I saw mammatus clouds by 3pm right over Marshall. Stupid day to fly, especially for students. My students used to rely on me to get a read on “weather” to fly or NOT. We were all relieved to hear the visiting pilot that couldn’t penetrate the gust front and got blown back behind launch had a relatively easy extraction in the downpour. Far better than being sucked into a cu nim. *photo taken while pilots still aloft.