...Seven tornadoes confirmed on April 6 2017...

A line of severe thunderstorms produced numerous instances of
straight-line wind damage from central through northern Virginia
and north-central Maryland, including the Washington DC and
Baltimore MD metro areas. Embedded along the line were seven
instances of brief tornadic damage.

Below is a summary of tornadoes confirmed by the National Weather
Service Forecast Office in Sterling VA following extensive surveys
and data analysis.

=========================================================================​


...Tornado confirmed near Unionville in Orange County Virginia...

Location...north of Unionville in Orange County Virginia
Date...April 6, 2017
Estimated Time...1229 PM EDT to 1233 PM EDT
Maximum EF-Scale Rating...EF-0
Estimated Maximum Wind Speed...85 mph
Maximum Path Width...175 yards
Path Length...2.7 miles
Beginning Lat/Lon...38.28 N / 77.97 W
Ending Lat/Lon...38.31 N / 77.94 W
* Fatalities...0
* Injuries...0

* The information in this statement is preliminary and subject to
  change pending final review of the event and publication in NWS
  Storm Data.

...Summary...
The National Weather Service in Baltimore MD/Washington DC has
confirmed a tornado near Unionville in Orange County Virginia
on April 6, 2017.

The tornado caused extensive convergent tree damage intermittently
along its path, along with some minor structural damage. The first
instances of uprooted and snapped trees occurred near the
intersection of Everona Road and Deertrail Lane. The tornado
continued north-northeast, causing additional tree damage on
Signal Hill Lane.

The most extensive impacts occurred along US Route 522 near Ida Mae
Lane, where many of the trees in the concentrated path of the
tornado were either snapped or uprooted in differing directions. At
least two trees fell on structures. Metal roofing and siding were
removed from a business on the sides of the building opposing storm
motion. Some of this material was lofted and landed in a yard 0.4
miles away. The wall of an outbuilding was displaced several
inches off its foundation. Several homes received minor damage to
shingles, gutters, and siding. Two residents in this area witnessed
the tornado and observed debris being lofted and swirling in the
air. The survey concluded that this concentrated tornadic damage was
embedded within a larger area of very strong straight-line winds, as
numerous trees were downed in unidirectional fashion along a 0.7 mile
stretch of US 522.

The next observable damage occurred on Pine Stake Road near Clover
Hill Farm Lane. Trees were downed in a convergent pattern along a
narrow path, and a wooden fence sustained damage. The tornado lifted
after this point, as no further damage was observed to the north-
northeast.

The National Weather Service would like to thank the Orange County
Emergency Management Agency and the residents interviewed for their
assistance in this survey.

This information can also be found on our website at
weather.gov/washington.

For reference...the Enhanced Fujita Scale classifies tornadoes into
the following categories:

EF0...wind speeds 65 to 85 mph.
EF1...wind speeds 86 to 110 mph.
EF2...wind speeds 111 to 135 mph.
EF3...wind speeds 136 to 165 mph.
EF4...wind speeds 166 to 200 mph.
EF5...wind speeds greater than 200 mph.

&&

ADS

=========================================================================


...Tornado confirmed southwest of Warrenton VA...

Location...southwest of Warrenton in Fauquier County Virginia
Date...April 6 2017
Estimated time...1258 PM EDT to 1259 PM EDT
Maximum EF-Scale Rating...EF-0
Estimated Maximum Wind Speed...80 mph
Maximum Path Width...50 yards
Path Length...0.3 miles
Beginning Lat/Lon...38.68 N / 77.86 W
Ending Lat/Lon...38.68 N / 77.86 W
* Fatalities...0
* Injuries...0

* The information in this statement is preliminary and subject to
  change pending final review of the event and publication in NWS
  Storm Data.

...Summary...
The National Weather Service in Baltimore MD/Washington DC has
confirmed a tornado southwest of Warrenton in Fauquier County
Virginia on April 6, 2017.

An extensive area of tree damage was noted along a several mile long
path in west-central Fauquier County. Embedded within this straight-
line wind damage was a small concentrated area of convergent tree
damage consistent with an EF-0 tornado.

