N.J. weather: Higher snow totals in latest forecast. Winter storm warnings expand to 10 counties.

Forecasts for the winter storm expected to dump up to 8 inches of heavy snow on New Jersey on Sunday have increased in the latest update from the National Weather Service.

“The forecast has trended colder and snowier,” the weather service said early Sunday just hours before the storm was expected to hit.

Gov. Phil Murphy has declared a state of emergency for all 21 counties starting at 8 a.m. Sunday.

Winter storm warnings have been expanded to now include all or parts of 10 counties – Bergen, Essex, Hunterdon, Mercer, Morris, Passaic, Somerset, Sussex, Union and Warren.

The biggest change in the latest snow forecast map is along the I-95 corridor, which is now included in the 6 to 8 inch forecast area that covers nearly half the state.

Sussex County could see pockets of 10 inches of snow at its higher elevations, the weather service says.

“Snow moves in late morning into the early afternoon (SW to NE) with the heaviest snow expected 4 to 9 p.m. during which time snowfall rates could exceed 1 inch per hour,” the weather service said in its final briefing before the storm.

The weather service has focused on the uncertain forecast for central New Jersey in the days leading up to the storm. A slight shift in the track overnight has pushed snowfall projections higher along those areas.

“Confidence is overall moderate (50-60%),” the weather service said. “There is still some uncertainty regarding precipitation and snowfall amounts with the system as well as how much mixing will occur.”

Winter weather advisories were also expanded overnight to now include parts of 11 counties as snowfall forecasts in southern New Jersey increased.

With the exception of the Jersey Shore, most of South Jersey could get 1 to 3 inches of snow, with higher amounts of 3 to 4 inches closer to the Delaware River.

The Philadelphia area is expecting 4 to 6 inches of snow, which will likely affect the NFL playoff matchup between the Eagles and Los Angeles Rams set for a 3 p.m. kickoff.

AccuWeather’s snow forecast has the northern half of New Jersey with 3 to 6 inches of snow except the northwestern corner in its 6 to 12 inch zone.

After the storm winds down on Sunday evening, temperatures will plunge and remain dangerously cold to start the week.

Expect “temperatures falling well below freezing Sunday night, and remain below freezing until at least Friday,” the weather service said.

Winter storm warnings

Hunterdon, Morris, Sussex and Warren counties from 1 p.m. Sunday through 1 a.m. Monday – Heavy snow expected. Total snow accumulations between 5 and 8 inches. Winds gusting as high as 35 mph. Roads, and especially bridges and overpasses, will likely become slick and hazardous. Travel could be very difficult. Areas of blowing snow could significantly reduce visibility. Snowfall rates to an inch per hour should develop at times this afternoon.

Mercer and Somerset counties from 1 p.m. Sunday through 1 a.m. Monday – Heavy snow expected. Total snow accumulations between 4 and 7 inches. Travel could be very difficult. Areas of blowing snow could significantly reduce visibility. Snowfall rates to an inch per hour should develop at times this afternoon.

Bergen, Passaic and western portions of Essex and Union counties from 1 p.m. Sunday through 4 a.m. Monday – Heavy snow expected. Total snow accumulations between 5 and 7 inches. Roads, and especially bridges and overpasses, will likely become slick and hazardous. Travel could be very difficult.

Winter weather advisories

Camden, Gloucester, Salem and northwestern Burlington counties from 10 a.m. Sunday to 1 a.m. Monday – Some mixed precipitation to snow expected. Total snow accumulations between 3 and 5 inches. Roads, and especially bridges and overpasses, will likely become slick and hazardous. Areas of blowing snow could significantly reduce visibility. The precipitation should start as a mix of light snow and rain with possibly some sleet before quickly changing to snow. Snowfall rates to an inch per hour should develop at times this afternoon.

Hudson, eastern Essex and eastern Union counties from 1 p.m. Sunday through 4 a.m. Monday – Snow expected. Total snow accumulations between 3 and 5 inches. Locally higher amounts up to 6 inches possible.

Middlesex County from 1 p.m. Sunday to 1 a.m. Monday – Snow expected. Total snow accumulations between 4 and 6 inches. Plan on slippery road conditions. Areas of blowing snow could significantly reduce visibility. Snowfall rates to an inch per hour should develop at times this afternoon.

Monmouth, Ocean and southeastern Burlington counties from 10 a.m. Sunday to 1 a.m. Monday – Some mixed precipitation to snow expected. Total snow accumulations between 2 and 4 inches. Plan on slippery road conditions. The precipitation should start as some light rain or a light rain, snow and sleet mix before changing to all snow. Snowfall rates up to an inch per hour should develop at times later this afternoon.

Dangerous cold temperatures

The snow from Sunday’s storm is unlikely to melt quickly as temperatures drop rapidly and will stay dangerously cold through the week.

Wind chills below zero are expected in parts of the state through Wednesday.

The coldest day could be Tuesday with highs in the teens and overnight lows in the single digits.

“The coldest period will be Monday night through Thursday morning,” the weather service said. “There will be an increased risk of hypothermia and frost bite. Impacts to infrastructure could include frozen pipes and increased demand for heating energy.”

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