EF0 tornado, Block Is, Rhode Island, August 10, 2012

1. EF065 to 85 mphthis tornado

   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. 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.

Rating

EF0

Date

August 10, 2012

Touchdown

3:54 PM EDT (19:54 UTC)

Lifted

4:00 PM EDT (20:00 UTC)

On the ground

6 minutes

Path length

3.8 miles (6.2 km)

Path width

20 yards (18 m)

Deaths

0

Injuries

0

Property damage

$50,000

County

Washington County

Touchdown point

41.149, -71.570

Lift-off point

41.204, -71.559

Record number

1208101354-01

A series of upper level disturbances rotated around a vertically stacked low pressure system in the Great Lakes. These provided a focus for showers and thunderstorms to develop across southern New England. Southerly winds drew tropical moisture over the area, resulting in very heavy rain in showers and thunderstorms that developed. In addition, strong winds in the upper levels and 30-40 knots of deep layer shear resulted in wind damage with the strongest of these storms.

A tornadic waterspout over the waters south of Block Island moved northward onto land as a tornado over the southern portion of the island a little before 4pm. On Lakeside Drive, it downed several trees, deck furniture was thrown 100 yards away, and screens were blown off a house. An anemometer at a house on Sand's Pond Road was damaged. Fifty trees were blown down on a farm. Several trees in New Shoreham were downed and there was lawn damage occurred on Chapel Street. Farther to the northeast, there were eyewitness reports of a rotating column that moved steadily across a narrow region just to the west of Jerry's Point. A path of flattened brush 50 feet wide was reported there.

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

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

The county was under a tornado watch, issued at 19:35 UTC and running to 22:09 UTC.

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 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 18:22 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 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.

The Boston radar (KBOX), 94 km away, was scanning. The volume nearest the touchdown began at 19:52 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.

Local storm reports within 60 km of the path, in the three hours either side.

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

The live radar over the trackEvery 2012 tornado in Rhode IslandEvery tornado in Rhode Island since 1950Warnings in force in Rhode Island nowThe forecast where you are

1 more were confirmed in the United States that day.

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.

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