A Case of Rapid Cooling near the Tropopause, near a Line of Tall Thunderstorms

Abstract

Five serial soundings at Ft. Worth, Tex., measured rapid cooling (5?7C in 1½?2 hr) just above the tropopause, near 150 mb, during and then again after the passage of a line of tall thunderstorms. The individual thunderstorm that penetrated the tropopause level do not appear to have been responsible for the temperature changes. One sounding which recorded rapid cooling passed through, or every close to, the tops of active thunderstorm cells as seen by radar, and a second sounding passed through the anvil clouds from these thunderstorms. The level of the tropopause shifted to a higher temperature discontinuity after the line passed, with the tropopause remaining 3000 ft higher than the undisturbed height four hours after the thunderstorm line passed Ft. Worth. The temperature change at 150 mb is shown to be unusually large when compared with other temperature changes at 150 mb.