The storm currently in the Southeast is expected to start affecting the area tomorrow, and we are going to see the effects of this storm last into Monday, with heavy rain, flooding and some winds being a part of this storm.
Despite there being cloudy skies outside, the rain should not start until at least tomorrow morning. The rain should be mainly light through tomorrow, with amounts less than 1/4 inch. The light rain continues through Saturday morning, with occasional periods of moderate rain, especially south of New York City. By Saturday morning, rainfall amounts should be between 1/4 and 1/2 inch, with the highest amounts south and west of NYC and the lowest amounts for Long Island and Connecticut.
As I previously mentioned, Saturday night should be the time frame for the heaviest rain, though there is still uncertainty on how much rain falls in that time period. The latest GFS run is much drier than its previous runs, with the heaviest rainfall rate being 1/2 inch in 6 hours, compared to other runs and models, including the 12z NAM which brought 1.5 inch of rain in 6 hours. The latest GFS and NAM runs end up bringing a total of 2-3 inches of rain, while their previous runs had 3-5 inches of rain. Whether it is a trend or not is still uncertain, though it is possible that rain amounts could end up being slightly lower if this does in fact become a trend.
Once the heavy rain ends by Sunday, lighter rain then continues until Monday, when the rain ends as the storm finally exits the area. By that time, we are looking at 2 to 4 inches of rain, with the highest amounts south of New York City.
Below is my updated rain map. I shifted the rain areas further south, as over the past 2 days, the trend has been to move the rain totals further south. Some models such as the NAM have the rain areas even further south, though at this time I decided to keep the northern boundary of the rain area slightly further north, in case there is a slight north trend.