As the first significant winter storm of the season bears down on the Garden State Sunday morning, here’s what to expect from the two-phase system set to coat New Jersey in a mix of snow, sleet, rain and ice.

The National Weather Service reported in its 6 a.m. Sunday update that while expected snow totals have decreased slightly around the state, North Jersey (Route 78 and north) should still prepare for significant snowfall Sunday morning into Monday night.

The service has lowered its snowfall totals to 6 to 8 inches for Sussex County, 3 to 4 inches for Morris and Warren Counties and less than an inch below Middlesex County.

A winter storm warning is in effect for Bergen, Passaic, Sussex, Warren and Morris counties from 4 a.m. Sunday to 1 a.m. Tuesday.

Snow is expected to begin as early as 7 a.m. Sunday morning in North Jersey before turning to rain later in the day. Then, late Sunday into Monday, the storm will again become snow throughout much of the state, with potential to snarl both morning and evening commutes. Significant airport delays are also expected Sunday.

The service says ice will develop on elevated surfaces, bridges, overpasses, trees and wires sooner than it will on roads and walkways.

A new briefing with updated forecasts will be released by the National Weather Service at 5 p.m. Sunday. Gov. Phil Murphy will give a storm press conference at 10 a.m. Sunday.

Bobby Olivier may be reached at bolivier@njadvancemedia.com. Follow him on Twitter @BobbyOlivier and Facebook. Find NJ.com on Facebook.