A row of trees just north of Harts Mill Road was blown down towards
the west-northwest, while several other trees just south of the road
were snapped and fell towards the northeast. A similar pattern of tree
damage was found at a residence on Woodbourne Lane a quarter mile to
the northeast, where several dozen hardwood trees were uprooted, mainly
falling towards the east but a couple fell towards the west.

Further southwest and to the northeast of the tornadic damage,
hardwood and softwood trees were snapped and uprooted but all falling
to the northeast over a nearly mile-wide swath, indicating straight-line
wind damage. It is notable that the straight-line wind damage was more
severe than that caused by the brief tornado.

The National Weather Service would like to thank the Fauquier County
Emergency Management Agency and the residents interviewed for their
assistance in this survey.

This information can also be found on our website at
weather.gov/washington.

For reference...the Enhanced Fujita Scale classifies tornadoes into
the following categories:

EF0...wind speeds 65 to 85 mph.
EF1...wind speeds 86 to 110 mph.
EF2...wind speeds 111 to 135 mph.
EF3...wind speeds 136 to 165 mph.
EF4...wind speeds 166 to 200 mph.
EF5...wind speeds greater than 200 mph.

&&

SMZ

=========================================================================


...Tornado confirmed north of Airlie VA...

Location...north of Airlie in Fauquier County Virginia
Date...April 6 2017
Estimated Time...108 PM EDT to 114 PM EDT
Maximum EF-Scale Rating...EF-0
Estimated Maximum Wind Speed...85 mph
Maximum Path Width...75 yards
Path Length...5.9 miles
Beginning Lat/Lon...38.75 N / 77.82W
Ending Lat/Lon...38.82 N / 77.75 W
* Fatalities...0
* Injuries...0

*The information in this statement is preliminary and subject
to change pending final review of the event and publication
in NWS Storm Data.

...Summary...

The National Weather Service in Baltimore MD/Washington DC has
confirmed a tornado near Airlie in Fauquier County Virginia on April
6, 2017.

The tornado caused a nearly continuous path of convergent tree damage.
Large to mid sized trees were snapped and uprooted. The most intense
of which was the result of estimated wind speeds of 85 mph that
snapped several large trees on Airlie Road between Artillery Road
and The Rainforest Trust. The first trees downed were noted just
west of US 17. After crossing Airlie Road, the tornado snapped and
uprooted trees all along Blantyre Road. Continuous damage stopped
just prior to Interstate 66.

The National Weather Service would like to thank the Fauquier County
Emergency Management Agency and the residents interviewed for their
assistance in this survey.

This information can also be found on our website at
weather.gov/washington.

For reference...the Enhanced Fujita Scale classifies tornadoes into
the following categories:

EF0...wind speeds 65 to 85 mph.
EF1...wind speeds 86 to 110 mph.
EF2...wind speeds 111 to 135 mph.
EF3...wind speeds 136 to 165 mph.
EF4...wind speeds 166 to 200 mph.
EF5...wind speeds greater than 200 mph.

&&

CAS/ADS

=========================================================================

​
...Tornado confirmed near New Baltimore VA...

Location...near New Baltimore in Fauquier County Virginia
Date...April 6 2017
Estimated Time...108 PM EDT to 110 PM EDT
Maximum EF-Scale Rating...EF-0
Estimated Maximum Wind Speed...85 mph
Maximum Path Width...75 yards
Path Length...1 mile
Beginning Lat/Lon...38.77 N / 77.72W
Ending lat/Lon...38.78 N / 77.72 W
* Fatalities...0
* Injuries...0

*The information in this statement is preliminary and subject
to change pending final review of the event and publication
in NWS Storm Data.

...Summary...
The National Weather Service in Baltimore MD/Washington DC has
confirmed a tornado near New Baltimore in Fauquier County
Virginia on April 6, 2017.

The tornado caused a continuous path of extensive tree damage,
along with some minor structural damage. The first instances
of uprooted and snapped trees occurred just northwest of the
intersection of Lee Highway and Electric Avenue. The tornado
continued north-northeast, generally along Beverlys Mill Road,
causing additional damage to just north of Fairview Lane.

Extensive tree damage was found along the tornado`s path,
where many hardwood and softwood trees were either snapped,
topped or uprooted in a convergent pattern. Several trees
fell on vehicles. Wooded fences were blown down in several
locations along its path. A roof was partially removed from
a barn. Other metal roofing was removed from smaller outbuildings.
Several sheds were either destroyed or severely damaged. Most homes
in the path had minor damage to shingles, gutters and siding.

