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June 30, 2014: Two Derechos Produce Widespread Wind Damage and Numerous Tornadoes (10-Year Anniversary Web Page)

Weather.gov > Chicago, IL > June 30, 2014: Two Derechos Produce Widespread Wind Damage and Numerous Tornadoes (10-Year Anniversary Web Page)

Graphic showing the title of the page "June 30, 2014 Double Derecho" next to a small collage. Subtitle "Including a prolific tornado-producing QLCS in the Kankakee River Valley."

Overview

  • Two derechos impacted northern Illinois and northwest Indiana in quick succession during the late afternoon and evening of June 30, 2014.

 

 

 

Map showing the general extent of the two derecho events that occurred on June 30, 2014. One shaded area extends from Nebraska through central Iowa into northern Illinois and southern Wisconsin. Another shaded area extends from near the Mississippi River across northern Illinois and northern Indiana.

 Map showing the general extent of the two derecho events that occurred on June 30, 2014. The map shows isochrons indicating the time that the storms reached different locations in Iowa, Wisconsin, Illinois, and Indiana.
  • Widespread wind damage, some of it significant, was caused by the storms -- particularly by the second derecho, which also ended up producing a total of 33 tornadoes across northern Illinois and northern Indiana.
    • 22 of those tornadoes occurred in the 博体育 Chicago forecast area. Up until 32 tornadoes occurred here on July 15, 2024, this was tied with the 22 tornadoes that occurred on March 31, 2023 for the most tornadoes to occur in the 博体育 Chicago forecast area in a single calendar day or 24-hour period. Official 博体育 tornado records date back to 1950.
    • Widespread damage caused by both straight-line winds and tornadoes made for a very challenging damage survey in the Kankakee River Valley. A  utilizing previously unavailable high-resolution satellite imagery was performed a few years after the event and led to the revision of several of the tornadoes' tracks and intensities, in addition to the confirmation of a few additional tornadoes that were not documented in the initial damage assessment.
  • 24-hour rainfall amounts were highest in parts of Cook, DuPage, and Kane Counties in Illinois and in Lake County in Indiana, where 2-3" of rain fell. There were isolated higher rainfall amounts, including 4.12" in Winnetka and 3.16" in Gibson City.

Tornadoes

The first 4 tornadoes out of the 22 that occurred in the during this event were scattered across portions of northern Illinois. The remaining 18 tornadoes occurred in a narrow corridor of the Kankakee River Valley.

Map showing the location of tornadoes that occurred in northeastern Illinois and northwestern Indiana on June 30, 2014.
Tornado

Start Time

(CDT)

End Time

(CDT)

Path Length

(miles)

Path Width

(yards)

 EF Rating

Maximum

Wind Speed
Earlville 9:16 PM 9:17 PM 1.5 50 EF-1 110 mph
Newark 9:38 PM 9:39 PM 1.2 50 EF-1 100 mph
Morris 9:44 PM 9:46 PM 2.2 50 EF-0 85 mph
Plainfield-Romeoville 9:55 PM 9:58 PM 3.1 75 EF-1 95 mph

 

 

1.) Earlville Tornado

Map showing the track of a tornado which occurred near Earlville on June 30, 2014.

(click on image to enlarge)

Summary:

An aerial survey from local media showed clear convergent swirling and scarring near Earlville. A short lived tornado touched down embedded within a larger area of straight-line wind damage. Numerous trees were blown down with damage to roofs and a garage blown out on the south and southwest portions of town. Maximum winds were estimated to 110 mph.

 

2.) Newark Area Tornado

Map showing the track of a tornado which occurred near Newark on June 30, 2014.

(click on image to enlarge)

Summary:

Concentrated damage was found at two farmsteads, including the destruction of an outbuilding and large trees snapped at their bases. Maximum winds were estimated to 100 mph.

 

3.) Morris Area Tornado

Map showing the track of a tornado which occurred near Morris on June 30, 2014.

(click on image to enlarge)

Summary:

An 博体育 storm survey team determined via an aerial survey that a tornado touched down over mainly fields north of Morris. Maximum winds were estimated to 85 mph.

 

4.) Plainfield-Romeoville Tornado

Map showing the track of a tornado which occurred near Plainfield and Romeoville on June 30, 2014.

