Heavy rain is headed to portions of the Northeast this Friday and Saturday as warm air moves in with many locations experiencing highs in the 40’s, 50’s, and even 60’s. That heavy rain on top of the significant snow cover, however, will be troublesome because of rapid snowmelt combined with inches of rain. This will lead to flooding for some locations, especially along rivers where ice jams are possible. A Flood Watch, as shown in the green shaded areas below, is in effect from western New York through Southern New England, which means continues are prime for flooding. This is where the best chance for flooding conditions exists.
We’re going to be watching an area of low pressure moving from the Mid-Missisppi Valley through the Northeast coast, drawing in warm, moist air to the east of the center of low pressure. Deep, tropical moisture all the way from the Caribbean will move in, allowing for inches of rain to fall, especially in Southern New England. This is the same storm that is responsible for the snow on the western and northern side of the center. So starting Thursday evening, a light to moderate rain will stream into western New York and Pennsylvania. During the overnight hours, that rain will continue while showers extend into the remainder of the Northeast. Then during the day Friday, the rain will start to become scattered across New York and Pennsylvania while a widespread light to moderate rain moves into much of New England. Heavier rain may even move into the Southern New England coast. Meanwhile in western Pennsylvania and New York, the rain will begin to transition into freezing rain and snow starting Friday evening. The wet weather will continue during most of Friday night across Southern New England while more inland areas in northern New England changeover to freezing rain and snow as well. The rain will begin to taper off Saturday morning across Southern New England and should end by noon. As soon as the rain comes to an end, however, there is the concern for a flash freeze in this region. A very sharp cold front will likely move through shortly after the end of the precipitation, turning all of the fallen rain into ice, and therefore will make roads and surfaces icy.
There will be two areas where the heaviest precipitation will fall: interior Northeast and Southern New England. Now in the interior Northeast, not all of the precipitation forecast will fall as rain. In fact, many of these areas will receive up to a foot of snow. On the other hand in Southern New England, it will be a rain event with localized areas receiving over three inches of rain.