Severe thunderstorms developed ahead of an approaching cold front during the afternoon and evening of Wednesday, July 14. Some of the storms produced damaging winds and numerous 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 DVN wrote it up.
Severe thunderstorms developed ahead of an approaching cold front during the afternoon and evening of Wednesday, July 14. Some of the storms produced damaging winds and numerous tornadoes. Brief torrential rainfall was also observed with the stronger storm cells. The areas that were hit hardest were in Buchanan, Delaware, Benton, Linn, and Jones counties in IA, where a total of 14 tornadoes occurred. 7 of the tornadoes had no visible damage.
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 Quad Cities, IA wrote its last area forecast discussion before the first event at Jul 14, 5:42 PM CST, 1 minute earlier.
Area Forecast Discussion National Weather Service Quad Cities IA IL 642 PM CDT Wed Jul 14 2021 ...00Z AVIATION UPDATE... .SYNOPSIS... Issued at 230 PM CDT Wed Jul 14 2021 Showers and thunderstorms continue though the afternoon along and east of the Mississippi River, with a greater chance this evening through tonight through much of the area. Severe thunderstorms are possible. The Storm Prediction Center has us in an Enhanced Risk for severe weather today through tonight, with a Slight Risk extending down to Interstate 80. Currently, temperatures are sitting in the mid 80s, coupled with dew points in the mid 70s. This is creating a very muggy environment, favorable for storms through the evening. Areas to the north are much cooler, in the low 70s and upper 60s, owing to the line of showers and heavy storms that moved through. Cut down on max temperatures due to the amount of cloud cover produced by morning and early afternoon convection. Gusty southerly winds will be seen through the evening, as we are within the warm sector of the slowly passing low pressure system sliding through our north. The strong LLJ continues to pump through the region, providing support for further development and maintenance of thunderstorms through the night. && .SHORT TERM...(This Evening through Thursday) ISSUED AT 230 PM CDT Wed Jul 14 2021 Potent little upper shortwave pushes through the upper Midwest tonight, with the attendant surface low trailing through our north. The low is very slow moving and nearly stalled out, where its boundaries will be the focus for thunderstorms tonight. Plenty of instability will be present tonight, coupled with many sources of surface and upper level forcing, which will help to develop and maintain thunderstorms through the night. Storms have the potential to be strong to severe, with main severe hazards being hail and severe wind gusts over night. Compared to previous model runs, the convective system from earlier today was much farther south than was advertised yesterday. With this said, it would seem that the boundary is a bit farther south than models initially indicated, which can push convective activity farther south into our area. Specifically, we can see more activity between Highways 20 and 30. More recently, short term guidance has been indicating favorable wind fields within the vertical, which would lead to a little higher tornado threat than was initially advertised. We will continue to monitor this, as there is low confidence due to the lack of consistency between guidance. High moisture content will also be found in much of the area, especially ovenight. This will assist in generating heavy rainfall for the areas experiencing thunderstorms. Again, areas in the north have been very dry, making the ground pretty solid. With this being the case, the ground won't be able to handle really heavy rainfall rates and can turn into more runoff. This would lead to flash flood concerns. Given moderate instability and sufficient shear, we can see some initially discrete supercells. Eventually, these storms are expected to quickly grow upscale, where embedded supercell structures may still exist. Prior to upscale growth, we will see our best chance for all hazards, such as large hail, damaging winds, and even a few tornadoes. As we transition into a more MCS structure, we will see the hazards switch to damaging winds, torrential rainfall (1-3" rain rates possible), and some embedded hail. After dark, the severe threat will start to wind down, but the thunderstorms are expected to continue through the night, slowly creeping south towards Interstate 80. This will be due, in part, to the continuously strong LLJ pumping air into the southward creeping cold front, enhancing convergence over our area. With all storms, there will be frequent lightning as well. Tomorrow will be another stormy day for most, as the cold front finally starts its departure from our area. There is still a risk for severe weather, where the Storm Prediction Center has a Marginal Risk for severe weather. Along with thunderstorms, we will still have some anomalously high moisture content in the vertical profile, which will aid in creating high rain rates, between 1-3" per hour possible. The Weather Prediction Center has issued a Slight Risk for Excessive rainfall, indicating that heavy rain is possible, which can lead to flash flooding. The southern half of our forecast area will be especially vulnerable, as these areas have seen several inches of rain over the past couple weeks. This will lead to rapid piling up of water in areas, especially if repeating thunderstorms .LONG TERM...