Tornadoes · United States · Illinois · 2021

Unrated tornado, Dawson to Mechanicsburg, Illinois, May 3, 2021

From Dawson to Mechanicsburg, this Unrated tornado ran 0.6 miles across Sangamon County on May 3, 2021, touching down at 6:14 PM CDT and reaching 50 yards wide. It killed nobody.

The rating scale

Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. EF065 to 85 mph

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. EF186 to 110 mph

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. EF2111 to 135 mph

    Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

  4. EF3136 to 165 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. EF4166 to 200 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. EF5over 200 mph

    Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

  7. Unratedthis tornado

    The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

The record

Rating
Unrated
Date
May 3, 2021
Touchdown
6:14 PM CDT (23:14 UTC)
Lifted
6:15 PM CDT (23:15 UTC)
On the ground
1 minutes
Path length
0.6 miles (1.0 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
County
Sangamon County
Touchdown point
39.827, -89.428
Lift-off point
39.825, -89.417
Record number
2105031714-01

What the Weather Service recorded

A Mesoscale Convective Vortex (MCV) generated by a large cluster of convection across Kansas during the pre-dawn hours tracked eastward into central Illinois by the late afternoon and evening of May 3rd. Despite weak instability and deep-layer synoptic shear, the MCV was able to enhance the low-level shear and trigger a broken line of convection. One of the cells on the east-southeast flank of the MCV became a supercell and tracked across central Illinois from Cass County southeastward to Coles County before dissipating after dark. That particular storm produced five brief tornado touchdowns and hail as large as half dollars along its path. Another thunderstorm cell further south dropped 2-inch diameter hail in southern Christian County.

A weak tornado touched down in a field about 0.8 miles southeast of Dawson just north of I-72 at 6:10 PM CDT. The tornado tracked southeastward and quickly dissipated by 6:11 PM CDT. No damage occurred.

A weak tornado touched down in a field about 2 miles northwest of Mechanicsburg at 6:14 PM CDT. The tornado tracked southeastward and quickly dissipated by 6:15 PM CDT. No damage occurred.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

What forecasters said that day

The local office's own words before the tornado touched down, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Lincoln, IL wrote its last area forecast discussion before the tornado touched down at May 3, 2:22 PM CDT, 3 hours 52 minutes earlier.

Area forecast discussion, May 3, 2:22 PM CDT, 3 hours 52 minutes before
Area Forecast Discussion
National Weather Service Lincoln IL
222 PM CDT Mon May 3 2021

.SYNOPSIS...
Issued at 222 PM CDT Mon May 3 2021

A frontal system tracking southeast across the state will bring
the threat of strong to severe thunderstorms into this evening.
Rain showers and a few thunderstorms will linger through Tuesday,
especially for areas east of the IL River. Cooler than normal
temperatures will continue into midweek.

&&

.SHORT TERM...(This evening through Tuesday)
ISSUED AT 222 PM CDT Mon May 3 2021

Forecast challenge in the short term remains convective trends
through this evening. Latest satellite trend show increasing
sunshine over west central IL, ahead of a shortwave/remnant MCV
tracking east through northeast MO. This should allow for
continued destabilization through early this evening, and with
increasing wind fields aloft due to the approach of the shortwave,
deep layer shear will grow to around 45 kt. Ascent associated
with the MCV and weak surface wave should allow scattered
convection late this afternoon and evening, with CAMs continuing
to focus on areas north of a Jacksonville to Paris line for
discrete cells and line segments. Damaging wind gusts will be the
main threat, but the tornado threat is non- zero due to locally
enhanced effective SRH downstream of the MCV. Expect a weakening
trend as we head into mid evening with increasing stabilization
when the storms track into far eastern and southeast IL. SPC has
removed the enhanced risk for southern IL tonight, keeping the
entire CWA in a slight risk.

Will likely see a lull in precip late tonight as the surface front
pushes into the Ohio Valley. However additional low pressure
development along the front to our south should send another round
of rain with embedded thunderstorms northeast, primarily affecting
areas east of I-55 on Tuesday.

&&

.LONG TERM...(Tuesday night through Monday)
ISSUED AT 222 PM CDT Mon May 3 2021

Wednesday will see a break between systems, as a brief period of
zonal flow aloft with high pressure at the surface shifts across
the Midwest. While the airmass remains cool, a return of sunshine
should boost highs into the low and mid 60s. A shortwave and weak
surface reflection moving through on Thursday will bring scattered
showers and cooler temperatures. Northwest flow behind this system
will keep seasonably cool air around for Friday. The active
pattern will see a warm front develop to our southwest Friday
night and track northeast into the area on Saturday. This appears
to be a more substantial system with a potential for heavy rain
and strong storms, depending on how the details play out next
weekend.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1211 PM CDT Mon May 3 2021

