A flash flood watch is in effect from 2 a.m. Friday through Friday afternoon in Darien and the surrounding area due incoming thunderstorms and heavy rain. The National Weather Service has issued the flash flood watch for southern Connecticut, and parts of New York and New Jersey. Heaevy rainfall from showers and thunderstorms will result in poor drainage flood. Rainfall rates of one to two inches per hour are possible with some of these storms and torrential downpours could impact the morning commute. The sky is expected to clear to partly cloudy by Friday night, and the weather is expected to be sunny and clear in time for Darien's firework celebration Saturday night at Darien High School. The full weekend forecast: Thursday night A 50 percent chance of showers and thunderstorms, mainly after 3am. Some of the storms could produce heavy rain. Mostly cloudy, with a low around 75. Southwest wind 8 to 13 mph. Friday Showers and thunderstorms, mainly before 2pm. Some of the storms could produce heavy rain. High near 84. Southwest wind 9 to 11 mph becoming west in the afternoon. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible. Friday Night Partly cloudy, with a low around 60. North wind 8 to 11 mph. Saturday Sunny, with a high near 79. North wind 5 to 10 mph becoming east in the afternoon. Saturday Night Clear, with a low around 61. South wind around 6 mph becoming calm in the evening. Sunday Sunny, with a high near 82.