The latest update from the Storm Prediction Center continues the elevated risk of severe weather over most areas south of Interstate 80 in the state. A look at the satellite imagery this afternoon shows a thinning cloud deck and some clearing even in many spots throughout the region, critical for peak daytime heating to occur, and henceforth, instability. This is something that is not being seen to the south, as of yet – potentially highlighting a higher risk area locally.

Surface observations from the top of the hour are showing plenty of moisture available as well across southwest Iowa and southeastern Nebraska, as indicated by dew points being in the mid-to-upper 50s in many locations. It would not be of particular surprise either to see some low 60s as well. In addition, even with the thick cloud deck in some spots, temperatures are already nearing the low-to-mid 70s in some spots.

Instability will continue to grow through the afternoon as heating continues, beneath a strong cap aloft. As the afternoon drags on, and instability peaks, this cap should gradually weaken and we’ll begin seeing storms developing ahead of a dryline/cold front in western Iowa, serving as an essential stage for development. As far as timing of storms go, we expect that things begin popping up in southeastern Nebraska in the 3:00 – 4:00 p.m. time frame, eventually spreading east into Iowa in the mid-afternoon to early evening hours. Storms will continue into the night and reach the Des Moines metropolitan area likely late tonight, at around 10:00 p.m. or so.

All modes of severe weather will be possible initially as the storms begin out discretely, including large hail to golf ball size, damaging winds to 70 MPH, and tornadoes. The tornado threat will be greatest along the Interstate 29 corridor across the Iowa, Nebraska, Kansas, and Missouri bordering “region.” Eventually, the primary mode should transition to damaging winds as things become more linear.

Stay tuned to the Iowa Weather Network for the latest information.