EF0 tornado, Weissport, Pennsylvania, May 23, 2011

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

May 23, 2011

Touchdown

7:25 PM EDT (23:25 UTC)

Lifted

7:26 PM EDT (23:26 UTC)

On the ground

1 minutes

Path length

0.4 miles (0.7 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

1

Property damage

$75,000

County

Carbon County

Touchdown point

40.837, -75.695

Lift-off point

40.842, -75.690

Record number

1105231725-01

Showers and thunderstorms that rode along a warm frontal boundary during the evening of the 23rd produced a tornado in Carbon County, a couple of other funnel clouds in the Poconos and Lehigh Valley and pockets of wind damage in the Poconos and Lehigh Valley.

An EF-0 tornado touched down in Franklin Township, badly damaged one home and caused minor damage to about a dozen others, a church and a baseball field. The tornado touched down to the rear of a few homes on Church Street and moved through Penn Street before lifting. On Church Street, a trampoline was blown thirty feet and trees were knocked down on one property. A neighboring trampoline was tossed into the sign of Saint Matthews Evangelical Lutheran Church. The church also suffered additional wind damage. The worst tornado damage occurred as it crossed Penn Street. A recently renovated home had its roof torn away. The dry walls fell onto a woman. A tree also fell on top of the house. A metal shed was also twisted, aluminum window awnings were mangled and a swing set was toppled. Numerous trees were either snapped or uprooted along the tornado's path. The estimated maximum winds were 75 mph. The estimated path length was about 0.4 miles and path width about 50 yards.

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. One was issued for the county at another hour that day.

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 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:39 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 Philadelphia radar (KDIX), 147 km away, was scanning. The volume nearest the touchdown began at 23:23 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 2011 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are

17 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.