February 5-6: Super Tuesday Outbreak... 57 dead

[CrazyC83]

The record for the longest track was the Tri-State Tornado, which was likely around 230 miles long.

[simplykristi]

The record for the longest track was the Tri-State Tornado, which was likely around 230 miles long.

I thought that the tri-state was the longest. I was just curious if the tornado that went from Yell to Sharp County ranked amont the longest.

Kristi

[Squarethecircle]

:uarrow:


Did I mention ?




EDIT: Though folks, remember, for a manufactured single wide house, the tornado only has to be about an EF-3 (expected) for complete gone-ness.

In fact, a single or double family residence (single or (double brick?), or concrete block walls) being levelled isn't enough to rate EF-5 according to the EF scale. The highest damage indicator, upper bound is 198 mph 3 sec gust, for a destroyed FR12 (family residence, 1 or 2 family, up to 5,000 sq.ft).

The link to the full EF scale on the spc NOAA website:
http://www.spc.noaa.gov/faq/tornado/ef-ttu.pdf

SNIP from the PDF:

One- and Two-Family Residences (FR12)
Typical Construction
• Asphalt shingles, tile, slate or metal roof covering
• Flat, gable, hip, mansard or mono-sloped roof or combinations thereof
• Plywood/OSB or wood plank roof deck
• Prefabricated wood trusses or wood joist and rafter construction
• Brick veneer, wood panels, stucco, EIFS, vinyl or metal siding
• Wood or metal stud walls, concrete blocks or insulating-concrete panels
• Attached single or double garage

3-sec gust mph mph mph
DOD* Damage description EXP Lowerbound Upperbound
1 Threshold of visible damage 65 53 80
2 Loss of roof covering material (<20%), gutters and/or 79 63 97
awning; loss of vinyl or metal siding
3 Broken glass in doors and windows 96 79 114
4 Uplift of roof deck and loss of significant roof covering
material (>20%); collapse of chimney; garage doors
collapse inward or outward; failure of porch or carport 97 81 116
5 Entire house shifts off foundation 121 103 141
6 Large sections of roof structure removed; most walls
remain standing 122 104 142
7 Top floor exterior walls collapsed 132 113 153
8 Most interior walls of top story collapsed 148 128 173
9 Most walls collapsed in bottom floor, except small
interior rooms 152 127 178
10 Total destruction of entire building 170 142 198
* DOD is degree of damage

If you go and look at the OKC/1999 tornado damage photos, you will see that a single brick family home of much smaller than 5,000 square feet being wiped clean with a slab remaining, but with some debris still on the slab, is listed as F5 damage. This would not be E-F5 damage. As you can see from the EF scale, vehicles being thrown for whatever distance is not a damage indicator, while a vehicle tossed 109 yard or greater on the old F scale is an indicator of F5 strength. A vehicle being stripped of it's innards and body or thrown over 400 m (a quarter mile) goes beyond this, and there is photo evidence (2 pictures showing a vehicle with the body and engine gone) on the NWS Little Rock site.


The net result result of this rewriting will be a reduction of reported EF-5 tornados as compared to the old F-scale, if strictly followed. Looking at the new scale, to my eye the other categories remain comparable to the old F-scale.

Correction: tree debarking only gives upper bound 168 mph according to the EF scale, hardwood or softwood. Not a EF5 damage indicator.

You're forgetting the hospital damage. A collapsed hospital gives an expected 210 mph wind speed. I'm not entirely sure, however, what they got there.

And the fact that they don't disregard the possibility indicates that there are some pieces of evidence with incredible damage to them.

[Bunkertor]

Some Videos

http://www.wzforum.de/forum2/read.php?2,1289060,1292427#msg-1292427

[wbug1]

:uarrow:


Did I mention ?




EDIT: Though folks, remember, for a manufactured single wide house, the tornado only has to be about an EF-3 (expected) for complete gone-ness.

