Y'all had to know it was coming, I just hadn't gotten time to type it up since I've been super busy and for all intents and purposes did not have time to go to NW IA tuesday but I did anyways because the setup was gas.
Targeted Sac City area primarily due to the presence of an area of enhanced moisture convergence giving me high confidence the area near Denison would convect. This strategy was spot on. For awhile, the storms really struggled with fast motions and being whisked away north of the front and it took multiple updrafts before one finally got established on the boundary.
I suspect there was still quite a bit of surface stability here, as inflow temps ranged from 66-70 depending on where I was, but inflow was impressively strong at 60+mph immediately prior to the tornado, and at multiple points afterward. I suspect the very strong (and more importantly spatially large) mesocyclone and impressive hodographs helped compensate for this surface stability and enabled the Palmer tornado to develop. Due to incredible fortuitous circumstances, the stage of the tornado which were brilliantly captured by Jim Tang (and others) occurred behind trees.
However, impressive views were still to be had of later stages of the tornado lifecycle.
The storm filled in with rain after this and I didn't see any of the subsequent tornadoes. Although I very nearly drove into one near Gilmore City and was caught in the rear inflow jet and, cognizant about what may lay ahead shrouded in rain, I pulled off the road and waited in winds which were likely exceeding 90mph and inflicted heavy damage to neighboring trees. Up ahead, a farmstead had a destroyed outbuilding and substantial tree damage, which was deemed to be caused by an EF1 tornado. The storm could never shake mergers from the rear either, and I called the chase at 7:30pm