Keep those umbrellas handy. Even though Thursday is shaping up to be a beautiful summer day in New Jersey, forecasters say Friday and early Saturday could be marred by cloudy skies, occasional showers and isolated thunderstorms.
The remnants of Tropical Depression Cindy, which made landfall down in southwestern Louisiana as a tropical storm Thursday morning, are expected to merge with a cold front that’s moving toward New Jersey from the Great Lakes, bringing unsettled weather conditions to the Garden State on Friday and early Saturday, said Sarah Johnson, a meteorologist at the National Weather Service’s regional forecast office in Burlington County.
“It’s certainly possible we could get some heavy rain,” Johnson said, but it appears the heaviest bands of rain may be confined to eastern and central Pennsylvania.
The weather service’s Mid-Atlantic River Forecast Center is predicting a half-inch to 1 inch of rain across most of New Jersey on Friday and Saturday, and 1.5 inches or more in parts of Pennsylvania.
The latest forecast map from the U.S. Storm Prediction Center has most of New Jersey under a marginal risk for severe thunderstorms on Friday. Marginal is the second lowest of risks on a six-point scale and means isolated severe thunderstorms are possible, with small hail and winds gusting to 40 mph to 60 mph.
With a southerly flow of air, temperatures across New Jersey will be rising into the mid-to upper 80s on Thursday and Friday, creating some instability in the atmosphere as tropical moisture starts moving in, Johnson said.
Late Wednesday, a line of strong thunderstorms swept through parts of central and southern New Jersey, toppling trees and power lines in several towns and generating scary-looking shelf clouds over the Jersey Shore. Wind gusts as high as 57 mph were reported in Long Beach Township on Long Beach Island during the thunderstorms, and a gust of 53 mph was reported in Cape May.
Coastal flood advisory
Unrelated to the tropical moisture that’s heading this way, a coastal flood advisory is in effect from 5 p.m. to 9 p.m. Thursday along Raritan Bay, lower Delaware Bay and the Atlantic coast, from Sandy Hook down to Cape May. Johnson said waves will be higher than normal because of the astronomical effects of Friday’s new moon.
“Wave heights on the ocean waters off the coast are forecast to be 3 to 4 feet,” the flood advisory says. “Wave heights on lower Delaware Bay are expected to be 1 to 2 feet.”
As a result, some local roads are expected to face minor flooding, and some could be temporarily closed, the weather service said.
Air quality alert
The state Department of Environmental Protection has issued an “air quality action day” for Camden, Cumberland, Gloucester and Salem counties because of high levels of ground-level pollution.
“Ozone is forecast to reach the unhealthy for sensitive groups category in southern portions of New Jersey due to calm recirculating winds, mostly sunny skies, and hot temperatures,” the alert says. “Sensitive individuals including the very young, the elderly, and persons with respiratory diseases such as asthma, should avoid strenuous outdoor activities during the afternoon and early evening hours. In addition, fine particles are expected to reach the moderate category in urban locations due to increasing temperatures and humidity.”
The alert is in effect until 10 p.m. Thursday.