The problem with this kind of storm setup is that there is a lot of heat/moisture to fuel the storms, but the triggers are very subtle. Unlike a squall line or supercell where movement can be counted on, these cell just kind of ooze around and then die out. So, putting up a warning box is especially tough. The storm last night looked really healthy, and 30 min late it was remnant clouds. Nature of the beast. Not to mention, the areas that get hit by severe conditions are almost always very small.