Strong warm advection ahead of surface low and associated cold front wil bring 60s surface dewpoints northward across much of the southern Plains and portions of the Ozarks... Some guidance suggests a secondary low may develop over northwest OK near a bulge in the dryline. This could help to enhance low level SRH, and an increased tornado threat with any cells that can maintain a semi-discrete storm mode. With time, convection is expected to grow upscale into one or more bowing segments as a low level jet develops during the early evening and as frontal forcing increases as a cold front develops southeastward across the southern Plains. Strong low level windfield and steep low level lapse rates will result in significant damaging wind potential across portions of the Enhanced risk.
NWS ICT Discussion
[A] cold front ... will push from northwest to southeast across Kansas tomorrow. In the morning a few showers or thunderstorms may develop within an area of increasing moisture across central Kansas. However, the main concern for tomorrow will be during the afternoon hours across south central and southeast Kansas. As the front moves through, instability will significantly increase ahead of it.
Between 18 and 21z (1pm to 4pm CDT) [storms should] begin developing along the boundary in the vicinity of the Kansas Turnpike corridor as capping weakens. MLCAPE well in excess of 2000 J/kg, 40 kts or so of deep layer shear, and modest mid-level lapse rates will be supportive of some strong and severe storms. [S]torms will likely move east-southeast. Deep layer shear vectors, though not completely orthogonal to the surface boundary, have at least some off-boundary component. This should present a scenario that optimizes a convective mode featuring separated updrafts (owing to the sufficient off-boundary storm motion) as well as maximizing residence time within the zone of surface-based effective inflow layer air. Therefore ... more of a cluster storm mode [is expected] with a couple of discrete cells possible near the Oklahoma border initially, but then will grow upscale into multi-cell cluster or line segments throughout the rest of the afternoon.
The main threats still look to be large hail and damaging wind gusts. Although a brief tornado cannot be ruled out, wind shear will be mostly uni-directional which should work to mitigate the tornado threat. By 00z, storms will have pushed outside of the forecast area for the most part as they continue southeast.
NWS Norman Discussion
A cold front is expected to enter far northwestern Oklahoma by mid morning Tuesday and move southward to near Stillwater-OKC-Lawton by mid afternoon (3- 4 pm). Overall, near surface winds will likely be veered some ahead of the cold front which will limit the risk of tornadoes. Winds may be backed more across western north Texas near a surface reflection, but overall confidence is not high.
The frontal depth should be more than sufficient for the development of scattered to numerous storms, perhaps initially across north central Oklahoma during the early afternoon. Storms that form should help accelerate the front southward with a lag in much drier air to the north. How far west storms will develop along the front is questionable with the NAM having little development west of Highway 81. Would expect the storm will develop farther west during the afternoon and evening.
By mid afternoon, CAPE values over 3000 J/KG are expected ahead of the advancing front. Given the amount of instability and sufficient mid level flow, severe storms are likely with damaging winds and large hail.
At this point, it looks like hail will be an issue south and east of the turnpike, particularly as the line of storms advances into Oklahoma. It will be an early event, getting started just after lunch time the way things look tonight. In the first few hours, if the forecast (by some modesl) secondary low forms in northern Oklahoma, some tornado risk could be there. But things are expected to get into a messy cluster supercell field pretty eqarly on and line out by mid afternoon. By sunset the event is over for Kansas.
Given proximity to the metro and the early start, I believe this will be a last-minute call on chasing. I’d probably target southern Butler county initially, with plans to move north or south along US 77 as needed. I won’t follow it very far east or south.