Good evening everyone! A busy evening is on tap across the area as an upper-level low continues to provide lift across eastern IA where scattered showers and storms are currently located as of 5pm CDT. Areas of isolated heavier showers in northwestern IA are persisting along the western periphery of the upper-level low. Further south, a frontal boundary remains draped across western MO and eastern KS. Strong to severe thunderstorms have begun to fire along this boundary and I expect coverage to increase over through the evening hours while gradually pushing eastward.
In collaboration with a few National Weather Service offices in eastern KS/western MO and the Storm Prediction Center (SPC), a Severe Thunderstorm Watch is in effect until 11pm CDT tonight. Storms will become more widespread in this region where the main threats will be large hail and damaging winds. An isolated tornado or two cannot be ruled out at this time given the dynamics at play.
Shown below is the Severe Weather Outlook issued by the SPC for the Central Plains. While areas from southern IA through MO into eastern KS are at play for severe weather this evening and tonight, the best chance for strong to severe thunderstorms will remain in eastern KS and western MO (where the Severe Thunderstorm Watch is in effect currently).
HRRR simulated radar through 7am CDT Friday morning: This model is not perfect as it’s failing to depict the recent development in eastern KS (too late on development), but it also has the best handle on the convection in eastern IA. As previously stated, scattered strong storm coverage will increase through the evening across eastern KS and western MO. The frontal boundary will continue to lift eastward overnight, pushing these storms that likely form into a cluster across MO. The HRRR depicts most storm activity exiting the state of MO by 5am CDT Friday with a few lingering areas of showers and storms possibly hanging back across central and southern MO. The NAM3km is a bit more aggressive while also hanging more storm coverage across southern MO at 5am CDT Friday. Due to some leftover energy likely to remain across southern MO Friday morning, I can’t rule out more storm coverage than what is depicted by the HRRR, though it does increase storm storm coverage slightly during the morning areas in the area. A disturbance hovering around far southwestern KS will continue shower/storm chances during the nighttime hours. Elsewhere across IA, most shower/storm activity will have pushed out of the state by 12am CDT tonight.
Model discrepancies increase heading into Friday afternoon and evening. The NAM3km model lifts most upper-level energy out of the region with just isolated areas of showers and storms developing, mainly in eastern/southern MO into eastern IA. Storm coverage is greater with the HRRR across far southern MO but it is the outlier as the NSSL is in agreement with the NAM3km, hence the use of the NAM3km model shown below from 1pm CDT Friday through 7am CDT Saturday. Any morning shower/storm activity across MO is expected to lift out of the area leaving room for additional isolated areas of showers and storms in the area during the afternoon and evening Friday. Another disturbance will lift out of the Rockies late Friday evening/night providing an uptick in shower/storm chances to far western KS Friday night.
Due to model discrepancies for Friday afternoon/evening, total rainfall shown below only runs through 10am CDT Friday. Pockets of 0.5-1.5″+ of rain are expected across portions of eastern KS into MO. Localized 1″+ is possible in northeast IA as convection pushes eastward through the evening hours. Due to the scattered nature of the storms in eastern KS and MO, some areas may miss out on these rains.
If you have any questions do not hesitate to reach out! Have a great evening!