As today’s severe weather threat draws closer, the possibility of a viable chase has not subsided. The only trouble in terms of keeping the chase in the eastern Iowa viewing market is timing. The storms are expected to develop between 4 and 6 p.m. Friday Evening. Right now the placement for initial convection looks to be near or just west of the Mason City area.
The trouble is it could take several hours for that development to move into the eastern Iowa area. If the storms remain surfaced based for 1-3 hours, forward movement will not be great (15-30mph range). Once the storms get some forward motion, the tornadic threat will decrease and strong winds will be the greatest threat.
At this time, looking at the most recent model runs, our best case scenario is for initial development around 4pm, two hours of tornadic activity followed by 2-4 additional hours of a wind/hail threat in eastern Iowa. The system will wrap up with an overnight heavy rain event that could impact portions of the viewing area. The good news is the region can handle several inches of rain as some parts of the state are approaching low-level drought conditions.