EF1 tornado, Coalmont to Colfax, Pennsylvania, May 27, 2011

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

May 27, 2011

Touchdown

5:10 PM EDT (21:10 UTC)

Lifted

5:15 PM EDT (21:15 UTC)

On the ground

5 minutes

Path length

3.7 miles (6.0 km)

Path width

300 yards (274 m)

Deaths

0

Injuries

0

Property damage

$10,000

County

Huntingdon County

Touchdown point

40.233, -78.218

Lift-off point

40.277, -78.177

Record number

1105271510-01

Severe thunderstorms and tornadoes moved through the area. Two EF1 tornadoes were confirmed in Huntingdon County. There was one report of localized flash flooding in Bedford County.

A National Weather Service survey team confirmed a tornado from the storms of May 27 along Little Valley Road near the Trough Creek Wild Area of Southern Huntingdon County. The tornado touched down about 1 mile north of Middletown, just west of Little Valley Road. It tracked northeast for about 3 1/2 miles to a final location about 4 miles north-northeast of Middletown. Although the beginning and ending locations for the tornado were to the west of Little Valley Road, the storm followed a cyclonic path, and crossed Little Valley Road twice...initially across the road from west to east...then again near the end of the path from east to west. Damage was mainly limited to trees, but a few cabins and summer homes sustained light damage to roofs and decking. Maximum estimated winds were between 95 and 100 mph based on the damage indicators, and classifies the storm as an EF1. There were no injuries or fatalities.

A National Weather Service Survey team confirmed a tornado near Calvin in Huntingdon County from a storm on Friday evening, May 27. the tornado touched down just south of Calvin just east of Route 829 around 530 pm EDT. It tracked North-northeast approximately 2.7 miles before lifting north of Calvin...again, just to the east of Route 829. The tornado path ran parallel to State Route 829 for it's length, and possibly crossed the roadway several times during it's track. Damage was mainly confined to trees. At least 75 trees were snapped or uprooted along the path. One large shed was destroyed on a farm. Significant peel-back of tin roofing material was also noted on a large barn. One home near the end of the tornado track had significant tree damage. Portions of the deck around the house was also damaged by falling trees. There were no injuries or fatalities.

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 17:09 UTC and running to 00:56 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 Slight Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:58 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.

Altoona/Blair Co. (AOO), 11 km from the path, in the two hours either side.

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

The State College radar (KCCX), 76 km away, was scanning. The volume nearest the touchdown began at 21:11 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

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.