A flood watch is in effect through Tuesday morning for all of Long Island with off and on flood advisories and warnings popping up in the hardest hit areas. Heavy rainfall from repeated rounds of showers and thunderstorms may result in flash flooding, especially in urban, poor drainage and low-lying areas.

Today: Periods of showers and thunderstorms continue throughout the day. Some storms may produce torrential rainfall, leading to flash flooding. Temperatures will reach the upper-70s.

Tonight: Rain and thunderstorms continue with another round of heavy rainfall possible before gradually diminishing late. Temperatures will be in the mid-60s.

Tuesday: Showers gradually become more scattered through the day, with a few thunderstorms still possible during the afternoon. Temperatures will range from the upper-70s to the low-80s.

Wednesday: Partly sunny, less humid and much quieter weather returns. Temperatures will be in the low to mid- 80s.

Thursday: Mostly sunny and warmer, with increasing humidity. Temperatures will be in the upper-80s.

Friday: Partly sunny, hot, and humid with scattered afternoon and evening showers and thunderstorms possible. Temperatures will reach the upper-80s to low-90s.

Saturday: Warm and humid, with a continued chance for scattered showers. Temperatures will be around 90.