Monitoring Tsunami Impacts Across the Pacific; Air Quality Concerns; Dangerous Heat; Critical Fire Weather for the West

Tsunami impacts continue for portions of the Pacific basin. Wildfire smoke causes unhealthy air in Midwest to Great Lakes. Heat dome spans Mississippi Valley to Mid-Atlantic with excessive heat warnings and advisories. Critical fire weather in Great Basin to Pacific Northwest (dry thunderstorms). Cold front spawns severe storms/heavy rain in Central U.S. today, shifts to East Coast Thursday. 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.