Currently sitting in Dubuque, IA, picking up a couple people for the chase tomorrow in South Dakota. Certainly not the best setup I've ever seen, but one that definitely has the potential for some nice tornadoes.
Latest runs of the NAM forecast model show an elongated low with associated warm front set up over Nebraska and South Dakota tomorrow afternoon/evening. Dewpoints are forecast to be in the lower 70s, CAPE values over 4000, and a moderate 500mb jet should be in place along the warm front by 4 PM. Helicity and bulk shear values look to be more than sufficient for supercell structures, and potentially strong tornadoes. Any cells that fire near the warm front and are able to latch on to it will have to greatest tornado threat. Only real question for the day is whether storms will be able to stay discrete...4000 CAPE normally denotes a derecho threat. Updates to follow!