During the afternoon of Sunday, October 11th, a line of thunderstorms developed along a cold front in far western Minnesota. These storms quickly became severe with wind gusts of 65 mph near Canby and Brandon, with damage around Canby.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS MPX wrote it up.
During the afternoon of Sunday, October 11th, a line of thunderstorms developed along a cold front in far western Minnesota. These storms quickly became severe with wind gusts of 65 mph near Canby and Brandon, with damage around Canby. As the storms moved eastward, more stable air and less wind shear allowed for the storms to decrease in severity.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Twin Cities, MN wrote its last area forecast discussion before the first event at Oct 11, 5:30 PM CST, 25 minutes earlier.
Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 630 PM CDT Sun Oct 11 2020 .UPDATE... Issued at 614 PM CDT Sun Oct 11 2020 Updated to include 00z aviation discussion below. && .SHORT TERM...(This evening through Monday night) Issued at 347 PM CDT Sun Oct 11 2020 Development of storms late this afternoon along the western border appears to be on track with previous thinking. CAMs are in very good agreement in general. Most CAMs suggest two lines at first, which seems to match up with satellite trends this afternoon, and then eventually one line. A surface low is also evident in east central South Dakota. A narrow corridor exists with surface dew points in the upper 50s to lower 60s, which is where the severe weather is most likely. This low does translate to west central MN by 7 pm, so a brief tornado cannot be ruled out early, but the vast majority of concern is damaging wind from bowing segments along with hail to some extent. SPC discussion describes all of this very well. Otherwise, the timing of storms has been slowed a bit from this morning, with the storms reaching the west metro no earlier than 10 pm, and then Wisconsin after midnight. Light rain will linger for a few hours, especially in eastern MN and western WI. Monday will be a mostly sunny day in western MN, with clearing Monday morning/midday in eastern MN and western WI. West winds will become gusty, and there may be some fire weather concerns if temps get a little warmer with lower dew points. For now, relative humidity levels should drop to 25 to 30 percent. Another trough approaches quickly Monday night, but it will be weak with no appreciable effects other than some mid and high level clouds and a switch in wind direction. .LONG TERM...(Tuesday through Sunday) Issued at 347 PM CDT Sun Oct 11 2020 The long term period begins with a large scale trough sliding eastwards through central Canada with high pressure building to our west as wide-scale subsidence becomes apparent. This brief period of high pressure will be short lived as a deepening shortwave trough pushes into the area by the second half of Wednesday resulting in another chance for showers across the area. Compared to yesterday, this area of showers is a bit further south, affecting mainly central Minnesota, but this trend would be good to mitigate some of the drought conditions seen across the area. We once again see a return to wide-scale subsidence behind this shortwave as the larger trough rotates eastwards across southeastern Canada, with northwesterly flow aloft keeping conditions relatively cool and dry. Cool and dry conditions are expected to remain the case through the end of the period with high temperatures struggling to get out of the 40s beginning Thursday and continuing through the weekend. On the other side of things, low temperatures will be in the mid 20s to low 30s likely giving us our first stretch of sustained below freezing conditions for this fall season. Most areas will likely see below freezing overnight temps except in the warmer parts of the Twin Cities metro. Overall weather threat is low for the period, with some showers possible on Wednesday and maybe a slight chance on Friday, with a period of cooler weather to go along with this. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 614 PM CDT Sun Oct 11 2020 Strong SSE winds to continue this evening in advance of the developing line of thunderstorms along the MN/Dakota border. As the line shifts east, winds will shift to W and NW while still maintaining the breezy speeds. Have used TEMPO groups to give some wiggle room for the initiation of the storms into each terminal with more solid RA/TSRA afterwards. MVFR conditions are likely with IFR conditions, mainly due to visibility, possible as the storms move across the area. Lingering showers behind the line look to develop overnight along with MVFR ceilings in eastern MN and western WI that will persist through daybreak before VFR conditions return during the day Monday. KMSP...Start time of storms into MSP looks to be around 04z with thunderstorms persisting thru midnight. Showers will linger overnight along with MVFR ceilings in the 025-030 range (nothing below 2 kft expected). Conditions will improve out of MVFR range by late morning, so the MVFR ceilings will remain through the Monday morning push. /OUTLOOK FOR KMSP/ Tue...VFR. Wind WNW 10-20 kts. Wed...Mainly VFR. Chance -RA/MVFR. Wind SE 10-15 kts becoming W. Thu...VFR. Wind NW 10-20 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && UPDATE...JPC SHORT TERM...TDK LONG TERM...TDH AVIATION...JPC
Hazardous Weather Outlook...UPDATED National Weather Service Twin Cities/Chanhassen MN 108 PM CDT Sun Oct 11 2020 MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028- 121200- Douglas-Todd-Morrison-Mille Lacs-Kanabec-Stevens-Pope-Stearns- Benton-Sherburne-Isanti-Chisago-Lac Qui Parle-Swift-Chippewa- Kandiyohi-Meeker-Wright-Hennepin-Anoka-Ramsey-Washington- Yellow Medicine-Renville-McLeod-Sibley-Carver-Scott-Dakota- Redwood-Brown-Nicollet-Le Sueur-Rice-Goodhue-Watonwan-Blue Earth- Waseca-Steele-Martin-Faribault-Freeborn-Polk-Barron-Rusk- St. Croix-Pierce-Dunn-Pepin-Eau Claire- 108 PM CDT Sun Oct 11 2020 This Hazardous Weather Outlook is for portions of central and southern Minnesota...and west central Wisconsin. .DAY ONE...This Afternoon and Tonight. Thunderstorms are likely to develop after 5:00 p.m. in far western Minnesota, move eastward across the rest of Minnesota this evening, reaching western Wisconsin around midnight. Some storms could be severe, especially in western Minnesota. The main threat is damaging wind. Hail is a secondary threat. The threat for tornadoes is low, but cannot be ruled out in west central or southwest Minnesota. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Dry and breezy conditions could lead to elevated fire weather concerns for Monday afternoon, and also Tuesday, especially across western Minnesota. .SPOTTER INFORMATION STATEMENT... SKYWARN spotter activation will likely be needed tonight. tdk
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</html>The Sioux Falls radar (KFSD), 130 km away, was scanning. The volume nearest the first event began at 23:53 UTC.
3 thunderstorm wind. Local standard time, as filed.
A few power poles were blown down near Canby.
No damage reports were received.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Minnesota in 2020Every state in 2020This day in weather historyWarnings in Minnesota, October 2020
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-10-01. Each event’s entry at NCEI: 917063, 917064, 917065.