The Northern Plains will once again become active today, with a more appreciable threat for severe weather across a broader area from the eastern Dakotas into the northwestern Great Lakes region.  A shortwave centered over the Prairie Provinces of west central Canada will progress eastward towards the central Canadian Shield.  H25 flow of ~ 100 kts will exist coterminously with strong westerly H5 flow of ~ 60 kts as a vort max approaches southeastern MB late this afternoon.

A concomitant surface low will move into WC ON by early afternoon, with an ancillary cold front extending from near YHD to ABR by 18z.  SW H85 flow of 30-40 kts will continue to anneal throughout the afternoon, as strong WAA in advance of the CF engenders SBCAPE values on the order of 2000 – 3000 J/KG, with LI values progged to be < -6C across the region and SFC-500 mb shear values AOA 55 kts across a broad swath from NC MN to SW ON.   While 700 mb temps of 10C – 12C will be found across the region, CIN should erode in advance of the front in association with strong forcing.  This strong forcing coupled with adequate low level moisture, instability and low level WAA courtesty of a strengthening SW H85 flow will provide the impetus for the development of deep convection.

Ample speed shear, with a 20 kt increase between 850mb and 250 mb per KDLH forecast SKEW-T via RUC guidance (the 12z observed sounding at INL is posted below), and suitable directional shear engender the threat for rotating updrafts and perhaps some discrete activity early in the evolution of this event.  While tornado potential exists courtesy of these favorable shear profiles, there is also an attendant threat for damaging winds, with mean downdraft CAPE >=1000 J/KG present across much of the area per SREF, and large hail.  Ongoing, elevated convection relatively along and north of I-94 should begin to clear the area through 17z, allowing for atmospheric recovery in the wake of diurnal heating.  Current thinking is that convection will re-initiate by late afternoon ahead of the front, with discrete supercells likely early in the evolution of the event, before transitioning more to a linear mode and moving ESE across the region.  The impact of this morning’s convection as it pertains to remnant OFBs will have to be watched, as any such boundaries will likely enhance tornado potential later this afternoon, should the atmosphere be able to recover across the risk area.

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JLR