Tornadoes · United States · Maryland · 2011
EF1 tornado, New London to Unionville, Maryland, April 16, 2011
From New London to Unionville, this EF1 tornado ran 4.4 miles across Frederick County on April 16, 2011, touching down at 7:38 PM EDT and reaching 50 yards wide. It killed nobody, and did $50,000 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.
EF065 to 85 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mphthis tornado
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
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.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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
- April 16, 2011
- Touchdown
- 7:38 PM EDT (23:38 UTC)
- Lifted
- 7:46 PM EDT (23:46 UTC)
- On the ground
- 8 minutes
- Path length
- 4.4 miles (7.0 km)
- Path width
- 50 yards (46 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $50,000
- County
- Frederick County
- Touchdown point
- 39.414, -77.240
- Lift-off point
- 39.447, -77.170
- Record number
- 1104161738-01
What the Weather Service recorded
Strong low pressure over the Midwest remained cutoff from the jet stream on the 16th. The warm front associated with this system passed through during the morning. Warm and moist southerly winds behind the front provided moderate amounts of instability. The instability combined with forcing from the low for showers and thunderstorms to develop. ||There was enough instability along with strong winds aloft for some thunderstorms to become severe.
A detached garage collapsed along New London Road. Shingles and siding were removed from a single-family home and softwood trees were snapped along New London Road. |Numerous hardwood trees were uprooted or snapped and barns were damaged or destroyed.
Roofing panels were removed from a detached garage near Detrick Road and Old Annapolis Road. Six or more softwood trees were snapped and pieces of large limbs and plywood were impaled in adjacent roofs.
Substantial tree damage was noted near Talbot Run road. Pine trees were snapped near Buffalo Road and there was also a report of siding and trim torn from a home near Buffalo Road.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
24 minutes of warning. NWS LWX issued a tornado warning for this county at 23:14 UTC, 24 minutes before the tornado touched down, in force until 23:45 UTC.
The county was under a tornado watch, issued at 17:29 UTC and running to 01:00 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 10:38 UTC | 21:00 UTC | Wind Advisory | LWX |
| 17:29 UTC | 01:00 UTC | Tornado Watch | LWX |
| 18:00 UTC | 02:01 UTC | Flash Flood Watch | LWX |
| 20:21 UTC | 21:00 UTC | Severe Thunderstorm Warning | LWX |
| 20:53 UTC | 01:45 UTC | Flood Warning | LWX |
| 20:59 UTC | 21:45 UTC | Severe Thunderstorm Warning | LWX |
| 23:01 UTC | 23:45 UTC | Severe Thunderstorm Warning | LWX |
| 23:14 UTC | 23:45 UTC | Tornado Warning | LWX |
| 23:38 UTC | 00:30 UTC | Severe Thunderstorm Warning | LWX |
| 23:46 UTC | 00:00 UTC | Tornado Warning | LWX |
| 01:48 UTC | 14:45 UTC | Flood Warning | LWX |
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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 20:03 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), 12:00Z
11.6 hours before the tornado, 56 km from the path. April 16, 2011.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -81332 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 533 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 473 m²/s²
