DAYTON, Ohio (WDTN) — A large area of high pressure is still firmly entrenched across the Appalachian Mountain Range keeping the Miami Valley in a warm, humid air flow. The high, however, will start to break down on Tuesday. That, along with a passing upper-level disturbance and increasing moisture, could lead to a shower or thunderstorm by Tuesday afternoon and evening.

There’s an even better chance of rain very late Tuesday night into the day on Wednesday as an area of low pressure drags a cold front across the Miami Valley. Any rain will be welcome as no measureable rain has fallen in nearly 2 weeks.

TONIGHT: Becoming partly cloudy. Unseasonably warm and muggy. Low 71

TUESDAY: Partly sunny, hot and humid. A shower or thunderstorm possible during the afternoon. High 90

TUESDAY NIGHT: Mostly cloudy with a chance of an evening shower or thunderstorm. Continued warm and muggy. Low 71

WEDNESDAY: Mostly cloudy with scattered showers and thunderstorms likely, especially during the morning. A little cooler. High 86

After the cold front passes through Wednesday, much cooler air will slowly work its way into the Miami Valley. Daily highs will drop from the lower 80s on Thursday into just the mid to upper 70s on Friday and lingering through the weekend.