National Weather Service Revisions to the EF Scale
The National Weather Service (NWS) in the US and NWS Canada rate tornado intensity using the Enhanced Fujita (EF) Scale.  Doppler radar is highly accurate in determining likely geographic locations for touchdowns but less accurate for determining actual touchdowns or wind speed at ground level.  Ground-truthing by a team of meteorologists and engineers routinely occurs post-event. There are 28 Damage Indicators (DI) each with multiple Degrees of Damage (DoD). Only two DI involve trees. Approximately 40% of the touchdowns in Kentucky involve sites where no man-made structures are impacted.

As a result of my work with the Louisville NWS and involvement with the national committee, the EF scale is being revised to give greater credibility to the type of damage that occurs to trees and to disallow damage to trees with a high likelihood of failure under normal weather events. This is an outgrowth of the work that I have done with the International Society of Arboriculture (ISA) Tree Risk Assessment Qualification (TRAQ).