Monday, May 23, 2011

Tornado FAQ

Given the interest in tornadoes because of the large number of fatalities this year, I'd like to point everyone to an excellent FAQ prepared by Roger Edwards of the NOAA Storm Prediction Center.

Roger Edwards' Tornado FAQ.  Everything you want to know
about tornadoes, but were afraid to ask.


  1. Hey Jim, my roommates both lived in Joplin, one is now back in Joplin volunteering and meeting with his girlfriend. The devastation is something he says the TV cannot get without seeing it personally. There houses are completely gone. He has asked me to check out some forecasts for him as the weather gets bad and showing him a skew-t, I came across the storm from the other day:

    The CAPE is some of the highest I have seen. (And I assume the CAPE over 4400 is an error but 2700 is insane)

  2. Tornadoes have been reported in environments with a wide range of CAPE, including low cape environments (<500 J/kg). 4000 is high, but there have been events with CAPE > 5000 J/kg.

    CAPE is great, but the ingredients for supercells also include storm-relative helicity and deep-layer shear. See

    for more info.