An extended stretch of hot, humid weather with daily chances for thunderstorms is expected to last through Wednesday in New Jersey. The heat index — how hot it feels due to the combination of high temperatures and humidity — will be around 100 or more across the state except for areas along the immediate coast, forecasters say. A variety of heat advisories and excessive heat warnings are or will be in effect around the state. One round of thunderstorms rolled through the state Monday morning with the potential for additional rounds of heavy rain later this afternoon, especially in the northwes…