UPDATE: School closings, delayed openings (Thursday, Feb. 9, 2017)

Most of Central New Jersey is now included in the areas of the state, along with North Jersey, expected to receive the heaviest snow Thursday in the latest forecast released Wednesday afternoon by the National Weather Service.

Forecasters are expecting snow to be falling hard -- perhaps as intensely as 2 inches per hour -- during the heart of the morning rush hour as a potent storm system brings the region its first significant snowfall since early January.

Although winds are not expected to be strong enough to classify the storm as a blizzard, forecasters say occasional gusts as high as 35 mph to 40 mph and heavy pockets of snow could make it tough for drivers to see at times. In addition, as temperatures drop as the day progresses, any melting snow or rain could freeze into ice.

The National Weather Service also says there could be occasional thunder during the storm. Known as "thunder snow," this happens during some major snowstorms when the atmosphere is unstable.

In its latest snowfall forecast, issued Wednesday afternoon, the weather service is still expecting 8 to 12 inches of snow across northern New Jersey but expanded that zone of heavy snow to now include most of central New Jersey.

This map, updated by the National Weather Service Wednesday afternoon, shows the latest snowfall projections across most of New Jersey. Projections for Bergen, Essex, Hudson, Passaic and Union counties are included in the map below. (National Weather Service)

Forecasters said a prolonged period of sleet could cut into some of the snow accumulations, but it's difficult to pinpoint how much sleet will fall when rain transitions into snow.

(Update: At about 9 p.m. Wednesday, the weather service made slight revisions in its official snowfall projections, calling for lower snow totals in Mercer and Monmouth counties -- 6 to 8 inches instead of 8 to 12 inches.)

Here's what the weather service is expecting in terms of the storm's timing and potential impact.

Timing: Snow is expected to start falling from 10 p.m. Wednesday through 4 a.m. Thursday, earlier in western regions of New Jersey and later in eastern sections. However, it will start as all rain from around the I-95 corridor and areas east of that.

Transition to snow: Rain is expected to change to snow between 1 a.m. and 7 a.m. from Interstate 95 to the east, and a mix of rain, snow and sleet is possible during that timeframe.

Heaviest snow: Expected from 3 a.m. to noon for most areas of New Jersey. Snow rates could get as heavy as 2 inches per hour at this time.

Ending time: Snow is expected to end between noon and 7 p.m., from western counties to eastern counties.

Warnings: Winter storm warnings are in effect for 18 of New Jersey's 21 counties from late Wednesday night through 4 p.m. Thursday, while winter weather advisories are active for Atlantic, Cape May and Cumberland counties from 8 a.m. to 2 p.m. Thursday. The weather service issued a blizzard warning for Suffolk County on Long Island, where as much as 14 to 18 inches of snow could fall and winds can gust as high as 45 mph.

Hazards/Impacts: The storm will pose "significant impacts to travel, especially for the Thursday morning commute, due to heavy snow, gusty winds, reduced visibility and snow-packed roads."

Ice threat: Driving could remain hazardous into Thursday night as "below-freezing temperatures are expected to continue," and any slushy or untreated surfaces could freeze up.

Potential for power outages: "The snow should be wet in consistency and therefore will tend to stick to trees and power lines, possibly resulting in some power outages. North to northwest winds will increase late tonight and Thursday with gusts in the 30-35 mph range."

This map, updated by the National Weather Service Wednesday afternoon, shows the latest snowfall projections across northeastern New Jersey, New York City, Long Island and Connecticut. A blizzard warning has been issued for Suffolk County on Long Island. (National Weather Service)

Len Melisurgo may be reached at LMelisurgo@njadvancemedia.com. Follow him on Twitter @LensReality or like him on Facebook. Find NJ.com on Facebook.