2018 has set rainfall records in the Philadelphia region — and the rain may not let up soon
Yes, it has been a very wet year. But unlike in past rainy years, there were no big storms to blame, just frequent showers. Blame the gulf stream — and climate change.
It rained on the final day of 2018.
It has been a soppy, sodden, spongy year that will float to the top of record books for many towns across the Philadelphia region. And, while the amount of precipitation in 2018 won’t set a record in Philadelphia — that infamy goes to 2011 — it will set records in Atlantic City, Wilmington, and Reading, to name just a few.
This was, however, a record setter for all of New Jersey, according to the state climatologist. And the same could be true for Pennsylvania once the numbers are crunched.
Another 2018 distinction: Rains weren’t driven by big weather events such as hurricanes or tropical storms. Rather, it was the steady drumbeat of downpours that led to the big deluge.
Philadelphia will likely end the year with just more than 61 inches, shy of the record 64.33 inches set seven years ago, according to data from the National Weather Service. But 2011′s record was due largely to Hurricane Irene and Tropical Storm Lee, both of which struck the Philadelphia region hard. This last year was marked by no-name nor’easters and a jet stream that favored conditions that produce wet weather on an ongoing basis.
That total comes from Philadelphia International Airport. Some sources also cite 67.4 inches for Philadelphia, but that’s an average based on multiple reporting sites.
“It’s just been a very moisture-rich atmosphere,” said David Robinson, who is New Jersey state climatologist and a Rutgers professor. “Everyone remembers just how darn humid it was this summer. The humidity and rain were just very persistent and recurrent.”
Robinson said 2018 will go down as the wettest on record for New Jersey as a whole, dating to 1895. As of Monday morning, before additional rains arrived, the state had averaged 64.49 inches of precipitation for the year. That beat the record of 63.95 set in 2011.
Atlantic City saw 67.90 inches before Monday’s rain. That bested the 65.80 inches that fell in 1948.
Robinson said there was a dip in the jet stream over the eastern part of the U.S. that introduced moisture up and down the coast in 2018, helping “bring a train of rain." But he also factors in climate change.
“The ocean surfaces and atmosphere have gotten warmer,” Robinson said. “So with that you have more moisture in the atmosphere. And the warmer atmosphere can hold more moisture.”
So, while climate change might not trigger a specific rainfall, it can magnify it.
Elsewhere, Wilmington blew by its record of 56.73 inches set in 2004. As of Monday morning, 60.68 inches of precipitation had fallen.
Reading was deluged this year with more than 67 inches of precipitation. The previous record, set in 1972, saw 56.85 inches.
A closer look at precipitation totals across the region shows just how soggy it has been.
For example, Philadelphia normally sees 41.44 inches of precipitation, which includes rain and the water equivalent of snow, in a year. In 2018, it got 20 inches more than that. Trenton will close out the year at 16 inches more than normal.
John Feerick, a senior meteorologist for AccuWeather.com, said it was possible it could also be the wettest year on record for Pennsylvania, but it was too early to call until all data are available.
“In a quick eyeball of the numbers, it looks like 2011 was wetter statewide,” Feerick said. “But this year is right up there, it’s real close.”
Some meteorological stations take readings at midnight. Others take them at 7 a.m., meaning it could take a day or two to get final data.
“So, it’s possible with today’s rain, 2018 could go down as the wettest year on record statewide,” Feerick said Monday.
"I know I’m tired of it, Feerick said of wet weather. “Hopefully, 2019 is drier.”
That of course, remains to be seen. Rain was expected to continue until about 4 a.m. New Year’s Day, which will see an unseasonable high of 61 degrees.
Friday, and Saturday bring the chance of more rain.