Storms fire along and near Theta E difference boundary – Henrietta storm has tornadic tendencies Posted in General on May 7, 2014 by Kristin Calhoun. Storms initiated across far western OK along and near a Theta E Difference boundary. At 20Z At 21Z At 22Z At 23Z At 2330Z – Henrietta Storm quickly developed a hook with a report of a rapidly rotating wall cloud. Scott Rudge.