Several storms moved across southern Minnesota during the mid afternoon hours of Wednesday, July 19th. A few of the storms bowed out from south of Redwood Falls to Mankato, and into Owatonna and Northfield.
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.
Several storms moved across southern Minnesota during the mid afternoon hours of Wednesday, July 19th. A few of the storms bowed out from south of Redwood Falls to Mankato, and into Owatonna and Northfield. There were numerous reports of downed trees and power lines with some corn fields flattened in southern Brown County near Comfrey.
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 Jul 19, 11:54 AM CST, 1 hour 54 minutes earlier.
Area Forecast Discussion...UPDATED National Weather Service Twin Cities/Chanhassen MN 1254 PM CDT Wed Jul 19 2017 .SHORT TERM...(Today and tonight) Issued at 343 AM CDT Wed Jul 19 2017 The short term concern is timing of possible severe convection and heavy rain threat. Surface cold front dropped south of the state into northern Iowa last evening. Temperatures cooled nicely with light winds and clear sky. Some fog developed in northeast cwa and will linger until around sunrise and should burn off quickly. Focus turns to possible development of large scale high wind severe weather event for much of the cwa late this afternoon and through the evening. Deterministic models have been pointing to this possibility now for last several days and the 00z runs continue this trend. Water vapor imagery showing rather vigorous short wave moving through eastern Montana this morning and will be the forcing and focusing mechanism for the MCS development over western central MN by early this evening. SPC Day 1 outlook with its enhanced risk paints the scenario and the HIRES ARW confirms our earlier thoughts regarding the event. We should see development by evening to the west as the short wave arrives and the warm front retreats to the north into southwest MN. Capping should limit development there for a time. Very unstable airmass in place and once development occurs, it should become predominately upscale and become a forward propagating MCS and ride the instability/CAPE gradient over the southern third of the cwa this evening. General movement of the QPF bullseye/RAP vort maxima gives a general 45 to 50kt southeast forward movement. Still could be some spatial and temporal issues but they should resolve themselves later this morning. Damaging winds, large hail and an isolated tornado or two is possible. The tornado threat should be mainly early in any discrete cell development and also possible in the mature MCS/Bow Echo/QLCS. The severe weather threat will likely end before 06z if models are correct due to fast forward movement. Heavy rain will be a threat with the storms as well, with high PWs around 2 or 3 standard deviations above normal. We still believe 2 to 3 inch an hour rainfall rates are likely but because of the fast movement and antecedent soil conditions a widespread flash flood threat is not anticipated at this time. Some HIRES models did show some indication of continued convective development to the northwest across southern MN after this complex moves through. This is certainly possible and the nw-se orientation of the scattered convection could pose some backbuilding threat later tonight. This will have to be monitored as it could certainly increase the potential flash flood threat. .LONG TERM...(Thursday through Tuesday) Issued at 343 AM CDT Wed Jul 19 2017 In the longer term we'll see mainly zonal flow (albeit with a low amplitude ridge over the center of the CONUS) evolve to cooler northwest flow for our area by the second half of the weekend. This pattern looks to stay in place through the first part of next week, but indications are that ridging will build across the center of the country again by the middle of next week. However, there is certainly some disagreement on the guidance at that point, so won't be going all in on any particular solution at this point, with a consensus approach looking to be the safest bet. A weak ridge of high pressure and drier air will work into the area on Thursday, with dry weather expected across the area. However, low pressure will work into the Plains by Friday, helping to lift the baroclinic zone and better moisture back north into our area. This will bring chances for showers and thunderstorms into the area from southwest to northeast late Thursday night into Friday night. The better forcing then looks to focus mainly north of our area Saturday. Cold frontal boundary looks to drop south through the area Saturday night and early Sunday, which won't be the ideal time for convection, but could