Ice and snow to affect Monday morning commute
A storm system will affect New Jersey all day Monday, with a treacherous mix of snow, freezing rain, sleet, and rain.
While this system is NOT a major winter storm, the storm and its associated cold front will make for a complex and potentially messy weather day. Temperatures both at the surface and up in the atmosphere will hover right around the magical freezing point of 32 degrees. Here is how I see the day playing out.
By about 2 am Monday morning, the first snowflakes and/or raindrops from this storm are expected in the southwest corner of the state. The precipitation will then spread to the north and east throughout the early morning hours. For most of the morning, temperatures across most of the state will likely be cold enough for a wintry mix of snow, sleet, and freezing rain. (The exception would be along the coastline of Ocean, Atlantic, Cape May, Cumberland, and Salem counties, where the storm will likely produce only rain all day.)
By about 5 am, I expect most (if not all) of New Jersey to be under light precipitation. Through the morning, the wintry mix that falls will be mostly light, and will likely take the form of sleet and/or freezing rain for North and Central Jersey. Unfortunately for commuters, it won't take much freezing rain to make for some very slippery roads.
By about 10 am, temperatures at the surface and aloft will warm above the freezing point, so we will start a slow transition from wintry mix to all rain. That transition will begin in South Jersey in the late morning hours. By early afternoon, Central and North Jersey will transition to all rain.
Through the afternoon, some pockets of atmospheric energy will cause some of the precipitation to pick up in intensity for a brief time. As long as the previously mentioned warming trend occurs on schedule, this would be moderate or heavy rain, and not frozen precipitation. However, if colder temperatures hang on longer than expected, heavy snow, sleet, and/or freezing rain would continue to make travel sloppy through the afternoon.
The final phase of the storm will occur as the trailing cold front passes through New Jersey on Monday evening. The quick cooldown of all layers of the atmosphere will possibly lead to some light snow on the backside of this system. No major accumulation is expected, although I could see an inch or two collecting on the ground in far North Jersey.
By 10 pm Monday evening, all precipitation should be done, or at least rapidly winding down.
I expect everyone in New Jersey to feel some impact from this storm. As I mentioned above, much of South Jersey (particularly along the coast) will likely be under liquid rain all day.
From the Philadelphia metro area up through Central Jersey, wintry mix will cause minor icing for the morning commute, and then change over to rain by late morning.
The "sweet spot" for this storm will likely be in a belt between I-78 and the top of the state, as significant icing may persist through most of the morning, followed by a changeover to rain in the early afternoon.
Because of the icing impacts, and the unfortunate timing of this storm during Monday morning's commute, the National Weather Service has issued a Winter Weather Advisory for most of the state.
I am fairly confident about the impacts with this storm: wintry mix will affect the morning commute, we'll see a changeover to rain at some point, followed by a potential switch back to snow as the cold front passes at night.
The big question mark at this time is how fast and how far will that warm air transact the change from wintry mix to rain. If it happens faster than forecast, a quicker switch to rain will make for a less slippery ride to work on Monday. If the warm air moves slower than expected, we could see wintry mix persist through the afternoon, making for poor road conditions for the evening commute.
As always, we will continue to monitor this ever-evolving weather situation, and provide updates online and on-air.