Discussion: The strong Arctic high that brought ridiculous cold temperatures to the region Sunday-Tuesday is now moving away from the E US coast. Therefore we’re at the mercy of strong southerly return flow. As strong as the front-side of that high was, which brought the cold down from the N, it is equally as strong behind it and that is why we are torching this evening. In addition to the high’s return flow, a cyclonic low is tracking through SE Canada which will add additional southerly umph to the flow. It you look at radar you’ll notice a strong moisture tap spanning all the way down to the Gulf of Mexico.
The 925mb and 850mb levels (~2500ft and ~5000ft) are very much above freezing and therefore there is zero chance of snowfall with this system. 99% of NJ is also above freezing at the surface which means rainfall without wintry concern. 1% of NJ (the highest elevations of Sussex County) however is holding near freezing so the concern for freezing rain has to at least be mentioned for safety. The freezing rain concern for said area will be over very quickly as the lower-levels continue to warm. But for a little bit overnight please be careful up there (near High Point Monument region) in case some rainfall makes it onto a 32F surface.
You might see some spotty drizzle/showers between now and the early AM hours of tomorrow. Rainfall should pick up after midnight and wrap up by late-afternoon tomorrow. Peak heavy rainfall should be between about 8am and 2pm tomorrow. Most precip has a convective nature especially closer to the Gulf. For that reason you may see/hear some lightning/thunder tomorrow morning during peak rainfall. Also winds are already picking up and will continue to intensify overnight. Expect winds to become very gusty by tomorrow morning out of the S/SW. We can thank the warm-sector jet for that. The 850mb jet is very impressive (in-excess of 70mph). With convective rainfall it’s not off the table for a few of those 850mb gusts to come down. Once the rain is through winds should switch to the W/NW…not as intense as when it was out of the S but still breezy-to-gusty. Back-end snow is an old wives tale but I’ve seen it happen after warmer rainstorms than this. Cold air is expected to return for the weekend.
In English: Expect rain and wind to pick up overnight. Rainfall should become heavy and winds should become very gusty by tomorrow morning. These conditions should last until tomorrow afternoon. Flash flooding and embedded thunderstorms are possible during peak conditions. In general about 1-2 inches of rain is expected to fall. Once everything clears out by late tomorrow afternoon, colder winds should return out of the W/NW. You might see some flurries when precip wraps up but wouldn’t hold your breath. Friday should be a half-step down to how cold it will be Saturday and Sunday. Tomorrow night’s weekend outlook will cover the weekend (obviously) and unsettled look to next week. Download the new free Weather NJ mobile app on Apple and/or Android. It’s the easiest way to never miss Weather NJ content. Have a great night and please be safe! JC
Jonathan Carr (JC) is the founder and sole operator of Weather NJ, New Jersey’s largest independent weather reporting agency. Since 2010, Jonathan has provided weather safety and forecasting services for New Jersey and immediate surrounding areas through the web and social media. Originally branded as Severe NJ Weather (before 2014), Weather NJ is proud to bring you accurate and responsible discussions ahead of high-stakes weather scenarios that impact the garden state. All Weather. All New Jersey.™