In fact, a single or double family residence (single or (double brick?), or concrete block walls) being levelled isn't enough to rate EF-5 according to the EF scale. The highest damage indicator, upper bound is 198 mph 3 sec gust, for a destroyed FR12 (family residence, 1 or 2 family, up to 5,000 sq.ft).

The link to the full EF scale on the spc NOAA website:
http://www.spc.noaa.gov/faq/tornado/ef-ttu.pdf

SNIP from the PDF:

One- and Two-Family Residences (FR12)
Typical Construction
• Asphalt shingles, tile, slate or metal roof covering
• Flat, gable, hip, mansard or mono-sloped roof or combinations thereof
• Plywood/OSB or wood plank roof deck
• Prefabricated wood trusses or wood joist and rafter construction
• Brick veneer, wood panels, stucco, EIFS, vinyl or metal siding
• Wood or metal stud walls, concrete blocks or insulating-concrete panels
• Attached single or double garage

3-sec gust mph mph mph
DOD* Damage description EXP Lowerbound Upperbound
1 Threshold of visible damage 65 53 80
2 Loss of roof covering material (<20%), gutters and/or 79 63 97
awning; loss of vinyl or metal siding
3 Broken glass in doors and windows 96 79 114
4 Uplift of roof deck and loss of significant roof covering
material (>20%); collapse of chimney; garage doors
collapse inward or outward; failure of porch or carport 97 81 116
5 Entire house shifts off foundation 121 103 141
6 Large sections of roof structure removed; most walls
remain standing 122 104 142
7 Top floor exterior walls collapsed 132 113 153
8 Most interior walls of top story collapsed 148 128 173
9 Most walls collapsed in bottom floor, except small
interior rooms 152 127 178
10 Total destruction of entire building 170 142 198
* DOD is degree of damage

If you go and look at the OKC/1999 tornado damage photos, you will see that a single brick family home of much smaller than 5,000 square feet being wiped clean with a slab remaining, but with some debris still on the slab, is listed as F5 damage. This would not be E-F5 damage. As you can see from the EF scale, vehicles being thrown for whatever distance is not a damage indicator, while a vehicle tossed 109 yard or greater on the old F scale is an indicator of F5 strength. A vehicle being stripped of it's innards and body or thrown over 400 m (a quarter mile) goes beyond this, and there is photo evidence (2 pictures showing a vehicle with the body and engine gone) on the NWS Little Rock site.


The net result result of this rewriting will be a reduction of reported EF-5 tornados as compared to the old F-scale, if strictly followed. Looking at the new scale, to my eye the other categories remain comparable to the old F-scale.

Correction: tree debarking only gives upper bound 168 mph according to the EF scale, hardwood or softwood. Not a EF5 damage indicator.

You're forgetting the hospital damage. A collapsed hospital gives an expected 210 mph wind speed. I'm not entirely sure, however, what they got there.

And the fact that they don't disregard the possibility indicates that there are some pieces of evidence with incredible damage to them.

Hospitals or *insert building of choice* have nothing to do with it. Max upper bound 198 mph is not EF-5, and is the wind speed indicated to level FR12 of less than 5,000 square feet, according to the EF scale.. What if there isn't a hospital or *insert building of choice* near a block of FR12 completely levelled by a tornado? By the book, EF-4.

[Squarethecircle]

Look at the rating for hospital. Upper bound is 268. Expected is 210.

There was a hospital, by the way, in one of the tornadoes.

Try to imagine the person talking to you has a point. Look it up. Then try and respond.

[wbug1]

:uarrow: Look at the rating for hospital. Upper bound is 268. Expected is 210.

There was a hospital, by the way, in one of the tornadoes.

Try to imagine the person talking to you has a point. Look it up. Then try and respond.

What is your point?

[Squarethecircle]

That hospitals have something to do with it because there was a hospital involved.

[wbug1]

Thank you for your point. I really appreciate it.

[Squarethecircle]

Hehe, lol.

