November 5, 2017 Ohio Tornado Outbreak (313)
Zach Sefcovic, National
Weather Service, Cleveland, Ohio
Cory Mottice, National
Weather Service
Nick Greenawalt, National
Weather Service
Abstract:
On November 5, 2017, an
intense quasi-linear convective system (QLCS) swept across the National Weather
Service (NWS) Cleveland, Ohio county warning area (CWA). This QLCS produced
extensive wind damage across the NWS Cleveland CWA with maximum wind gusts of
over 100 mph in some of the most heavily impacted areas. In addition, NWS
survey teams confirmed 14 tornadoes across the NWS Cleveland CWA. Of these
tornadoes, three were classified as strong EF-2 tornadoes. With 17 tornadoes
confirmed across the state of Ohio, this tornado event is one of the largest
November tornado outbreaks across Ohio in recorded history.
This study will analyze the
low CAPE, high shear environment that was in place over the region during the
event and will provide an in depth analysis of the synoptic and mesoscale
features. This study will also illustrate many unique features documented by
the KCLE WSR-88D and TLVE TDWR radars during the event and further investigate
how external influences such as boundaries and gravity waves may have played a
role in tornadogenesis and tornado intensity. Tornadic debris signatures (TDSs)
were prevalent during many of the tornadoes, which showed up on average just
one minute after touchdown. These signatures played an important role in messaging
along with the post analysis and damage survey processes. Key findings on
azimuthal shear and how it relates to potential tornado detection will be also
be presented. A examination of the post-event surveys and assessments from NWS
Cleveland will be discussed including difficulties before, during, and after
the event. Finally, there will be a discussion of where this event fits in the
climatology of Ohio severe weather and an overview of a routine severe weather
season during the fall months.