Author Topic: Tornadoes Severe weather outbreak a certainty today over MN, IA, and WI!  (Read 2408 times)

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Severe weather outbreak a certainty today over MN, IA, and WI!

A widespread severe weather outbreak is a near certainty this afternoon and evening over eastern MN into WI extending south into northern IA, as a strong trough strengthens even further to the northwest of the Great Lakes Region.  A 40-50 knot low-level jet will pump 70s dewpoints northward and contribute to strong low-level shear to the east of a cold front currently surging into western MN, and deep layer shear will be more than sufficient for supercells.  It looks like there will be a classic "bimodal" structure to the severe weather geography today, which means the strongest storms and highest chances for tornadoes typically reside in two areas - one to the north and one to the south.  Indepedent of Lakes Superior and northern Lake Michigan being a huge obstacle, I would probably chose the northern mode over northern WI into the eastern MN arrowhead, where low-level shear will be maximized and storm motions will be more perpendicular to the cold front allowing them to move off the boundary and into the favorable environment.  However, the heavily forested areas near the Great Lakes are very difficult chase terrains, so the southern mode over southeast MN into northeast IA might be the ideal target.  While the environment looks very favorable for tornadoes in the southern mode, the only concern I would have if chasing the southern target up there (the dissertation is destroying my late season storm chasing) would be an unfavorable southwest-to-northeast boundary orientation given a near-parallel storm motion, which could cause any supercells that form to merge and quickly become an outflow dominant MCS.  Nevertheless, it will be interesting to see how this severe weather event evolves, and to watch the live video from streamers in the field!  I'm definitely not used to watching potential tornado outbreaks from my home computer...NOT EASY!
« Last Edit: 16 July 2010, 03:48:14 AM by Jimmy Deguara »