(Thursday Night through Wednesday) ISSUED AT 230 PM CDT Wed Jul 14 2021 Key Message: 1) Lingering showers and storms can be seen through part of Friday, generally along and south of Interstate 80. 2) Upper ridge in west build east, leading to relatively dry and seasonal weather though next week. Friday Through Weekend... Exiting wave from Thursday has a chance to lead to some residual showers and storms through the forecast area. Some placement differences exist between guidance, but the wave is progged to move out by evening on Friday. As this wave exits, high pressure builds into the area, leaving us dry through the remainder of the weekend. This will be associated with a large upper ridge that sets up over the upper Midwest and Plains. Within this ridge, long term guidance indicates the potential for a cut of low to form beneath the ridge. This can lead to some chances for precipitation, but currently looks to be south of our area. The CMC wants to bring some spotty showers through the area on Saturday, but it is an outlier compared to guidance. With that in mind, will keep it dry over the weekend. Temperatures will be below normal, sitting around and in the low 80s, and the humidity will be relatively pleasant. Next Week... Upper ridge begins to weaken and center over the Rockies, resulting in broad northwest flow over the forecast area. This is reflected well with long term guidance. With this pattern setting up, that can open up the door for shortwaves into the area. With this said, low level flow will not be from the south, limiting the flow of moisture and heat into the area. Considering these factors, we should have a relatively dry and quiet week with near normal temperatures. Humidity will be relatively high through the week, as dew points are progged to be near 70. As mentioned prior, this coupled with the abundance of corn can lead to some higher humidity than currently advertised. && .AVIATION...(For the 00Z TAFS through 00Z Thursday Evening) ISSUED AT 642 PM CDT Wed Jul 14 2021 Strong thunderstorms moving into eastern Iowa will impact the CID, DBQ and eventually MLI terminals this evening. These storms may be capable of producing wind gusts over 50kts and very heavy rain as they move through CID and DBQ between 00Z and 03Z this evening. There is a lower potential for severe storms at MLI and BRL, but thunderstorms are possible with strong gusty winds overnight. A front slowly moving through the area will eventually bring in MVFR and possibly IFR ceilings that will linger through much of Thursday. There will also be areas of rain and scattered thunderstorms Thursday, focusing more on the BRL and MLI terminals. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && SYNOPSIS...Gunkel SHORT TERM...Gunkel LONG TERM...Gunkel AVIATION...Sheets
Hazardous Weather Outlook National Weather Service Quad Cities IA IL 303 AM CDT Wed Jul 14 2021 IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007- 009-015>018-024>026-034-035-MOZ009-010-150815- Buchanan-Delaware-Dubuque-Benton-Linn-Jones-Jackson-Iowa-Johnson- Cedar-Clinton-Muscatine-Scott-Keokuk-Washington-Louisa-Jefferson- Henry IA-Des Moines-Van Buren-Lee-Jo Daviess-Stephenson-Carroll- Whiteside-Rock Island-Henry IL-Bureau-Putnam-Mercer-Henderson- Warren-Hancock-McDonough-Scotland-Clark- 303 AM CDT Wed Jul 14 2021 This Hazardous Weather Outlook is for portions of north central Illinois...northwest Illinois...west central Illinois...east central Iowa...northeast Iowa...southeast Iowa and northeast Missouri. .DAY ONE...TODAY AND TONIGHT The Storm Prediction Center has an enhanced risk for severe thunderstorms along and north of a Freeport, Illinois to Belle Plaine, Iowa line. There is a slight risk as far south as a Mendota, Illinois to Ottumwa, Iowa line. Super cells and organized bowing segments are likely ahead of a slow moving cold front, especially in the afternoon and evening. The main threats will be damaging winds, large hail and isolated tornadoes. There is the potential for flash flooding especially where slow moving thunderstorms move repeatedly over the same areas. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY Thursday, there is a marginal risk for severe storms south of a Rockford, Illinois to Bloomfield, Iowa line. The main threats will be strong winds and large hail. .SPOTTER INFORMATION STATEMENT... Spotter activation will likely be needed today and tonight.