Ceilings have recently risen to MVFR, and will likely see a
window of VFR this afternoon. However a cold front pushing in from
the northwest will bring scattered thunderstorms for the late
afternoon and evening and have tempo groups for this to MVFR,
though brief LIFR and gusty/damaging winds are possible if a
stronger storm hits a terminal. Several hours of MVFR ceilings are
likely behind the storms, before ceilings lower to IFR overnight.
These may persist towards midday Tuesday with some guidance
raising ceilings to MVFR by late morning. Winds outside of storms
will generally be near 10 kt from the southwest this afternoon
and veering west behind the front, then northwest later this
evening.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SYNOPSIS...25
SHORT TERM...25
LONG TERM...25
AVIATION...25
Hazardous weather outlook, May 3, 3:15 PM CDT, 2 hours 59 minutes before
Hazardous Weather Outlook
National Weather Service Lincoln IL
315 PM CDT Mon May 3 2021

ILZ027>031-036-037-040-041-041100-
Fulton-Knox-Marshall-Mason-Peoria-Schuyler-Stark-Tazewell-
Woodford-
315 PM CDT Mon May 3 2021

This Hazardous Weather Outlook is for portions of central
Illinois and west central Illinois.

.DAY ONE...THIS AFTERNOON AND TONIGHT...

Thunderstorms are likely through sunset as a weather system moves
east across the area through sunset. These storms could be
severe, with hail 1 to 2 inches in diameter and damaging winds of
60 to 70 mph. Isolated tornadoes are also possible.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY...

Isolated thunderstorms are possible Thursday afternoon and again
from Saturday afternoon through Sunday. The risk of severe storms
is low during this time, though lightning hazards exist.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will be needed through 7 pm.

ILZ038-042>057-061-041100-
Cass-Champaign-Christian-Coles-De Witt-Douglas-Edgar-Logan-Macon-
McLean-Menard-Morgan-Moultrie-Piatt-Sangamon-Scott-Shelby-
Vermilion-
315 PM CDT Mon May 3 2021

This Hazardous Weather Outlook is for portions of central
Illinois, east central Illinois and west central Illinois.

.DAY ONE...THIS AFTERNOON AND TONIGHT...

Thunderstorms are likely across central Illinois as a weather
system moves east across the area late this afternoon through
mid evening. These storms could be severe, with hail 1 to 2 inch
diameter and damaging winds of 60 to 70 mph. A brief tornado
touchdown is also possible.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY...

Isolated thunderstorms are possible on Tuesday, Thursday
afternoon and again from Saturday afternoon through Sunday.
The risk of severe storms is low during this time, though
lightning hazards exist.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will be needed between 6 and 10 pm.

ILZ062-063-066>068-071>073-041100-
Clark-Clay-Crawford-Cumberland-Effingham-Jasper-Lawrence-Richland-
315 PM CDT Mon May 3 2021

This Hazardous Weather Outlook is for portions of east central
Illinois and southeast Illinois.

.DAY ONE...THIS AFTERNOON AND TONIGHT...

Thunderstorms are likely across southeast Illinois tonight as a
weather system moves east across the area. These storms could be
severe, with hail 1 to 2 inch diameter, damaging winds of 60 to
70 mph and isolated tornadoes.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY...

Isolated thunderstorms are possible on Tuesday and Tuesday
evening, and again Thursday afternoon. More isolated thunderstorms
are possible Saturday afternoon through Sunday. Severe storm risk
is low during this time, though lightning hazards exist.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be required between 8 pm and 1 am tonight.

07

In the hours before

Local storm report, May 3, 5:20 PM CDT, 54 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LINCOLN IL
520 PM CDT MON MAY 3 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0504 PM     HAIL             VIRGINIA                39.95N 90.21W
05/03/2021  E1.50 INCH       CASS               IL   PUBLIC

            RELAYED BY BROADCAST MEDIA. DAMAGE TO CARS.

&&

SB
Local storm report, May 3, 5:21 PM CDT, 53 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LINCOLN IL
521 PM CDT MON MAY 3 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0515 PM     HAIL             4 WSW NEWMANSVILLE      39.98N 90.08W
05/03/2021  E1.00 INCH       CASS               IL   FIRE DEPT/RESCUE

            RELAYED BY ASHLAND FIRE.

&&

SB
Local storm report, May 3, 5:30 PM CDT, 44 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LINCOLN IL
530 PM CDT MON MAY 3 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0527 PM     TORNADO          2 WNW PLEASANT PLAINS   39.93N 90.00W
05/03/2021                   CASS               IL   STORM CHASER

&&

SB
Local storm report, May 3, 5:40 PM CDT, 34 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LINCOLN IL
540 PM CDT MON MAY 3 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0505 PM     TORNADO          3 S VIRGINIA            39.91N 90.21W
05/03/2021                   CASS               IL   TRAINED SPOTTER

            ON GROUND IN OPEN FIELD. DIME SIZED HAIL.

&&

SB
Special weather statement, May 3, 6:02 PM CDT, 12 minutes before
Special Weather Statement
National Weather Service Lincoln IL
602 PM CDT Mon May 3 2021

ILZ042-032345-
Logan-
602 PM CDT Mon May 3 2021

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL LOGAN COUNTY UNTIL 645 PM
CDT...

