Iowa looks to be under the gun yet again today after yesterday’s severe weather event, which produced a large complex of showers and thunderstorms over the region and 15 Severe Thunderstorm Warnings across the state. The bigger action was seen in Kansas where several tornadoes were reported. 21 tornado reports were seen in the Central Plains with 125 hail reports and 165 wind reports.
An upper-level trough continues to dig into southern California and Arizona today. At the surface, a pair of low pressure centers were observed in both northern Wisconsin and central Kansas, alongside a quasi-stationary front draped essentially in the middle of the northwest and southeast halves of the state, which has moved little in recent days and likely will not until Friday morning. This front has served as the stage for the recent days of severe weather and will do so once again today. Dew points have risen into the mid-60’s over southern Iowa with temperatures in the 70s. Cloud cover over southern Iowa has hampered our instability potential some, but some almost-moderate CAPE has already developed. If additional clearing happens early this afternoon, this should help destabilize things further for our threat today. In the far northeastern part of Kansas, up to 3,000 j/kg CAPE has formed simply as a result of a little bit of clearing.
The Storm Prediction Center currently has our far southern counties under an enhanced risk of severe weather, including Lamoni, Ottumwa, and Burlington. As with yesterday, the worst severe weather will likely stay to the south in the form of a damaging wind threat (where a moderate risk currently lies). How much of this activity we get is not completely clear. The short-range HRRR model seems to think that we may see some discrete-to-clustered storms east of Interstate 35 by mid-afternoon, essentially from Corydon to Davenport. These won’t be in the best thermodynamic or shear environment, so the worst we may see is some strong thunderstorms in this area — but it’s important to watch them regardless as there is some tornado potential. The bigger “showcase” storms with this outlook appear to form in the central one-third of Kansas by 2:00 or 3:00 p.m. These will approach our area by early-to-mid evening with potential for damaging winds and large hail. Tornadoes cannot be ruled out. Storms look to be completely out of the state before daybreak tomorrow, which leads into the next day’s round of storms.
The SPC currently has much of the state under an elevated risk of severe weather for Thursday. As always, some of these details will need to be grinded out as we see how today’s storms evolve. The stalled front will continue to act as the focal point with southeast and south central Iowa more of the concern, with the greatest threat to the south. Dew points in the mid-60s and mid-level lapse rates will support plenty of instability to be sufficient for superceullular development. We will probably see a few clusters of storms along a line, producing primarily a damaging wind threat. Isolated tornadoes will also be possible with any of the more discrete storms.
Stay tuned to the Iowa Weather Network for the latest information!