04:20 UTC)
- Expired
- Oct 10, 2021, 1:15 AM CDT
- In force
- 115 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 515
Counties Benton County, MN, Cass County, MN, Chippewa County, MN, Crow Wing County, MN, Kandiyohi County, MN, Lac qui Parle County, MN, Meeker County, MN, Morrison County, MN, Pope County, MN, Stearns County, MN, Swift County, MN, Todd County, MN, Yellow Medicine County, MN
The radar
The Minneapolis radar (KMPX), 156 km from the middle of the area, began a volume at 04:22 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
Minneapolis, MN (KMPX), launched 00:00Z, 4.3 hours before the alert went out and 154 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
- 458 J/kg
- Mixed-layer CIN
- -239 J/kg
- Mixed-layer LCL
- 1239 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 247 m²/s²
- 0-3 km storm-relative helicity
- 346 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted.
471
ACUS11 KWNS 100421
SWOMCD
SPC MCD 100420
MNZ000-SDZ000-100615-
Mesoscale Discussion 1818
NWS Storm Prediction Center Norman OK
1120 PM CDT Sat Oct 09 2021
Areas affected...Southwestern-Central MN
Concerning...Severe Thunderstorm Watch 515...
Valid 100420Z - 100615Z
The severe weather threat for Severe Thunderstorm Watch 515
continues.
SUMMARY...Strong convection will continue along a corridor from
southwestern through central MN. Locally damaging winds are the
primary risk for the next few hours.
DISCUSSION...Earlier MCS that formed over eastern SD has advanced
downstream and weakened somewhat as surface low is now lifting north
across southeast ND. However, a southwest-northeast corridor of
strong storms continues across MN, strongly influenced by low-level
warm advection in association with 40-50kt LLJ. Latest
satellite/radar data depict a well-defined upper vort over Hand
County SD approaching the southwestern flank of MN convection. This
feature will likely contribute to the maintenance of thunderstorm
activity across the upper MS Valley during the pre-dawn hours. Given
the observed shear within the warm advection zone, there is some
concern for a few strong/locally severe storms. While this activity
has not been particularly productive over the last few hours, some
severe threat will linger due to the shear/forcing.
..Darrow.. 10/10/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DLH...MPX...FGF...FSD...ABR...
LAT...LON 44799657 45969529 46979464 47489399 46629345 45219427
44539560 44799657SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 9, 8:27 PM CDT | Mesoscale Discussion | SPC | Becker, Douglas, Grant, Otter Tail, Pope, Stevens and 4 more | 93 min |
| Oct 10, 12:57 PM CDT | Mesoscale Discussion | SPC | Itasca, Koochiching, Lake, Lake of the Woods, Saint Louis | 2 hr |
| Oct 10, 1:42 PM CDT | Severe Thunderstorm Watch | SPC | Cook, Itasca, Koochiching, Lake, Saint Louis | 7 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.