Storm Event Synopsis

August 04, 2012

Convection began to develop just before 5:00 pm CDT across southeastern Kansas and the Missouri Ozarks. Storms initiated along two boundaries moving east across the region, the first being a cold front extending from northeastern Missouri into central Oklahoma and the second being a remnant boundary which had been slowly moving east across southern Missouri, left over from overnight/early morning convection. Through the evening these storms prompted numerous severe thunderstorm warnings with over 50 reports of thunderstorm wind damage, severe wind gusts, and hail associated with the strongest of these storms.

Afternoon temperatures across the region climbed into the upper 90s to the upper 100s. Accompanying these excessively hot temperatures, south winds continued to transport moisture rich air from the gulf. The combination of the two resulted in not only hot and humid conditions, but good amounts of surface based instability as well. Through the late morning and early afternoon, convection was suppressed by a sizable capping inversion spread across the region. Warm and dry air in the mid-levels of the atmosphere was responsible for this capping inversion. Lacking sufficent lift to "break the cap," instability continued to build in the lowest levels of the atmosphere. With the advancement of the primary cold front into southeastern Kansas and the boundary along the Ozark Plateau through 5:00 pm, enough lift was provided to develop thunderstorm updrafts capable of pushing through the capping inversion. Thunderstorms were quick to develop along the two boundaries, and with such dry air in the mid levels, thunderstorm downburst winds were the primary severe weather concern.

The first severe thunderstorm warning was issued at 5:49 pm CDT as thunderstorms intensified across Cherokee County Kansas and Jasper and Newton Counties in Missouri. Through the course of the evening, 27 severe thunderstorm warnings were issued across the region, with over 50 reports of severe weather, the majority being severe thunderstorm wind damage and gusts over 60 mph. Severe storms would continued through midnight across the region, with scattered showers and thunderstorms continuing through the overnight hours into the early morning of August 5th.


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