Tornadoes · United States · Massachusetts · 2021
EF0 tornado, Clinton, Massachusetts, August 19, 2021
This EF0 tornado ran 0.5 miles across Worcester County on August 19, 2021, touching down at 1:30 PM EDT and reaching 35 yards wide. It killed nobody, and did $12,000 of property damage.
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.
EF065 to 85 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
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.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
Unrated
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
- EF0
- Date
- August 19, 2021
- Touchdown
- 1:30 PM EDT (17:30 UTC)
- Lifted
- 1:31 PM EDT (17:31 UTC)
- On the ground
- 1 minutes
- Path length
- 0.5 miles (0.9 km)
- Path width
- 35 yards (32 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $12,000
- County
- Worcester County
- Touchdown point
- 42.415, -71.679
- Lift-off point
- 42.421, -71.673
- Record number
- 2108191130-01
What the Weather Service recorded
The remnants of Tropical Storm Fred moved across Southern New England producing heavy rain, gusty winds, and two tornadoes - one that moved from northeast Connecticut into Worcester County and another in central Worcester County.
A weak tornado touched down in the early afternoon in the town of |Clinton in eastern Worcester County, Massachusetts. A NWS |meteorologist conducted a storm survey following tips from amateur |radio operators and the local fire chief. The following information |summarizes all of the reports. ||The tornado touched down near the intersection of Cedar Street and |Church Street. It tracked northeastward, impacting Benefit Street, |Haskell Avenue, and Water Street at Beech Street. This is a path |length of 0.5 miles. The approximate path width was 35 yards. Damage |photos led to estimates of maximum wind speeds of 75 to 80 mph, |which is an EF0 on the Enhanced Fujita Scale. The time, based on |radar and eyewitness accounts, was from 130 PM to 131 PM EDT. ||A row of trees was snapped and downed in a convergent fashion near |Church Street at Cedar Street. Other trees were downed on Haskell |Avenue at Beech Street. The fire chief relayed that multiple |residents witnessed a tornado touchdown on Water Street, where |extensive damage was observed.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
12 minutes of warning. NWS BOX issued a tornado warning for this county at 17:18 UTC, 12 minutes before the tornado touched down, in force until 17:45 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 12:14 UTC | 15:15 UTC | Flash Flood Warning | BOX |
| 13:18 UTC | 16:15 UTC | Flash Flood Warning | BOX |
| 14:14 UTC | 14:58 UTC | Severe Thunderstorm Warning | BOX |
| 14:21 UTC | 14:50 UTC | Tornado Warning | BOX |
| 14:46 UTC | 17:45 UTC | Flash Flood Warning | BOX |
| 15:36 UTC | 16:14 UTC | Severe Thunderstorm Warning | BOX |
| 17:18 UTC | 17:45 UTC | Tornado Warning | BOX |
Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.
The forecast that day
The Storm Prediction Center had this point in a General Thunderstorms Risk. The outlook in force was issued at 16:44 UTC.
SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.
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.
Albany, NY (KALY), 12:00Z
5.5 hours before the tornado, 179 km from the path. August 19, 2021.
- Mixed-layer CAPE
- 5 J/kg
- Mixed-layer CIN
- -104 J/kg
- Surface CAPE
- 50 J/kg
- Mixed-layer LCL
- 523 m above ground
- 0-6 km bulk shear
- 11 kt
- 0-1 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 194 m²/s²
- 0-3 km storm-relative helicity
- 350 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
- 0-3 km lapse rate
- 4.5 K/km
Albany, NY (KALY), 00:00Z
6.5 hours after it, 179 km from the path. August 20, 2021.