[brunota2003]

Note that they say "earlier rated an EF-4". That makes it sound like they're expressing some sort of doubt or lack of confidence that it will remain so.

Or are they just saying that this particular tornado was rated earlier as an EF-4? It was rated prior to the survey, not afterwords

[wbug1]

:uarrow: Hehe, lol.

I looked up my response in my gut. It's a no-fact zone in there.

[HarlequinBoy]

That path length is crazy. I'm not surprised, but that's very impressive.. I think that also furthermore highlights terrain doesn't matter. That area is pretty hilly. A few minutes after the tornado lifted in Sharp County it produced another smaller and less intense tornado in Randolph County.

[Squarethecircle]

Note that they say "earlier rated an EF-4". That makes it sound like they're expressing some sort of doubt or lack of confidence that it will remain so.

Or are they just saying that this particular tornado was rated earlier as an EF-4? It was rated prior to the survey, not afterwords

But, if they were to say that, they might have said something closer to "evidence received prior to this search supported an EF-4 rating," which sounds more or less objective.

[wbug1]

A huge number of photos from NWS Nashville and damage overview:

http://www.srh.noaa.gov/ohx/surveys/ima ... 020508.php

I spotted this from the Nashville NWS Sumner county damage pics, shows a structure with a concrete block wall within the single brick outer layer. The building is demolished, although some of the lower parts remain standing up to 10 feet high.

http://www.srh.noaa.gov/ohx/surveys/ima ... ?start=107
http://www.srh.noaa.gov/ohx/surveys/ima ... ?start=106
http://www.srh.noaa.gov/ohx/surveys/ima ... ?start=108


Memphis and area photos:

http://www.srh.noaa.gov/meg/events/2008 ... /index.php


Jackson County, Al:

Rosalie/Pisgah

http://www.srh.noaa.gov/hun/stormsurvey ... son117.JPG - houses swept clean

EF-4 Atkins/Clinton/Mountain View/Zion - I picked some pics

Atkins: razed area

http://www.srh.noaa.gov/lzk/html/imgvie ... ial020508j

Clinton:

http://www.srh.noaa.gov/lzk/html/imgvie ... ial020508c

Mountain View:

http://www.srh.noaa.gov/lzk/html/imgvie ... orm020508r

Zion:

http://www.srh.noaa.gov/lzk/html/imgvie ... orm020508j

Link to most of the major tornados in the outbreak:

http://wx5tvs.com/blog/2008/02/08/super ... k_surveys/

[CrazyC83]

:uarrow: Look at the rating for hospital. Upper bound is 268. Expected is 210.

There was a hospital, by the way, in one of the tornadoes.

Try to imagine the person talking to you has a point. Look it up. Then try and respond.

That is if the hospital is completely destroyed or flattened, which I don't believe it was.

I believe Greensburg got its EF5 by virtue of large commercial buildings being completely flattened. One thing that might change ratings later is video evidence of the tornado though...

[Squarethecircle]

Again, I was saying we don't fully know the damage yet, so it's hard to discount it. You misinterpret me.

[Dionne]

Why in the world someone would build a structure with concrete block and not incorporate any vertical steel with poured cells is beyond me? A mortar joint alone has very little shear strength. In some of these links you can see evidence that there wasn't any tie down to the slabs, no anchor bolts, no stubbed up rebar.

One particular link shows a home with all the walls standing and the roof gone. That tells me that the rafters were secured to the top plate with toe nails. A Simpson H25 tie down (aka hurricane clip) costs less than a dollar.



Builders taking shortcuts and penny pinching. It's called OVE.....optimum value engineering. Sounds good doesn't it? What it really means is that everything is at maximum span and load.

It's sad. We can do better.

[Squarethecircle]

People generally don't seem to be concerned enough, and order the least expensive packages for building their houses. They never plan too far ahead for a tornado.

[HarlequinBoy]

Some areas affected by the Arkansas tornadoes are going to have a wintry mix tomorrow.