Weather Briefing and Flight
The pilot of an aircraft received a full weather briefing for an instrument flight rules (IFR) flight at 7,000 feet. The briefing included forecasted thunderstorms along the intended route. Additionally, a convective SIGMET was in effect for the route of flight.
In-Flight Weather Encounter
While in the area of Springfield, Tennessee, the aircraft was observed on radar approaching an area of precipitation. The pilot communicated to air traffic control that the conditions were getting "a little rough." The controller approved a deviation around the weather and an altitude change if necessary. A few minutes later, the flight was advised that it was in the middle of a weather area and that additional weather areas were ahead.
Radar Loss and Witness Observations
Shortly after the advisory, the aircraft was lost from radar. Witnesses on the ground reported seeing the aircraft emerge from an area of lightning and thunder in a 70-degree nose-low attitude.