Early-morning showers should be the extent of the wet weather Sunday as the heat and humidity climb. Tropical air will be present for a mostly dry Monday. Then, we turn to Tuesday, when Hurricane Isaias likely will bring some impact to South Jersey.
A few showers will be present until 8 a.m. Sunday as a warm front passes through the region. Low temperatures will start in the 70s. On Friday, Atlantic City International Airport set the active record (15) for the longest streak of days with a low temperature of 70 degrees or greater. And Saturday morning only dropped into the low 70s, so the streak extends. Sen. Frank S. Farley State Marina in Atlantic City is in fourth place with 25 days, and that streak also will live on.
It was the second hottest July since records started at the airport in 1943. That also makes it the second hottest month of all time. The marina also sweltered through the fifth hottest month and the fourth hottest July since records started in the 1870s. While there was no extreme heat near 100 degrees, 16 of the 31 July days were above 90 at the airport. Of course, the low temperatures felt more like South Florida than South Jersey. The marina was warmer at night than Palm Beach and Big Cypress, Florida, among others, throughout the month.
Turning back toward the forecast, Sunday in South Jersey will feel awfully like Florida. Mainland highs will be in the low to mid-90s, feeling like the triple digits during the afternoon. Dew points will be sticky, in the low 70s. At the shore, we’ll get a bit of a sea breeze providing some relief in the mid- to upper 80s.
I’m hopeful that most of us will be dry after those early showers. Storms, potentially bringing damaging winds and even a weak tornado, will flare up, associated with a cold front. However, they should stay west of the New Jersey Turnpike.
Sunday evening will be very mild, sliding through the 80s. As the cold front approaches, a few showers and storms will pass through after midnight. These will end around 8 a.m. Most look dry, though, and given the nighttime timing, the severe weather should be limited. Monday morning lows will be in the mid- to upper 70s.
Monday looks to be a dry day as Iasias picks up speed as it moves onto or near the Southeast. This often happens in these setups, as dry air is “exhaled” by the tropical system. It will be mostly cloudy, but that will cap the heat into the mid- to upper 80s for highs.
Now, let’s turn to Iasias. If we need them, tropical storm watches would be up Sunday morning or midday, with a tropical storm warning Monday morning or midday. This would be the time to prepare. A reasonable worst- case scenario is six hours of tropical storm force conditions at the shore.
However, the rip current risk will be high Sunday and last through Wednesday. Seas will begin to build Sunday as well. Coastal flooding, already expected to be in spotty minor flood stage Sunday, likely will be on a widespread basis for one to three rounds between Monday night and Wednesday morning. Thankfully, we’re talking minor to perhaps moderate flood stage.
The rain will be the biggest impact from the storm. It should begin as early as the overnight hours Monday and last through Tuesday. Two to four inches of rain looks like a good bet, but the placement is highly dependent on the track of the storm.
WATCH NOW: Latest update for Isaias in South Jersey
Where is Isaias now? Where is the forecasted path?
New Jersey remains in the forecast cone. Options from a graze up the coast to an inland track near the Delaware River are possible. Tropical storm warnings extend from Boston, down the I-95 corridor to Myrtle Beach, South Carolina.
It is important to note that the heaviest rain will be to the west of Isaias' center. Meanwhile, the strongest winds will be to the east.
The forecast has narrowed, with a few changes
As more data comes in and the storm gets closer to South Jersey, the timing of the storm has narrowed, along with a few small changes.
First, the storm has been slower to move. Eventually, it will speed up. However, the storm will still only be near the Florida-Georgia line Monday morning.
For South Jersey, this means impacts will be centered around Tuesday, likely during the afternoon. However, heavy rain could begin Monday night. Rain and dangerous rip currents increasingly look to be the biggest local impacts from this storm, similar to Tropical Storm Fay in July.
The reason for this is in part due to a high-pressure system that also has been responsible for the track of the storm so far. This extends into Florida, which prevents Isaias from moving too quickly to the north. Hence, the slowdown in the forward speed, at least until it reaches near Georgia.
So what do we know will happen in South Jersey? What about this "Predcessor Rain Event?"
As of Saturday, expect the following in South Jersey.
Dangerous rip currents: The rip current risk was moderate Saturday and will likely become a high risk Sunday, lasting through Tuesday and slowly declining for the rest of the week.
