If you don't count the out-of-season snowstorm this past October, it's been nearly a year since New York City and surrounding area(s) were impacted by a moderate snowstorm. Things will change beginning tonight and continuing through Saturday. A winter storm is on it's way, and it will deliver a moderate snowfall  for most of the area, including much of New Jersey, New York City, Southeast New York, Connecticut, and Long Island. Almost all areas should see at least some snow from this system, with a majority of the area likely seeing 2 to 5 inches of snow.  That being said, forecast models still indicate a bit of a "battle ground" of sorts over New Jersey as warmer air works in over the mid levels of the atmosphere. This will bring sleet and potentially freezing rain into the forecast over Central New Jersey and portions of the New Jersey shore by later Wednesday morning..as well as possibly working towards Southern Long Island. Where this specific boundary sets up will determine where the heavier snow falls, and which areas have their snowfall totals hampered by mixed precipitation. Our latest snowfall forecast map is posted to the right -- but we've got the down and dirty details on the storm below. 

Watches and Warnings: The National Weather Service has issued Winter Weather Advisories for the entire forecast area for the potential of 3 to 6 inches of snow, with 4 to 8 inches in some areas. Click the above link for text and details.


Rest of tonight:  By evening, clouds begin to increase...lower...and thicken. It will start "feeling like snow" as some would say. Radar images could start to indicate snow by 10pm, but most of that will be "virga" (or radar indicated precipitation that doesn't reach the ground) due to the dry air at the low levels of the atmosphere.

11:00pm Friday - 2:00am Saturday: Overcast skies, with the potential for flurries in the air. After midnight, light snow begins from west to east. Areas of moderate snow will begin to move eastward from Pennsylvania and begin affecting Western New Jersey.

2:00am Saturday - 6:00am Saturday: Moderate snow throughout the entire forecast area. Localized areas of borderline heavy snow are possible in some locations. Snow should begin to accumulate, but will take longer to do so in the city and near the immediate shore due to southeast winds off the water.


6:00am Saturday - 11:00am Saturday: Moderate snow continues throughout most of the area. Over Central New Jersey, the New Jersey shore, and the South Shore of Long Island...snow may begin to mix with sleet or freezing rain. Elsewhere, moderate snow will begin to show signs of tapering off from west to east...especially over Western New Jersey.


11:00am Saturday - 3:00pm Saturday: Snow ends from west to east, possibly ending as sleet or graupel as far north as New York City. The snow will be slowest to end over Connecticut and Long Island, and could continue into the afternoon there. Skies will gradually clear by around 8pm.

STORM OVERVIEW, ORIGIN, AND CONCERNS...

This storm system is unique in it's origin and track/strength. It certainly does not fit the mold of the storms we have been experiencing over the past several years. Instead, it's moving towards our area from the southwest. The storm is actually relatively weak, but the gradient in the pattern (between warm and cold) will create enough lift for precipitation. The surface low pressure is expected to track from the Plains, through the Central US, and then towards the Ohio Valley. Here, the storm will meet resistance from a disturbance to the north (and at the surface, a building high pressure). This will force the storm to slide east/northeast and re-develop off the coast (if it didn't, we'd be looking at a rain storm). The nature of the event also ensures it will be relatively quick, and that high snowfall amounts are out of reach. Still, the potential for 6 inches in some locations is remarkable for this winter so far. Pictured left: NAM model showing the storm system at the surface (left) and the precipitation (right). Notice the weak and strung-out nature of the surface low.

In terms of what could go wrong, our focus is on the potential for mid level atmospheric warming. This event is originating from our southwest, and southwest winds in the atmosphere are helping to bring the system towards us. However, these southwest winds are advecting warm air towards the area as well. So, we are all watching carefully for the potential for this warm air to make it slightly farther north than forecasted by most guidance. If it did, the cold upper levels and warm mid levels would mean snowflakes could form, but would melt to liquid in the warm layer as they fell. Finally, at the cold surface (where we are)...they could re-freeze into sleet or freezing rain. This "warm tongue" as we call it in meteorology is currently not forecast to make it farther north than Central New Jersey. But forecast models aren't perfect--and can sometimes be off with their forecast of these features. We will be watching very carefully. Pictured right: Our snowfall probabilities table, including percentage chances for 1, 4, 6, and 8 inches of snow at several locations.