4:55PM UPDATE: The Storm Prediction Center has issued a Severe Thunderstorm Watch for parts of central Indiana. The watch is in effect until 11pm Sunday.
The main threat from thunderstorms this evening will initially be large hail – up to 2″ in diameter – and damaging wind gusts to 70mph.
3:10PM UPDATE: The atmosphere is in the process of priming itself to allow showers and thunderstorms to develop later today.
At 3pm, temperatures have risen to the 70°s in much of central Indiana.
Humidity is also increasing due to southerly winds drawing low-level moisture up from the south. Dew points are in the lower to middle 50°s.
The Storm Prediction Center has expanded the “Slight Risk” area to cover much of central Indiana. The outlook is valid through 8am Monday, but the main threat for thunderstorms will be from 4pm until midnight in central Indiana.
Latest high-resolution computer model data suggests isolated thunderstorms could being to develop between 4pm and 5pm in southwestern Indiana. Any storms that develop will be moving to the northeast around 40mph.
Thunderstorms will have the potential to tap in to strong winds, located 15,000-20,000 feet above the ground, and bring the wind to the surface. Damaging winds will be the main threat. However, large hail will also be possible. I can’t completely rule out a tornado, especially from Martinsville to Evansville.