The sunny weather will continue on Long Island through this weekend. High temperatures will be 70 to 75 degrees, with overnight lows in the 50's. However, a frontal system will be approaching that will bring some much-needed rainfall to Long Island on Tuesday. The rain should start in the morning and be done late Tuesday night. While the heavier rain amounts will be to our west, Long Island should see between a half inch and one inch of rain. However, there is the potential for between 1 and 2 inches of rain.
The following image from the GFS model is showing rainfall amounts through 8 AM Wednesday:
Image from tropicaltidbits.com