Insider Blog: Wednesday storms bring a threat of flash flooding

SETUP:

A warm front will lift into the region, as our low level winds from the south ramp up behind it. This will generate storms along and parallel to the front late Tuesday night through Wednesday morning. Storms will have some motion parallel to the front thanks to a jet stream of the same orientation.

This is a setup common with training thunderstorms; storms that can bring repetitive rainfall to a localized area as they are slow to move away. For some areas, we may need to wait for the warm front to exit before rain stops.

TIMING:

Timing is a little tricky at onset, as we are uncertain exactly when storms develop, but the general time frame puts initiation of storms between 11 p.m. and 2 a.m. Timing is also a bit of a question because of the location of storm development.

Still, the margin of error seems to keep all solutions developing storms SOMEWHERE in mid-Missouri. Once storms develop, they will drift slowly east as the front does. This makes for plenty of time for rain to accumulate before coming to an end in the early afternoon as the low level winds die down.

IMPACTS:

Potential impacts are fairly straight forward, with flooding being our main concern. The swath of heaviest rain varies greatly across model guidance. It will run from northwest to southeast, but through which communities is the question. It's still uncertain if this will favor the Lake of the Ozarks, or areas further north towards Columbia and Jefferson City. Wherever the best rain falls, some could measure more than 4 inches. Most in this swath are likely closer to 2-4 inches.

Also, flooding is not a guarantee. If we see winds aloft come slightly out of alignment, or get a progressive enough warm front, we could see less of a flood impact. Either way, it's worth watching during the morning commute timeframe, which could see some of the greatest impacts Wednesday.