Special Weather Statement
National Weather Service Quad Cities IA/IL
217 PM CDT Wed Jul 14 2021
ILC011-073-195-141945-
Whiteside-Henry-Bureau-
217 PM CDT Wed Jul 14 2021
...A LINE OF STRONG THUNDERSTORMS WILL AFFECT WHITESIDE...
NORTHEASTERN HENRY AND NORTHWESTERN BUREAU COUNTIES UNTIL 245 PM
CDT...
At 217 PM CDT, radar indicated strong thunderstorms were located
along a line extending from near Emerson to Cambridge. Movement was
east at 40 mph.
Winds in excess of 40 mph are possible with these storms.
Locations impacted include...
Sterling, Rock Falls, Morrison, Cambridge, Geneseo, Prophetstown,
Erie, Walnut, Atkinson, Sheffield, Annawan, Tampico, Lyndon,
Hooppole, Deer Grove, Emerson, Fenton, Yorktown, Round Grove and
Manlius.
This includes the following highways...
Interstate 80 in Illinois between mile markers 18 and 44.
Interstate 88 between mile markers 21 and 44.
Torrential rainfall is also occurring with these storms. Minor
flooding of low lying areas, creeks, streams and urban areas is
possible. If you encounter water over a roadway, do not drive through
it.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
LAT...LON 4135 8972 4129 9026 4184 9000 4191 8963
4159 8963 4158 8955
TIME...MOT...LOC 1917Z 262DEG 33KT 4184 8984 4132 9018
UttechSpecial Weather Statement National Weather Service Quad Cities IA/IL 249 PM CDT Wed Jul 14 2021 ILC011-073-142030- Henry-Bureau- 249 PM CDT Wed Jul 14 2021 ...A STRONG THUNDERSTORM WILL AFFECT EAST CENTRAL HENRY AND NORTHWESTERN BUREAU COUNTIES UNTIL 330 PM CDT... At 249 PM CDT, a strong thunderstorm was located over Annawan, or 10 miles north of Kewanee, moving east at 35 mph. Winds in excess of 40 mph are possible with this storm. Locations impacted include... Princeton, Wyanet, Atkinson, Sheffield, Annawan, Buda, Neponset, Manlius, Mineral, New Bedford, Johnson-Sauk Trail State Park and Bureau County Fairgrounds. This includes Interstate 80 in Illinois between mile markers 29 and 57. Torrential rainfall is also occurring with this storm. Minor flooding of low lying areas, creeks, streams and urban areas is possible. If you encounter water over a roadway, do not drive through it. Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. LAT...LON 4127 8996 4145 9000 4157 8948 4134 8945 TIME...MOT...LOC 1949Z 260DEG 31KT 4138 8990 Uttech
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
252 PM CDT WED JUL 14 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1237 PM RAIN 1 S ASBURY 42.51N 90.76W
07/14/2021 M0.60 INCH DUBUQUE IA PUBLIC
1033 AM RAIN JESUP 42.47N 92.07W
07/14/2021 M0.40 INCH BUCHANAN IA PUBLIC
1046 AM RAIN 1 W THREE ELMS COUNTY 42.45N 91.89W
07/14/2021 M0.46 INCH BUCHANAN IA PUBLIC
&&Special Weather Statement
National Weather Service Quad Cities IA/IL
330 PM CDT Wed Jul 14 2021
ILC011-155-142115-
Putnam-Bureau-
330 PM CDT Wed Jul 14 2021
...A LINE OF STRONG THUNDERSTORMS WILL AFFECT NORTHWESTERN PUTNAM AND
CENTRAL BUREAU COUNTIES UNTIL 415 PM CDT...
At 330 PM CDT, radar indicated strong thunderstorms were located
along a line extending from near Walnut to near Osceola. Movement was
east at 35 mph.
