Discussion: Helene made landfall at Florida’s Big Bend as a category 4 major hurricane last night. Both winds and surge were catastrophic local to the landfall area while other Gulf Coast areas experienced damaging winds and extreme surge. Craploads of rainfall were realized before, during, and after Helene’s landfall across the entire US. A lot of troubling NC/SC imagery of rainfall aftermath yesterday and today. The SE US rainfall that preceded Helene’s arrival was due to a meridional upper jet alignment. This by itself caused flooding issues Wed into Thurs before the rainfall surrounding Helene’s immediate area even started Thursday night. And today it’s still dumping rain over parts of VA/NC/SC/TN/KY and a handful of other interior E US states. We’re talking about serious flooding in the mountains of SE US…dam failures, washed away roads and houses, etc. It’s a disaster for many with Florida’s Big Bend area being ground zero.
Helene has been downgraded to a tropical storm by the NWS NHC, packing just 45mph sustained winds. As of right now (Friday 2pm) the center of Helene has made it across Georgia from S to N and is just entering the TN/NC border area. The upper low (UL) that helped steer Helene during landfall will now absorb Helene’s remnant upper-level energy and everything will sort of park over the ~Kentucky area for this weekend. We also have the ridge to our N that is inhibiting any further N or E movement of Helene. You will now see extra-tropical transition as the overall satellite and radar displays of the US indicate more of a comma head with fronts rather than a closed off concentric circulation.
New Jersey is looking at two chances for some much-needed rainfall, especially SNJ/SENJ where it is droughting the most. First will be the remnant feeder bands that were supplying Helene. These are more immediate and should produce rain between basically now (Friday afternoon) and Saturday morning/afternoon. These bands however look to fizzle as they get to NJ. Remember the main energy is being ripped towards the UL over Kentucky and these bands will be moving from SW to NE right into the ridge/high pressure. So I wouldn’t count on significant rainfall…might just be more light rain/drizzle at times. Once these bands push through (by Saturday PM), NJ should see a lull for Sunday-Monday. It might remain on the cloudy side, especially SNJ, but little-to-no rainfall. The second chance for rainfall is when the central Helene remnants finally leave the Kentucky area and push eastward over the Mid-Atlantic US. This would be Monday night through Tuesday, possibly into Wednesday morning. Again, might not be significant. Could just be light rain/drizzle. But we’ll take whatever we can get. A cold front is then expected to clear everything out Wednesday into Thursday and set up a more traditional fall-feeling NJ weekend. Highs in the low-to-mid 70s. Lows in the upper-40s/50s. Low humidity and fall-looking clouds. We just need to get through the rest of this cloudy and unsettled pattern ending Tuesday night/Wednesday morning.
But as it stands right now, there is no expectation for violent hurricane remnants in New Jersey. The UL and ridge will prevent that from happening but might just allow enough remnants for some much needed rainfall. Clouds and humidity this weekend are a given. Rainfall amounts are uncertain.
Friday (Sept 27) high temperatures should reach the low-to-mid 70s for most NJ locations but with a very humid feel. The sun might pop out in NNJ here and there but CNJ/SNJ should remain cloudy with periods of rain possible, especially during afternoon/evening hours. Winds should be light-to-breezy out of the E/SE. Overnight lows should range from 60-70 from NNJ elevations to SNJ coasts with periods of rainfall persisting into Saturday morning.
Saturday (Sept 28) high temperatures should reach into the low-to-mid 70s for most NJ locations away from the ocean. SNJ and SENJ coastal areas could push slightly warmer into the mid-to-upper 70s. Clouds and humidity are expected with high confidence. The lower confidence forecast is the end time of rain beginning today (Friday). At some point the rain should clear out from SW to NE but clouds and E winds off the ocean should linger. Rain could end as early as 7am, as late as afternoon. Very uncertain since the rainfall is coming from very erratic, but fizzling, bands formerly feeding Helene. Overnight lows should again fall to the 60-70 range with clouds, humidity, and light passing showers possible.
Sunday (Sept 29) high temperatures should range from 65-75 from NNJ elevations to SNJ coasts. Sunday looks like a break day in this cloudy and unsettled NJ weather pattern. The sun should poke through again. NNJ should be clearer and dry-feeling. SNJ cloudier and more humid. Winds should be light out of the E/NE for most of NJ away from the ocean, breezy/gusty along the immediate ECNJ/SENJ coasts. Overnight lows should range from 55-65 from NNJ elevations to SNJ coasts.
An early look at next week (Sept 30-Oct 4) indicates the lull in rainfall possibly lasting into some of Monday (at least Monday AM). At some point, Helene’s central remnants will push through as a very weakened disturbance but enough to warrant more rainfall expectation through at least Tuesday night, possibly Wednesday morning. Then at some point between Wednesday and Thursday, a cold front will push all this crap out to sea and we’ll be back to typical NJ fall conditions. Have a great weekend and please be safe! JC
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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.™