(click on image to enlarge)

Summary:

This tornado caused damage to trees and residences between Plainfield and Romeoville. Over 50 trees, including many large softwood trees, were uprooted within a concentrated path. A dozen modest to large trees were blown to the northwest against the eastward path of the storm. Numerous roads were blocked due to fallen trees. There was minor damage to numerous residences in the Woodlands of the Reserve and Lakewood Falls subdivisions. This damage mainly included peeled off siding and shingles, along with blown out windows. The tornado crossed I-55 near mile marker 261. The tornado was embedded within a larger area of straight-line wind damage. Maximum winds were estimated to 95 mph.

 

 

Map showing the track of tornadoes which occurred in the Kankakee River Valley on June 30, 2014. Text near the map indicates that the tornadoes occurred during a 45-minute period beginning about 10:20 PM, and that two areas of rotation spaced about 5 miles apart were responsible for these tornadoes.
Tornado

Start Time

(CDT)

End Time

(CDT)

Path Length

(miles)

Path Width

(yards)

 EF Rating

Maximum

Wind Speed
Momence 10:22 PM 10:31 PM 10.4 150 EF-1 90
Manteno #1 10:23 PM 10:25 PM 3.1 45 EF-0 85
Manteno #2 10:24 PM 10:25 PM 2.7 110 EF-1 95
Grant Park #1 10:26 PM 10:28 PM 4.6 110 EF-1 105
Grant Park #2 10:25 PM 10:29 PM 5.2 450 EF-1 110
Momence-Shelby 10:29 PM 10:43 PM 15.7 175 EF-1 110
Grant Park #3 10:30 PM 10:33 PM 2.7 295 EF-0 75
Grant Park #4 10:32 PM 10:35 PM 3.9 240 EF-2 115
Grant Park #5 10:33 PM 10:34 PM 0.7 120 EF-0 75
Lowell #1 10:33 PM 10:44 PM 8.7 415 EF-1 110
Lowell #2 10:37 PM 10:38 PM 1.6 175 EF-1 90
Lowell #3 10:38 PM 10:41 PM 3.8 260 EF-1 100
Lowell #4 10:39 PM 10:42 PM 3.2 370 EF-1 110
Lowell #5 10:42 PM 10:43 PM 2.2 315 EF-1 100
Shelby-DeMotte 10:42 PM 10:54 PM 13.2 395 EF-1 110
Lowell #6 10:44 PM 10:46 PM 3.2 295 EF-2 115
Lowell #7 10:46 PM 10:47 PM 2.1 185 EF-1 105
Stoutsburg/Wheatfield 10:56 PM 10:57 PM 2.0 100 EF-1 105

 

 

5.) Momence Area Tornado

Map showing the track of a tornado which occurred near Momence on June 30, 2014.

(click on image to enlarge)

Summary:

This tornado started near the intersection of E. 6000N Rd and N. County Highway 51. Roof damage was done to a barn along with numerous trees snapped and uprooted. The tornado ended along County Highway 13. Maximum winds were estimated to be 90 mph.

 

6.) Manteno Area Tornado #1

Map showing the track of a tornado which occurred near Manteno on June 30, 2014.

(click on image to enlarge)

Summary:

This tornado touched down near N. 5000E Rd and ended near N 8000E Rd. It snapped a wooden power pole and damaged corn along its path. Maximum winds were estimated to 85 mph.

 

7.) Manteno Area Tornado #2

Map showing the track of a tornado which occurred near Manteno on June 30, 2014.

(click on image to enlarge)

Summary:

This tornado began near 10000N Rd and ended near a farmstead along N. 8000E Rd. A large machine shed was heavily damaged, and trees were snapped and uprooted. Maximum winds were estimated to 95 mph.

 

8.) Grant Park Area Tornado #1

Map showing the track of a tornado which occurred near Grant Park on June 30, 2014.

(click on image to enlarge)

Summary:

This tornado began near a farmstead on N. 8000E Rd and would end near the intersection of 9000N Rd and N. 11000E Rd. A barn was destroyed, a 4,000 lb. trailer moved 50 feet, and numerous hardwood trees were snapped and uprooted. Maximum winds were estimated to 105 mph.

 

9.) Grant Park Area Tornado #2

Map showing the track of a tornado which occurred near Grant Park on June 30, 2014.

