ST. LOUIS (KMOX/NWS) — The National Weather Service says to brace yourself – several rounds of severe weather are possible for St. Louis now through Wednesday night.

A frontal boundary will remain stalled over northern Missouri and central Illinois through Wednesday night as a wound up area of low pressure to our west slowly approaches.

This front will serve as a focus for several rounds of thunderstorms as well as maintaining the moist air over much of the bi-state region.

While some thunderstorms are possible later today, thunderstorm chances will increase heading into tonight and Wednesday as the center of the main storm system approaches.

Any thunderstorms that do form could become severe, but the greatest chance for severe weather will be Wednesday afternoon and evening where a widespread outbreak of severe thunderstorms is expected.

In addition to severe weather, locally heavy rainfall may cause rises on area streams, creeks, and rivers.

(Copyright KMOX Radio)