Tornadoes · United States · Virginia · 2011

EF0 tornado, Capon Rd to Middletown, Virginia, April 28, 2011

From Capon Rd to Middletown, this EF0 tornado ran 4.3 miles across Frederick and Shenandoah counties on April 28, 2011, touching down at 3:45 AM EDT and reaching 175 yards wide. It killed nobody, and did $25,000 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 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.

The record

Rating
EF0
Date
April 28, 2011
Touchdown
3:45 AM EDT (07:45 UTC)
Lifted
3:49 AM EDT (07:49 UTC)
On the ground
4 minutes
Path length
4.3 miles (6.9 km)
Path width
175 yards (160 m)
Deaths
0
Injuries
0
Property damage
$25,000
Counties
Frederick and Shenandoah counties
Touchdown point
39.001, -78.336
Lift-off point
39.046, -78.281
Record number
1104280145-01

What the Weather Service recorded

A strong cold front slowly passed through the region during the morning and early afternoon hours of the 28th. A southerly flow ahead of the front caused deep moisture over the area. The deep moisture combined with a mid-level trough to produce moderate amounts of instability. The cold front combined with the instability to trigger showers and thunderstorms. Some thunderstorms were able to mix down strong winds from aloft.||Low level wind speed and direction changed rapidly with height causing tornadoes to develop in some of the stronger thunderstorms.

Several trees were uprooted and snapped. A Pole Barn was unroofed and several shingles were removed from a house. The tornado crossed Interstate 81 and Route 11. The tornado path continued into Frederck County.

The tornado uprooted and snapped several trees near Middletown.

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

The warnings

22 minutes of warning. NWS LWX issued a tornado warning for this county at 07:23 UTC, 22 minutes before the tornado touched down, in force until 08:02 UTC.

The county was under a tornado watch, issued at 04:42 UTC and running to 09:07 UTC.

Issued (UTC)ExpiredProductOffice
17:26 UTC22:19 UTCTornado WatchLWX
22:19 UTC04:42 UTCTornado WatchLWX
02:00 UTC11:51 UTCFlash Flood WatchLWX
04:42 UTC09:07 UTCTornado WatchLWX
05:33 UTC09:24 UTCFlash Flood WarningLWX
06:10 UTC07:15 UTCSevere Thunderstorm WarningLWX
06:24 UTC06:49 UTCTornado WarningLWX
06:53 UTC07:29 UTCTornado WarningLWX
07:04 UTC09:28 UTCFlash Flood WarningLWX
07:23 UTC08:02 UTCTornado WarningLWX
07:50 UTC08:17 UTCTornado WarningLWX

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 General Thunderstorms Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 06:09 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 air that afternoon

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.

Washington/Dulle, VA (KIAD), 00:00Z

7.8 hours before the tornado, 79 km from the path. April 28, 2011.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 00:00Z on 2011-04-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1143 joules per kilogram, CIN -34, lifted condensation level 834 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 2011-04-28The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 283 square meters per square second, 0 to 6 km bulk shear 47 knots.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
1143 J/kg
Mixed-layer CIN
-34 J/kg
Surface CAPE
649 J/kg
Mixed-layer LCL
834 m above ground
0-6 km bulk shear
47 kt
0-1 km bulk shear
31 kt
0-1 km storm-relative helicity
283 m²/s²
0-3 km storm-relative helicity
353 m²/s²
Significant tornado parameter
1.8
Supercell composite
14.0
0-3 km lapse rate
5.3 K/km

Open this sounding in Storm Lab

Washington/Dulle, VA (KIAD), 12:00Z

4.2 hours after it, 79 km from the path. April 28, 2011.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2011-04-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1240 joules per kilogram, CIN -3, lifted condensation level 687 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2011-04-28The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 382 square meters per square second, 0 to 6 km bulk shear 62 knots.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
1240 J/kg
Mixed-layer CIN
-3 J/kg
Surface CAPE
1177 J/kg
Mixed-layer LCL
687 m above ground
0-6 km bulk shear
62 kt
0-1 km bulk shear
38 kt
0-1 km storm-relative helicity
382 m²/s²
0-3 km storm-relative helicity
586 m²/s²
Significant tornado parameter
4.8
Supercell composite
15.6
0-3 km lapse rate
6.4 K/km

Open this sounding in Storm Lab

The surface observations

Winchester Regional (OKV), 19 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
06:00 UTC73.7670150° 8 kt191004.7
06:20 UTC73.5869.8160° 8 kt151004.7-DZ
06:40 UTC73.7669.62160° 10 kt191004.7VCTS
07:19 UTC66.266.2210° 6 kt221004.7TSRA
07:20 UTC6765.66210° 6 kt221004.7TSRA
07:40 UTC6664.76220° 6 kt1004.7-TSRA
08:20 UTC65.4865.48170° 8 kt1003.7+TSRA
08:22 UTC66.266.2170° 6 kt1003.4+TSRA
08:40 UTC66.2270° 4 kt1003.7VCTSRA
09:00 UTC66.2 1003.7-VCTSRA
09:20 UTC66.2190° 3 kt1004.1-TSRA
09:40 UTC67.82200° 6 kt1003.4VCTS

