A Flash Flood Watch for much of central Indiana continues until 8pm Monday.
Areas from Indianapolis and south could pick up an additional 1" to 2" of rain through Monday evening. Through 6:30pm, many locations south of I-74 have received over one inch or rain since midnight.
Data is divided as to what we can expect to see overnight. For several days data pointed to the heaviest rains falling Sunday night in to Monday morning, with rain coming to an end by Monday afternoon. However, higher resolution computer data is suggesting rain will be relatively light overnight and pop-up showers/thunderstorms developing during the heating of the afternoon. I am going to keep rain in the forecast overnight, but think the additional rain projected to come will be spread out through Monday.
FLASH FLOOD POTENTIAL
The Weather Prediction Center - similar to the Storm Prediction Center but handles forecasts for rain and snow - has placed the southern half of Indiana in a "Moderate Risk" for flash flood potential though 8am Monday.
Looking at the latest flash flood guidance suggests 2" to 3" of rain in a six hour period could produce flash flooding in parts of central Indiana.
While flash flooding remains a possibility, I think the possibility for widespread flash flooding is diminishing. If there is any flash flooding, I think it will be very localized and in south-central Indiana.
RETURN OF THE MUGGLIES
Long range computer model data suggests heat and humidity return to central Indiana later this week. A warm front should pass through Indiana Wednesday. Behind the front, warm, humid air will infiltrate the state. Highs should jump to the lower 90°s Thursday and Friday. More importantly, humidity will surge as dew points climb to the lower/middle 70°s creating peak heat indices 98°-103°.