Severe WX May 2019 Plains Severe Event (3 Viewers)


vanni9283

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Wayne, PA
Per the survey toolkit, they're calling the QRT for the home posted above. Description says "need QRT here. some sill plates ripped from bolts."
How can a sill plate be ripped from a bolt? That alone I don't think would justify an upgrade. A stronger case for EF-5 can be made if there were was no debris left on the foundation (in addition to the sill plates ripped from the bolts).
 

Equus

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Saragossa, AL
Yeah the lack of really high contextual DIs make me think we dont go especially high end but that's definitely classic low EF4 DI right there if it's that well attached. No denying that
 

Equus

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1,239
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Saragossa, AL
How can a sill plate be ripped from a bolt? That alone I don't think would justify an upgrade. A stronger case for EF-5 can be made if there were was no debris left on the foundation (in addition to the sill plates ripped from the bolts).
In the same way you can pull a board out with force and some of the nails stay put, I assume; definitely a sign of good anchoring when the bolts stay
 

vanni9283

Member
Messages
88
Location
Wayne, PA
Yeah the lack of really high contextual DIs make me think we dont go especially high end but that's definitely classic low EF4 DI right there if it's that well attached. No denying that
If anything, they might increase the wind speed a little, maybe to 180 or 190 mph, but nothing more than that.
 

locomusic01

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84
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Pennsylvania
The lesson from yesterday: don't have an attached garage, and if you do, get that sucker reinforced. I'd imagine we'll find many of these homes fared far worse than they otherwise might have because of the vulnerable garage doors.
 

Equus

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1,239
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Saragossa, AL
If the greenhouses were built like most are, that's not shocking in itself but it DID look like there were other DIs there that make that seem low (shredded trees, vehicles tossed)
 

locomusic01

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Location
Pennsylvania
Unless it was especially severe, tree and vehicle damage probably wouldn't be a factor there. IIRC, snapped and uprooted trees and such typically fall into the EF1-2 range. It takes really pronounced debarking and denuding, especially of low-lying vegetation, to get into EF3+ range. Vehicles are also kinda weird because they aren't official DIs, so there isn't any specific guidance. Studies have given us at least some data to work with, though:

Results from both survey teams suggest that vehicles are rarely moved (~1 in 10) in EF0 wind zones, but the likelihood of lateral movement increases to about 1 in 3 vehicles in EF1 and EF2 zones, 1 in 2 in EF3 and EF4 zones, and 2 in 3 for a small sample of vehicles exposed to EF5 wind speeds. For vehicles tipped, results from all surveys incorporated into this study suggest that passenger vehicles are rarely rolled or lofted (~1 in 25) in wind zones at EF2 or lesser intensities. Even in EF3 and EF4 damage, only about 15% (~1 in 7) vehicles are tipped. A smaller sample of vehicles in EF5 damage indicates that 31% (~1 in 3) are tipped.
https://journals.ametsoc.org/doi/full/10.1175/WCAS-D-15-0051.1

Outside of that, the EF2 isn't surprising. That place was classified as the "small barns and farm outbuildings" (SBO) indicator; even the upper bound of the highest DOD for that DI falls within EF2 range.
 

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