Another heat wave officially arrives for much of New Jersey on Thursday with temperatures expected to be 90 or higher in most of the state for a third consecutive day.
Temperatures will soar in the upper 90s on Thursday and Friday with the heat index later this afternoon climbing as high as 104 along the Interstate 95 corridor, the National Weather Service said.
The extreme heat could lead to isolated thunderstorms developing this afternoon anywhere from the Lehigh Valley to Central Jersey, the weather service said in its morning forecast discussion.
“Severe risk is not high but …. (we) can’t rule out an isolated flooding event either,” the weather service said.
A heat advisory begins at 11 a.m. Thursday in 17 of the state’s 21 counties. It runs until 8 p.m. Friday in Bergen, Burlington, Camden, Essex, Gloucester, Hudson, Mercer, Middlesex, western Monmouth, Ocean, Passaic, Somerset and Union counties.
In Morris, Hunterdon, Sussex and Warren the advisory expires at 8 p.m. Thursday. Heat index values as high 101 are expected in those four counties.
Though there is no heat advisory for Atlantic, Cape May, Cumberland and Salem, the heat index is still likely to climb to 100 or higher on Thursday.

Forecasters say Thursday will be “dangerously hot” in much of New Jersey with a heat index of 100 or higher expected.National Weather Service
High temperature records for Aug. 4 will be threatened Thursday. Newark and Trenton are forecast to hit 98. The daily record for Newark is 100 in 1993. In Trenton, the temperature reached 98 in 1987.
Atlantic City’s high is expected to be 85, well short of a temperature record.
Friday will be another hot day with temperatures in the low-to-mid 90s and a heat index slightly lower than Thursday. Afternoon heavy rain is possible, but not certain.
The weekend looks generally dry, though forecasters haven’t completely ruled out a period of rain on Saturday. Highs will be in the upper 80s on Saturday and the low 90s Sunday.
Any rain would help the drought conditions much of the state is experiencing after a very dry July.
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Jeff Goldman may be reached at jeff_goldman@njadvancemedia.com.