Upper bound on the EF-scale

[STurner]

I am not sure exactly how NWS goes about using the upper bound on the EF-scale, but am wondering if they use it if a home or building is built better than code. Like for instance the Greensburg and Parkersburg tornado were both rated EF5 and had winds of approximately 205mph but is there any reason to beleive the wind speeds on both of these two tornadoes may have been higher. Like the high school in Greensburg was very impressively built and was utterly destroyed and if you use the upper bound DOD 11 on a high school it is 223mph. The same as for Parkersburg several homes that were built better than code were swept clean off their foundation and the upper bound DOD 10 on a well-constructed/engineered home is 220mph. I know it doesnt matter if the winds are 205, 250, or 300mph, an EF5, is an EF5. Its the damage that matters but am wondeing if the NWS will ever assign a higher wind speed estimate to an EF5 tornado. I know so little but am wondering if a NWS employee or engineer could answer these.

 

[rdale]

The NWS has pretty much abandoned any modifications to the EF scale, it's been two years and nobody is in charge of doing anything to it. Lower bound is still defective. Dr Doswell has a great writeup at http://www.flame.org/~cdoswell/EFScale_ownership.html

 

[Greg Stumpf]

The NWS has pretty much abandoned any modifications to the EF scale

Actually, motion is currently underway within the NWS (by the National Warning Coordination Meteorologist) to reconstitute the EF-Scale committee and to put in place sustainable "ownership" of the EF-scale to review new science, add DoDs, etc.

 

[STurner]

Actually, motion is currently underway within the NWS (by the National Warning Coordination Meteorologist) to reconstitute the EF-Scale committee and to put in place sustainable "ownership" of the EF-scale to review new science, add DoDs, etc.

There are some concerns with the new EF-scale, but am sure NWS and other experts are trying to correct them as we move towards more understanding tornadoes. I am not trying to dog anybody out but it seems though at times NWS does not use the specific wind speed of the DOD when assigning an estimated value. I do not expect them to call the tornado an EF4 with winds aroud 198mph. Calling it an EF4 tornado with winds near 200mph seems reasonable but they seem to stick 10-15 mph lower than the actual DOD. Maybe NWS has there reason why they do this. I am also glad to here they are working at getting more DOD's for the new EF-scale.

 

[rdale]

to reconstitute the EF-Scale committee and to put in place sustainable "ownership" of the EF-scale to review new science, add DoDs, etc.

GREAT news... Thanks for the update Greg.