The 11:30 AM Convective Outlook issued by the Storm Prediction Center on Friday, March 31st, featuring two rare "High Risk" areas

The Tornado Watch that was issued for the area during the early afternoon of March 31st

The 22 confirmed tornadoes in the NWS Chicago forecast area

Downloadable KMZ File with All Tornado Tracks

Downloadable Shapefile with All Tornado Tracks

Graphics and GIS data for each individual tornado can be found below. An interactive map with all 22 tornado tracks and other findings of our storm surveys can also be viewed on ourDamage Viewer web application (just change the date range in the top right corner to include both 3/31/2023 and 4/1/2023).

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Downloadable KMZ File

Downloadable Shapefile

This brief tornado occurred north of Pontiac, IL and was captured on video by a storm chaser. It was on the ground for about 10 seconds, only kicking up some dirt before it lifted. Since the tornado did not produce any damage, it has been assigned an EF-Unknown (EF-U) rating.

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Downloadable KMZ File

Downloadable Shapefile

This tornado began just south of Illinois Highway 92 in northwest Bureau County in the NWS Quad Cities County Warning Area. It then tracked through far southeast Whiteside County within 3 miles of the town of Deer Grove. This tornado would continue for 6 additional miles into southwest Lee County, where it dissipated near Maytown Road and Atkinson Road. The damage from this tornado included numerous heavily damaged outbuildings, several snapped power poles, and dozens of trees. The worst damage was to a large farmstead outbuilding along the Whiteside and Bureau County border, with the roof and two of the four walls destroyed and debris slung well into a field.

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Downloadable KMZ File

Downloadable Shapefile

This tornado began southeast of Lanark in Carroll County and tracked into northwestern Lee County before lifting shortly after crossing Montague Rd. into Stephenson County west of Baileyville. This tornado caused extensive damage to several farm buildings and also downed a few trees along its path.

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Downloadable KMZ File

Downloadable Shapefile

This tornado began in the Woodhaven Lakes campground and tracked across U.S. Highway 52 between Amboy and Sublette. This tornado produced substantial and concentrated tree damage along its track, with several dozen large trees snapped and many branches sheared off. Damage was clearly in a convergent pattern. Multiple campers were damaged, including at least two rolled, in the Woodhaven Lakes campground. Farther along in its path, there were two trees downed on one homestead that was basically demolished. Another nearby homestead had a large garage completely destroyed. The tornado gradually waned in intensity as it crossed Shaw Rd, causing minor damage to an additional outbuilding before lifting as it reached Butler Hill Rd.

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Downloadable KMZ File

Downloadable Shapefile

This tornado appeared to begin just south of Sublette as it crossed U.S. Highway 52, snapping multiple wooden utility poles. This tornado then increased in intensity as it entered the community of West Brooklyn. It downed several large trees, tore the roof of a bank in downtown, and folded an approximately 120 ft. tall tower. One of the wooden beams from the roof of the bank was impaled into a garage roof to its north-northeast. This tornado weakened prior to crossing Illinois Highway 251.

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Downloadable KMZ File

Downloadable Shapefile

The Davis Junction to Belvidere tornado touched down in the northeast portion of Ogle County southwest of Davis Junction at 724 PM CDT. The tornado tracked northeast through the village of Davis Junction where it caused generally EF-0 damage with isolated EF-1 damage to a single family home on the north side of town. The tornado continued northeast into southeastern Winnebago County, causing generally EF-0 damage to multiple farms as the tornado reached its widest extent of about 600 yards. The tornado then continued into Boone County causing damage to farms. As the tornado neared Belvidere, the width decreased to about a quarter of a mile as it briefly intensified near the central business district. Peak winds estimated at about 100 mph occurred at the Apollo Theatre, where a portion of the roof collapsed, causing 1 fatality and 40 injuries. The tornado continued northeast into rural areas of Boone County, causing EF-0 damage until lifting near Orth Road and Capron Road at about 7:49 PM CDT.

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Downloadable KMZ File

Downloadable Shapefile

This tornado touched down about 1 mile southeast of downtown Rockford southwest of the intersection of Railroad Ave and 8th St. It then tracked northeastward through the city of Rockford for about 7 minutes and just under 6 miles before lifting as it approached the intersection of Riverside Blvd and Mulford Rd. The tornado caused widespread tree damage, which was most concentrated at and near the Sinnissippi Golf Course, where the tornado reached its peak width of about 300 yards. Most structural damage was caused by trees that were uprooted and fell onto houses, but the tornado itself did also cause mostly minor roof damage to multiple homes.

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Downloadable KMZ File

Downloadable Shapefile

This tornado began southwest of the intersection of Elmwood Rd. and Rockton Ave. and tracked northeastward for almost 9 miles, straddling the Rock River as it tracked through the west side of Machesney Park before weakening and lifting over Roscoe. This tornado caused damage to several trees and outbuildings, as well as multiple homes, which primarily suffered roof damage. A couple of homes had entire portions of their roofs removed where the tornado was at its peak intensity and featured 90-100 mph winds.

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Downloadable KMZ File

Downloadable Shapefile

The most extensive damage that this tornado caused was to a farm east of Caledonia on IL-173. Numerous outbuildings were destroyed along its track in Boone County. Additionally, a silo was heavily damaged and a grain bin collapsed. The rest of the path in Illinois consisted of tree damage and occasional light damage to farm outbuildings. There were also a few homes near Candlewick Lake southeast of Caledonia that sustained roof and siding damage. The tornado then continued into Wisconsin, where it went through rural areas, mainly causing damage to roofing materials on a few barns before lifting northeast of the village of Sharon.