- 0-3 km storm-relative helicity
- 699 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 4.5 K/km
Washington/Dulle, VA (KIAD), 00:00Z
0.4 hours after it, 56 km from the path. April 17, 2011.
- Mixed-layer CAPE
- 132 J/kg
- Mixed-layer CIN
- -18 J/kg
- Surface CAPE
- 48 J/kg
- Mixed-layer LCL
- 547 m above ground
- 0-6 km bulk shear
- 77 kt
- 0-1 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 574 m²/s²
- 0-3 km storm-relative helicity
- 593 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.5
- 0-3 km lapse rate
- 5.4 K/km
The radar
The Sterling radar (KLWX), 56 km away, was scanning. The volume nearest the touchdown began at 23:36 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) | Report | Where | County | Remark |
|---|---|---|---|---|
| 21:00 UTC | NON-TSTM WND DMG | Elkridge | Howard, MD | TREES DOWN AT ELK RIDGE AND COLUMBIA. |
| 21:17 UTC | FLOOD | 2 Ne Granite | Baltimore, MD | WATER ON ROAD AT 8800 MILLER ISLAND ROAD. |
| 21:40 UTC | TSTM WND DMG | Finksburg | Carroll, MD | TREES DOWN NEAR ROUTE 140. |
| 21:45 UTC | NON-TSTM WND DMG | Carney | Baltimore, MD | TREE DOWN. |
| 21:48 UTC | TSTM WND DMG | 2 Ene Carrollton | Carroll, MD | LARGE 3 TO 4 INCH DIAMETER BRANCHES BROUGHT DOWN FROM THUNDERSTORM WINDS. |
| 22:00 UTC | FLOOD | Leitersburg | Washington, MD | HARPERS FERRY ROAD CLOSED DUE TO FLOODING IN NUMEROUS AREAS. |
| 22:10 UTC | NON-TSTM WND DMG | Bethesda | Montgomery, MD | TREES DOWN IN BETHESDA DUE TO GUSTY WINDS. |
| 22:30 UTC | FLOOD | Baltimore | Baltimore City, MD | ALICEANNA STREET CLOSED DUE TO FLOODING |
| 23:30 UTC | TSTM WND DMG | Frederick | Frederick, MD | TREES SNAPPED UPROOTED |
| 23:30 UTC | FLOOD | 1 Nne Thurmont | Frederick, MD | RODDY CREEK ROAD WAS CLOSED NEAR ROUTE 15. |
| 23:30 UTC | FLOOD | Myersville | Frederick, MD | HIGH WATER RESCUE OF A PERSON IN A SUBMERGED VEHICLE ON ROUTE 40 IN VICINITY OF CATOCTIN CREEK. |
| 23:30 UTC | FLOOD | Thurmont | Frederick, MD | HIGH WATER RESCUE IN NORTHWEST FREDERICK COUNTY. |
| 23:36 UTC | TORNADO | 2 Nne New Market | Frederick, MD | TORNADO CONFIRMED EF1. MAX WINDS 90-100 MPH. MAX WIDTH 50 YARDS. PATH LENGTH 1 MILE. NUMEROUS TREES UPROOTED. BARNS PARTIALLY DESTROYED. ROOF DAMAGE TO RESIDENCE. |
| 23:38 UTC | TORNADO | 3 Ne New Market | Frederick, MD | TORNADO CONFIRMED EF-1. MAX WINDS 90-100 MPH. MAX WIDTH 75 YARDS. PATH LENGTH 5 MILES. SEVERAL SMALL BARNS DESTROYED. ROOFS PARTIALLY OFF OF WAREHOUSES. NUMEROUS TREES SNAPPED. |
| 23:43 UTC | TSTM WND DMG | 3 S Unionville | Frederick, MD | SEVERAL DOWNED AND SNAPPED TREES NEAR INTERSECTION OF WOODVILLE ROAD AND GLISSANS MILL ROAD. |
| 23:44 UTC | TORNADO | 3 Se Unionville | Frederick, MD | TORNADO CONFIRMED EF-0. MAX WINDS 70-80 MPH. MAX WIDTH 50 YARDS. PATH LENGTH 3 MILES. TREES SNAPPED AND SHINGLES REMOVED FROM RESIDENCE. TORNADO ENDED IN CARROLL COUNTY. |
| 23:45 UTC | TSTM WND DMG | 3 Sse Unionville | Frederick, MD | LARGE BRANCHES DOWN. |
| 23:46 UTC | TSTM WND DMG | 3 W Winfield | Carroll, MD | TREE DOWN |
| 23:48 UTC | TSTM WND DMG | 2 Wnw Winfield | Carroll, MD | 2 SMALL TREES DOWN. |
| 23:49 UTC | TSTM WND DMG | 2 Wnw Winfield | Carroll, MD | TELEPHONE POLE SNAPPED |
| 23:50 UTC | TSTM WND DMG | 2 W Winfield | Carroll, MD | BARN MOVED OFF FOUNDATION AND ONTO MD HWY 27 NEAR BRADDOCK RD ALONG WITH TREE DAMAGE. |
