A line of severe thunderstorms moved across northeast Iowa during the late afternoon of July 19th. These storms produced two tornadoes.
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 ARX wrote it up.
A line of severe thunderstorms moved across northeast Iowa during the late afternoon of July 19th. These storms produced two tornadoes. The first, an EF-0, touched down north of Elma (Howard County) and damaged some crops. The second tornado, an EF-1, touched down west of McGregor (Clayton County) and then moved east through McGregor before dissipating over the Mississippi River. The tornado did extensive damage to the downtown area where two buildings were completely destroyed and numerous others were damaged. One person was killed in an accident cleaning up debris from the tornado when a tractor rolled and pinned the person beneath it. The storms produced a path of damaging winds from Nora Springs (Floyd County) and Mitchell (Osage County) east to Waukon (Allamakee County). Within this path, winds were estimated to range from 65 to 80 mph with numerous trees and power lines blown down. Southeast of Waukon, a barn was blown down trapping a farmer in the debris. The Governor of Iowa declared a disaster proclamation for Allamakee, Chickasaw, Clayton, Fayette, Floyd and Winneshiek Counties. The President of the United States issued a disaster declaration for Allamakee, Chickasaw, Fayette and Mitchell Counties.
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 La Crosse, WI wrote its last area forecast discussion before the first event at Jul 19, 1:22 PM CST, 2 hours 28 minutes earlier.
Area Forecast Discussion National Weather Service La Crosse WI 222 PM CDT Wed Jul 19 2017 .SHORT TERM...(Tonight through Thursday Night) Issued at 222 PM CDT Wed Jul 19 2017 Attention focused on severe potential tonight. Currently watching a complex of storms that has a history of high winds pushing across eastern SD/southwest MN. These storms are expected to continue as they move east/southeast along a fairly strong CAPE gradient with 70+ dew point in place south of I-90. Question is, how strong will the storms be as they approach? Plenty of CAPE to continue fueling storms while RAP/NAM indicating 30-35kt of 0-3km Bulk Shear for storm organization. Will maintain a close watch of this over the next several hours. Later this evening, after this complex passes, a strong 850mb low level jet kicks in and will likely kick off more storms over the existing cold pool with development expected to be . somewhere near the I-94 corridor. Again plenty of CAPE to fuel storms into the overnight hours with ample shear. These storms will be elevated in nature with large hail being the main threat, along with torrential downpours given precipitable water values nearing 2 inches. Storms look to be progressive in nature, so flooding rains do not look likely. Although, localized ponding of water/brief nuisance flooding cannot be ruled out. A bit of a break in the action for Thursday as models indicating high pressure moving in. Kept a small chance of showers/storms in for areas south of I-90/ closer to frontal/outflow boundary left behind from departing storms. Otherwise, a fairly warm/muggy day in tap with highs in the 80s and dew points in the upper 60s to the lower 70s. Storm chances return to areas mainly south of I-94 later Thursday night as low pressure over the Plains pulls that boundary back north as a warm front. .LONG TERM...(Friday through Wednesday) Issued at 222 PM CDT Wed Jul 19 2017 Strong to severe storms look likely Friday into Friday night as a warm front sets up across northern IA/IL and weak low pressure tracks east out of the Central Plains. Ample CAPE and Bulk Shear will dictate a severe threat. Looks like right now we would be north of the warm front with elevated storms. So, main severe threat looks to be large hail and torrential downpours/possible localized flooding. However, if the front can manage a slight nudge north some storms could get rooted in the boundary layer, producing a tornado threat as well. Right now, looking like a widespread 1-2 inch rainfall is likely south of I-94 with some localized higher amounts as precipitable water values peak out in the 2-2.5 inch range. This could pose a threat for some slightly more than localized flooding, especially for those areas with poor drainage. Will maintain a close eye on this severe/flooding potential. Showers and a few storms still possible through the weekend as a fairly strong mid-level trough moves slowly southeast across the area. Otherwise, remaining very warm/humid through Saturday with some drying/cooling on Sunday. Looks dry on Monday into Tuesday with high pressure drifting across the region but then shower/thunderstorm chances return Tuesday Night/Wednesday as a cold front tracks out of the Northern Plains into the Upper Mississippi River Valley region. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) Issued at 1232 PM CDT Wed Jul 19 2017 Currently watching a complex of thunderstorms moving east/southeast across eastern SD/southwest MN. These storms are expected to continues moving southeast and possibly brushing KRST/KLSE sites later this afternoon into this evening. Shra/TS activity expected to continue overnight as a low level jet brings more moisture/unstable air into the region. This low level jet will also cause some LLWS at KLSE with approximately 40KT at 2KFT from the SSW by 04z. Overall, looks like VFR conditions prevail, but cannot rule out some MVFR/IFR if thunderstorms do manage to impact the KRST/KLSE site directly. Drier air works into the area Thursday morning after sunrise with VFR conditions expected through the rest of the morning. && .Hydrology...(For Tonight through Friday) Issued at 222 PM CDT Wed Jul 19 2017 Storms this evening through tonight look to produce some localized heavy rainfall in the 1-2 inch range. Storms will be progressive in nature, so no widespread heavy runoff is expected for any major rises on stream/rivers. Will have to keep a watch though Friday into Friday nigh as a warm front lays up just to our south with a respectable feed of moist/unstable air. This will likely produce more heavy rainfall and possible flooding. Right now, the highest threat for any flooding would be south of I-94. Will maintain a close eye on this scenario. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && SHORT TERM...DAS LONG TERM...DAS AVIATION...RRS HYDROLOGY...DAS
Hazardous Weather Outlook National Weather Service La Crosse WI 345 PM CDT Wed Jul 19 2017 MNZ079-WIZ017-029-032>034-201200- Wabasha-Taylor-Clark-Buffalo-Trempealeau-Jackson- 345 PM CDT Wed Jul 19 2017 This Hazardous Weather Outlook is for portions of southeast Minnesota into central Wisconsin. .DAY ONE...Through Tonight Thunderstorms are probable overnight, forming over eastern Minnesota into central Wisconsin after 10 pm, shifting southeast across the entire area. Severe storms are possible overnight, and the threat shifts from north to south by sunrise. Damaging winds are the main threat, however large hail and isolated tornadoes are also possible. Short-lived heavy rain could lead to brief flooding impacts. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday Thunderstorms are possible at times Thursday through Sunday. Any storms will be capable of producing locally heavy rainfall. Severe storms are possible Friday into Friday evening, with damaging winds and large hail the primary threats. Localized flooding is possible in any areas impacted by repeated thunderstorms with heavy rainfall through late this week. Heat indices may reach 95 to 100 across northeast Iowa into southwest Wisconsin during the afternoon hours Thursday through Saturday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not likely. .EMERGENCY MANAGEMENT COORDINATION... No webinar is scheduled. IAZ008>011-018-019-029-030-MNZ086>088-094>096-WIZ041>044-053>055- 061-201200- Mitchell-Howard-Winneshiek-Allamakee-Floyd-Chickasaw-Fayette- Clayton-Dodge-Olmsted-Winona-Mower-Fillmore-Houston-La Crosse- Monroe-Juneau-Adams-Vernon-Crawford-Richland-Grant- 345 PM CDT Wed Jul 19 2017 This Hazardous Weather Outlook is for portions of southeast Minnesota...northeast Iowa and southwest into central Wisconsin. .DAY ONE...Through Tonight Thunderstorms will move through the area this afternoon and early evening. Southeast Minnesota and northeast Iowa will be affected through 7 pm, and southwest Wisconsin will see the storms in the 6-9 pm window. Damaging winds are the main threat, mainly south of I-90. The potential for wind gusts to 70 mph does exist south of an Austin, Minnesota to Richland Center, Wisconsin line. Isolated large hail and tornadoes are also possible. Short-lived heavy rain could lead to brief flooding impacts. Thunderstorms are possible again after midnight and a few could be severe. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday Thunderstorms are possible at times Thursday through Sunday. Any storms will be capable of producing locally heavy rainfall. Severe storms are possible Friday into Friday evening, with damaging winds and large hail the primary threats. Localized flooding is possible in any areas impacted by repeated thunderstorms with heavy rainfall through late this week. Heat indices may reach 95 to 100 across northeast Iowa into southwest Wisconsin during the afternoon hours Thursday through Saturday. .SPOTTER INFORMATION STATEMENT... Spotter activation may be requested through the evening. .EMERGENCY MANAGEMENT COORDINATION... No webinar is scheduled. baumgardt
Special Weather Statement
National Weather Service La Crosse WI
404 PM CDT WED JUL 19 2017
IAZ008>010-018-019-MNZ086-087-094-095-192230-
Winneshiek-Floyd-Howard-Chickasaw-Mitchell-Olmsted-Dodge-Fillmore-
Mower-
404 PM CDT WED JUL 19 2017
...A LINE OF STRONG THUNDERSTORMS COMING TOWARD SOUTHEAST MINNESOTA
AND NORTHEAST IOWA...
At 401 PM CDT, radar indicated strong thunderstorms located along a
line extending from near Fairibault to Blue Earth Minnesota. These
storms have produced winds from 40 to 60 mph. Movement was east at
60 mph.