(click on image to enlarge)

Summary:

This tornado started near the intersection of 11000N Rd and N 8000E Rd. A large shed was destroyed with all of its posts and several anchors to the posts pulled from the ground. There was also minor buckling of a house's foundation, numerous trees snapped and uprooted, a snapped wooden power pole, and damage to corn crops. The tornado dissipated near Illinois Highway 1. Maximum winds were estimated to 110 mph.

 

10.) Momence-Shelby Tornado

Map showing the track of a tornado which occurred near Momence and Schneider on June 30, 2014.

(click on image to enlarge)

Summary:

This tornado began north of Momence along Illinois Highway 17, crossed the Illinois-Indiana state line and tracked near 241st Ave. in Indiana. The tornado then passed through the far south end of the town of Schneider and ended near the Kankakee River southwest of Shelby. Damage was done to a roof of a barn along with numerous hardwood trees snapped and uprooted. Maximum winds were estimated to 110 mph.

 

11.) Grant Park Area Tornado #3

Map showing the track of a tornado which occurred near Grant Park on June 30, 2014.

(click on image to enlarge)

Summary:

This tornado that began near the intersection of 11000N Rd and Slaughter House Rd damaged a greenhouse and brought roof damage to a house, along with snapping large tree limbs. The tornado ended near County Highway 13. Maximum winds were estimated to 75 mph.

 

12.) Grant Park Area Tornado #4

Map showing the track of a tornado which occurred near Grant Park on June 30, 2014.

(click on image to enlarge)

Summary:

This strong tornado touched down slightly north of the intersection between E. 10500N Rd and N. 14000E Rd. The tornado torqued a house on its foundation beyond repair and damaged a small church. There were also numerous barns and outbuildings destroyed and severe damage to several large trees. The tornado dissipated near N. 17500E Rd. Maximum winds were estimated to 115 mph.

 

13.) Grant Park Area Tornado #5

Map showing the track of a tornado which occurred near Grant Park on June 30, 2014.

(click on image to enlarge)

Summary:

This very short-lived tornado tracked near E. 10500N Rd. Damage occurred to both a house and a barn, to a swimming pool, and to trees. Maximum winds were estimated to 75 mph.

 

14.) Lowell Area Tornado #1

Map showing the track of a tornado which occurred near Lowell on June 30, 2014.Map showing the track of a tornado which occurred near Lowell on June 30, 2014.

(click on images to enlarge)

Summary:

This tornado began near Kankakee County Highway 13 in Illinois and crossed into Indiana just south of E. 10500N Rd. A house under construction (but sealed) had an exterior wall of the garage blown out, part of a second story exterior wall blown in, and a portion of roof removed. A barn also had substantial roof damage along with numerous large trees snapped, uprooted, and partially stripped of their branches. The tornado dissipated south of Lowell, Indiana near Colfax St. Maximum winds were estimated to 110 mph.

 

15.) Lowell Area Tornado #2

Map showing the track of a tornado which occurred near Lowell on June 30, 2014.

(click on image to enlarge)

Summary:

This short-lived tornado began just west of the Illinois-Indiana state line and crossed the state line into a grove of trees and ended near Calumet Ave. There were multiple large trees downed with this tornado. Maximum winds were estimated to 90 mph.

 

16.) Lowell Area Tornado #3

Map showing the track of a tornado which occurred near Lowell on June 30, 2014.

(click on image to enlarge)

Summary:

This tornado started slightly east of the Illinois-Indiana state line and crossed U.S. Highway 41 before ending just east of Austin St. There were multiple large hardwood trees snapped and uprooted because of this tornado, as well as roof damage to a barn. Maximum winds were estimated to be 100 mph.

 

17.) Lowell Area Tornado #4

Map showing the track of a tornado which occurred near Lowell on June 30, 2014.

(click on image to enlarge)

Summary:

This tornado touched down near the intersection of U.S. Highway 41 and Belshaw Rd and tracked due east ending near Colfax Rd. Damage was done primarily to trees. Maximum winds were estimated to 110 mph.

 

18.) Lowell Area Tornado #5

Map showing the track of a tornado which occurred near Lowell on June 30, 2014.

(click on image to enlarge)

Summary:

This tornado started near Cline Avenue southwest of the community of Lowell and ended near W. 197th Rd. Numerous trees were snapped and uprooted. Maximum winds were estimated to 100 mph.