Winds in excess of 40 mph are possible with these storms.
Locations impacted include...
Princeton, Hennepin, Spring Valley, DePue, Ladd, Wyanet, Sheffield,
Tiskilwa, Buda, Bureau Junction, Mark, Cherry, Malden, Manlius,
Seatonville, Milo, Arlington, Dover, Hollowayville and Coal Hollow.
This includes the following highways...
Interstate 80 in Illinois between mile markers 44 and 70.
Interstate 180 between mile markers 1 and 13.
Torrential rainfall is also occurring with these storms. Minor
flooding of low lying areas, creeks, streams and urban areas is
possible. If you encounter water over a roadway, do not drive through
it.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
LAT...LON 4123 8927 4119 8964 4123 8964 4124 8980
4151 8965 4152 8917 4143 8917
TIME...MOT...LOC 2030Z 258DEG 29KT 4151 8957 4124 8971
UttechPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
334 PM CDT WED JUL 14 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0241 PM HEAVY RAIN ERIE 41.66N 90.08W
07/14/2021 M1.10 INCH WHITESIDE IL PUBLIC
&&PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
451 PM CDT WED JUL 14 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0415 PM HEAVY RAIN 2 WSW CEDAR RAPIDS 41.96N 91.70W
07/14/2021 M0.75 INCH LINN IA TRAINED SPOTTER
RAINFALL FROM EARLIER TODAY.
&&
12The La Crosse radar (KARX), 145 km away, was scanning. The volume nearest the first event began at 23:41 UTC.
15 tornado, 5 thunderstorm wind. Local standard time, as filed.
Brief tornado touchdown in Buchanan County, which crossed into Fayette County at 17:44 LST, and then into Oelwein.
The Emergency Manager reported blown over corn damage mainly along and east of Highway 150. The time of the event was estimated using radar.
A tornado began in Tama County and crossed into Benton County, just south of Dysart, around 6:08 pm CST. As the tornado entered Benton County, the max width was around 560 yards. This includes the main tornado and satellite vortices, which are supported by video evidence. The tornado caused damage to trees and farm outbuildings at a farmstead just over the county line. This damage was rated EF-1, with maximum winds around 100 mph. The tornado then followed an intermittent path to the east-northeast for about 4.5 miles through rural areas, before dissipating.
Brief touchdown in a field with no visible damage.
Brief touchdown in a field with no visible damage.
Brief touchdown in a field with no visible damage.
Brief EF-1 tornado snapped large tree limbs and tree trunks southwest of Manchester.
An EF-1 tornado briefly touched down on the southwest side of town damaging several farm outbuildings and a large show barn. No injuries were reported.
Brief touchdown in a field with no visible damage.
Brief touchdown in a field with no visible damage.
Brief touchdown in a field with no visible damage.
A trained spotter reported a large area of flattened corn.
Brief touchdown in a field with no visible damage.
Photos from a trained spotter and high resolution satellite data confirm a brief tornado in a corn field southwest of Hopkinton. The tornado did not cause any damage that could be used to assign an EF-scale rating. Time estimated by radar.
An EF-1 tornado touched down southwest of Monticello damaging outbuildings and snapping large trees on two farmsteads.
An EF-1 tornado developed southeast of Monticello and tracked across rural areas east of Monticello along an intermittent 8 mile path through farmland and wooded areas.
An EF-1 tornado tracked across rural Jones county snapping trees and ending just south of Canton.
A Cedar County Official estimated thunderstorm wind gusts up to 60 MPH generally 6 miles west of the Tipton area.
A Ham Radio operator relayed an estimated thunderstorm wind speed gust of 60 MPH , just west of New Liberty.
Law Enforcement relayed a public report of 60 MPH thunderstorm winds near Springbrook.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2021Every state in 2021This day in weather historyThe tornado archive for Iowa, 2021Warnings in Iowa, July 2021
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: 971920, 972437, 993316, 964226, 964228, 964224, 964214, 964217, 964235, 964234, 964237, 972436, 964238, 993310, 964211, 964198, 964201, 972432, 972433, 972434.