By Meteorologist Joe Martucci
The day-to-day hustle and bustle of the shore is slowing down. There are a variety of reasons for this: School is starting soon. In fact, some colleges are already in session.
However, on the weather side of the things, we’re in the best time to be outside, without fear of rain. It’s the driest 30-day stretch of the year. Add in the warmest waters of the year and we’re in for a wonderful stretch.
The driest time of the year began this week
Aug. 23 to Sept. 21 is the average driest time of the year at Sen. Frank S. State Marina in Atlantic City. On any day during this time, there’s about a 26% chance of getting a tiny bit of rain (one-hundredth of an inch), according to the National Oceanic and Atmospheric Administration.
However, there are some days that average is even drier. For example, on Sept. 5 and 6, the chance of rain drops to 19%.
It comes as no surprise. As the saying goes “Shiver on Memorial Day, sweat on the Fourth of July, smile on Labor Day.” More than likely, you’re smiling because your outdoor plans will be fine in the likely dry weather.
There are a few reasons for this stretch being so dry.
First, the afternoon and evening thunderstorms we see often in the summer drop significantly. This is because the sun is lower in the sky, directly heating the ground less. As a result, less air rises, which creates clouds and then thunderstorms.
Think of a flame under a pot of water. The bubbles from the boiling water are the thunderstorms. The higher the heat of the flame is, the more bubbles you have. As soon as you lower the heat, the bubbles lessen, even if the water is still hot. It’s the same concept for thunderstorms.
Secondly, the cold fronts responsible for rain aren’t as strong. The strongest cold fronts have the biggest clashes of warm air to the south and cool air to the north.
During the fall equinox, the Earth is not tilted as much. The temperature difference between the North Pole and the Equator are as small as they’ll be all year.
In New Jersey, the small difference between ocean and air temperatures keeps us drier, too. The average ocean temperature is in the low to mid-70s, and the air temperature isn’t much higher. Because of this, the sea breeze, which can cause thunderstorms, tends to weaken.
Now, to be fair, precipitation in New Jersey is spread out fairly evenly throughout the year. The wettest 30-day period is from March 18 to April 16, with a 37% chance of precipitation. Even though a 10% difference might seem small, it’s enough to notice. This is why we say “April showers bring May flowers.”
Dry, with one big exception
While this is the best time of year to plan outdoor activities without fear of rain, when it rains, it really rains.
Thank hurricane season for that.
Our driest time of the year falls right in the middle of our most active time of hurricane season, from mid-August to mid-October. Torrential downpours can bring inches of rain in a day, carrying massive amounts of moisture from the tropics.
New Jersey has a 31% chance of a tropical storm being within 50 miles of the coast, according to the researchers Colorado State University.
Even if a storm doesn’t directly impact us, the remnants of storms can bring widespread flooding. Ophelia in 2023 and Ida in 2021 are examples of that in the state.
Then there was Irene in August 2011, which brought 5 to 8 inches of rain in Cape May and Atlantic counties. The next year, Superstorm Sandy brought about the same in late October.
Shore Summer Weekend Weather Report Card
Threes company with our report card. For the third weekend in a row, it was a ‘B’ when it came to the weather.
Friday was an excellent day. Saturday and Sunday weren’t washouts. I figured it wouldn’t be, given the nature of the low-pressure system. However, with some showers, along with muggy air and cloud cover, it could have been better. Either way, it was more than passing.
That continues our 3.2 grade point average for the summer semester. In my seven years of the report card, we’ve never had a 3.2 to end the year.
Joe earned his Meteorology Degree from Rutgers University. He is approved by the American Meteorological Society as a Certified Broadcast Meteorologist and Certified Digital Meteorologist, the only one in the state with both. He’s won 10 New Jersey Press Association Awards. You can find him on social media @joemartwx
