This is a tough forecast, imo, and has been with the uncertainties offered by the overnight convection. Forecast models all offering pretty poor guidance, and observations are still sorting themselves out following the overnight convection. Not sure about the latest SPC forecast mentioning 70 dews into central SD - hard to imagine given their current location in extreme se NE with nw winds, but certainly could get to se SD by evening. Anyhow - plenty of sunshine - and the cap is really quite resonable for June even with only 60 dews. Weak surface low near Imperial NE has held tight this morning (beneath strongest mid-level cap) - and should slowly lift northward. To me - this is the feature to follow, with nearly dry adiabatic ll lapse rates in it's wake, along with improving moisture to the north with backed surface winds. Best current guess puts this feature near Valentine by this evening, when storms may be able to develop there, but this could be way off. Like further south with more veered upper level flow, and potential to tap into a better low-level moisture tongue - somewhere between VTN and ONL perhaps. Otherwise, should see storms move off the higher terrain into gradually improving instability. Not much of a cap at UNR this morning - so storms could develop out that way early. Serious cyclogenesis will be needed though to make the current surface wind fields in central and western SD adequate - and I fear this won't happen before the cold pool becomes organized into a line. Current surface ridge holding backed winds and some modest convergence around the Philip area may well dissolve before storms can initiate - though vis sat shows this area is currently trying. So, this is why I favor hoping for a more discrete cell further south. Again - this is all too far west for me to go after - so it's easy for me to sit back and throw out some random targets - reality in the field is you pick something based on where you currently are. It will be interesting to see if a rogue cell or two can develop well east of the main forcing. Anyhow, good luck to all in the field today.
Glen