Flash Flood Watch Issued For Nassau, Western Suffolk

The National Weather Service has issued a flash flood watch for Nassau County and western Suffolk County. It will be in effect from midnight until 11 a.m. Monday.

An area of low pressure will develop along a frontal boundary to our south and pass just south and east of Long Island, the NWS says. Rainfall rates of 1 to 2 inches an hour are possible and may lead to flash flooding.

A flash flood watch means that conditions may develop that lead to flash flooding. Flash flooding is a very dangerous situation. Residents should monitor later forecasts and be prepared to take action should flash flood warnings be issued, the NWS says.

The full forecast:

Sunday Night- A chance of showers between 10pm and 2am, then rain and possibly a thunderstorm after 2am. Some of the storms could produce heavy rainfall. Low around 69. East wind 9 to 13 mph. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.

Monday- Rain and possibly a thunderstorm before 11am, then showers likely and possibly a thunderstorm between 11am and 1pm, then a chance of showers after 1pm. Some of the storms could produce heavy rainfall. Steady temperature around 71. Northeast wind around 16 mph. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.

Monday Night- A 30 percent chance of showers, mainly before midnight. Cloudy, with a low around 65. Northeast wind 7 to 11 mph.

Tuesday- A 20 percent chance of showers. Mostly cloudy, with a high near 73. East wind around 11 mph.

Tuesday Night- Mostly cloudy, with a low around 63. East wind 10 to 13 mph.

Wednesday- Sunny, with a high near 79.

Wednesday Night- Partly cloudy, with a low around 66.