We had some light snow come through the area today with 2 specific areas , one was from Southeast PA to Northwest NJ then the next was the immediate NJ coast through Long Island , both these areas got a general coating to 1 inch of snow , the I95 corridor from Philadelphia to Northeast NJ kinda missed out on it and only got a few flurries
Now we have been watching a potential storm system for the Sunday-Tuesday time frame for a few days now, and its looking likely that a coastal low will impact the area, the good news is that most models agree that the low will track too far south for our region to feel the full brunt of this due to the strong negative NAO block besides perhaps south and southeastern NJ and the Delmarva, the bad news with a farther south track means winds will be more out of the east so coastal flooding issues may arise again.
There is actually quite a bit of model agreement on the track and impacts which is surprising given how badly they performed this winter
First we are going to have a low pressure system form over the Tennessee river valley Saturday into Sunday, the low will head northeast and attempt to head into the Ohio River Valley . but will hit a brick wall (the NAO block) and transfer its energy off of the Virginia coast, the secondary low is expected to bomb out
As the low moves east-northeast it will throw some moisture into the region late Sunday night and especially Monday, but as I said with such a track the highest impact from precipitation and wind will likely remain south of most of the forecast area
While like I sad most of the models have this general track I am using the NAM model because I think the others are under-doing the precipitation shield, with such a strong low I think the precipitation shield should be stronger and more expansive than what the GFS/European models show.
What expect is tranquil but cold conditions through Sunday, with highs generally in the mid to upper 30s NE PA to middle 40s along the coast Friday and Saturday than moderating slightly to upper 30s low 4os NE PA to upper 40s along the coast with an isolated 50 degree reading possible .
We will have increasing clouds Sunday then an increasing chance of snow to the NW of I95 , and increasing chance of rain/snow mix along and southeast of I95 then the precipitation will likely become more steady Monday morning , mainly New York City points south , more scattered and light for areas like NW NJ and NE PA
Overall it looks like a nuisance event winter weather wise, as areas that will be cold enough for snow will likely lack in the precipitation field , so generally a swath of light to moderate accumulation is possible from Central PA to New York City or just south including the northwest suburbs of Philadelphia, with periods of moderate to heavy rain/snow mix with little accumulation along the coast , the timing of this storm being during the day with the late March sun angle will also limit potential accumulations. I think coastal flooding will be the biggest issue here which could approach moderate levels with some gusty winds possible. Areas like Central PA will likely see the most snow with possible heavy accumulation as they get impacted by both the primary and the secondary low.These are the expected impacts as of now
We still have quite a bit of uncertainty though, while the models agree on a track there’s still a few days to go and if the upper level low over the northwest Atlantic is just a tad weaker or a bit farther east, then the storm could come farther north and change the whole forecast or the other way around, it would not take much of a shift west of this block to suppress the storm completely south of the region so I will be able to iron out more details Friday and especially Saturday. This is a pretty similar situation to what we saw earlier this month around March 8th, it’s just a matter of if the low is able to move northeast or does it move due east after the transfer.