2nd to 3rd day as ml-d AOI resets from Sunday May 18th the reset order is, last to reset is middle AOI towards inner most AOI. Could it be that you get
whatever the blob over Chicago-Penn is as a result?. Last year a couple of Derechos (Read Wundergrounds weather glossary for an explanation) occurred during a similar period of the ml-d resetting in 2013.
