EF1 tornado, Hallam to Highmount, Pennsylvania, February 25, 2017

1. EF065 to 85 mph

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

2. EF186 to 110 mphthis tornado

   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

EF1

Date

February 25, 2017

Touchdown

3:15 PM EST (20:15 UTC)

Lifted

3:17 PM EST (20:17 UTC)

On the ground

2 minutes

Path length

1.7 miles (2.7 km)

Path width

100 yards (91 m)

Deaths

0

Injuries

0

Property damage

$200,000

County

York County

Touchdown point

39.998, -76.592

Lift-off point

40.011, -76.564

Record number

1702251415-01

An EF1 tornado touched down in Hellam Township, just southeast of Hallam borough, and tracked east-northeastward for just under two miles, lifting just west of Wrightsville in York County. This spin-up occurred in the middle of more widespread damage caused by a microburst that created a larger swath of damage across east-central York County.

An EF1 tornado was confirmed in Hellam Township, between Hallam and Wrightsville, by a NWS storm survey. Maximum wind speeds were estimated at 90 mph, with a path length of just under two miles and a maximum path width of 100 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.

The county was under a severe thunderstorm watch, issued at 18:30 UTC and running to 20:47 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 General Thunderstorms Risk. The outlook in force was issued at 19:55 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.

Middletown/Olmsted (MDT), 26 km from the path, in the two hours either side.

From the Iowa Environmental Mesonet's archive of airport observations.

The Sterling radar (KLWX), 138 km away, was scanning. The volume nearest the touchdown began at 20:16 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 2017 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are

4 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.