Now that I am retired, I have more flexibility about when to chase, though not unlimited (See other threads on chasing vs. life). Generally for me there are two categories - relatively local, one-day chases and longer, multi-day chases. For the one-day chases, I will usually have a limit of a 3 or 4 hour drive to the target, and a lower threshold for how good a setup needs to be - though to go the upper limits of that range, it needs to be a relatively better setup. Aside from that, I usually try to do two or three multi-day trips to the high plains each season, usually when I see what looks like a few consecutive decent chase days coming up. On these I will generally travel from our southern CO/northern NM home base to anywhere in eastern NM or CO, western KS, or the Panhandles, IF there is a decent multi-day setup where I can get more than one chase day. I like to pre-position the night before somewhere reasonably close to the next day's target, since from where we live it is a few hours drive just to really even get into the plains of eastern CO or NM. So I would say for multi-day trips, I will go for a target up to about 8 hours away for the first day, and maybe farther from home on subsequent days. I generally avoid the OKC area and prefer to stay west of I-35, both because of chase terrain and distance to return home. One area I have not had much luck yet is the Palmer Divide. Often the setups there are just for one-day, and that is about a 6-hour haul for me, a bit much for one day. So I have failed to pull the trigger on a few of the really good days, and when I have chased there I have tended to mess up. I have had better luck around the Raton Mesa, which also has the advantage for me of being closer.
Back when I lived in IL, I chased a lot there and some in MO, IA, AR, and IN, with occasional trips to the plains. Much of MO is less than ideal chase terrain, but they do get powerful storms there and there are some places with decent terrain, and there are parts of IL, IN, IA, and AR that are really pretty good chase terrain. Specifically regarding AR, much of the east-central part is pretty flat with not too many trees, although western and northern parts of AR are very hard to chase. Comparing the Midwest to the High Plains where I mostly chase now, I would say the biggest difference is that haze and low cloud bases often make storms in places like IL harder to see, even if the terrain is good. But they do get some good storms in that part of the country. I just find the chasing a little easier now that I usually chase in places like KS, NM, and CO. Although if the storms are in or near the mountains in CO and NM - and they sometimes are - that adds its own element of challenge.