still see some activity Sunday, with the best chance looking to be over the southern and eastern portion of the area where instability looks to be best as forcing from the upper wave and low level boundary work through the area. High pressure will build over the region Sunday night and Monday, with cooler and drier weather expected. We will then need to wait for return flow to setup again, which looks to occur later Tuesday into Wednesday as the 500 mb ridge builds to our west and the 850 mb theta-e ridge starts to work back into the area. The GFS and ECMWF are in reasonable agreement that we'll see some activity develop in the return flow during that time frame, with chances persisting into Wednesday as the warm frontal boundary sets up shop nearby. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) Issued at 1254 PM CDT Wed Jul 19 2017 Showers and thunderstorms will push east across MN this afternoon with severe storms expected to track south of the MN river, likely south of MKT and RWF. After this round, another may develop across central MN this evening and push southeast tonight. VFR conditions expected outside of precipitation until late tonight when MVFR cigs may develop. KMSP...Should see some showers pushing in between 20-21Z and persist for a couple hours. Embedded thunderstorms are expected. Confidence is quite low tonight, but another round of storms may develop mid to late evening. /OUTLOOK FOR KMSP/ Fri...Mainly VFR. -SHRA/TSRA likely. Winds SE 5-10 kts. Sat...Mainly VFR. Chc MVFR in -SHRA/TSRA. Winds lgt and vrbl. Sun...VFR. Wind NW 10 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && SHORT TERM...DWE LONG TERM... AVIATION...BORGHOFF
Hazardous Weather Outlook...UPDATED National Weather Service Twin Cities/Chanhassen MN 1259 PM CDT Wed Jul 19 2017 MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028- 201800- 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- 1259 PM CDT Wed Jul 19 2017 This Hazardous Weather Outlook is for portions of central and southern Minnesota...and west central Wisconsin. .DAY ONE...This Afternoon and Tonight There is an enhanced risk of severe weather. A complex of thunderstorms is expected to impact southern Minnesota this afternoon, with the potential for widespread damaging wind gusts. Another round of storms could develop this evening across central Minnesota and track southeast into the overnight, with mainly a large hail threat. A couple tornadoes are possible with either round. Very heavy rainfall is also possible, which could lead to localized flooding. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday Thunderstorm chances return late Thursday night into Friday. There is a slight risk of severe weather, mainly south of I-94. Large hail, damaging winds, and heavy rainfall appear to be the primary threats. Thunderstorms will be possible late Saturday and Sunday, and again from Tuesday into Wednesday. Widespread severe weather during those time frames is not anticipated at this time. .SPOTTER INFORMATION STATEMENT... SKYWARN spotter activation will likely be needed this afternoon and tonight. Borghoff
The Minneapolis radar (KMPX), 139 km away, was scanning. The volume nearest the first event began at 19:47 UTC.
12 thunderstorm wind, 1 tornado, 1 flash flood. Local standard time, as filed.
A fast moving tornado touched down near a farm, where it removed roofs off of two sheds and knocked over some trees. It then moved across a number of fields, occasionally hitting trees along the way.
Several trees were blown down near Comfrey.
A semi-trailer was tipped over near County Roads 8 and 18, east of Comfrey.
A large tree was blown down near St. James.
Power lines were blown down near Searles.
Numerous trees were blown down in Mankato. There were other reports of small limbs blown down throughout northern and central portions of Blue Earth County.
Two trees were blown down southwest of Janesville, near the intersection of County Road 14, and 360th Avenue.
A tree was blown down in Janesville.
Several trees were blown down south of Highway 19, near Northfield.
A tree was blown down in Owatonna.
Several trees were blown down northeast of Owatonna.
Local law enforcement officials had to close portions of Highway 316 between 200th Street and Ravenna Trail due to washed out roads and flooding.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Minnesota in 2017Every state in 2017This day in weather historyThe tornado archive for Minnesota, 2017Warnings in Minnesota, July 2017
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 2026-09-24. Each event’s entry at NCEI: 716797, 713793, 713797, 713799, 713801, 713814, 713805, 713815, 713802, 713804, 713808, 713809, 713811, 715476.