• Welcome to TalkWeather!
    We see you lurking around TalkWeather! Take the extra step and join us today to view attachments, see less ads and maybe even join the discussion.
    CLICK TO JOIN TALKWEATHER
  • Current Tropical Systems
    Erin

Severe WX April 1-2 (overnight) Severe Weather Event

It’s funny how non of these offices are willing to go. Hey, there’s some really extreme forestry damage that easily indicates EF4+ intensity. Let me just slap a simple 167mph di on that to get this clearly violent tornado the rating it deserves!
 
It’s technically still prelim and they haven’t published descriptions or di’s for the grand junction or selmer tornadoes. So…there’s a chance.
 
tornado examiner said:
It’s funny how non of these offices are willing to go. Hey, there’s some really extreme forestry damage that easily indicates EF4+ intensity. Let me just slap a simple 167mph di on that to get this clearly violent tornado the rating it deserves!
Click to expand...
Yeah right, that office will go to great lengths before giving a tornado an EF4+ rating. They made us wait all this time to deliberately disappoint every last one of us. Also Gary Woodall who rated the Westminster 2006 tornado a high-end F3 said tree debarking and ground scouring cannot go higher than F3.
 
Shakespeare 2016 said:
Yeah right, that office will go to great lengths before giving a tornado an EF4+ rating. They made us wait all this time to deliberately disappoint every last one of us. Also Gary Woodall who rated the Westminster 2006 tornado a high-end F3 said tree debarking and ground scouring cannot go higher than F3.
Click to expand...
Laughs in JAN marking 4 EF4 labeled scouring di’s for cycloidal marks from the rolling fork tornado. And also EF4 indicators for thrown vehicles bassfield 2020.
And also them stretching the very limits of a slabbed home in their CWA this year for a 166mph EF4 rating that met the bare minimum.
 
tornado examiner said:
Laughs in JAN marking 4 EF4 labeled scouring di’s for cycloidal marks from the rolling fork tornado. And also EF4 indicators for thrown vehicles bassfield 2020.
And also them stretching the very limits of a slabbed home in their CWA this year for a 166mph EF4 rating that met the bare minimum.
Click to expand...
Gary Woodall I believe works for MEG. The 166 mph windspeed was weird for the Tylertown tornado.
 
Yawn. MEG botched the Lake City survey. What a surprise!

I also find it hilarious that they gave an anchor bolted home in Lake City a lower windspeed estimate than a home in Senatobia 'anchored' with cut nails.

Also, based on the recent posts in this thread, I fully expect it to turn into a carbon copy of the Matador thread.
 
TH2002 said:
Yawn. MEG botched the Lake City survey. What a surprise!

I also find it hilarious that they gave an anchor bolted home in Lake City a lower windspeed estimate than a home in Senatobia 'anchored' with cut nails.

Also, based on the recent posts in this thread, I fully expect it to turn into a carbon copy of the Matador thread.
Click to expand...
MEG logic!!! I can't wait to hear what Buckeye05 has to say.
 
I’m really scratching my head at this particular DI. This brick home which had a poured concrete foundation and anchor bolts adequate nuts and washers was completely flattened and largely swept clean off its foundation, some of the sill plates were removed as well. However, it got slapped with an EF3(150mph) rating. The description says the slab was not swept clean (???) and that anchor bolts were in proper locations. I know in the description of the tornado some areas weren’t rated higher because “wall structures remained intact,” but that certainly doesn’t appear to be the case here.
345EFBA4-EFC5-4277-92F3-4403487EA904.jpegD608C1FC-2A41-43AC-8ABB-6E8ADA82E8CD.jpeg44BE5EAC-4388-45E2-A881-E7BB316C786A.jpeg
DA45C3F5-BC77-41EF-BACD-69DD933E4E9D.jpeg
 
Western_KS_Wx said:
I’m really scratching my head at this particular DI. This brick home which had a poured concrete foundation and anchor bolts adequate nuts and washers was completely flattened and largely swept clean off its foundation, some of the sill plates were removed as well. However, it got slapped with an EF3(150mph) rating. The description says the slab was not swept clean (???) and that anchor bolts were in proper locations. I know in the description of the tornado some areas weren’t rated higher because “wall structures remained intact,” but that certainly doesn’t appear to be the case here.
View attachment 39600View attachment 39601View attachment 39602
View attachment 39604
Click to expand...
The slab doesn't have to be completely swept clean for an EF4 rating.
 
This survey does appear to be pretty poor application of the EF scale. Dare I say verging on EF scale misuse (as opposed to more common laziness or incompetence.)