- Mixed-layer CAPE
- 24 J/kg
- Mixed-layer CIN
- -162 J/kg
- Surface CAPE
- 87 J/kg
- Mixed-layer LCL
- 532 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- -103 m²/s²
- 0-3 km storm-relative helicity
- -31 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 4.5 K/km
The surface observations
Fitchburg (FIT), 16 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 15:30 UTC | 110° 5 kt | 1014.6 | -RA BR | |||
| 15:35 UTC | 73 | 71 | 100° 3 kt | 1014.6 | -RA BR | |
| 15:40 UTC | 110° 4 kt | 1014.6 | -RA BR | |||
| 15:42 UTC | 73 | 71 | 90° 4 kt | 1014.6 | -RA | |
| 15:45 UTC | 100° 2 kt | 1014.6 | -RA | |||
| 15:50 UTC | 100° 2 kt | 1014.2 | ||||
| 15:52 UTC | 75 | 71 | 3 kt | 1014.2 | ||
| 15:55 UTC | 110° 4 kt | 1014.2 | ||||
| 16:00 UTC | 90° 2 kt | 1014.2 | -RA | |||
| 16:05 UTC | 90° 4 kt | 1014.2 | -RA | |||
| 16:10 UTC | 120° 4 kt | 1013.9 | -RA | |||
| 16:10 UTC | 76 | 72 | 120° 4 kt | 1013.9 | -RA | |
| 16:15 UTC | 90° 2 kt | 1013.9 | ||||
| 16:18 UTC | 76 | 72 | 110° 3 kt | 1013.9 | ||
| 16:20 UTC | 100° 4 kt | 1013.9 | -RA | |||
| 16:25 UTC | 100° 4 kt | 1013.9 | RA BR | |||
| 16:25 UTC | 76 | 72 | 100° 4 kt | 1013.9 | RA BR | |
| 16:30 UTC | 90° 2 kt | 1013.9 | -RA BR | |||
| 16:34 UTC | 76 | 73 | 0° 0 kt | 1013.9 | -RA BR | |
| 16:35 UTC | 0° 0 kt | 1013.9 | -RA BR | |||
| 16:45 UTC | 80° 4 kt | 1013.5 | -RA BR | |||
| 16:50 UTC | 70° 2 kt | 1013.5 | -RA BR | |||
| 16:52 UTC | 76 | 72 | 3 kt | 1013.5 | -RA BR | |
| 16:55 UTC | 70° 2 kt | 1013.5 | -RA BR | |||
| 17:05 UTC | 0° 0 kt | 1013.2 | -RA BR | |||
| 17:05 UTC | 76 | 73 | 0° 0 kt | 1013.2 | -RA BR | |
| 17:10 UTC | 0° 0 kt | 1013.2 | -RA BR | |||
| 17:11 UTC | 76 | 72 | 0° 0 kt | 1013.2 | -RA BR | |
| 17:15 UTC | 0° 0 kt | 1013.2 | -RA BR | |||
| 17:20 UTC | 0° 0 kt | 1013.2 | RA BR | |||
| 17:23 UTC | 76 | 72 | 0° 0 kt | 1013.2 | RA BR | |
| 17:25 UTC | 0° 0 kt | 1013.2 | RA BR | |||
| 17:30 UTC | 320° 2 kt | 1013.2 | +RA BR | |||
| 17:35 UTC | 310° 4 kt | 1012.9 | +RA BR | |||
| 17:38 UTC | 77 | 73 | 340° 5 kt | 1012.9 | -RA BR | |
| 17:40 UTC | 77 | 73 | 350° 4 kt | 1012.9 | -RA BR | |
| 17:40 UTC | 350° 4 kt | 1012.9 | -RA BR | |||
| 17:45 UTC | 350° 2 kt | 1012.9 | -RA | |||
| 17:50 UTC | 360° 2 kt | 1012.9 | ||||
| 17:52 UTC | 79 | 73 | 360° 3 kt | 1012.5 | ||
| 17:55 UTC | 350° 2 kt | 1012.5 | ||||
| 18:00 UTC | 350° 5 kt | 1012.5 | ||||
| 18:05 UTC | 0° 0 kt | 1012.5 | ||||
| 18:10 UTC | 0° 0 kt | 1012.5 | ||||
| 18:15 UTC | 20° 4 kt | 1012.5 | ||||
| 18:20 UTC | 10° 4 kt | 1012.5 | ||||
| 18:25 UTC | 40° 4 kt | 1012.2 | ||||
| 18:30 UTC | 30° 5 kt | 1012.2 | ||||
| 18:35 UTC | 40° 2 kt | 1012.2 | ||||
| 18:40 UTC | 40° 4 kt | 1012.2 | -RA | |||
| 18:45 UTC | 40° 2 kt | 1012.2 | -RA | |||
| 18:50 UTC | 30° 2 kt | 1012.2 | -RA | |||
| 18:52 UTC | 78 | 73 | 40° 4 kt | 1011.9 | -RA | |
| 18:55 UTC | 40° 2 kt | 1011.9 | -RA | |||
| 19:00 UTC | 0° 0 kt | 1012.2 | ||||
| 19:04 UTC | 78 | 73 | 0° 0 kt | 1012.2 | ||
| 19:05 UTC | 0° 0 kt | 1011.9 | ||||
| 19:10 UTC | 40° 4 kt | 1011.9 | ||||
| 19:19 UTC | 77 | 73 | 80° 3 kt | 1011.9 | +RA BR | |
| 19:20 UTC | 70° 4 kt | 1011.5 | +RA BR | |||
| 19:25 UTC | 80° 5 kt | 1011.5 | +RA BR | |||
| 19:29 UTC | 77 | 73 | 6 kt | 1011.9 | -RA BR |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The Boston radar (KBOX), 68 km away, was scanning. The volume nearest the touchdown began at 17:32 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.
