The atmosphere appears ready to blow across NE SD and parts of SE ND and W MN. A warm front is clearly evident on KABR as well as in surface obs and satellite imagery oriented roughly WNW-SSE from the central SD-ND border through NE SD and through C MN with pretty good surface flow (10 - 20 kts ESE and gusting) north of the boundary. This is also the location of a strong SBCAPE gradient with up to and over 4000 J/kg SBCAPE into SE SD and SW MN and points south of there. There is also a pocket of > 60 kts effective bulk shear in NE SD, SE ND, and WC MN with a tongue of > 40 kts of effective bulk shear extending SSW from the St. Cloud area towards Sioux City, IA. 0-1 km shear is > 20 kts in a similar area, with a maximum of > 30 kts 0-1 km shear northeast of Aberdeen. As a result, effective SRH is up to nearly 700 m2/s2 around the tri-state area of ND/SD/MN. Low-level CAPE is building in the area also, and with good surface theta-e advection and convergence near the low that is centered in C SD, the forcing is there to get storms going soon. Could be some tornadic supercells early on.
One thing I will add: the effective-layer significant tornado parameter is currently peaking at > 9 in NE SD, and to my knowledge there hasn't been a non-tornadic-supercell day (both no supercells and no tornadic supercells) when that parameter has been so high (for as long as that parameter has been included in analyses).
ADD: as of the 21Z analysis, effective-layer sig tor is up to 11 in the tri-state area.
One thing I will add: the effective-layer significant tornado parameter is currently peaking at > 9 in NE SD, and to my knowledge there hasn't been a non-tornadic-supercell day (both no supercells and no tornadic supercells) when that parameter has been so high (for as long as that parameter has been included in analyses).
ADD: as of the 21Z analysis, effective-layer sig tor is up to 11 in the tri-state area.
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