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

The radar

The Sterling radar (KLWX), 71 km away, was scanning. The volume nearest the touchdown began at 07:43 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
05:35 UTCTSTM WND DMG2 Wnw IdaPage, VATREE DOWN AT INTERSECTION OF MERTENS RD AND OLDTOWN ORLEANS RD SE
06:16 UTCTSTM WND DMG1 N TunisRockingham, VAMULTIPLE TREES DOWN. TOPS TWISTED OFF.
06:21 UTCTORNADO2 Sse Orkney SpringsShenandoah, VATREES DOWN AND STRUCTURAL DAMAGE TO HOUSE.
06:46 UTCTSTM WND GST 622 Ene AlonzavilleShenandoah, VA
06:49 UTCTSTM WND GST 581 Wsw StrasburgShenandoah, VA
07:44 UTCTSTM WND DMG1 Ene StrasburgShenandoah, VATREE UPROOTED ON HITE LANE.
07:45 UTCTORNADO1 Ne StrasburgShenandoah, VAEF-0 TORNADO. PEAK WINDS 70 MPH. PATH LENGTH 5.3 MILES. PATH WIDTH 175 YARDS. TORNADO CONTINUED INTO FREDERICK COUNTY.
09:16 UTCTSTM WND DMGMiddleburgLoudoun, VATREE DOWN ON WIRES.

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

This ground now

The live radar over the trackEvery 2011 tornado in VirginiaEvery tornado in Virginia since 1950Warnings in force in Virginia nowThe forecast where you are

The other tornadoes of April 28, 2011

39 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 282:12 AM EDTEF2Rockingham, VA33.5400$450,000
April 282:17 AM EDTEF1Augusta, VA4.0150$100,000
April 282:20 AM EDTEF1Huntingdon, PA2.950$10,000
April 282:50 AM EDTEF1Putnam, GA6.7200$1.0 million
April 282:53 AM EDTEF1Juniata, PA8.5100$25,000
April 283:01 AM EDTEF1Rockingham, VA0.950$50,000
April 283:20 AM EDTEF2Chenango, NY7.4400$625,000
April 283:22 AM EDTEF1Caldwell, NC4.51001
April 283:33 AM EDTEF1Alexander, NC4.375
April 283:39 AM EDTEF1Warren, GA7.8440$1.0 million
April 283:55 AM EDTEF1Rockingham, VA2.6150$75,000
April 283:58 AM EDTEF1Chenango, NY3.4150$75,000
April 284:58 AM EDTEF1Chenango, NY3.5100$50,000
April 285:04 AM EDTEF1Herkimer, NY2.9250
April 285:50 AM EDTEF0Susquehanna, PA1.080$40,000
April 284:50 AM CDTEF1Jackson, FL3.0150$500,000
April 285:55 AM EDTEF2York, PA2.6100$50,000
April 286:20 AM EDTEF1Lebanon, PA1.9100$10,000
April 286:30 AM EDTEF2Lebanon, PA1.1200$15,000
April 286:45 AM EDTEF0Montgomery, MD0.850$2,000
April 287:37 AM EDTEF0Carroll, MD0.750$5,000
April 287:37 AM EDTEF1Calhoun, SC4.7440$250,000
April 287:50 AM EDTEF1Sumter, SC10.8220$48,000
April 288:09 AM EDTEF0Baltimore, MD1.150$5,000
April 288:18 AM EDTEF0Sumter, SC1.680$18,000
April 289:54 AM EDTEF0Baltimore, MD1.175$1,000
April 2810:15 AM EDTEF1Hanover, VA2.5150$25,000
April 2811:25 AM EDTEF1Saint Mary's, MD3.4150$35,000
April 2811:41 AM EDTEF0Calvert, MD1.750$7,000
April 283:00 PM EDTEF1Duplin, NC1.4100$10,000
April 283:43 PM EDTEF0Columbus, NC0.620$27,000
April 284:07 PM EDTEF1Pender, NC0.360$66,000
April 284:10 PM EDTEF0Pender, NC6.350$33,000
April 284:20 PM EDTEF0Craven, NC0.150
April 284:22 PM EDTEF0Glynn, GA0.01
April 284:29 PM EDTEF1Pender, NC3.160$105,000
April 284:30 PM EDTEF0Martin, NC0.130
April 284:38 PM EDTEF0Pender, NC0.230$12,000
April 285:23 PM EDTEF0Beaufort, NC0.330

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.