The storm system tonight will pack quite a punch, as the system rapidly strengthens off the coast of New Jersey and Long Island overnight. However, although the focus has been mostly on pinpointing the exact positioning of the heaviest snows, the main story throughout most of our area will actually be heavy rain. The rain will spread northward throughout the evening, becoming heavy at times throughout most of the area. Rainfall amounts could exceed two to three inches in some locations. As the system begins to move nearer to our area and pass to the east, cold air will slowly be drawn into the system. This process will be underway first over the interior, across Northwest New Jersey and Southeast New York (Orange County). Here, rain could mix with and change to snow after midnight and continue through Thursday morning. Farther to the south and east across the immediate suburbs, the transition will be slower to occur with only a brief period of snow expected (possibly some slushy accumulations). Nearer to the coast, the snow should be brief and at the very tail end of the system and no accumulations are expected. Pictured right: NAM Model showing the strong storm system affecting our area tonight. The left frame shows the energy at 500mb in the atmosphere, and the right frame shows the forecast surface pressure and thickness. 

EXPECTED TIMELINE OF EVENTS...


7:00pm - 10:00pm: Steady moderate to heavy rain across the area, falling temperatures. The temperature drop will be more rapid over the interior. Temperatures between 40 and 50, highest near the coast.

10:00pm - 1:00am: Moderate to heavy rain continuing across the area. Snow mixing in with the rain over the interior of Northwest NJ and Orange County, NY, and possibly changing to all snow in the highest elevations. Temperatures between 35 and 43, highest near the coast and near the city. Some isolated spots of higher temperatures (possibly in the 50's) on the New Jersey coast.

1:00am - 4:00am: Moderate to heavy rain over the New Jersey coast and Long Island. Moderate snow continues over the interior, then begins to work towards the immediate suburbs of New Jersey, Southeast New York, and Connecticut. Precipitation wraps up quickly thereafter. Some flakes could fly in the New York Metro as well, but no accumulations expected. Temperatures in the low 30's to low 40's, coldest in the interior and warmest near the coast.

4:00am - 7:00am: Gradual clearing, with some rain/snow mix still likely over Connecticut. New Jersey will be the first to clear out, from southwest to northeast. The precipitation should end in Connecticut around 8-10am. Temperatures in the low 30's to low 40's, coldest in the interior and warmest near the coast.

WHAT ABOUT ACCUMULATIONS?


Accumulations will be gradient-oriented throughout the area, meaning that there will be a sharp cutoff from west to east. The accumulations from this storm system should be relegated to the interior and elevated locations, but some areas even in Northeast New Jersey could see a coating of snow. The best chance for slight to moderate accumulations, as mentioned, will be over Western/Northwestern New Jersey (elevated areas of Warren and Sussex counties) and into Orange County, New York..where 2 to 5 inches of snow could fall by the time the event is over. Along the coast of New Jersey, New York (Long Island/NYC) and Connecticut, little to no snow accumulation is expected. We have included our final storm total snowfall forecast map to the left, which includes all the details on the expected gradient. It should be noted that a coating of snow is possible slightly east of where the "Slushy T-2" area cuts off.

 Article written by JH. Published December 7th, 2011 at 6:30pm. Looking for a forecast? Use our new Forecast Beta tool to see the latest forecast in your specific area for the upcoming week, or view our Technical Forecast Discussion for the more serious weather enthusiasts. Also, check out our new Forecast Overview tab. For up to the minute details on forecasts, watches, warnings, and alerts, follow us on Twitter and Facebook.