 

19.) Shelby-DeMotte Tornado

Map showing the track of a tornado which occurred near Shelby and De Motte on June 30, 2014.

(click on image to enlarge)

Summary:

This tornado started near Colfax St. and tracked through the south side of Shelby, through DeMotte, and ended slightly east of N. 600W Rd. A large barn was completely destroyed, and damage was done to houses in both Shelby and DeMotte. In addition, numerous hardwood trees were snapped and uprooted. Maximum winds were estimated to 110 mph.

 

20.) Lowell Area Tornado #6

Map showing the track of a tornado which occurred near Lowell on June 30, 2014.

(click on image to enlarge)

Summary:

This strong tornado touched down near the intersection of Clark St and Belshaw Rd and ended slightly east of Harrison St. Outbuildings as well as two large grain bins were destroyed, and numerous large high-tension wood power poles were snapped. There were also numerous trees snapped and uprooted along with crop damage. Maximum winds were estimated to 115 mph.

 

21.) Lowell Area Tornado #7

Map showing the track of a tornado which occurred near Lowell on June 30, 2014.

(click on image to enlarge)

Summary:

This tornado began over a farmstead along Grant St and tracked due east ending near Mississippi St. A large barn was destroyed with the top half of the barn ripped off and the bottom half severely damaged. Numerous trees were snapped and uprooted. Maximum winds were estimated to 105 mph.

 

22.) Stoutsburg/Wheatfield Area Tornado

Map showing the track of a tornado which occurred near Stoutsburg and Wheatfield on June 30, 2014.

(click on image to enlarge)

Summary:

This tornado occurred northwest of Wheatfield tracking near W. 1450N Rd. Damage was done to a large pole barn with the roof blown off and multiple walls collapsed. There were also numerous trees snapped and uprooted. Maximum winds were estimated to 105 mph.

 

The Enhanced Fujita (EF) Scale classifies tornadoes into the following categories:

EF0
Weak
65-85 mph		 EF1
Moderate
86-110 mph		 EF2
Significant
111-135 mph		 EF3
Severe
136-165 mph		 EF4
Extreme
166-200 mph		 EF5
Catastrophic
200+ mph
ef-scale

When a tornado is known to have occurred but does not cause damage to any qualified damage indicators, or if the only damage is located in an area that is inaccessible to 博体育 storm survey personnel, then a tornado may be assigned the EF-Unknown (EF-U) rating.

Straight-Line Winds

In addition to the 22 tornadoes that occurred across the 博体育 Chicago forecast area, including the numerous tornadoes in the Kankakee River Valley, corridors of damaging straight-line winds also occurred -- the most notable of which was also in the Kankakee River Valley. While most areas in these corridors experienced peak winds up to approximately 60 mph, a few isolated areas experienced damage consistent with peak wind gusts up to 80 mph.

Map showing the estimated peak wind gusts in the Kankakee River Valley on June 30, 2014. A swath of winds is shown from near Grant Park eastward to near De Motte. Most areas are depicted as experiencing 60 mph winds with isolated areas depicted as 70-80 mph.

Storm Reports

Map of preliminary storm reports collected by the Storm Prediction Center from June 30, 2014

Map of Storm Reports from June 30, 2014

Click on the links below for a listing of quality-controlled storm reports from this event in the :

 

(Boone, Cook, DeKalb, DuPage, Ford, Grundy, Iroquois, Kane, Kankakee, Kendall, Lake, La Salle, Lee, Livingston, McHenry, Ogle, Will, and Winnebago)

 

(Benton, Jasper, Lake, Newton, and Porter)