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Downloadable KMZ File

Downloadable Shapefile

This tornado began near the intersection of Concord Drive and Columbia Lane in Montgomery and tracked northeast over the Fox River before dissipating near Phillips Park in Aurora. The tornado caused minor damage to an outbuilding shortly after onset, but most of the damage was confined to trees and consistent with wind speeds of 80 mph. There was also evidence of straight-line wind damage to trees near the tornado path.

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Downloadable KMZ File

Downloadable Shapefile

A tornado formed over the northwest part of Vermilion County near CR-3800N with the first visible damage of uprooted trees and a nearby shed at CR-3800N and 170E occurring at approximately 7:57 PM CDT. There was a consistent path of destruction and indicators, including distinct swirls over roads in a line from 4 miles south-southwest of Rankin to just north of Wellington.

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Downloadable Shapefile

This tornado began in an open field south of Engstrom Family Park and tracked east-northeast towards downtown Batavia before lifting shortly after it crossed the Fox River near Wilson St. Damage along the tornado`s path consisted of several uprooted and damaged trees, downed fences, downed power lines, roof shingles peeled off of houses, and a toppled chimney.

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Downloadable KMZ File

Downloadable Shapefile

This tornado began south of Dean St. near 15th St. and tracked northeast, passing over Boy Scout Island and the Fox River before lifting shortly after it crossed Illinois Route 25. Damage along the tornado`s path consisted of several uprooted and damaged trees, downed power lines, roof shingles peeled off of houses, and a damaged HVAC unit on the roof of a construction facility.

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Downloadable KMZ File

Downloadable Shapefile

This tornado began near the intersection of Arbeiter and Black roads in eastern Kendall County and damaged several homes in neighborhoods, causing shingle damage and the collapse of a chimney. A trampoline was also thrown into a tree. The tornado then crossed into Will County, causing additional damage to shingles and trees near Troy Middle School. The tornado lifted shortly before reaching Illinois Route 59, but straight-line wind damage continued farther to the east past Interstate 55.

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Downloadable KMZ File

Downloadable Shapefile

The tornado began near W 135th Street just west of Meadow Lane and tracked east northeast before weakening near Illinois Route 59. The damage was confined to primarily trees, but some shingles and siding were removed from homes along the path, consistent with the 80 mph EF-0 rating.

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Downloadable KMZ File

Downloadable Shapefile

This tornado began in an industrial park on the far north side of Lombard where it caused roof damage to a couple of buildings. It then tracked into Addison, where security camera footage from a fire station captured it causing roof damage to nearby office buildings. The tornado then caused primarily tree damage as it tracked across a residential area of Addison south of Fullerton Ave. before lifting as it crossed Fullerton Ave. at Hale St. To the south and east of the tornado`s track, a wider swath of damage caused by straight-line winds of up to approximately 85 mph was noted. This damage included additional instances of roof damage to office buildings, a large portion of a roof peeled off an apartment complex, a semi truck blown over on I-290, and damage to a billboard and brick sound barriers along I-290.

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Downloadable KMZ File

Downloadable Shapefile

A brief EF-1 tornado occurred south of Stockland causing damage to trees, power poles, and leading to the destruction of at least one small farm outbuilding.

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Downloadable KMZ File

Downloadable Shapefile

This EF-2 tornado primarily downed trees and power poles and damaged farm outbuildings. However, the tornado also caused damage to a few homes, two of which were significantly damaged.

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Downloadable Shapefile

This EF-2 tornado damaged a few homes and multiple wind turbines, including one wind turbine that was snapped about halfway up. This tornado also downed trees and power poles along its 11.7 mile path.

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Downloadable KMZ File

Downloadable Shapefile

Most of the damage caused by this EF-1 tornado consisted of snapped power poles, downed trees, and damage to small farm outbuildings.

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Downloadable KMZ File

Downloadable Shapefile

This tornado touched down north of U.S. Route 30 near Grant St. in Merrillville and then tracked eastward for roughly 3.3 miles before lifting over the far south side of Hobart. The tornado blew out windows and tore sections of roofs off of multiple homes where its winds were able to compromise the residences` garage doors. The tornado also caused damage to power lines and several trees along its path.

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Downloadable KMZ File

Downloadable Shapefile

This brief EF-0 tornado damaged trees, outbuildings, and farm equipment over its short 0.6 mile long track.

Map of preliminary storm reports for March 31, 2023

Preliminary National Storm Reports for March 31, 2023

Interactive Map of Preliminary Storm Reports for March 31, 2023

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Hand-analyzed surface map at 21Z (4 PM CDT) on Friday, March 31, 2023. Isodrosotherms (lines of equal dewpoint temperature) at 60 and 63 degrees F are shown (in green), and surface stations gusting over 25 kts are highlighted with orange arrows. 

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Hand-analyzed surface map at 23Z (6 PM CDT) on Friday, March 31, 2023. Notice how the warm front has "surged" northward right up to about the I-80 corridor in the past two hours. This set the stage for the second round of widespread severe storms. 

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SPC mesoanalysis image (valid at 7 PM CDT) of MLCAPE (a measure of atmospheric instability), MLCIN (stability), and deep layer shear (vectors). Deep layer shear values were very high during this event, at times in excess of 60-70 knots which is very supportive for rotating thunderstorms (supercells). 

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SPC mesoanalysis image (also valid at 7 PM CDT) of the effective Significant Tornado Parameter (eSTP). This is a composite parameter which combines instability, deep layer shear, stability, and low-level shear together in one value. Values increasing over 1 tend to suggest an increased potential for tornadoes.