NASA - Giant Waves Over Iowa: "'For one thing, we believe undular bores can amplify tornadoes.' He cites as an example an F5 tornado that struck the outskirts of Birmingham, Alabama, in April 1998. 'At first the tornado was doing relatively little damage. But our research shows that, just before the tornado reached Birmingham, it was hit by an undular bore.' The wave spun up the twister, increasing its intensity and size; the tornado went on to wreck more than 1000 homes and business totaling $200 million in damage. Tornado-wave interactions are the subject of Coleman's PhD dissertation, which he is completing now under the direction of University of Alabama-Huntsville professor Kevin Knupp."
That is a cool bit of weather, but for some reason I was reminded of an Umgubular Slashkilter.