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Inclement Weather Continue to in California; Fire Weather Threat In The High Plains

A slow-moving storm impacting California will produce periods of rain, mountain snow, and gusty winds statewide today, and then move south and remain across southern California through Thursday. Mountain snow will impact travel; and heavy rainfall may cause flooding and debris flows in Southern California. There is an elevated to critical fire weather risk across the Southern High Plains. Read More >

Slide 11

A Tornado and an Overpass - What is Reality?

This topic, of course, begs the question: When it comes to a tornadic circulation interacting with an overpass - What is reality? This is an extremely difficult question to answer because it depends on many factors including (but not limited to):

  1. the strength of the tornado circulation,
  2. the tornado's "angle of attack" on the overpass,
  3. the overpass location relative to the path of the center of the tornado circulation,
  4. the construction of the overpass (particularly underneath), and
  5. the amount and type of debris that has been entrained into the circulation.

To our knowledge, this topic has never been studied scientifically. There have been no modeling studies done regarding the interaction of tornadic winds and an overpass. In the absence of careful scientific and engineering research into this question, no definitive recommendations can be made. There are some widespread misconceptions about this topic, however. These misconceptions are illustrated on the next few slides.

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