Photos

Photo showing damage from a tornado near Earlville. Trees are uprooted near a house. Photo showing damage from a tornado near Earlville. A house has a garage with a collapsed wall, a damaged roof, and a blown in garage door. Photo showing damage from a tornado near Earlville. Aerial imagery shows a convergent path in a field.
Tornado damage in Earlville. Photo from 博体育 damage survey. Tornado damage in Earlville. Photo from 博体育 damage survey. A swirling pattern in corn fields near Earlville caused by a tornado. Aerial imagery courtesy of ABC 7 Chicago.
Photo showing damage from a tornado near Earlville. Aerial imagery shows a convergent path in a field. Photo showing damage from a tornado near southwest Kendall County. Large tree branches are broken. Photo showing damage from a tornado near southwest Kendall County. A tree trunk is snapped near the base with a 博体育 employee looking at the damage.
A swirling pattern in corn fields near Earlville caused by a tornado. Aerial imagery courtesy of ABC 7 Chicago. Tornado damage in southwest Kendall County. Photo from 博体育 damage survey. Tornado damage in southwest Kendall County. Photo from 博体育 damage survey.
Photo showing damage from a tornado near Plainfield. Pieces of siding have been pulled from a house. Photo showing damage from a tornado near Plainfield. A large tree branch has been broken. Photo showing damage from a tornado near Plainfield. A tree trunk has been snapped.
Tornado damage in Plainfield. Photo from 博体育 damage survey. Tornado damage in Plainfield. Photo from 博体育 damage survey. Tornado damage in Plainfield. Photo from 博体育 damage survey.
Photo showing damage from a tornado near Grant Park. A farm outbuilding has been damaged with collapsed walls and debris spread across a yard. Photo showing damage from a tornado near Grant Park. A shed has been destroyed with only the foundation remaining. Photo showing damage from a tornado near Grant Park. A large window of a church has been separated from the wall and blown into the interior of the building.
Tornado damage near Grant Park. Photo from 博体育 damage survey. Tornado damage near Grant Park. Photo from 博体育 damage survey. Tornado damage near Grant Park. Photo from 博体育 damage survey.
Photo showing damage from a tornado near Grant Park. A tree branch has been impaled into the side of a house. Photo showing damage from a tornado near Grant Park. Walls have collapsed at a building under construction. Photo showing damage from a tornado near Grant Park. A farm outbuilding has been completed destroyed with all walls collapsed.
Tornado damage near Grant Park. Photo from 博体育 damage survey. Tornado damage near Grant Park. Photo from 博体育 damage survey. Tornado damage near Grant Park. Photo from 博体育 damage survey.
Photo showing damage from a tornado near Grant Park. Multiple large tree branches have been broken. Photo showing damage from a tornado near Grant Park. A portion of the roof has been removed from a metal farm outbuilding. Photo showing damage from a tornado near Lowell. Multiple large branches have been broken.
Tornado damage near Grant Park. Photo from 博体育 damage survey. Tornado damage near Grant Park. Photo from 博体育 damage survey. Tornado damage near Lowell. Photo from 博体育 damage survey.
Photo showing damage from a tornado near Lowell. A power pole has been snapped and the power lines are lying on the ground. Photo showing damage from a tornado near Lowell. Metal grain silos have been damaged, with one partially collapsed. Photo showing damage from a tornado near Lowell. A large tree branch has been broken.
Tornado damage near Lowell. Photo from 博体育 damage survey. Tornado damage near Lowell. Photo from 博体育 damage survey. Tornado damage near Lowell. Photo from 博体育 damage survey.
Photo showing damage from a tornado near De Motte. Debris from a farm outbuilding is spread across a yard and field. Photo showing damage from a tornado near De Motte. A tree is uprooted. Photo showing damage from straight-line winds near Morris. Part of the roof has been removed from a metal industrial building.
Tornado damage near DeMotte. Photo from 博体育 damage survey. Tornado damage in DeMotte. Photo from 博体育 damage survey. Wind damage in Morris. Photo from 博体育 damage survey.

Radar

Animation showing radar imagery from June 30, 2014. Two lines of thunderstorms are shown moving across northern Illinois and northwestern Indiana.

Radar reflectivity loop from 6:30 PM to 11:30 PM CDT

Radar imagery from June 30, 2014, at the time a tornado occurred near Earlville. Images show radar reflectivity, velocity, and correlation coefficient from the 博体育 Chicago NEXRAD.

Radar imagery at the time of the Earlville tornado

(Clockwise from top left to bottom left: Reflectivity (Z), Velocity (V), Storm-Relative Velocity (SRM), Correlation Coefficient (CC))

Radar imagery from June 30, 2014, at the time a tornado occurred near Plainfield and Romeoville. Images show radar reflectivity, velocity, and correlation coefficient from the 博体育 Chicago NEXRAD.

