Possible March 25th-26th Coastal Storm

Mother Nature may be trying to end this winter with a big bang in the Northeast region of the U.S. with a possible coastal storm looming for early next week. Of course, a lot of uncertainty exists with the exact track of this storm, but I am confident that a storm will develop. Now it's just trying to figure out if it will be a storm for the fishes or one we will have to worry about, which would bring heavy snowfall and high winds to the area if it took a track close to the coast.

The above graphic is the 500 mb level 12z EURO model around Monday morning. 

One important thing to note with the setup for early next week is the sub-tropical jet stream (STJ) will be an ingredient to the evolution of the storm. A stream of energy will travel through the STJ and feed into the coastal storm. A poleward ridge in the west (+PNA) connecting with the ridge over Alaska (-EPO) will help bring down extremely potent northern stream energy which digs into the eastern U.S. and phases with the STJ energy to form the coastal storm. 

Moving forward with the 12z EURO, it closes off the H5 trough which allows the coastal storm to get pretty close to the coast, bringing moderate snow accumulations to the area. Any closer to the coast, this would be a substantial snowstorm with blizzard-like conditions given its extreme strength and size. 

The one thing working against a possible Nor'easter is the fact that there is no high latitude blocking, or         -NAO. Low heights continue to reign over Greenland which means the flow along the east coast is progressive. If the phase is timed correctly and a High Pressure system positions itself where the EURO currently projects it to be, there will be a storm along the east coast bringing snowfall to the region. That is a big if though and there still remains a lot of uncertainty with how strong the energy coming out of Canada will be, and how much interaction it has with the southern stream energy. 

The GFS and Canadian models also develop the coastal storm. The GFS has it well east of the area coast since it phases the storm much later than the other models. However, if you look above, some of the GEFS individual members show some pretty big hits and the GEFS mean itself brings .50-.75 qpf into the area. This is indicative to me that the GFS OP is playing to its progressive bias and it may eventually catch onto the other models and come further west with the storm over the weekend. 

The purple zone are the areas I feel are in line to see coastal storm impacts come Tuesday of next week. I do think there will be snow, but I am uncertain about how much will fall. Could be a coating to a few inches or it could be much more. Snow will not be the only thing to worry about, though. Coastal flooding and high winds will also be possible impacts. 

The blue zone may also feel coastal storm impacts but the phase will have to occur much sooner than where current guidance has it to be. This is definitely possible still, but with the progressive pattern along the east coast, I could see how only the immediate coast benefits from this storm. If the NAO were negative I would feel differently. 

Nothing is set in stone yet and the models have been pretty horrific of late. Just realize that the potential for a big storm is there early next week with very cold temperatures (much below normal for this time of year). 

Enjoy your weekend and follow along at www.njstrongweatherforum.com for the latest information

Frank