EF0 tornado, Milnor to Kauffman, Pennsylvania, August 26, 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 26, 2012

Touchdown

1:56 PM EDT (17:56 UTC)

Lifted

2:07 PM EDT (18:07 UTC)

On the ground

11 minutes

Path length

5.6 miles (8.9 km)

Path width

100 yards (91 m)

Deaths

0

Injuries

0

Property damage

$10,000

Crop damage

$1,500

County

Franklin County

Touchdown point

39.755, -77.754

Lift-off point

39.835, -77.751

Record number

1208261156-01

A slow-moving upper level circulation moved from western Virgina east-northeast into the Chesapeake Bay/Delmarva region. This system tapped into a narrow axis of deep moisture and instability to trigger scattered thunderstorms across northern Maryland and south-central Pennsylvania. Storms moved north-northwest as they crossed the Mason-Dixon line. Wind shear profiles were marginally favorable for rotating low-topped storms. An EF0 tornado was confirmed near Greencastle in south-central Franklin County.

An EF0 tornado touched down around 1356pm EDT along the 13000 block of Williamsport Pike in Antrim township; approximately 1.5 miles south-southwest of Greencastle. Damage at this location consisted of roofing material blown off of a barn and a toppled farm wagon. The EF0 tornado skipped northward on the west-side of Greencastle, knocking down trees and limbs along Williamson Road. A corn field was flattened just beyond the Greencastle city limits near Craig Road. The EF0 tornado continued to skip northward producing sporadic damage and finally lifted up around 1407pm EDT near the intersection of Williamson and Guitner Roads, where it removed a portion of a house roof. The estimated path length and width was approximately 6 miles long and 100 yards at its widest point. The estimated maximum wind speed was 85 mph, rating the tornado at the top-end of the EF0 wind speed range.

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 General Thunderstorms Risk. The outlook in force was issued at 16:28 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 Sterling radar (KLWX), 94 km away, was scanning. The volume nearest the touchdown began at 17:54 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 PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are

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.