| 23:53 UTC | TSTM WND DMG | 5 Ne Uniontown | Carroll, MD | FIFTEEN TREES DOWN ON FARM. |
| 23:54 UTC | TSTM WND DMG | 6 Ne Uniontown | Carroll, MD | TREES DOWN ON FARM. |
| 23:55 UTC | TSTM WND DMG | 6 N Westminster | Carroll, MD | 2 TREES DOWN. |
| 23:55 UTC | TSTM WND DMG | 7 N Westminster | Carroll, MD | 12 LARGE TREES UPROOTED |
| 23:56 UTC | TSTM WND DMG | 5 Wnw Manchester | Carroll, MD | TREE DOWN |
| 23:56 UTC | TSTM WND DMG | 6 Wnw Manchester | Carroll, MD | DOZENS OF TREES DOWNED |
| 23:56 UTC | TORNADO | 1 Sw Deep Run | Carroll, MD | TORNADO CONFIRMED EF-0. MAX WINDS 80 MPH. MAX WIDTH 200 YARDS. PATH LENGTH 2 MILES. NUMEROUS TREES UPROOTED AND SNAPPED. ONE TREE INTO HOUSE. TWO BARNS PARTIALLY UNROOFED. |
| 23:57 UTC | TSTM WND DMG | 6 Wnw Manchester | Carroll, MD | NUMEROUS TREES DOWN. BARN PARTIALLY UNROOFED. SMALL SHED FLATTENED. |
| 23:58 UTC | TSTM WND DMG | 5 Nw Manchester | Carroll, MD | SEVERAL TREES SNAPPED. BARN PARTIALLY UNROOFED. |
| 23:58 UTC | TSTM WND DMG | 5 Wnw Manchester | Carroll, MD | SEVERAL LARGE TREES DOWN. ONE INTO A HOME. SHED AND DECK DAMAGE AT ANOTHER HOME FROM LARGE BRANCHES. |
| 23:59 UTC | TSTM WND DMG | 5 Nw Manchester | Carroll, MD | 4 TREES SNAPPED. |
| 00:00 UTC | TSTM WND DMG | Westminster | Carroll, MD | NUMEROUS TREES DOWN ACROSS THE COUNTY. |
| 00:03 UTC | TSTM WND DMG | 2 Ene Carrollton | Carroll, MD | SEVERAL SMALL BRANCHES BROUGHT DOWN FROM THUNDERSTORM WINDS. |
| 00:03 UTC | TSTM WND DMG | 3 Nnw Manchester | Carroll, MD | SHINGLES AND TAR PAPER BLOWN OFF HOUSE ROOF |
| 00:03 UTC | TORNADO | 5 Wnw Manchester | Carroll, MD | TREE AND STRUCTURAL DAMAGE ON ARBOR DRIVE IN WESTMINSTER |
| 00:04 UTC | TSTM WND DMG | 4 W Lineboro | Carroll, MD | UPROOTED TREE ONTO A TRUCK. TREES TWISTED. ONE TREE 6 TO 8 INCHES IN DIAMETER BROKEN OFF. SIDING WRAPPED AROUND A TREE NEAR THE TOP. BOARD JAMMED INTO GROUND. PILLARS ON PORCH OFF SET. NEIGHBOR ACROSS STREET SUSTAINED SO |
| 00:05 UTC | TSTM WND DMG | West Manheim | York, PA | TREE ON TRUCK...MINOR HOUSE DAMAGE |
| 00:30 UTC | FLOOD | 1 Nne Thurmont | Frederick, MD | RODDY CREEK ROAD WAS CLOSED NEAR ROUTE 15. |
| 00:35 UTC | FLOOD | Harpers Ferry | Jefferson, WV | WATER CASCADING DOWN CHESTNUT HILL ROAD TOWARD US HIGHWAY 340. ROAD CLOSED. |
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 MarylandEvery tornado in Maryland since 1950Warnings in force in Maryland nowThe forecast where you are
The other tornadoes of April 16, 2011
56 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| April 16 | 4:50 AM EDT | EF1 | Chattahoochee, GA | 0.3 | 50 | $250,000 | ||
| April 16 | 6:02 AM EDT | EF1 | Bibb, GA | 3.5 | 500 | $2.0 million | ||
| April 16 | 12:41 PM EDT | EF1 | Rowan, NC | 4.0 | 100 | |||
| April 16 | 12:59 PM EDT | EF0 | Union, NC | 3.0 | 50 | |||
| April 16 | 2:03 PM EDT | EF0 | Rockbridge, VA | 1.3 | 100 | $6,000 | ||
| April 16 | 2:06 PM EDT | EF1 | Alamance, NC | 10.7 | 300 | $980,000 | ||
| April 16 | 2:20 PM EDT | EF0 | Augusta, VA | 3.8 | 200 | $2.2 million | ||
| April 16 | 1:40 PM CDT | EF2 | Person, NC to VA | 26.2 | 300 | 6 | $1.1 million | |
| April 16 | 2:53 PM EDT | EF3 | Moore, NC | 65.2 | 500 | 6 | 103 | $172 million |
| April 16 | 3:25 PM EDT | EF1 | Dillon, SC | 1.5 | 440 | 3 | $180,000 | |
| April 16 | 3:27 PM EDT | EF0 | Clarendon, SC | 9.6 | 40 | $12,000 | ||
