NJ weather: Two nice late summer days, then a big cooldown
The Bottom Line
We are still eyeing Thursday as a big weather transition day for New Jersey. That is quite appropriate, since Thursday is the first day of fall. (The autumnal equinox will occur at 9:04 p.m.)
Before the transition, our weather looks great. Temperatures and humidity levels will scale back from Monday's summerlike conditions.
During the transition, scattered rain and thunderstorms are likely. Thursday will not be a total washout. But also not a nice day.
After the transition, cool fall weather takes over for at least Friday and Saturday. Morning lows in the 40s. Afternoon highs only in the 60s. Get the jacket ready.
As of this writing (5:30 a.m.), a weak cold front is introducing a new air mass in New Jersey. So Tuesday will not be as hot, nor as humid as Monday. (Which may have been NJ's last 90-degree day of the year.)
Temperatures are mainly in the 60s to start the day, with some spotty areas of shallow fog around. (Especially to the south and east, ahead of the front.)
The rest of Tuesday will be mostly sunny, with a refreshing northwesterly breeze at times. High temperatures are forecast to reach the upper 70s to around 80 degrees. That is decidedly cooler than Monday. But still a hair above normal for mid-to-late September.
So overall, a great weather day. Tuesday night will stay comfortable, with mainly clear skies, light winds, and low temps around 60.
I got nothing. Like so many recent days, Wednesday will be beautiful.
Look for a mix of sun and clouds, with high temperatures again near 80. Humidity will rise slightly higher than Tuesday, leading to just a hint of stickiness in the air.
I had previously suggested that rain could enter New Jersey as early as Wednesday evening. But all model guidance has now slid our approaching cold front slower and later. While wet weather may creep in after Midnight Wednesday night, most raindrops will fall during the day Thursday.
Bottom line: Not a nice day, as a strong cold front drives in some rain and wind and then cooler air.
Rain and clouds will push into northwestern New Jersey pre-dawn Thursday, eventually traveling to the southern coast through the afternoon. It will not be an "all day total washout," but I think everyone in New Jersey has a shot at some rain. Also, nothing crazy like severe weather or flooding, although rain could be steady for a time with some rumbles of thunder.
The timing of steadiest rain is still a little hazy. But I'd wager that the morning hours will be the wettest part of the day.
Temperatures are tricky too. North Jersey will be the first to experience clouds, rain, and cooler air — so we may be stuck in the 60s all day. For most of the state, we'll see highs in the 70s. In far southern New Jersey, 80 is a possible on Thursday — if clouds and rain hold off until midday or afternoon.
Behind the rain and the frontal boundary, skies should start to clear by sunset Thursday. And temperatures will start to fall sharply, as the coldest air of the season (so far) arrives.
The first full day of fall will fully feel like fall. (Wow, try saying that 10 times fast.) Friday will be positively October-ish, in fact.
Morning lows in the 40s (away from cities and coast). Afternoon highs only in the mid 60s. It will be sunny, but also breezy. The day may even have a blustery feel.
Yup, jacket weather is coming soon.
The Extended Forecast
On Saturday, conditions will moderate a little bit. Partly sunny skies will meet lighter winds, with high temperatures closer to 70 degrees. Still unseasonably cool. But if you're a fan of fall weather, here you go. A great day for football, soccer, and any of those autumnal outdoor activities.
And then on Sunday, we warm up again. Thermometers swing from five below normal to five above normal, with highs near 80. Again, I'll call it partly sunny.
Another storm system is showing up in model guidance for early next week, centered around the Monday time frame. There are some big question marks here. Could we see raindrops as early as Sunday night? Could wet weather linger into Tuesday too? Will tropical moisture get involved, pushing rainfall totals past 2 inches?
Early next week could turn into a real soaker, although that is not guaranteed at this point. Just "the next thing to watch" at this point.
Dan Zarrow is Chief Meteorologist for Townsquare Media New Jersey. Follow him on Facebook or Twitter for the latest forecast and realtime weather updates.