A wild weather forecast for NJ: Warm, then wet, then wintry
Another blast of arctic air is just around the corner for the Garden State.
Fair warning: The forecast over the next four days is incredibly active, and quite tumultuous. I will warn you that the precise details — temperatures and rain totals, for example — are fairly low confidence. Therefore, in this post, (and on-air too), I'm going to focus on timeline, trends, and overall impacts.
Even though the sky will be full of clouds, Thursday looks like a fantastic mid-January day. I believe most of New Jersey will see high temperatures in the lower to mid 50s, which is 10+ degrees above normal for this time of year. Some (but not all) forecast models paint North Jersey as a bit colder Thursday afternoon. All models show the Jersey Shore to be held in the 40s at best, due to the cold influence of the bays and ocean. Meanwhile, I wouldn't be surprised to see a 60 degree temperature reading in inland South Jersey.
Thursday daytime should stay dry, but rain showers look to arrive after Midnight Thursday night. I'm confident in declaring it'll be rain (and nothing wintry), as increased humidity will prevent overnight temperatures from falling below about 50 degrees.
Band of steady, potentially heavy rain will push through New Jersey on Friday. While timing is up in the air, downpours could impact part of the AM and/or PM rush hour. Persistent showers, drizzle, and patchy dense fog will make for a pretty damp Friday overall. I'm not calling it a washout though — it is not going to rain all day.
Meanwhile, amidst the raindrops, our January thaw will peak with high temperatures soaring into the upper 50s to lower 60s. We will be close to record high temperatures — which, interestingly enough, were mostly set last year. ('Tis the season for unseasonable warmth?)
The warmth will be nice. And we really do need the rain. But there are several potential issues from this springlike combination:
--The combination of warm temps and heavy rain will lead to rapid snowmelt. At the very least, the ground is going to be a slushy mess.
--Many storm drains are still blocked by last week's snow and ice. Rain and melt water may have nowhere to go, causing ponding and flash flood issues.
--Oceans, bays, canals, rivers, streams, and creeks are iced over from our extended cold snap. As that ice melts, it will flow downstream and potentially "jam" against bridges, banks, or other chunks of ice. That can cause water to backup and rise further upstream, again leading to a flooding risk.
--Patches of dense fog will reduce visibility, potentially obstructing the easy flow of traffic.
One more batch of steady, heavy rain is expected Saturday morning as the center of this storm system passes by New Jersey.
Then a cold front will open the door to the arctic once again. Even though thermometers will hold close to 60 degrees through early Saturday, temperatures will start to plummet: in North Jersey around 5 a.m. and in South Jersey by around 10 a.m. It will get breezy, but not terribly gusty — my forecast shows gusts to 30 mph.
As colder air arrives, a quick hit of wintry mix (mainly sleet and freezing rain) will be possible Saturday morning. The best chance for icing will be in northwestern New Jersey. Although I wouldn't rule out some "sleety" showers and sprinkles throughout the state through the rest of the day too.
Temps will fall below freezing right around sunset Saturday, setting up a "flash freeze" situation. Any puddles leftover from Saturday morning's rain could rapidly refreeze as sheet of ice Saturday night.
By Sunday, we will have officially returned to the frigid side of the world. Morning lows potentially in the teens (with colder wind chills). Afternoon highs around 30 degrees. Sigh, I hope your heavy winter gear is still easily accessible.
With colder air in place, we'll have to keep an eagle-eye on the horizon for potential winter storms. The next such threat will come in the Tuesday-Wednesday time frame, but it's way too early for details. The GFS model paints a few inches of snow over New Jersey, while the Euro is slower and much heavier (showing some double-digit snowfall). Again, worth watching, but that's it for right now. If warranted, we'll start to obtain some forecast clarity over the weekend (not before).