| April 16 | 3:30 PM EDT | EF1 | Lunenburg, VA | 16.9 | 300 | $100,000 | ||
| April 16 | 3:33 PM EDT | EF1 | Robeson, NC | 0.7 | 50 | $1.5 million | ||
| April 16 | 3:33 PM EDT | EF3 | Hoke, NC | 52.9 | 800 | 2 | 176 | $141 million |
| April 16 | 3:47 PM EDT | EF1 | Robeson, NC | 1.5 | 352 | $3.0 million | ||
| April 16 | 4:13 PM EDT | EF1 | Clarendon, SC | 8.9 | 50 | $14,000 | ||
| April 16 | 4:25 PM EDT | EF2 | Bladen, NC | 29.9 | 800 | 3 | 13 | $11 million |
| April 16 | 4:37 PM EDT | EF1 | Dinwiddie, VA | 7.0 | 400 | 5 | $1.5 million | |
| April 16 | 4:50 PM EDT | EF1 | Johnston, NC | 8.6 | 100 | |||
| April 16 | 4:58 PM EDT | EF2 | Bladen, NC | 13.1 | 440 | 1 | $3.1 million | |
| April 16 | 5:03 PM EDT | EF1 | Berkeley, SC | 7.9 | 120 | |||
| April 16 | 5:12 PM EDT | EF0 | Duplin, NC | 0.2 | 30 | |||
| April 16 | 5:12 PM EDT | EF2 | Wilson, NC | 9.0 | 200 | 10 | $3.0 million | |
| April 16 | 5:20 PM EDT | EF2 | Halifax, NC | 8.2 | 300 | $1.2 million | ||
| April 16 | 5:32 PM EDT | EF3 | Wayne, NC | 20.4 | 400 | 30 | $30 million | |
| April 16 | 5:33 PM EDT | EF0 | Columbus, NC | 0.2 | 25 | |||
| April 16 | 5:41 PM EDT | EF0 | Georgetown, SC | 0.2 | 30 | $28,000 | ||
| April 16 | 5:45 PM EDT | EF0 | Georgetown, SC | 0.6 | 30 | $40,000 | ||
| April 16 | 5:50 PM EDT | EF1 | Southampton, VA | 1.9 | 300 | $30,000 | ||
| April 16 | 5:53 PM EDT | EF1 | Georgetown, SC | 0.5 | 60 | $100,000 | ||
| April 16 | 5:59 PM EDT | EF1 | Georgetown, SC | 0.5 | 60 | $60,000 | ||
| April 16 | 5:59 PM EDT | EF1 | Pitt, NC | 3.3 | 75 | 5 | $1.0 million | |
| April 16 | 6:05 PM EDT | EF1 | Columbus, NC | 1.1 | 50 | $35,000 | ||
| April 16 | 6:20 PM EDT | EF0 | Southampton, VA | 1.8 | 50 | $2,000 | ||
| April 16 | 6:30 PM EDT | EF1 | Middlesex, VA | 1.1 | 400 | $100,000 | ||
| April 16 | 6:35 PM EDT | EF0 | Duplin, NC | 0.6 | 150 | |||
| April 16 | 6:45 PM EDT | EF3 | Surry, VA | 26.5 | 800 | 2 | 24 | $8.0 million |
| April 16 | 6:55 PM EDT | EF3 | Bertie, NC | 17.9 | 1,300 | 12 | 58 | $3.3 million |
| April 16 | 7:05 PM EDT | EF2 | Bertie, NC | 17.5 | 500 | 8 | $1.1 million | |
| April 16 | 7:07 PM EDT | EF2 | Jones, NC | 2.4 | 200 | $100,000 | ||
| April 16 | 7:09 PM EDT | EF0 | Martin, NC | 0.1 | 75 | $10,000 | ||
| April 16 | 7:10 PM EDT | EF2 | Isle of Wight, VA | 22.6 | 400 | $300,000 | ||
| April 16 | 7:12 PM EDT | EF0 | Loudoun, VA | 4.1 | 50 | $4,000 | ||
| April 16 | 7:25 PM EDT | EF2 | Middlesex, VA | 2.8 | 400 | $6.0 million | ||
| April 16 | 7:37 PM EDT | EF1 | Frederick, MD | 1.2 | 50 | $50,000 | ||
| April 16 | 7:40 PM EDT | EF0 | Craven, NC | 0.1 | 30 | |||
| April 16 | 7:47 PM EDT | EF1 | Carroll, MD | 3.5 | 50 | $30,000 | ||
| April 16 | 7:51 PM EDT | EF0 | Carroll, MD | 1.9 | 75 | $20,000 | ||
| April 16 | 8:08 PM EDT | EF0 | Beaufort, NC | 0.6 | 30 | $4,000 | ||
| April 16 | 8:11 PM EDT | EF3 | Onslow, NC | 3.8 | 450 | 30 | $9.4 million | |
| April 16 | 8:20 PM EDT | EF0 | York, PA | 0.5 | 200 | 2 | $20,000 | |
| April 16 | 8:43 PM EDT | EF2 | Craven, NC | 4.1 | 200 | 7 | $4.0 million | |
| April 16 | 8:52 PM EDT | EF0 | Pamlico, NC | 0.1 | 30 | |||
| April 16 | 9:01 PM EDT | EF1 | Tyrrell, NC | 7.4 | 550 | $400,000 | ||
| April 16 | 9:30 PM EDT | EF1 | Currituck, NC | 2.0 | 200 | $40,000 | ||
| April 16 | 9:35 PM EDT | EF1 | Dare, NC | 0.7 | 250 | $767,000 |
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.