Aside from tornadoes, what makes supercells more deadly?

[crm6360]

Aside from the obvious tornado threat, why are supercells generally more likely to have an enhanced wind/hail threat compared to a severe multicell? How does storm rotation enhance the wind/hail threat?

[Squarethecircle]

It's not always that they're spinning and what not that makes them so deadly, part of it is that supercells almost by definition are extraordinarily powerful storms; not only that, but usually only fairly strong systems can produce them anyway. I'm sure there's someone here who knows more about it than I do though.

[RL3AO]

Its not the rotation that increases the hail and wind threat, it is the very strong updraft.

[crm6360]

So why would a supercell be more likely to have a very strong updraft than a severe multicell?

[wxmann_91]

So why would a supercell be more likely to have a very strong updraft than a severe multicell?

Multicells are consisted of a group of multiple thunderstorm cells. Each cell, each updraft, requires inflow to thrive. With multicells, there are so many updrafts that each try to compete for the best inflow, and thus, no one updraft can get too strong without being "checked" by the other updrafts, so to speak.

An isolated supercell, on the other hand, has all the good inflow to itself to feed its updraft. Given sufficient vertical wind shear to separate the updraft/downdraft, and enough instability, supercell updrafts can be very intense and long-lasting indeed, and this longevity and strength of the updraft is one of the reasons why most strong tornadoes and >2" hail reports are associated with supercells.

[crm6360]

Severe derechos are known for very intense, long-lived downdrafts... which implies updrafts of similar strength.

[TexasStooge]

Severe derechos are known for very intense, long-lived downdrafts... which implies updrafts of similar strength.

I know. I've been through a derecho a week after my birthday this year. It felt like I was in a hurricane.

[wall_cloud]

So why would a supercell be more likely to have a very strong updraft than a severe multicell?

the low pressure area in the middle of the rotation creates dynamic pressure differences that increase the strength of the updraft. This can greatly increase the hail potential for a storm.