At 602 PM CDT, Doppler radar was tracking a strong thunderstorm near
Middletown, or 7 miles southwest of Lincoln, moving east at 30 mph.

Half inch hail and wind gusts of 50 to 55 mph will be possible with
this storm.

Locations impacted include...
Lincoln, Mount Pulaski, Elkhart, Chestnut, New Holland, Lawndale and
Broadwell.

This includes the following highways...
 Interstate 155 between mile markers 0 and 2.
 Interstate 55 between mile markers 114 and 136.

A Severe Thunderstorm Watch remains in effect until 900 PM CDT for
central Illinois.

LAT...LON 4000 8954 4018 8959 4024 8922 4002 8917
TIME...MOT...LOC 2302Z 269DEG 26KT 4010 8949

37
Local storm report, May 3, 6:09 PM CDT, 5 minutes before
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The air that afternoon

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

Lincoln, IL (KILX), 12:00Z

11.2 hours before the tornado, 79 km from the path. May 3, 2021.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2021-05-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -87523, lifted condensation level 460 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Lincoln, IL at 12:00Z on 2021-05-03The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 44 square meters per square second, 0 to 6 km bulk shear 11 knots.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
-87523 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
460 m above ground
0-6 km bulk shear
11 kt
0-1 km bulk shear
8 kt
0-1 km storm-relative helicity
44 m²/s²
0-3 km storm-relative helicity
56 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.5 K/km

Open this sounding in Storm Lab

Lincoln, IL (KILX), 00:00Z

0.8 hours after it, 79 km from the path. May 4, 2021.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2021-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 758 joules per kilogram, CIN -32, lifted condensation level 843 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Lincoln, IL at 00:00Z on 2021-05-04The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity -13 square meters per square second, 0 to 6 km bulk shear 48 knots.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
758 J/kg
Mixed-layer CIN
-32 J/kg
Surface CAPE
1044 J/kg
Mixed-layer LCL
843 m above ground
0-6 km bulk shear
48 kt
0-1 km bulk shear
17 kt
0-1 km storm-relative helicity
-13 m²/s²
0-3 km storm-relative helicity
74 m²/s²
Significant tornado parameter
0.3
Supercell composite
1.4
0-3 km lapse rate
6.0 K/km

Open this sounding in Storm Lab

The surface observations

Springfield (SPI), 22 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
00:00 UTC

From the Iowa Environmental Mesonet's archive of airport observations.

The radar

The Lincoln radar (KILX), 37 km away, was scanning. The volume nearest the touchdown began at 23:13 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

This ground now

The live radar over the trackEvery 2021 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

The other tornadoes of May 3, 2021

30 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 38:08 AM CDTEF1Monroe, KY0.560
May 310:00 AM EDTEF1Douglas, GA1.4250$250,000
May 310:22 AM EDTEF1Fulton, GA5.7400$250,000
May 312:39 PM EDTEF0Walton, GA1.4200$100,000
May 312:39 PM EDTEF1York, SC0.5150$350,000
May 311:42 AM CDTEF0Coffee, TN0.850$15,000
May 312:54 PM EDTEF1Madison, GA5.5250
May 31:29 PM EDTEF0Oglethorpe, GA1.9200$100,000
May 31:41 PM EDTEF1Elbert, GA0.125$50,000
May 32:04 PM EDTEF2Abbeville, SC29.41501$115,000
May 32:23 PM EDTEF0Stanly, NC1.5150$50,000
May 33:01 PM EDTEF2Northumberland, VA4.4250$500,000
May 34:57 PM CDTUnratedCass, IL0.550
May 35:05 PM CDTUnratedCass, IL1.5100
May 36:27 PM EDTEF1Jefferson, WV1.81251$100,000
May 35:27 PM CDTUnratedSangamon, IL0.350
May 36:02 PM CDTEF0Hood, TX0.450$500
May 36:10 PM CDTUnratedSangamon, IL0.450
May 37:10 PM CDTUnratedHill, TX0.025
May 38:14 PM EDTEF0Frederick, MD0.8200$150,000
May 37:18 PM CDTEF2Hill, TX3.4150$350,000
May 38:35 PM EDTEF0Frederick, MD0.6150$100,000
May 37:41 PM CDTEF0Collin, TX0.550$500
May 38:47 PM EDTEF0Carroll, MD0.275$50,000
May 38:00 PM CDTEF0Johnson, TX0.250$500
May 39:37 PM EDTEF0Lawrence, PA0.250
May 38:43 PM CDTEF2Ellis, TX5.46598$1.5 million
May 39:33 PM CDTEF1Sequoyah, OK to AR28.82,2001$16 million
May 39:36 PM CDTEF1Sequoyah, OK to AR10.3900$110,000
May 310:06 PM CDTEF1Crawford, AR2.7300$20,000

What this means

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.