The home, which many others are posting above, was a clearly well constructed home which was ~50% swept clean. The surveyors then assign DOD 9 - all walls destroyed, as opposed to DOD 10 - I suppose you can make a justification for this, even though its probably not consistent with the ratings from other offices. Yet, they then assign 20mph below the EXP... for apparently no reason?? They even themselves state the proper placement of anchor bolts, the connections are completely sound, and the foundation is not CMU. Even in today's climate, I am confident most other offices would go at least 165mph on this, and even a majority of those would probably go EXP 170mph. And then again, I think the decision was to go DOD 9 was slightly unusual.

Essentially there are multiple chains of reasoning which together just dont make sense. We've ended up with objectively the highest-end damage from Lake City being rated lower than a couple other, less impressive structures *even* when considering construction. Is almost comical to be honest.

Normally I err on the side of exact rating being unimportant when considering the damage, particularly right in the wake of a tornado. But the distinction in EF3/4 tornadoes is often quite an important one - both for climatology and environmental intensity, and especially for this day where we had a SPC High Risk, in which the SPC is explicitly aiming to forecast violent tornadoes. This has potential implications for the forecast without reason, in particular when you consider the transition to even more explicit conditional intensity forecasting that is to come in the next few years and am sure is being tested in outlooks like this. It is fairly obvious this event contained multiple EF4 intensity tornadoes.
 
Western_KS_Wx said:
Right, seems like we’re using logic that’d typically be a reason to downgrade potential EF5-candidates to instead downgrade EF4 damage indicators. Very confused by this survey to say the least lol.
Click to expand...
MEG doesn't use logic unfortunately. Either that or they are flat out lying. I wish I really knew why some NWS offices shy away from rating tornadoes as EF4 or EF5. Maybe the inconvenience to call in a QRT.
 
Western_KS_Wx said:
I’m really scratching my head at this particular DI. This brick home which had a poured concrete foundation and anchor bolts adequate nuts and washers was completely flattened and largely swept clean off its foundation, some of the sill plates were removed as well. However, it got slapped with an EF3(150mph) rating. The description says the slab was not swept clean (???) and that anchor bolts were in proper locations. I know in the description of the tornado some areas weren’t rated higher because “wall structures remained intact,” but that certainly doesn’t appear to be the case here.
View attachment 39600View attachment 39601View attachment 39602
View attachment 39604
Click to expand...
One issue I notice here is that several of the anchor bolts were installed too close to the edge of the sill plate. Additionally, large portions of the home—walls, floor system, etc.—remained on the foundation. With a typical DoD-9 damage indicator, we’d expect near-total destruction of the structure and the large portions, but with most of the debris still present on or near the foundation, this was an issue we saw with Newnan (and why it should not have gotten EF4).

When anchor bolts are placed too close to the edge of the sill plate, even without visible splitting, it weakens the continuous load path. There’s less surrounding wood for the bolt to grip, which reduces its ability to resist uplift and lateral forces. This weakens the connection to the foundation and increases the likelihood of failure under tornado loads. 160 mph EF3 seems to be the right call here—I also discussed this with one of the NWS meteorologists from a different office who contributed to the survey. Also, the 150 mph DI for the home is supposed to say 160 mph, they just forgot to adjust the wind speed up after the preliminary survey.

As for the Senatobia home discussed here—using cut nails as the primary connection is a major weakness. That shouldn’t be rated at 160 mph EF3. Based on DoD-9, I’d say more in the 140–145 mph range (lower-bound).
 
Shakespeare 2016 said:
MEG doesn't use logic unfortunately. Either that or they are flat out lying. I wish I really knew why some NWS offices shy away from rating tornadoes as EF4 or EF5. Maybe the inconvenience to call in a QRT.
Click to expand...
They didn’t even label anything about the rest of the home’s construction that would be grounds for such a horrendous downgrade.
 
Yikes. That’s a horrible rating, lol. Lake City was without a doubt at least an EF4 tornado, especially based on the damage to that home. 20 MPH below expected windspeed is absolutely absurd. All this does is further completely erode the confidence in the EF scale as being at all a rational scale for measuring the intensity of tornadoes. It’s about to get to the point where nobody will take it seriously.

It’s really important for surveyors to use context. I am so annoyed with the fact that there’s so many offices not doing this. MEG sucks.
 
NickKrasz_Wx said:
When anchor bolts are placed too close to the edge of the sill plate, even without visible splitting, it weakens the continuous load path. There’s less surrounding wood for the bolt to grip, which reduces its ability to resist uplift and lateral forces. This weakens the connection to the foundation and increases the likelihood of failure under tornado loads. 160 mph EF3 seems to be the right call here—I also discussed this with one of the NWS meteorologists from a different office who contributed to the survey. Also, the 150 mph DI for the home is supposed to say 160 mph, they just forgot to adjust the wind speed up after the preliminary survey.
Click to expand...
Side question because I’m not familiar with the terminology: What is a “continuous load path?” Does it have to do with debris impacts?
 
You must log in or register to reply here.
Top