Radar imagery at the time of the Plainfield tornado

(Clockwise from top left to bottom left: Reflectivity (Z), Velocity (V), Storm-Relative Velocity (SRM), Correlation Coefficient (CC))

Radar imagery from June 30, 2014, at the time tornadoes were occurring near Manteno and Grant Park. Images show radar reflectivity, velocity, and correlation coefficient from the 博体育 Chicago NEXRAD.

Radar imagery at the time the derecho was producing tornadoes northwest of Momence and northwest of Grant Park

(Clockwise from top left to bottom left: Reflectivity (Z), Velocity (V), Storm-Relative Velocity (SRM), Correlation Coefficient (CC))

Radar imagery from June 30, 2014, at the time tornadoes were occurring near Momence and Grant Park. Images show radar reflectivity, velocity, and correlation coefficient from the 博体育 Chicago NEXRAD.

鈥婻adar imagery at the time the derecho was producing tornadoes north of Momence and north of Grant Park

(Clockwise from top left to bottom left: Reflectivity (Z), Velocity (V), Storm-Relative Velocity (SRM), Correlation Coefficient (CC))

Radar imagery from June 30, 2014, at the time tornadoes were occurring near Grant Park. Images show radar reflectivity, velocity, and correlation coefficient from the 博体育 Chicago NEXRAD.

鈥婻adar imagery at the time the derecho was producing tornadoes northeast of Grant Park

(Clockwise from top left to bottom left: Reflectivity (Z), Velocity (V), Storm-Relative Velocity (SRM), Correlation Coefficient (CC))

Meteorology and Environment

The severe weather event of June 30th, 2014 was quite unique. Two especially standout characteristics were that 1.) the event encompassed two separate derecho episodes in the Midwest, with one literally forming on the heels of its predecessor and 2.) the second derecho brought over two dozen embedded tornadoes to northern Illinois and northern Indiana. 

A complex of storms, even one not as potent as a derecho, often alters the environment for hours after in such a way that it is no longer conducive for thunderstorm redevelopment or intensification. This is because rain-cooled air limits convective lift, the low-level wind field is quite disrupted, and broad descent is often occurring in the atmospheric mid-levels (the opposite of what storms need). On June 30, 2014, the first complex of storms had little to no effect on the environment. In fact, it may have even slightly helped the environment for embedded tornadoes in Kankakee County and into northwest Indiana, as it placed an east-to-west boundary over that region. The southern portion of the first derecho began weakening in intensity as it moved across northeast Illinois into northwest Indiana, with the cooling of the atmosphere being very shallow. Thus, when the trailing well-organized complex of storms moved into that environment, its associated downdrafts (winds) could easily punch their way through that layer.

 

Map showing mean sea level pressure and 2 hour pressure change at 6 PM on June 30, 2014. The map illustrates that strong warm air advection brought unstable air back into northern Illinois shortly after the first round of storms had moved through the area. Map showing wind shear over the 0 km to 6 km layer at 6 PM on June 30, 2014. The image shows the highest wind shear over Iowa and far northwestern Illinois. Map showing effective storm-relative helicity at 9 PM on June 30, 2014. The image shows the highest values near the line of thunderstorms in northern Illinois.
Mean sea level pressure (and 2-hour pressure change) at 6 PM CDT Wind shear in the 0-6 km layer at 6 PM CDT Effective storm-relative helicity (SRH) at 9 PM CDT
Map showing wind speeds at 500 mb at 2 PM on June 30, 2014. The image shows the highest wind speeds extending from Nebraska through Iowa and Minnesota up to Wisconsin, along with two shortwave troughs moving into the Great Lakes. Graphic showing the vertical wind profile from 0 to 3 km at the 博体育 Chicago KLOT radar. The image shows a shallow cold pool generated from the first line of storms subsiding just prior to the arrival of the second line of storms. Map showing radar reflectivity and surface weather features at 9 PM on June 30, 2014. A line of strong radar echoes is moving into northeastern Illinois with a warm front to the southwest of the Chicago metro area.
500 mb level analysis at 2 PM CDT showing two shortwave troughs in close proximity approaching Illinois and Indiana Evolution of the vertical wind profile up to 3 km between 7 and 10 PM CDT as sampled by the KLOT radar. The depth of the shallow cold pool from the first line of storms is also overlaid, showing how it slowly diminished in the lead up to the Plainfield tornado. Radar reflectivity and surface observations at 9 PM CDT. The location of the warm front and the leading edge of the cold pool from the first line of storms are also plotted.
Graphic showing an airplane-derived sounding from Midway Airport at 9:37 PM on June 30, 2014. The plot shows instability and low-level wind shear that is supportive of severe thunderstorms.
An aircraft sounding from Midway Airport at 9:37 PM showing
plenty of instability and a significant amount of low-level wind shear