What was reported nearby
Local storm reports within 60 km of the path, in the three hours either side.
| Time (UTC) | Report | Where | County | Remark |
|---|---|---|---|---|
| 15:38 UTC | FLOOD | Worcester | Worcester, MA | WILLIAM AT SOMERSET STREET FLOODED AND IMPASSABLE |
| 15:42 UTC | FLOOD | Worcester | Worcester, MA | MULTIPLE FLOOD REPORTS OUT OF WORCESTER A THE FOLLOWING LOCATIONS. SOUTHBRIDGE ST MCKEON RD QUINSIGIMEOND AT LAMARTINE EAST CENTRAL UNDER I-290 BRIDGE GLENNY ST MILBROOK ST UNDER THE 190 BRIDGE ENID ST AT COMMONWEALTH. |
| 15:45 UTC | TSTM WND DMG | Medford | Middlesex, MA | TREE DOWN AT 900 BLOCK OF HIGHLAND AVE |
| 16:05 UTC | TSTM WND DMG | Malden | Middlesex, MA | LARGE TREE BRANCH DOWN AT SALEM AND BRANCH STREET. |
| 16:42 UTC | TSTM WND DMG | Somerville | Middlesex, MA | TREE DOWN AT 40 BLOCK OF DERBY STREET. RELAYED BY AMATEUR RADIO. |
| 16:56 UTC | FLOOD | Somerville | Middlesex, MA | MCGRATH HIGHWAY AT MIDDLESEX AVE FLOODED AND IMPASSABLE |
| 17:00 UTC | TSTM WND DMG | Lynnfield | Essex, MA | TREE DOWN ON POWER LINES AT HEATH CIRCLE |
| 17:00 UTC | FLOOD | Peabody | Essex, MA | PIERMONT STREET FLOODED AND IMPASSABLE |
| 17:23 UTC | FLOOD | Lynn | Essex, MA | MULTIPLE ROAD CLOSED DUE TO FLOODING ACROSS TOWN |
| 17:30 UTC | TSTM WND DMG | 1 E Clinton | Worcester, MA | TREE AND WIRES DOWNED ON BEECH ST IN CLINTON. RELAYED BY AMATEUR RADIO |
| 17:30 UTC | TSTM WND DMG | 1 Ene Clinton | Worcester, MA | POWERLINE WIRES DOWNED ON CENTENNIAL ST IN CLINTON. RELAYED BY AMATEUR RADIO |
| 17:30 UTC | TSTM WND DMG | Clinton | Worcester, MA | TREE DOWN ON CEDAR ST. RELAYED BY AMATEUR RADIO |
| 17:30 UTC | TORNADO | Clinton | Worcester, MA | A NWS SURVEY CONFIRMED AN EFO TORNADO IN CLINTON, MA. MAXIMUM WINDS WERE ESTIMATED AT 80 MPH. THE PATH WIDTH WAS 35 YARDS AND THE PATH LENGTH WAS 0.5 MILES. IT BEGAN NEAR CEDAR AND CHURCH STREETS, TRAVELED NORTHEAST, AND |
| 17:35 UTC | TSTM WND DMG | Harvard | Worcester, MA | MULTIPLE TREE DOWN ON HOUGTON LANE |
| 17:40 UTC | TSTM WND DMG | 2 N Harvard | Worcester, MA | LARGE TREE DOWNED ON HOUGHTON LANE IN HARVARD. RELAYED BY AMATEUR RADIO. |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2021 tornado in MassachusettsEvery tornado in Massachusetts since 1950Warnings in force in Massachusetts nowThe forecast where you are
The other tornadoes of August 19, 2021
5 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| August 19 | 2:38 AM EDT | EF0 | Morris, NJ | 0.9 | 50 | |||
| August 19 | 9:15 AM CDT | EF0 | Northeastern Connecticut Planning Region, CT to MA | 4.6 | 50 | $25,000 | ||
| August 19 | 5:07 PM MDT | EF1 | Phillips, CO | 0.0 | 50 | $20,000 | ||
| August 19 | 5:09 PM MDT | EF0 | Phillips, CO | 0.0 | 25 | |||
| August 19 | 5:20 PM MDT | EF0 | Phillips, CO | 0.0 | 25 |
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.