Parkersburg, Iowa tornado rated EF5!

[MiamiensisWx]

http://www.desmoinesregister.com/apps/pbcs.dll/frontpage

Wow...

[RL3AO]

Its not official yet.

[MiamiensisWx]

Its not official yet.

They would not post that rumor if they didn't receive inside information from the NWS via personal communication. The EF5 information was just posted on the site. The conference is currently starting within a few minutes to reveal the rating.

In other words, EF5 is likely the official rating.

[MiamiensisWx]

"National Weather Service personnel have rated the Parkersburg-New Hartford-Dunkerton tornado as a low-end EF 5 on the Enhanced Fujita Scale at the point of maximum damage."

http://www.desmoinesregister.com/apps/pbcs.dll/section?category=TORNADOES

The press conference has started around this time.

[MiamiensisWx]

http://www.crh.noaa.gov/crnews/display_story.php?wfo=dmx&storyid=14909&source=0

EF5

[KWT]

Very impressive indeed and the damage photos are simply amazing, though to be honest I'd have probably rated a top end EF4, there are still some walls on houses standing. Still its very impressive and a very dangerous tornado, certianly the storngest since Greensburg IMO.

[RL3AO]

Wow

[CrazyC83]

They saw something we didn't...I hadn't seen anything to warrant EF5 but I am not the surveyor.

[KWT]

Yeah I have to admit it doesn't look like EF5 damage to me either, esp from the shot in the air but maybe that image doesn't represent the worst of the damage I don't know, that image suggests to me EF4.

[RL3AO]

Maybe this?

[KWT]

Hmm thats a very impressive photo RL3AO, its close between EF4-5 IMO looking at that photo, however the walls are still there below a certain point, surely a EF5 would remove all that wall thats sticking above the surface, the only side this is the case is on the side closest to the photographer.

[MiamiensisWx]

You can't question the surveyors if you weren't there after the event. The overhead view showed a large building that was completely swept clean in the center of the town, and it hasn't been shown in ground based photographs. The EF5 rating was deserved, in my view. Additionally, please remember that a low end EF5 on the Enhanced Fujita Scale would be a low end F4 (?) on the old Fujita Scale.

The actual EF5 damage was likely not photographed.

[SamSagnella]

Additionally, please remember that a low end EF5 on the Enhanced Fujita Scale would be a low end F4 (?) on the old Fujita Scale.

Actually, that's not how it works. The rating deserved does not change with the new Enhanced Fujita scale (the levels of damage remained constant to preserve records as well as possible), it is only the estimated wind speeds that are different. This tornado would have been rated an F5 on the old scale, but its peak strength would have been estimated to be ~270mph. I absolutely agree though, one cannot argue with the rating without seeing the damage for themselves.

[HurricaneBill]

Additionally, please remember that a low end EF5 on the Enhanced Fujita Scale would be a low end F4 (?) on the old Fujita Scale.

No, an EF5 would be an F5 on the old Fujita Scale. The rating is still based on damage, not wind speed.

[HarlequinBoy]

Additionally, please remember that a low end EF5 on the Enhanced Fujita Scale would be a low end F4 (?) on the old Fujita Scale.

Actually, that's not how it works. The rating deserved does not change with the new Enhanced Fujita scale (the levels of damage remained constant to preserve records as well as possible), it is only the estimated wind speeds that are different. This tornado would have been rated an F5 on the old scale, but its peak strength would have been estimated to be ~270mph. I absolutely agree though, one cannot argue with the rating without seeing the damage for themselves.

Oh... I always wondered about that! That makes much more sense.

[MiamiensisWx]

Additionally, please remember that a low end EF5 on the Enhanced Fujita Scale would be a low end F4 (?) on the old Fujita Scale.

Actually, that's not how it works. The rating deserved does not change with the new Enhanced Fujita scale (the levels of damage remained constant to preserve records as well as possible), it is only the estimated wind speeds that are different. This tornado would have been rated an F5 on the old scale, but its peak strength would have been estimated to be ~270mph. I absolutely agree though, one cannot argue with the rating without seeing the damage for themselves.

Here is the source for my statement.

"NWS personnel have rated the Parkersburg-New Hartford-Dunkerton tornado as a Low-end EF 5 (correlated to wind speeds up to 205 MPH) on the Enhanced Fujita Scale at the locations of maximum damage."

http://www.crh.noaa.gov/crnews/display_story.php?wfo=dmx&storyid=14909&source=0

F5 Incredible tornado 261-318 mph

http://www.tornadoproject.com/fscale/fscale.htm

I was referring to the difference in wind speeds, though both scales are obviously based on observed and documented damages.

Edit: You're definitely correct; I had a lapse in my previous post.

[Bunkertor]

Maybe this?

OK, i only justifies an EF 5 rating when the floor was concrete and steel. When it was made of wood - no proof.

[CrazyC83]

Additionally, please remember that a low end EF5 on the Enhanced Fujita Scale would be a low end F4 (?) on the old Fujita Scale.

No, an EF5 would be an F5 on the old Fujita Scale. The rating is still based on damage, not wind speed.

Correct. They would have estimated the wind speed at around 265-270 mph using the old Fujita scale.

[SamSagnella]

Here is the source for my statement.

"NWS personnel have rated the Parkersburg-New Hartford-Dunkerton tornado as a Low-end EF 5 (correlated to wind speeds up to 205 MPH) on the Enhanced Fujita Scale at the locations of maximum damage."

http://www.crh.noaa.gov/crnews/display_story.php?wfo=dmx&storyid=14909&source=0

F5 Incredible tornado 261-318 mph

http://www.tornadoproject.com/fscale/fscale.htm

I was referring to the difference in wind speeds, though both scales are obviously based on observed and documented damages.

I understand what you're saying, but I just want to reiterate that the Parkersburg tornado would have been rated F5 on the old scale as well. You can't take wind speed from the Enhanced Fujita Scale and transfer it to the Fujita Scale, as the original system GROSSLY overestimated the winds, especially as you move up the damage ladder. F5=EF5, but 205mph on the EF Scale ≠ 205mph on the F Scale.

[Cyclone1]

All it takes is one home wiped off a foundation and you have an EF-5 guarantee. I would classify that damage as EF5.