Tornadoes · United States · Pennsylvania · 2015

EF1 tornado, Dice, Pennsylvania, August 20, 2015

This EF1 tornado ran 0.2 miles across Union County on August 20, 2015, touching down at 6:05 PM EDT and reaching 100 yards wide. It killed nobody, and did $40,000 of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  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.

The record

Rating
EF1
Date
August 20, 2015
Touchdown
6:05 PM EDT (22:05 UTC)
Lifted
6:06 PM EDT (22:06 UTC)
On the ground
1 minutes
Path length
0.2 miles (0.3 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
Property damage
$40,000
County
Union County
Touchdown point
40.890, -77.040
Lift-off point
40.892, -77.038
Record number
1508201605-01

What the Weather Service recorded

The NWS confirmed an EF1 tornado just south of Mifflinburg on August 20, 2015. The tornado touched down just west of Route 304 and crossed a farm property just north of the village of Dice. A large shed was completely destroyed, and a barn had a portion of its roof torn off. The tornado passed eastward across Route 304 and dissipated. The path length was approximately a quarter of a mile, and the path width was around 100 yards.

An EF1 tornado was confirmed by an NWS survey team just south of Mifflinburg in Union County. A large shed was destroyed and a roof was partially torn off of a barn. Peak winds were estimated at 90 mph, classifying this as an EF1.

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

The warnings

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

Issued (UTC)ExpiredProductOffice
21:48 UTC23:45 UTCFlood AdvisoryCTP

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 forecast that day

The Storm Prediction Center had this point in a Marginal Risk. The outlook in force was issued at 19:57 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 radar

The State College radar (KCCX), 81 km away, was scanning. The volume nearest the touchdown began at 22:06 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.

What was reported nearby

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

Time (UTC)ReportWhereCountyRemark
21:45 UTCTSTM WND DMGMillerstownPerry, PALIMB DOWN ON ROAD IN MILLERSTOWN.
22:05 UTCTSTM WND DMG2 S MifflinburgUnion, PAPOSSIBLE TORNADO DAMAGE INTERSECTION OF RTE 304 AND RED RIDGE ROAD.
22:05 UTCTORNADO2 S MifflinburgUnion, PAEF1 TORNADO CONFIRMED ON SR 304 SOUTH OF MIFFLINBURG. SIGNIFICANT DAMAGE TO BARN AND LARGE SHED. FEW TREES KNOCKED DOWN ALSO.

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

This ground now

The live radar over the trackEvery 2015 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are

What this means

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.

Sources

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