Tornadoes · United States · Massachusetts · 2004

F0 tornado, Pittsfield, Massachusetts, August 20, 2004

This F0 tornado ran 1.0 miles across Berkshire County on August 20, 2004, touching down at 6:37 PM EDT and reaching 150 yards wide. It killed nobody, and did $30,000 of property damage.

The rating scale

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

  1. F040 to 72 mphthis tornado

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

  2. F173 to 112 mph

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

  3. F2113 to 157 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. F3158 to 206 mph

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

  5. F4207 to 260 mph

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

  6. F5261 to 318 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. 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
F0
Date
August 20, 2004
Touchdown
6:37 PM EDT (22:37 UTC)
Path length
1.0 miles (1.6 km)
Path width
150 yards (137 m)
Deaths
0
Injuries
0
Property damage
$30,000
County
Berkshire County
Touchdown point
42.450, -73.250
Lift-off point
42.450, -73.250
Record number
395

What the Weather Service recorded

Survey team observed several structures with shingle damage to roofs. Many limbs and several trees were knocked down. Upon observation these trees were determined to be shallow rooted. Roofs dislodged from clubhouse and dugout of Waconah Park baseball stadium. Eyewitnesses with various vantage points reported observing rotating debris consistent with a tornado. Additional reports indicate a portion of the fencing at Waconah Park was also knocked down, and bleachers along the left field were pushed backward. In addition, trees and wires were downed on Tyler Street and Woodlawn Avenue, and two moored motor boats at Burbank Park were flipped over and partially submerged. There was also a report of a tree falling on a house on Charles Street. Top winds estimated at 70 mph.

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

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

Issued (UTC)ExpiredProductOffice
22:23 UTC23:15 UTCSevere Thunderstorm WarningALY

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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:31 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

10.6 hours before the tornado, 54 km from the path. August 20, 2004.

Skew-T log-pSkew-T log-p diagram, Albany, NY at 12:00Z on 2004-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 244 joules per kilogram, CIN -24, lifted condensation level 569 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°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, Albany, NY at 12:00Z on 2004-08-20The 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 77 square meters per square second, 0 to 6 km bulk shear 51 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
244 J/kg
Mixed-layer CIN
-24 J/kg
Surface CAPE
38 J/kg
Mixed-layer LCL
569 m above ground
0-6 km bulk shear
51 kt
0-1 km bulk shear
17 kt
0-1 km storm-relative helicity
77 m²/s²
0-3 km storm-relative helicity
142 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2
0-3 km lapse rate
4.8 K/km

Open this sounding in Storm Lab

Albany, NY (KALY), 00:00Z

1.4 hours after it, 54 km from the path. August 21, 2004.

Skew-T log-pSkew-T log-p diagram, Albany, NY at 00:00Z on 2004-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 78 joules per kilogram, CIN -102, lifted condensation level 1074 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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, Albany, NY at 00:00Z on 2004-08-21The 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 -4 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
78 J/kg
Mixed-layer CIN
-102 J/kg
Surface CAPE
174 J/kg
Mixed-layer LCL
1074 m above ground
0-6 km bulk shear
48 kt
0-1 km bulk shear
22 kt
0-1 km storm-relative helicity
-4 m²/s²
0-3 km storm-relative helicity
78 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.0
0-3 km lapse rate
5.2 K/km

Open this sounding in Storm Lab

The radar

The Albany radar (KENX), 68 km away, was scanning. The volume nearest the touchdown began at 22:37 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)ReportWhereCountyRemark
22:30 UTCTSTM WND DMGPittsfieldBerkshire, MALARGE TREE UPROOTED...CAR WINDSHIELD SUCKED OUT OF CAR...AND LARGE SIGN TORN OFF PARKING GARAGE AT THE BERKSHIRE MEDICAL CENTER CAMPUS.
22:37 UTCTSTM WND DMGLanesboroughBerkshire, MATREES DOWN IN ROAD.
22:37 UTCTSTM WND DMGLanesboroughBerkshire, MATREES DOWN IN ROAD.
22:37 UTCTSTM WND DMGPittsfieldBerkshire, MAROOF PARTIALLY TORN OFF CLUBHOUSE OF WAHCONAH PARK. ROOF PARTIALLY TORN OFF DUGOUT OF WAHCONAH PARK. NATIONAL WEATHER SERVICE PERSONNEL WILL INVESTIGATE EVENT SATURDAY.
22:37 UTCTSTM WND DMGPittsfieldBerkshire, MAROOF PARTIALLY TORN OFF CLUBHOUSE OF WAHCONAH PARK. ROOF PARTIALLY TORN OFF DUGOUT OF WAHCONAH PARK. NATIONAL WEATHER SERVICE PERSONNEL WILL INVESTIGATE EVENT SATURDAY.
22:40 UTCHAIL 0.88WilliamstownBerkshire, MA
22:40 UTCHAIL 0.88WilliamstownBerkshire, MA

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2004 tornado in MassachusettsEvery tornado in Massachusetts since 1950Warnings in force in Massachusetts nowThe forecast where you are

The other tornadoes of August 20, 2004

2 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 203:23 PM CDTF0Jackson, AL1.030
August 203:35 PM CDTF0Moore, TN1.030

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.