Enhanced F Scale for Tornado Damage

[John Olexa]

What do you think of the enhanced Fujita scale that started 1 February?


http://www.spc.noaa.gov/faq/tornado/ef-scale.html

 

[Jeff Snyder]

As a reference, here are a few of links to recent threads about the EF scale (within the past 7 days):

The EF Scale is put into effect today
Public perception vs. the public
Enhanced Fujita Scale (again?)

Edit: This is not to discourage discussion, but to provide additional resources for previous comments on this topic.

 

[Chris Nuttall]

As has been posted elsewhere, we officially have our first EF rated tornado. It happened in central Florida in the early morning hours of Feb. 2. Prelim rating from NWS-Tampa Bay/Ruskin was a "low-end EF-3."

This will definitely be a nice piece of weather trivia. The prelim survey indicates that the traditional F-rating would have been "a strong F2." Isn't it interesting how everyone was complaining about how difficult it would be to get an EF-5? I don't remember too many people talking about the fact that the new scale would essentially "bump up" stronger F2s to EF-3. Essentially, the EF scale will create a bell curve in the ratings and a normal distribution somewhere in the neighborhood of strong EF-2 to low EF-3.

I also thought the folks at Tampa did a nice job in explaining their results, especially since they are "premiering" the EF scale.

 

[Greg Stumpf]

As has been posted elsewhere, we officially have our first EF rated tornado.

Technically, yes, the first official EF rating since the scale went into effect on 1 Feb. However, other tornadoes were rated using the EF scale in 2006, including the 24 April 2006 El Reno OK tornado.

[FONT=lucida sans typewriter, lucida console, courier]INTENSITY...LOW END EF-3 (SCALE 139-167 MPH). TRADITIONAL F-SCALE: STRONG F-2 (F-2 SCALE RANGES FROM 113 TO 157 MPH). [/FONT]

If this rating was based on single-family residences, the new EF scale was incorrectly applied. The F and EF ratings for single-family residences remain the same across both scales (the only difference being the wind speeds attached to the ratings).

However, it is more likely that they bumped up the rating to account for damage to other DIs (not single-family residences). The guidance offered using the EF scale provided a better estimate of the damage intensity. This is another advantage of using the EF scale.