I was crossing the ITCZ a few years ago at FL390 and flew into a green radar return. The OAT before entering was -56C. In a few seconds it had risen to -28C. We received a message from out FMC that we were cruising above Max Flight level. The ride however was smooth and the aircraft, a 767, coped well. Flying out of the cloud brought an instantaneous reduction in Temp back to -56C.
Tim Vasquez may be a fine meteorologist, but he doesn't know everything.