Rip currents are caused by breaks in the sand bar. Water escapes quickly through them, dragging swimmers out to sea. During Tropical Storm Fay, an 18-year-old New York man drowned while saving two others in the waters.
Heavy rain: Where the most rain will fall still needs to be worked out. However, it is increasingly likely that 2 to 4 inches of rain will fall somewhere in the region as Isaias moves closer.
Even though the closest approach to the center of the storm will occur Tuesday, likely in the afternoon, there is increasing concern that the heaviest rain will come before the storm passes, Monday night into Tuesday morning. The storm will eventually get picked up by an upper level-low pressure system in the Midwest, which will sweep it up to sea.
This would enhance rainfall and bring areas of roadway and river flooding. Flooding at the shore would occur even before the tides become higher, similar to what occurred with Tropical Storm Fay. Known as a Predecessor Rain Event, they occur before tropical cyclones move nearby.
Coastal Flooding: The full sturgeon moon Monday alone will brings areas of minor flood stage to the Saturday and Sunday p.m. high tides.
However, combined with Isaias, 1 to 3 rounds of coastal flooding will be likely. Coastal flooding likely will be in minor or moderate stages and would occur between the Tuesday morning and Wednesday morning high tides.
Minor flood stage is the nuisance flooding that occurs many times during the year. While roads my be flooded and closed, no damage to homes or businesses is likely. In moderate flood stage, water inundation into homes and businesses is possible.
What is still left to be determined?
The track ultimately will determine the possibility and severity of all impacts. Specifically, though, this is what remains to be seen.
Will there be tropical storm force winds? Isaias is not a large storm. It will essentially be a pinball in the pinboard machine of the East Coast. According to the National Hurricane Center in its 11 a.m. update, hurricane force sustained winds, over 74 mph, only extend 25 miles from the center. Tropical storm force winds, over 39 mph, extend 115 miles from the center.
More specifically, tropical storm force sustained winds extend 115 miles from the northeast side of the storm. On the western side, the side South Jersey will most likely deal with, winds that strong only extend 30 miles on the southwest side, to 100 miles on the northwest side.
If needed, tropical storm watches would go out Sunday morning, indicated that now is the time to prepare. The watch would turn into a warning Monday morning or midday.
How much coastal flooding will be seen: One to three rounds is likely, but the severity of which will be tied to the path and speed of the storm. A storm going 25 to 30 mph near the region, which is expected, yields hope for potentially just one widespread round of flooding.
Remember, heavy rain will likely cause flooding issues, with or without coastal flooding.
Will there be storm surge? The answer is likely to be yes, barring a storm track on the western edge of the forecast cone, which would then make this a remnant storm by the time it reaches South Jersey. 1 to 2 feet of surge is a good bet for now Tuesday.
More about Isaias' path, which could bring a second landfalling storm
All options within the forecast cone are possible. In fact, the center of the storm could be out of the cone, which indicates the two-thirds probability of where the center would be.
A track along the western edge of the forecast cone would bring a primarily torrential rain event, along with dangerous rip currents, but with no other significant impacts. This would mean landfall in Florida and the Carolinas, bringing a remnant storm and losing the tropical characteristics.
A track on the eastern side of the forecast cone would mean a tropical storm, possibly even a hurricane. Marine hazards would be high and coastal flooding would be likely. However, for many, it would bring low impacts.
Models have converged on a close-to-shore solution for South Jersey, possibility making it the 11th tropical system to make landfall in South Jersey since 1900 and the first time two storms have made landfall in the same year. A landfall near Brigantine or Long Beach Island is not ruled out since the islands jut out from the landmass.
The close-to-shore track would bring roughly 6 hours of tropical storm force winds.
How do you say Isaías?
"Isaías" is the Spanish and Portuguese word for the biblical Isaiah. It is pronounced ees-ah-EE-ahs.
For more context on Isaías and the 2020 hurricane season
The Press of Atlantic City's Hurricane section of the Weather Center has the information you need to know to protect yourself and learn more about tropical systems in South Jersey.
Ten tropical storms and hurricanes have made landfall in South Jersey since 1900. Here's the list, newly updated with Tropical Storm Fay, which made landfall July 10. As long as the storm makes landfall in New Jersey, it will be the first time with two storms making landfall within the same year.
An active 2020 hurricane season was predicted by Colorado State University. With Isaias, 2020 continues its record breaking pace to hurricane season, beating out the historic 2005 year.