9:30 AM | ***Precipitation closing in as next winter storm approaches the Mid-Atlantic region; heaviest snow axis likely from DC to the Jersey Shore, but accumulating snow throughout much of the I-95 corridor***

[Latest infrared satellite image of the US; courtesy SSEC, University of Wisconsin]

Discussion

Precipitation is already moving into western sections of Pennsylvania this morning from the next winter storm to affect the Mid-Atlantic region at the same time Arctic cold air is situated just to the north ready to pounce on the region from northwest-to-southeast during the overnight hours. Some light precipitation will break out in the I-95 corridor later today, but the heaviest stuff will begin this evening and continue into Monday and temperatures will crash tonight following the Arctic frontal passage. It appears that the axis of heaviest snowfall of 8-12 inches will occur by late Monday in the area from the DC metro region to right across the central part of the Delmarva Peninsula to the Jersey Shore, but accumulating snow will occur throughout much of the I-95 corridor. Snowfall accumulations will drop off quickly to the north with areas like New York City likely ending up in the 3-6 inch zone and New England largely being spared from this storm.

Now for the specifics:

NYC: light snow or a light wintry mix breaks out this afternoon and changes to all snow early this evening. The snow continues heavy at times into the late morning or mid-day hours on Monday with total snowfall accumulations on the order of 3-6 inches. Temperatures peak today near 40 degrees then drop through the 20’s overnight and into the teens early Monday and then they’ll plunge late tomorrow night/early Tuesday to the brutally cold single digits for lows.

PHL: light snow or a light wintry mix breaks out this afternoon and changes to all snow early this evening. The snow continues heavy at times into the late morning or early afternoon hours on Monday with total snowfall accumulations as follows: 6-10 inches in the southern half of the metro region (i.e., Chester County, Delaware County, Philadelphia County, southern half of Montgomery County, southern half of Bucks County) and 4-8 inches across the northern half of Montgomery County and northern Bucks County. Temperatures peak today in the mid-to-upper 30’s then drop through the 20’s overnight and into the teens by early Monday and then they’ll plunge by late tomorrow night/early Tuesday to right around 0 degrees for lows.

DC to the Jersey Shore: light rain develops later today and changes to a wintry mix this evening and then to all snow by late tonight. Snow continues for much of the day on Monday, heavy at times, and there can be a “thunder snow” event or two mixed in. Total snowfall accumulation amounts by the time the storm winds down late tomorrow on the order of 8-12 inches. Temperatures peak today well up in the 40’s and then drop right through the 30’s this evening reaching the low 20’s by early tomorrow and probably hold relatively steady around there during the day on Monday. By late tomorrow night/early Tuesday, temperatures will plunge to the brutally cold single digits for lows.

Stay tuned for updates as a small shift can make big differences and mesoscale banding can have big impacts on the final results.