Two residents in the area witnessed the tornado with debris
being lofted.

The National Weather Service would like to thank Fauquier
County Emergency Management Agency and the residents interviewed
for their assistance in this survey.

This information can also be found on our website at
weather.gov/washington.

For reference...the Enhanced Fujita Scale classifies tornadoes
into the following categories:

EF0...wind speeds 65 to 85 mph.
EF1...wind speeds 86 to 110 mph.
EF2...wind speeds 111 to 135 mph.
EF3...wind speeds 136 to 165 mph.
EF4...wind speeds 166 to 200 mph.
EF5...wind speeds greater than 200 mph.

&&

IMR

=========================================================================


...Tornado confirmed near Herndon and Sterling Park VA...

Location...Herndon to Sterling Park in Fairfax and Loudoun
Counties in Virginia
Date...April 6 2017
Estimated Time...134 PM EDT to 139 PM EDT
Maximum EF-Scale Rating...EF-0
Estimated Maximum Wind Speed...70 mph
Maximum Path Width...25 yards
Path Length...3.3 miles
Beginning Lat/Lon...38.97 N / 77.41W
Ending lat/Lon...39.01 N / 77.38 W
* Fatalities...0
* Injuries...0

* The information in this statement is preliminary and subject to
  change pending final review of the event and publication in NWS
  Storm Data.

...Summary...
The National Weather Service in Baltimore MD/Washington DC has
confirmed a tornado near Herndon and Sterling Park in Fairfax and
Loudoun Counties in Virginia on April 6, 2017.

A path of sporadic damage, mainly to trees, began just east
of Rock Hill Road in between the Dulles Greene and Capstone
apartment complexes in Herndon. About a half dozen trees here
were either snapped or uprooted in a convergent pattern. One of
the trees was thrown into the window of a nearby apartment
building.

The tornado continued north-northeast, where additional tree
damage was noted near the intersections of Summerfield Drive
and Autumn Breeze Court, and Sterling Road (VA-606) and
Herndon Parkway. Several trees were downed from east to west,
and fencing was blown down north to south.

It appears the tornado lifted briefly as it continued
north-northeast, before touching down again near the intersection
of Crestview Drive and Builders Road. Here, nearly a dozen trees
were snapped or uprooted, mainly to the north, with fencing
blown down towards the trees (to the west).

Additional minor and sporadic tree damage was noted in a
north-northeastward path, with several trees snapped and
uprooted and an instance of siding damage noted by a trained
spotter just east of South Lincoln Avenue. The tornado likely
lifted for a final time just northeast of the intersection of
East Frederick Drive and Sugarland Road in Sterling Park.

The National Weather Service would like to thank Fairfax and Loudoun
County Emergency Management Agency and the residents interviewed
for their assistance in this survey.

This information can also be found on our website at
weather.gov/washington.

For reference...the Enhanced Fujita Scale classifies tornadoes
into the following categories:

EF0...wind speeds 65 to 85 mph.
EF1...wind speeds 86 to 110 mph.
EF2...wind speeds 111 to 135 mph.
EF3...wind speeds 136 to 165 mph.
EF4...wind speeds 166 to 200 mph.
EF5...wind speeds greater than 200 mph.

&&

LEE/SMZ

=========================================================================


...Tornado Confirmed in Arlington VA and Washington DC...

Location...Arlington Virginia to Washington DC
Date...April 6 2017
Estimated Time...139 PM EDT to 145 PM EDT
Maximum EF-Scale Rating...EF-0
Estimated Maximum Wind Speed...70 mph
Maximum Path Width...50 yards
Path Length...4.5 miles
Beginning Lat/Lon...38.85 N / 77.07 W
Ending lat/Lon...38.90 N / 77.01 W
* Fatalities...0
* Injuries...1

* The information in this statement is preliminary and subject to
change pending final review of the event(s) and publication in
NWS Storm Data.

...Summary...
The National Weather Service in Baltimore MD/Washington DC has
confirmed an EF-0 tornado initiating in Arlington VA and ending in
Washington DC on April 6, 2017.

