EF1 tornado, Jalappa to West Hamburg, Pennsylvania, July 9, 2015

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

July 9, 2015

Touchdown

6:40 PM EDT (22:40 UTC)

Lifted

6:41 PM EDT (22:41 UTC)

On the ground

1 minutes

Path length

0.7 miles (1.2 km)

Path width

75 yards (69 m)

Deaths

0

Injuries

1

Property damage

$750,000

County

Berks County

Touchdown point

40.549, -76.043

Lift-off point

40.557, -76.035

Record number

1507091640-01

17 damage points were recorded along this path by NWS PHI, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 108 mph.

• roofing material displayed in a cyclonic pattern. t
• Roof truss 90 deg from patten of storm movement.
• several trees snapped and uprooted.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

A line of strong to severe thunderstorms formed in the warm sector of the Susquehanna Valley and moved through southeast Pennsylvania during the late afternoon and first half of the evening on the 9th. The line also spawned an EF-1 tornado in Berks County. During the evening the line of thunderstorms also caused flash flooding. A warm front lifted northeast into the Lehigh Valley during the afternoon of the 9th. This permitted sufficient daytime heating preceding an approaching cold front. In addition, there was enough shear in the atmosphere for a tornado to occur.

An EF1 tornado occurred in Tilden Township in Berks County and injured one person. The tornado touched down near Stone Road and moved eastnortheast, passing through the Blue Mountain Academy before crossing Mountain Road into a campground area before lifting. The most significant damage occurred to the Blue Mountain Elementary School. The roof of the school was completely removed by the tornado. The building is a total loss. The 52-year-old principal inside the school at the time of the tornado was injured and was found covered by ceiling tiles. Pieces of the roof were found hundreds of yards away in trees. Hardwood trees were snapped along the tornado's path with a soybean field having debris dragged through it with visible arcing marks. ||The estimated path length of the EF-1 tornado was three-quarters of a mile with a maximum path width of 75 yards. The estimated maximum wind speed was 105 mph.

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 severe thunderstorm watch, issued at 20:57 UTC and running to 00:39 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 Enhanced Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:35 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 Philadelphia radar (KDIX), 154 km away, was scanning. The volume nearest the touchdown began at 22:41 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 2015 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are

9 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.