We did a probwarn mini-IOP on a supercell (and a few other storms) crossing the Rio Grande near Eagle Pass, TX. The storm had an unconfirmed report from law enforcement of a tornado after it crossed into the US, but a chaser on the scene we called from the HWT could not confirm it. This provided an interesting decision by our forecasters on how much confidence they put in the law enforcement report for their initial tornado probabilities. What was more certain to the forecasters is the large hail threat was very high, given the well-defined bounded weak echo region (below). Later, a 2.5″ diameter measured hail report was received from near Eagle Pass, along with downed trees.

Kevin Scharfenberg (EWP Backup Weekly Coordinator, 12-16 May)