Weather Alert Day: Multiple rounds of storms forecast for Monday with severe possible

Monday is an ABC17 Stormtrack Weather Alert Day, with multiple chances for thunderstorms

SETUP

Relatively flat west-to-east flow aloft has sent small disturbances and short-wave troughs of low pressure near our region this weekend. This triggered storms across Nebraska, Kansas, and Northeast Missouri Saturday night.

These are embedded in the upper-level jet stream, which is strongest to our north. If there's one limiting factor for severe storms this weekend, it's that a northern jet stream may keep our overall wind shear and support relatively low with each event until a deeper dip in the jet stream drives higher storm chances by bringing a deeper trough and stronger wind support on Monday and Tuesday.

At the surface, and at the lower levels of the atmosphere, an area of low pressure will strengthen to our west, and draw warmth and moisture in from the Gulf through Tuesday.

The warm and muggy pattern remains Monday, ahead of a larger dip in the upper-level flow, which will push the more active pattern and greater support for strong storms into mid-Missouri.

Similar to Saturday night, storms are likely to develop across the plains, weakening as they push into mid-Missouri. It's uncertain as to how long they may linger throughout the morning, but as instability builds ahead of the line, the outflow of decaying morning storms raises concern for a severe threat during Monday afternoon, meaning any storms or showers that linger could intensify. Again, storms are expected to develop to our west Monday night, then spread east overnight, bringing a better chance for severe storms with greater support forecast, as the cold front makes more progress into our region.

TIMING

The warm front is lifting north on Sunday, which will take the focus for storms north of our region, leaving us warmer and drier.

Monday may start with a weakening line of showers and storms after remnant Sunday night activity drifts in from the west. If this happens, it could send clouds and rain behind an outflow boundary through the morning. Warmth and storm energy are expected to lift north again through the afternoon and evening, restoring fuel for late-night storms. In fact, as this outflow boundary interacts with more instability lifting north, we may see a new round of storms develop during the afternoon and early evening. The focus for Monday's greatest severe chance centers on the approaching cold front and upper-level wind shear, which are both expected late in the night, potentially overnight. It's still uncertain exactly how Monday unfolds, but given the ingredients expected, Monday night looks to be the greatest threat for severe storms out of this active pattern.

To a lesser extent, there is some potential for storms to redevelop locally on Tuesday, but this will greatly depend on the speed of the front, which may entirely clear the region of a severe threat.

IMPACTS

Storms late Sunday night into Monday will pose mainly a damaging wind threat. The best chance for strong storms in our region will be on Monday night into Tuesday morning, when hail, wind, and tornadoes will be possible. Severe storms may develop again on Tuesday afternoon before pushing east.