Above is the current radar and 500 mb pattern, we can see the storm is now developing and well underway, now its time to in-depth in details.
We can see the low pressure developing in the Gulf on the radar and its picking up a TON of moisture, meanwhile a northern stream disturbance is diving east south-east, these 2 will slowly merge today and lead to a RAPIDLY INTENSIFYING low coming up the east coast by later tonight and early Thursday
With a full phase this storm will be very slow-moving and will be a solid 24-30 hr event for most of the area, and im seeing some factors that I believe will make this storm track just a bit farther east than modeled and just a bit colder than modeled now
I’m using the GFS below, not because I believe it fully but just to show the set up and my reasoning for a potentially slightly colder and snowier solution all the way to the coast
Here we are at 12 hrs, we see theres a nice arctic high near Maine but this is exiting eastward, thus the reason why much of the area is expected to see at least some mixing of sleet and rain , HOWEVER
Here we are during the storm and there’s another polar high pressure moving into SE Canada which could reload the cold air before to much can be scoured out, and we also see that the ridge in the west is very flat , this combined with confluence coming in from the new high pressure system may force the storm just a bit farther east and thus a little colder ,don’t get me wrong here the immediate coast will mix with and change to rain, these factors would more so influence the I95 corridor more so than the immediate coast
Another thing to take into consideration is the power of the storm, it will produce intense precipitation which can be capable of keeping things colder than expected, I do expect a mixture to take hold along I95 and just northwest but I am thinking now its more sleet than rain when this occurs. I’m going to make a new map this evening if I see these factors influencing the storm which would include the cities in the higher amounts 0f 8+ inches and also shift the heaviest axis of snow farther east just by a bit, it wont be a big shift but enough to make a difference.
Ok so now that I got that out of my system let’s go into timing and precipitation type
The snow will begin overspreading from 1-4 am from south to north, the snow will turn heavy, quick for the area, now areas in EXTREME SE NJ and Eastern LI will change to sleet and rain quickly , but just north and west and throughout the rest of the area a prolonged period of heavy snow is expected, starting around 7-9 am as the low tracks up the coast it will bring in easterly winds which will push the mix line slowly northwest and we will see the snow slowly change to rain/sleet for all of southern NJ and eastern parts of Central NJ, however given the intensity of the system the mix line will slow down significantly approaching the I95 corridor leading to a very heavy thump of snow to start, it will slowly change to sleet/rain (now leaning towards more sleet/less rain with the dynamics in play here) and there may even be a dry slot tomorrow late morning into the mid afternoon which would keep any mixed precipitation mostly light and scattered for I95 and points just west.
A deformation band is then expected to form and run through the area with another round of moderate to heavy precipitation, with this round as the low slowly pushes away all areas who change to sleet or rain will change back to snow as colder air rushes back into the region including the immediate coast with additional accumulation late afternoon and evening , this band has the capability to be very heavy and may bring some off guard as again there will likely be a rapid drop in intensity of the precipitation during the afternoon
Winds will also increase out of the East and Northeast tonight and especially tomorrow as the storm gets cranking to our east, coastal flooding is expected and there could be isolated wind damage and power outages and wind gusts could reach 40-50 mph for much of the area and up to 60 along the coast, the peak of the wind would be tomorrow afternoon and evening.
This is the going map for now, again I will likely be making some slight adjustments later today.