Election Day in New Jersey looks to be a rainy one, with patchy precipitation in the late morning giving way to thunderstorms in the afternoon. The weather pattern will be dominated by a frontal boundary and associated thunderstorms moving through the state from west to east, with the heaviest precipitation likely in the midday and afternoon hours.   However, skies are expected to clear into the evening hours, especially after 6 p.m.     

For North Jersey, including Sussex, Warren, Hunterdon, Somerset, Passaic, Morris, Bergen, Essex, Hudson, and Union counties: 

Patchy drizzle and fog will linger over the region early tomorrow morning, gradually transitioning to patchy showers and thunderstorms through the late morning hours. Current high resolution model forecasts show the transition will begin around 8 a.m. north of Trenton and rapidly propagate north and east, with more consistent precipitation reaching Sussex, Passaic, Bergen, Hudson, and Union counties shortly after 9 a.m. Temperatures will generally be in the mid-40s, increasing into the mid-50s by late afternoon. 

Around 10:00 a.m., humid air over North Jersey will become increasingly disturbed by an approaching line of thunderstorms moving east out of the Ohio Valley. Heavy, drenching rains will form from west to east, covering the entire region just before noon. The primary line of thunderstorms will follow shortly after, potentially preceded by a slight lull in rainfall. This line will cross the Delaware around 1 p.m. and sweep steadily eastward, reaching western Passaic, Morris, and Somerset counties by 2 p.m., and finally passing through Bergen, Passaic, Essex, Hudson, and Union counties by 3 p.m. or slightly later. Temperatures will increase to the low 60s throughout the passage of the storm system. 

There is some uncertainty regarding the integrity of the storm line as it moves through the area, and it is possible the southern extremity of the line could dissipate from south to north. As a result, thunderstorm activity may taper off in Union and Essex counties before 2 p.m. Regardless of the exact timing of the storms’ passage, weather in the evening hours will gradually improve from west to east, rainy conditions transitioning to partly cloudy skies between 5 and 6 p.m. Temperatures in the evening will remain in the low 60s to high 50s.    

For Central Jersey, including Middlesex, Monmouth, Mercer, northern Ocean, and northern Burlington counties: 

Temperatures will start out in the low 50s, with patchy drizzle overspreading the region around 8 a.m. Humid air lingering over the area will rapidly become disturbed by the approaching line of thunderstorms and begin transitioning into scattered thunderstorms from west to east, with the first storms forming along the Delaware by 9 a.m. and reaching the coast by 10 a.m.  

Unlike in northern counties, it is not clear that the primary line of thunderstorms moving east out of the Ohio Valley will be intact when it reaches Central Jersey. However, portions of Mercer could see storms associated with this line around 1 p.m. In any case, with temperatures slowly increasing into the low 60s by midday, scattered thunderstorms will likely persist over the entire region from 10 a.m. to 4 p.m. By 6 p.m., residual showers will give way to partly cloudy skies. Temperatures are expected to remain in the low 60s through the remainder of the evening. 

For South Jersey, including southern Burlington, southern Ocean, Atlantic, Camden, Gloucester, Salem, Cumberland, and Cape May counties: 

The morning will start with cloudy, humid conditions and temperatures in the mid-50s. Around 6 a.m., patchy drizzle could overspread the region, light rain likely after 8 a.m. Compared to the rest of the state, precipitation in South Jersey will be more sporadic, with thunderstorms firing up anytime between 9 a.m. and 4 p.m. The greatest chance for downpours will be in the late morning hours, although a portion of the primary thunderstorm line moving across the state could impact the Philadelphia suburbs around 1 to 2 p.m.  

Temperatures during the day could reach 70 in spots, with rainfall generally tapering out across the region by 6 p.m. Skies will rapidly clear in the evening hours, and temperatures will fall back to the mid-50s by 10 p.m.