About Derechos

  • A derecho is a well-organized thunderstorm complex that produces a swath of particularly damaging thunderstorm winds (specifically, wind gusts of at least 58 mph along most of its length with several well-separated 75 mph or greater gusts) over an area at least 250 miles long.
  • Wind speeds in a derecho can sometimes exceed 100 mph, which is equivalent to that of an EF-1 tornado, but over a vastly larger area than a tornado would impact.
  • Tornadoes can also be embedded within derechos and produce concentrated areas of even more intense damage.
  • Derechos develop in environments with very warm and moist air at ground-level, colder air aloft, and moderate to strong winds in the upper levels of the atmosphere.
  • Derechos occur most frequently in the Midwest, southern Plains, and mid-South.

A map showing the approximate frequency of derechos in the eastern United States. Areas in the mid south, southern Great Plaines, and Midwest are depicted as very common areas for derechos. Close to the Rocky Mountains, the frequency of derechos is depicted as rare. In the far northeast and in Florida, derechos are also depicted as rare.

Info graphic that provides information about derechos. The graphic indicates the criteria for a storm system to be classified as a derecho, including severe wind gusts over most of the path with severe significant gusts of 75 mph or higher and a length of at least 250 miles. The graphic also indicates that the term derecho is not new and that some derechos may produce winds over a large area consistent with that of a EF1 tornado.

 Info graphic that provides information about derechos. The graphic shows a map illustrating a derecho from August 2020, and then indicates features about the shape of the complex of storms.

More information about derechos is available from .

Research

Over the past several decades, our understanding of the environments favorable for, and the mechanisms by which, tornadoes develop has drastically improved, allowing for a corresponding increase in our forecast and warning skill identifying tornadic thunderstorms. Generally speaking, we now understand that the key factors in determining whether or not a tornado will develop are related to the steadiness and strength of low-level updrafts, which themselves are related to key environmental parameters. By forecasting environments and parts of a storm that are supportive of steady and strong low-level updrafts, we can provide better warnings for life-threatening tornadoes. 

The second of the two June 30, 2014 derechos was particularly efficient in the production of tornadoes. Many of these tornadoes occurred simultaneously and in close proximity to one another, which posed a significant challenge in both warning and ultimately surveying the eventual damage paths. As a result, the storms provided the opportunity for additional study using unique datasets and platforms to clarify the paths and potential formation mechanisms of each tornado. Over the course of several years, research teams led by Dr. Anthony Lyza (current affiliation: NOAA/OAR/National Severe Storms Laboratory) that included staff from 博体育 Chicago analyzed the circulations and damage paths to ultimately provide a more accurate assessment of the damaging derecho event. Two peer-reviewed studies that resulted from their work are provided below:

 

 

Perhaps one of the most lasting findings from the studies on the June 30, 2014 derechos was a reinforcement in the idea that squall lines can be exceptionally prolific producers of tornadoes. Indeed, a single squall line can produce similar quantities and intensities of tornadoes to those that occur in tornado outbreaks driven primarily by supercells. Our local area is prone to tornadoes produced by both squall lines and supercells, and many of the most prolific tornado events that have occurred here in recent memory involved squall lines. Several notable examples are provided below (in reverse chronological order):

 

Event Date/Name # of Tornadoes in Local Area Storm Mode Max Tornado Intensity 
July 28, 2023 Tornado Event 13 Squall Line EF-1
March 31, 2023 Tornado Outbreak 22 Squall Line and Supercells EF-2
June 20, 2021 Tornado Event 4 Squall Line EF-3
August 10, 2020 Derecho 15 Squall Line EF-1
June 30, 2014 Derechos 22 Squall Line EF-1
August 4, 2008 Derecho 5 Squall Line EF-2

 

Additional information about squall lines and other types of thunderstorms can be found . 

 

Additional Information

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