NJ weather: Showers and a cooldown, first widespread frost coming
The Bottom Line
It is remarkable how "gentle" this autumn has been so far in New Jersey. Usually, fall is full of big wind gusts, noisy thunderstorms, and huge temperature swings. However, aside from the early October mess caused by Ian's remnants, it has been a mild and peaceful season thus far.
Our next "gentle" transition arrives Monday, as a cold front approaches New Jersey. That will lead to an "unsettled" weather day, with occasional raindrops and clouds. But at least we'll hold on to seasonable temperatures for one more day.
As cooler, drier air arrives Monday night, we face three consecutive days of unseasonably cool temperatures. We're talking 10 degrees below normal for mid to late October. Furthermore, Wednesday morning could be the first widespread frost of the season for most of New Jersey.
Despite this week's stretch of "jacket weather," temperatures should moderate back into the 60s (at least) by next weekend.
On my drive to work early Monday morning, I experienced a 15-second downpour. That's pretty much the story of the day. Spotty to scattered showers. Hit-or-miss stuff. So you may need the umbrella and windshield wipers at times, but certainly not all day.
The grand finale round of rain, accompanying the actual cold front passage Monday evening, could spark some rumbles of thunder.
Otherwise, Monday will be mostly cloudy and seasonable. That means temperatures will be close to the long-term averages for this time of year. Morning lows are in the 40s and 50s. Afternoon highs should reach the lower to mid 60s. (Largely dependent on how much sun peeks through the clouds, and how much of the day is plagued by wet weather.)
Following that front Monday evening, skies will slowly dry out and clear out. (Especially after Midnight.) A brief period of breezy conditions is possible.
Overnight, Northwestern New Jersey only may drop into the 30s — cold enough for some patchy frost. I expect most of the state to bottom out in the still-chilly 40s.
What a difference. Tuesday will end up about 10 degrees cooler than Monday, with high temperatures limited to the lower to mid 50s. We may start the day with clouds and even some coastal sprinkles. But sunshine should dominate through the afternoon, as we tap into a very dry air mass.
As long as skies are clear enough and winds are calm enough, I still expect the first widespread frost/freeze of the season early Wednesday morning. That is, away from city centers and the coast, which naturally trend warmer at night.
Remember: It does not need to hit 32 degrees for frosty ice crystals to form. Because the coldest air pools in the lowest few inches of the atmosphere, 37 degrees is generally cold enough for frost to form.
So we'll start Wednesday in the frosty 30s. And only topping out around 50 to 55 degrees. The bottom of the barrel of this mini cold snap.
It will be mostly sunny and breezy Wednesday too.
Status quo, more of the same. If all goes well, a flip to southwesterly winds will make Thursday about five degrees warmer than Wednesday. My forecast puts highs in the 55 to 60 degree range. Again, mostly sunny and breezy. Not a bad day — just very autumnal.
Friday & Beyond
On Friday, the warmup will escalate even more, as temperatures push back into the 60s. It looks like skies will become mostly cloudy, as the atmosphere captures a little bit of energy and moisture. But I do not expect any rain.
Saturday should be beautiful, with highs pushing closer to 70 degrees under a mix of sun and clouds. Sunday has potential too, although the Euro model does try to spark some showers.
The tropics are quiet. And there's no threat of snow/ice on the horizon. (Yes, I need to say that regularly this time of year!)
Dan Zarrow is Chief Meteorologist for Townsquare Media New Jersey. Follow him on Facebook or Twitter for the latest forecast and realtime weather updates.