NJ weather: Very nice for now, potentially nasty this weekend

The Bottom Line

I can not believe we are counting down the final days of summer. (The Autumnal Equinox — the official start of Fall — is coming up early Saturday morning at 2:50 a.m.) Temperatures are getting cooler. And days are getting shorter. In fact, Wednesday is Trenton's last 7 p.m. sunset until March.

We are in the middle of a beautiful stretch of September weather right now. Plentiful sunshine, low humidity, dry weather. Crisp, cool mornings and seasonable, comfortable afternoons. The pleasant conditions will last for a few more days — hopefully until the end of the workweek.

There is only one chance of rain in the forecast. But it is a doozy. A coastal storm system will parallel the Atlantic seaboard at the start of the weekend. And New Jersey could see some rain and wind. In fact, depending on the exact track of this thing, New Jersey could see a lot of rain and some serious wind gusts.

Even though the details are fuzzy, it is becoming clear that nasty weather is likely in the Friday night, Saturday, and Sunday morning time frame. Unfortunately, many outdoor plans are in trouble this weekend.

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Nice for Now

With a big dome of high pressure in control of our atmosphere, New Jersey will enjoy another gorgeous day Wednesday.

Temperatures are starting off on the cool side, in the 40s and 50s. Highs will reach the mid 70s Wednesday afternoon, just a touch warmer than Tuesday. There will be some clouds around early on, then sunshine wins out.

Wednesday night will be cool, back down to around the 50-degree mark.

And Thursday will be bright and sunny, with dry weather and highs in the lower 70s.

We will start to see changes on Friday, although most of the state will salvage quiet, dry weather during the daytime hours. Highs will come down to around 70 degrees, with increasing clouds.

Coastal Storm Setup

The storm system we are anticipating for this weekend doesn't even exist yet. And that is part of the problem with piecing together a confident forecast. Until we have something to "track," we have to rely solely on model forecast solutions, which can be all over the place. And in this case, there are wild differences among those computer models.

So here's what we know. A piece of energy over the Gulf of Mexico will spark a cluster of rain as it crosses Florida into the Atlantic Ocean. That area of low pressure will then organize, grow, and intensify as it parallels the U.S. East Coast through the rest of the week.

The exact impacts that we see here in New Jersey will depend heavily on the exact track of that coastal low. If it hugs the coast, we could see some serious rain and wind. A little farther east, and we don't.

It is important to note that I do not really see a complete "escape route" at this point. It's pretty clear that New Jersey will see at least some rain from this thing, with miserably cloudy skies and temperatures no higher than the 60s. (Keep scrolling to see the two potential storm scenarios that are in play.)

There is one other important detail to ponder: What to call this thing. I have settled on "coastal storm system" at this moment, which seems pretty descriptive and appropriate. But there is a chance that low pressure deepens enough and picks up tropical characteristics. In which case — if it's strong enough — it could become a named tropical storm. (In case you're wondering, Ophelia is the next name on the 2023 Atlantic hurricane list.)

"Best" Case Scenario: Wet

If our present dome of high pressure lingers around longer, it would steer the impending area of low pressure farther east. That is the out-to-sea direction. And that would put New Jersey on the edge of the storm, rather than in the thick of it.

We would still see rain, from Friday night to Saturday morning. On the order of an inch along the coast. Most like a quarter-inch (at the most) for western NJ.

But prolonged heavy rain, flooding, damaging winds, and the threat for severe weather would be mitigated in this scenario. It would just be wet.

FYI, this is the current situation depicted by the European (ECMWF) forecast model.

"Worst" Case Scenario: Very Wet & Windy

If the center of low pressure hugs the coast as it passes New Jersey, we would end up in the strongest part of the storm.

Rain would become very heavy Saturday morning, potentially dumping 1 to 2 inches in just a few hours. Additionally, even though there might be some lulls during the day Saturday, heavy rain would return by Saturday night, potentially pumping out another inch or two. Up to 3 or 4 inches of rain? Yeah, that's plenty to cause flash flooding concerns.

Wind gusts of 40 to 60 mph would be possible, especially along the Jersey shore. Coastal flooding, rough surf, and rip currents would be part of the conversation too.

In other words, it would be a tropical rainstorm. Nasty weather conditions would envelop New Jersey for about 36 hours.

FYI, this is the current situation depicted by the GFS ("American") forecast model.

The Good News: Sunday

Again, there's very little "middle ground" here and practically no chance for completely dry weather. It's either the "wet" or "nasty" scenario for the weekend. Boom or bust rainfall.

All model guidance is pointing to a drier Sunday though. While showers may linger as late as 8 a.m. Sunday morning, the rest of the day will feature clearing skies. It will still be breezy (if not windy). High temperatures should recover into the lower 70s.

Pleasant weather with calmer winds should prevail for Monday and Tuesday.

Dan Zarrow is Chief Meteorologist for Townsquare Media New Jersey. Follow him on Facebook for the latest forecast and realtime weather updates.