Today the ingredients are coming together for a rather nasty storm to hit the forecast area and really all up and down the east coast including the Appalachians up through SE Canada, it will bring a wide variety of weather, anywhere from snow to sleet, from rain to freezing rain and of course wind , our forecast area will be dealing mostly with the rainy side of this storm, I guess we can call it a nor’easter.
For today the cold air will remain in place with highs in the upper 20s to mid 30s for the area, however this evening clouds will begin to increase so temperatures will not fall much overnight with mid 20s to low 30s expected, still cold for this time of year but not nearly as cold as this mornings lows, which by the way many locations yesterday broke records for record cold high temperatures including Newark NJ , Central Park, Philadelphia and many more
Anyway, in the above radar image we see the northern jet stream and sub tropical jet beginning to interact, and an early phase is beginning to occur thanks to lack of blocking and the presence of a weak SE ridge , if this phase occurred just a tad later this would have been much more wintry for the area. But these 2 are beginning to interact and we will see a low begin to develop along the gulf coast soon , if it not already occurring, this will pull up copious amounts of Gulf moisture as we can see on the radar.
The storm is expected to track NE from the Gulf along the eastern side of the Appalachians through Eastern PA somewhere between NE PA and NW NJ while intensifying nicely, which will mean a east-southeast wind for a lot of the area and thus mostly rain, and a lot of it at that
As the storm begins to really get its act together we will see the precipitation shield expand through the day and tonight and clouds will increase from south to north tonight and that will give way to developing showers by late tomorrow morning through the mid afternoon, the precipitation will gradually become steadier and heavier and along with increasing wind we will have an all out storm by tomorrow night
Precipitation Type :
NE PA/NW NJ- Start as snow, quickly change to sleet and freezing rain with minor accumulation (1-2 inches snow ) probably no significant ice accumulation before the changeover the heavy rain occurs, the precipitation may end as snow as well and lead to a quick 1-2 inches
Rest of the area- Easy forecast for the rest, rain followed by rain and ending as rain with maybe a few snow flurries or snow showers behind the main storm Wednesday night into Thursday morning, no accumulation expected
The true wintry part of this will be west of the forecast area from the Central Appalachians to Western PA and from Alabama up through Upstate NY where many folks will see a significant snowfall generally between 4-12 inches through these areas with a little battle zone of ice in between the Rain and snow areas, likely setting up over the Central Appalachians and into southeastern sections of Upstate NY , im going to make an impact map on this later on today or tonight with more details
Back to our forecast area
Above is the onset of the precipitation , we can see temperature prfiles support snow nowhere besides extreme NW NJ and the Poconos
As the heavier precipitation is arriving and the low comes closer we have increasing southeasterly winds driving warm air throughout the region this is especially true for NJ, NYC metro, Philadelphia metros as the low passes west of these areas and we are warm sectored, its still cold in NW NJ/NE PA but not cold enough
As the heaviest precip is coming in and low begins to enter the area we have strong southeast winds driving very mild air into much of the forecast area, again especially true as you head farther east but even the Poconos eventually warm into the 40s
Here is the peak of the storm, Wednesday afternoon with VERY strong south-east winds driving into the coastline and very heavy rainfall as well, if it rains to the magnitude that many of our short-range models show flooding may become a concern too
Finally as the storm is exiting we can see the potential for a changeover to snow over the higher elevations, especially in NE PA where IF and that’s a big IF the cold air can come in quick enough behind the storm , there’s many times where the precipitation dries out too quick to interact with the cold air with these types of storm so its a volatile forecast for our high elevations but even if it does change over it would be maybe 1-3 inches at most
The highest threat for the rest of the area will be strong winds and very heavy rainfall with winds 20-30 with gusts up to 50 along the coast line then 15-25 mph with gusts up to 40 elsewhere, im still sticking with a 1.5-3 inch rainfall around the area with the highest amounts expected towards north-east sections of the area like Connecticut , Massachusetts etc, this is a general consensus between the global models and the short-range models with the global models showing more of a 1-2 inch rainfall and short-range models showing a widespread 3-4 with locally higher amounts, the short-range models have a tendency to over do amounts but on the other hand we have a lot of moisture at play here
Here is the HPC precipitation forecast showing a widespread 2-4 inch rainfall up and down the east coast so with rainfall amounts like this coming in a relatively short period of time some flooding, especially localized urban or flash flooding will be possible.