Above: 3 Kilometer Grid NAM Surface Forecast for 10 AM Friday. (Click to enlarge).
A powerful nor'easter will take shape south of our area late tonight into Friday & Friday night.
Showers develop between 8 PM-midnight, with steadier, heavier rain during the predawn hours.
Rain, heavy at times Friday, mixing with wet snow at times - especially across the northwest hills.
Winds gusting to 40+ mph inland by late Friday/Friday night, 50+ mph along the coast, and maybe as high as 60-70 mph along the New London County shoreline. This could result in some power outages in southeastern CT. A High Wind Watch is in effect across southern CT and a High Wind Warning for New London County Friday & Friday night.
Most areas will change to wet snow at times by Friday night. The heavier the precipitation comes down Friday night, the more likely it will be snow. It may go back to rain at other times when it lightens up. Right now it looks like northwestern CT will probably pick up 3"-6" of heavy, wet snow, which combined with the gusty wind could lead to power outages. Outside of the northwest hills, a coating to an inch or two (or three) of wet snow may accumulate - especially on grassy surfaces. There is a small chance that snow amounts will be higher across the board (see probability graphics below).
Rainfall amounts of 1.5"-3.0" are likely with the potential for locally higher amounts. This may lead to issues with flooding. A Flood Watch is in effect across the state for this storm. There is also a coastal flood advisory up for the western coast of CT.
If temperatures at the surface & aloft end up being 1-2 degrees colder than currently forecast, snow amounts will end up being higher. I agree with the NWS depiction of these probabilities linked below.
Hartford, Tolland & Windham Counties