Wind gusts up to 50 mph and brief very heavy rain are possible with
these storms. However, severe thunderstorm warnings may be needed
for winds in the 60-70 mph range.
People attending the Dodge County Free Fair should seek safe shelter
immediately!
Prepare now for possible severe weather. Move indoors and if a
warning is issued, take actions to protect life and property.
Persons in campgrounds should consider seeking sturdy shelter until
these storms pass.
LAT...LON 4420 9304 4420 9237 4418 9232 4411 9232
4411 9208 4291 9208 4291 9303
TIME...MOT...LOC 2101Z 281DEG 53KT 4419 9321 4340 9381
DABPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
438 PM CDT WED JUL 19 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0435 PM TSTM WND DMG CLAREMONT 44.04N 93.00W
07/19/2017 DODGE MN EMERGENCY MNGR
0435 PM TSTM WND DMG 2 NE CLAREMONT 44.07N 92.97W
07/19/2017 DODGE MN EMERGENCY MNGR
BUILDING DAMAGE REPORTED
&&
SHEAPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
439 PM CDT WED JUL 19 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0435 PM TSTM WND GST CLAREMONT 44.04N 93.00W
07/19/2017 E65 MPH DODGE MN TRAINED SPOTTER
POWER OUT
&&
SHEAThe La Crosse radar (KARX), 152 km away, was scanning. The volume nearest the first event began at 21:52 UTC.
29 thunderstorm wind, 2 tornado. Local standard time, as filed.
On a farm near Carpenter, tin silos were twisted and large trees were blown down. On another farm, a downed tree fell on a house.
An estimated 65 mph wind gust occurred south of Nora Springs.
An estimated 65 mph wind gust occurred north of Nora Springs.
Numerous trees were blown down in Nora Springs.
At least 15 power lines were blown down in St. Ansgar.
An estimated 65 mph wind gust occurred in Rudd.
An estimated 70 mph wind gust occurred in Osage. Numerous trees were blown down with one blocking U.S. Highway 218.
Power lines were blown down and a tree was snapped off northeast of Mitchell.
The catholic church in New Haven sustained wind damage.
An estimated 60 mph wind gust occurred in Charles City.
A 62 mph wind gust occurred in Colwell blowing down some tree branches.
An EF-0 tornado touched down north of Elma and traveled a short distance to the northeast. The tornado pulled a corner of a pole shed out of the ground and drone footage showed a narrow path through a corn field.
A 66 mph wind gust occurred in New Hampton.
An estimated 70 mph wind gust occurred in Alta Vista that blew down numerous trees.
Power lines were blown down east of New Hampton along State Highway 24.
Trees were blown down in Waucoma.
Numerous trees were blown down in Spillville.
Two foot diameter trees were blown down in Ridgeway.
Trees were blown down in El Dorado.
Numerous trees were blown down on a farm northwest of West Union.
Trees were blown down at the Fayette County Courthouse and fairgrounds in West Union.
Power lines were blown down in Cresco.
Trees were blown down in Clermont. At least one tree landed on a house and another destroyed a garage. Numerous trees and power lines were blown down in a campground on the southwest edge of town.
Trees were snapped off or uprooted east of Decorah.
Numerous trees and power lines were blown down just east of Monona. The strong winds also impacted some corn fields.
An EF-1 tornado touched down about 5 miles west of McGregor and then moved through McGregor before dissipating just east of town over the Mississippi River. The most damage occurred in McGregor with two buildings downtown completely destroyed while numerous others were damaged. Two people sustained minor injuries due to flying glass. Hundreds of trees across town were snapped off. West of McGregor, the tornado damaged a storage shed, ripped back part of a metal roof from an outbuilding and damaged numerous trees. One person was killed in an accident cleaning up debris when a tractor rolled over pinning the person underneath it.
Part of a roof was removed from an outbuilding and corn was pushed over near Waukon.
A tree was blown down onto a house, an outbuilding was damaged and corn was blown down south of Waukon.
Hundreds of trees were blown down in Pikes Peak State Park and Effigy Mounds National Monument near Marquette. Some of the trees fell on vehicles in the two parks.
A farmer sustained injuries when the barn he was doing chores in was blown down on top of him.
Trees and power lines were blown down in Guttenberg.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Tornado, Clayton | 2017-07-21 | 72 | Male | Vehicle/Towed Trailer | Indirect |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2017Every state in 2017This day in weather historyThe tornado archive for Iowa, 2017Warnings in Iowa, 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: 714260, 708965, 708966, 708973, 714173, 708967, 708968, 708979, 714259, 708987, 708988, 708991, 708989, 708990, 708992, 709014, 709928, 709933, 709929, 714289, 714288, 709009, 709931, 709942, 709935, 709960, 709938, 709939, 714287, 714111, 714286.