The weather across the Northeast and in the mid-Atlantic states Monday should pick up where Sunday left off.
There’s a ridge of high pressure on the surface weather map, which is still expected to bring a fair amount
of sunshine. Temperatures should climb to around 80 Monday afternoon. We can’t seem to say enough nice things about the weather, but it does appear that the pattern will be going downhill Monday night and Tuesday. And, especially around the central and southern Appalachians, this process isn’t going to take very long. Last Friday, we talked briefly about a series of upper-level disturbances that will be marching across the eastern half of North America. The southern-most of these features, which is expected to bring some heavy thunderstorms to the central Gulf Coast and to parts of the Tennessee Valley Monday, will be unlocking some warm and moist air that originates from the Gulf of Mexico.
Meanwhile, looking farther to the north, there is currently a vigorous impulse of jet stream energy that is moving across south-central Canada. This parcel of energy, which has a low pressure system and a very strong cold front associated with it, will be moving across the Great Lakes Monday night before slowing down somewhat as it approaches the Appalachians later Tuesday.
So, with these “two pieces” coming together over the eastern third of the nation — the warm, rich source of moist air
flowing in from the south, and that strong front pushing into the region from the north and west — we feel strongly
there is going to be a good, thorough soaking rain occurring around here during the next 48 hours. And, based on the
timing of the front’s arrival and the consensus which is now being built amongst the global forecast models, the bulk
of this rain will occur later Tuesday afternoon and Tuesday night. But, that rationale doesn’t prohibit the idea that a
couple of showers can occur as early as late Monday or even Tuesday morning along the I-95 corridor.
Precipitation forecasts show a general 1-2 inches of rain will fall between late Monday night and early Wednesday morning.