Alert archive / Minnesota / Severe Thunderstorm Watches in 2021
Severe Thunderstorm Watch 463
The Storm Prediction Center issued this severe thunderstorm watch at Aug 26, 2021, 9:05 AM CDT for 17 counties in Minnesota; 13 counties in South Dakota. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 26, 2021, 9:05 AM CDT (14:05 UTC)
- Expired
- Aug 26, 2021, 12:57 PM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 65 kt
All 30 counties
Big Stone County, MN, Chippewa County, MN, Kandiyohi County, MN, Lac qui Parle County, MN, Lincoln County, MN, Lyon County, MN, Meeker County, MN, Murray County, MN, Pipestone County, MN, Pope County, MN, Redwood County, MN, Renville County, MN, Stearns County, MN, Stevens County, MN, Swift County, MN, Traverse County, MN, Yellow Medicine County, MN, Beadle County, SD, Brookings County, SD, Clark County, SD, Codington County, SD, Deuel County, SD, Grant County, SD, Hamlin County, SD, Kingsbury County, SD, Lake County, SD, Miner County, SD, Moody County, SD, Roberts County, SD, Sanborn County, SD
The radar
The Sioux Falls radar (KFSD), 181 km from the middle of the area, began a volume at 14:06 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 5%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 50%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 26, 9:14 AM CDT | Severe Thunderstorm Warning | ABR | Big Stone, Traverse | 46 min |
| Aug 26, 9:18 AM CDT | Severe Thunderstorm Warning | FSD | Beadle, Kingsbury | 57 min |
| Aug 26, 9:22 AM CDT | Severe Thunderstorm Warning | ABR | Clark, Hamlin, Spink | 38 min |
| Aug 26, 9:26 AM CDT | Severe Thunderstorm Warning | ABR | Clark, Codington, Hamlin | 49 min |
| Aug 26, 9:57 AM CDT | Severe Thunderstorm Warning | ABR | Big Stone, Traverse | 33 min |
| Aug 26, 9:58 AM CDT | Severe Thunderstorm Warning | ABR | Deuel, Hamlin | 62 min |
| Aug 26, 10:00 AM CDT | Severe Thunderstorm Warning | ABR | Codington, Deuel, Grant, Hamlin | 60 min |
| Aug 26, 10:01 AM CDT | Severe Thunderstorm Warning | FSD | Brookings, Kingsbury, Lake, Miner, Moody | 59 min |
| Aug 26, 10:39 AM CDT | Severe Thunderstorm Warning | FSD | Lincoln, Lyon | 66 min |
| Aug 26, 10:39 AM CDT | Severe Thunderstorm Warning | MPX | Lac qui Parle, Yellow Medicine | 51 min |
| Aug 26, 11:05 AM CDT | Severe Thunderstorm Warning | MPX | Chippewa, Swift | 40 min |
| Aug 26, 11:37 AM CDT | Severe Thunderstorm Warning | MPX | Chippewa, Kandiyohi, Swift | 23 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Minneapolis, MN (KMPX), launched 12:00Z, 2.1 hours before the alert went out and 179 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1566 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 65 m²/s²
- 0-3 km storm-relative helicity
- 146 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
307
WWUS20 KWNS 261402
SEL3
SPC WW 261402
MNZ000-SDZ000-262000-
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 463
NWS Storm Prediction Center Norman OK
905 AM CDT Thu Aug 26 2021
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
southwest Minnesota
eastern South Dakota
* Effective this Thursday morning and afternoon from 905 AM until
300 PM CDT.
* Primary threats include...
Scattered damaging winds and isolated significant gusts to 75
mph possible
Isolated large hail events to 1.5 inches in diameter possible
SUMMARY...Line of storms may remain capable of producing damaging
wind as it continues through eastern South Dakota and southwestern
Minnesota this morning into the early afternoon.
The severe thunderstorm watch area is approximately along and 70
statute miles east and west of a line from 5 miles east northeast of
Alexandria MN to 40 miles southwest of Brookings SD. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU3).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
30035.
...DialSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 26, 8:36 AM CDT | Mesoscale Discussion | SPC | Big Stone, Lac qui Parle | 84 min |
| Aug 26, 10:43 AM CDT | Mesoscale Discussion | SPC | Lac qui Parle, Lincoln, Lyon, Murray, Pipestone, Redwood and 1 more | 92 min |
| Aug 26, 1:12 PM CDT | Mesoscale Discussion | SPC | Fillmore, Houston, Winona | 93 min |
| Aug 26, 1:53 PM CDT | Mesoscale Discussion | SPC | Carver, Dakota, Goodhue, Hennepin, Le Sueur, Ramsey and 3 more | 97 min |
| Aug 26, 2:35 AM CDT | Mesoscale Discussion | SPC | Brown, Campbell, Corson, Dewey, Edmunds, Faulk and 6 more | 2 hr |
| Aug 26, 3:10 AM CDT | Mesoscale Discussion | SPC | Bon Homme, Charles Mix, Clay, Hutchinson, Turner, Yankton | 3 hr |
| Aug 26, 5:34 PM CDT | Mesoscale Discussion | SPC | Clay, Lincoln, Turner, Union, Yankton | 116 min |
Nearby
Severe Thunderstorm Watches in Minnesota, 2021Severe Thunderstorm Watches in South Dakota, 2021Every severe thunderstorm watch 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.