Under a tornado watch for most of the day, central Missouri has escaped severe weather due to recurrent periods of torrential rain. Developing by early afternoon along a cold front that stretched from Oklahoma to Wisconsin, these training storms cooled and stabilized the atmosphere, greatly reducing our risk of tornadoes.
Indeed, today's twisters formed along the southern and northern ends of the front, where daytime heating, in combination with the front and a potent jet stream, was sufficient to ignite relatively isolated, rotating storm cells. Between these areas, the storms coalesced into a swath of heavy rain, studded with thunderstorms, dropping up to 5 inches of rain that produced widespread flooding.
Moving northeastward along the front, the thunderstorms that crossed Missouri dampened the potency of storms in their wake. Tornadic supercells, like hurricanes, rely on an inflow of warm, humid air at the surface and may ignite other supercells along their outflow boundaries. Once a supercell enters rain-cooled air, however, it begins to dissipate and the risk of a tornado falls in concert.
