Excessive Rainfall and Tropical Storm in the South; Severe Thunderstorms in the Midwest

Excessive rainfall may produce considerable, potentially life-threatening, flooding across the lower Mississippi River Valley and central Great Lakes region through tonight. Tropical Storm Arthur will move northeastward along the Texas coast today and then move inland over southwestern Louisiana by tonight. An outbreak of severe thunderstorms is expected across portions of Illinois and Indiana. Read More >

April 29, 2014
Severe Weather - Damaging Thunderstorm Winds

An area of strong to severe winds associated with a cluster of showers and thunderstorms moved from northern Kentucky to central Ohio during the late afternoon and evening of April 29, 2014. A small bow echo became evident in radar reflectivity with the corridor of strongest winds as the storms traveled northeast.

Radar Imagery:

NWS Wilmington OH (KILN)
0.5° Z -- 5:20-8:30 PM

There are several interesting things to note in this radar imagery: Initially the reflectivity values are fairly weak (more greens and yellows). However, the atmosphere was conducive to strong thunderstorm downdrafts. There is an eastward transfer of the strongest storms over southwest Ohio. This occurred as the thunderstorm cold pool organized and tracked toward a region of higher downdraft instability. Afterward, a more pronounced "bowing" structure develops. An outflow boundary from previous rains existed over the Scioto Valley. As the existing bow intersected this boundary, it strengthened, and new storms fired instantly along the colliding boundaries in Franklin, Pickaway, and Ross Counties. While severe weather was not produced southeast of the existing bow, heavy rainfall occurred as strong thunderstorm updrafts developed.