Tornadoes · United States · Maryland · 1996

F1 tornado, Whites Ferry to Dawsonville, Maryland, July 19, 1996

From Whites Ferry to Dawsonville, this F1 tornado ran 0.5 miles across Montgomery County on July 19, 1996, touching down at 3:36 PM EDT and reaching 150 yards wide. It killed nobody.

The rating scale

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

  1. F040 to 72 mph

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. F173 to 112 mphthis tornado

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2113 to 157 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. F3158 to 206 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4207 to 260 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5261 to 318 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
F1
Date
July 19, 1996
Touchdown
3:36 PM EDT (19:36 UTC)
Path length
0.5 miles (0.8 km)
Path width
150 yards (137 m)
Deaths
0
Injuries
0
County
Montgomery County
Touchdown point
39.230, -77.470
Lift-off point
39.230, -77.470
Record number
615

What the Weather Service recorded

A short-lived weak tornado briefly touched down approximately 2 miles north of Whites Ferry. Numerous trees were knocked down on a small island (in the Maryland portion) of the Potomac River. More trees were knocked down along the C&O Canal and along Whites Ferry Road. This tornado was associated with the parent thunderstorm that produced earlier damage in southern Washington and Frederick Counties.

A weak tornado, captured on videotape along the Potomac River, and assumed to originate in Seneca Creek State Park (Montgomery Co MD) 4 miles south of Dawsonville, crossed the Potomac River into extreme eastern Loudoun Co before dissipating just southeast of the Lowes Island Golf Club. One tree was uprooted, and several others damaged, along the short track.

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

The warnings

16 minutes of warning. NWS LWX issued a tornado warning for this county at 19:20 UTC, 16 minutes before the tornado touched down, in force until 19:55 UTC.

Issued (UTC)ExpiredProductOffice
19:20 UTC19:55 UTCTornado WarningLWX
20:08 UTC20:55 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. The outlook in force was issued at 06:17 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

7.6 hours before the tornado, 32 km from the path. July 19, 1996.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 1996-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 531 joules per kilogram, CIN -151, lifted condensation level 810 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 12:00Z on 1996-07-19The 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 207 square meters per square second, 0 to 6 km bulk shear 43 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
531 J/kg
Mixed-layer CIN
-151 J/kg
Surface CAPE
169 J/kg
Mixed-layer LCL
810 m above ground
0-6 km bulk shear
43 kt
0-1 km bulk shear
26 kt
0-1 km storm-relative helicity
207 m²/s²
0-3 km storm-relative helicity
229 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.7
0-3 km lapse rate
3.5 K/km

Open this sounding in Storm Lab

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

4.4 hours after it, 32 km from the path. July 20, 1996.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 00:00Z on 1996-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1401 joules per kilogram, CIN -8, lifted condensation level 784 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 1996-07-20The 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 135 square meters per square second, 0 to 6 km bulk shear 42 knots.193958Sfc1 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
1401 J/kg
Mixed-layer CIN
-8 J/kg
Surface CAPE
1968 J/kg
Mixed-layer LCL
784 m above ground
0-6 km bulk shear
42 kt
0-1 km bulk shear
25 kt
0-1 km storm-relative helicity
135 m²/s²
0-3 km storm-relative helicity
119 m²/s²
Significant tornado parameter
1.2
Supercell composite
7.6
0-3 km lapse rate
5.0 K/km

Open this sounding in Storm Lab

This ground now

The live radar over the trackEvery 1996 tornado in MarylandEvery tornado in Maryland since 1950Warnings in force in Maryland nowThe forecast where you are

The other tornadoes of July 19, 1996

19 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 1910:20 AM EDTF2Clarion, PA10.0100$50,000
July 1910:45 AM EDTF2Jefferson, PA27.42006$200,000
July 1912:10 PM EDTF1Blair, PA1.5880
July 1912:10 PM EDTF2Cambria, PA6.0100
July 191:30 PM EDTF0Bedford, PA5.050
July 192:00 PM EDTF0Fulton, PA2.050
July 192:30 PM EDTF1Franklin, PA3.050
July 192:35 PM EDTF1Adams, PA1.0150
July 193:02 PM EDTF0Washington, MD2.075$10,000
July 193:12 PM EDTF2Washington, MD2.0125$400,000
July 192:20 PM CDTF1Frederick, MD to VA6.2200$130,000
July 193:25 PM EDTF1Preston, WV0.250$10,000
July 193:42 PM EDTF3Carroll, MD2.23503$5.0 million
July 192:48 PM CDTF0Montgomery, MD to VA2.050$10,000
July 193:55 PM EDTF1Baltimore, MD1.250$70,000
July 194:30 PM EDTF0City of Baltimore, MD0.125
July 193:04 PM MDTF0Sherman, KS0.210
July 196:00 PM EDTF1Russell, VA3.650$200,000
July 197:40 PM CDTF0Franklin, MO0.150

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.