Trees were snapped along Interstate 395 adjacent to Army-Navy
Country Club at approximately 1:39 PM EDT. Video of a portion of
the Pentagon Parking Lot showed a vortex cross between two light
poles, ripping off one lamp from the top of the poles. Additional
video from the Pentagon showed two rope-like funnel clouds form at
the same time, although it could not be determined from the video
whether these funnels touched the ground or were attached to the
cloud base.

Arlington County Fire Department in Crystal City provided care for
1 patient with minor injuries when part of a Macys storefront fell
on a car.

Video from the National Park Service National Mall and
Memorial Parks showed a waterspout over the Potomac River west of
the Tidal Basin; however, it is not clear the vertical extent of
this waterspout and whether it was sourced from the cloud base, or
an independent vortex associated with the gust front.

The waterspout then moved onshore near the George Mason Memorial
at the Tidal Basin at approximately 1:41 PM EDT. Here, multiple
large softwood and hardwood trees, including several ornamental
cherry trees, had large branches downed and/or were uprooted
around the Tidal Basin. While some minor tree damage was evidenced
near the George Mason Memorial on the southwest side of the Tidal
Basin, the most concentrated damage was in the grove of trees
directly adjacent to the parking lot of the Tidal Basin Marina.

The last damage reported to the NWS was to the roof of the St.
Aloysius Church at the intersection of North Capitol and I
Streets NW at 145 PM EDT.

This tornado is rated EF-0 with estimated winds 65-70 mph, path
length of 4.5 miles, and a path width of 25-50 yards. The wind
estimates were based on the damage observed, weather radar
velocity observations from the KLWX WSR-88D and from Federal
Aviation Administration Terminal Doppler Weather Radars at Joint
Base Andrews and Reagan National Airport, and the fact that
several of the larger downed trees around the Tidal Basin had
evidence of ample rot in the base of their trunks.

This information can also be found on our website at
weather.gov/washington.

For reference...the Enhanced Fujita Scale classifies tornadoes
into the following categories:

EF0...wind speeds 65 to 85 mph.
EF1...wind speeds 86 to 110 mph.
EF2...wind speeds 111 to 135 mph.
EF3...wind speeds 136 to 165 mph.
EF4...wind speeds 166 to 200 mph.
EF5...wind speeds greater than 200 mph.

&&

LEE

=========================================================================


...Tornado confirmed near Anacostia in southeast Washington DC...

Location...Joint Base Anacostia Bolling and Anacostia DC
Date...April 6 2017
Estimated Time...141 PM EDT to 143 PM EDT
Maximum EF-Scale Rating...EF-0
Estimated Maximum Wind Speed...75 mph
Maximum Path Width...25 yards
Path Length...2.2 miles
Beginning Lat/Lon...38.84 N / 77.02 W
Ending lat/Lon...38.86 N / 76.99 W
* Fatalities...0
* Injuries...1

* The information in this statement is preliminary and subject to
change pending final review of the event(s) and publication in
NWS Storm Data.

...Summary...
The National Weather Service in Baltimore MD/Washington DC has
confirmed an EF-0 tornado initiating in Joint Base Anacostia Bolling
and continuing into Anacostia DC on April 6, 2017.  On the two mile
path, the weak tornado caused several small and midsized trees to be
snapped and uprooted on base in a convergent manner. Flags were
stripped off their posts in the central roundabout.  A large soccer
net was thrown from the athletic field. Shingle damage was noted to
one of the buildings. As the tornado crossed over Interstate 295 it
likely lifted off the ground. Trees were snapped higher up on the
trunks on the hill just east of the interstate. An apartment complex
was unroofed on Stanton Rd SE. Media reported one person was injured
by flying drywall.

This information can also be found on our website at
weather.gov/washington.

For reference...the Enhanced Fujita Scale classifies tornadoes
into the following categories:

EF0...wind speeds 65 to 85 mph.
EF1...wind speeds 86 to 110 mph.
EF2...wind speeds 111 to 135 mph.
EF3...wind speeds 136 to 165 mph.
EF4...wind speeds 166 to 200 mph.
EF5...wind speeds greater than 200 mph.

&&

CAS

$$

DH/IMR/SMZ