Location…Fombell to Lancaster Township in Beaver/Butler County
Date…Jul 10, 2017
Estimated Time…357 – 401 pm EDT
Maximum EF-Scale Rating…EF0
Estimated Maximum Wind Speed…70 MPH
Maximum Path Width…75 yd
Path Length…3.2 mi
Beginning Lat/Lon…40.828N / 80.189W
Ending lat/Lon…40.842N / 80.131W
* The information in this statement is preliminary and subject to
change pending final review of the event(s) and publication in
NWS Storm Data.
The National Weather Service in Pittsburgh PA has confirmed a
tornado near Fombell in Beaver County and into Lancaster Township in
Butler County in Western Pennsylvania on Jul 10, 2017.
A coherent, continuous swath of damage was discovered from near
Bowers Lane/North Camp Run Road in Fombell east-northeastward to
near the Strawberry Ridge Golf Course in Lancaster Township.
Damage was universally to trees, consisting of snapped large limbs
and trunk snappage or uproots of both healthy and unhealthy
At its most significant, the damage exhibited a rotationally-
convergent debris pattern consistent with a weak tornado as it
traversed a hillside through the golf course. Observers on the
golf course at the time of this storm event reported tree debris
being lofted and swirled cyclonically, which was consistent with
the debris pattern noted by the survey team. Although not an
accepted damage indicator, corn stalks just upstream from this
location also were laid over and exhibited a swirl pattern.
It should be noted that no structural damage was discovered at any
point through the survey path. This lack of damage to structures
enables the team to cap the storm’s estimated wind speed.
Farther to the northeast (at least as far as Eagle Mill Road and
Whitestown Road), a coherent, discontinuous damage swath was
noted, but lacked sufficient conclusive evidence to identify its
origin. It is entirely possible that this damage was an extension
of the tornado, but the debris was too sparse for any conclusions.
The survey team has concluded that a brief, weak tornado occurred
from near Bowers Lane through at least the Scott Ridge Road/
McNulty Lane area. The damage was consistent with a tornado of
peak wind speed of 60-70 mph, which yields a rating of EF0 on the
Enhanced Fujita Scale.
Appreciation is extended to the public for their assistance in
reporting and documenting the damage along the survey path.