A winter storm is headed to Southern California, with rain, mountain snow and gusty winds expected to last through Wednesday.

Some light rain was possible after midnight Sunday, and most areas of Los Angeles and Orange County will experience substantial rainfall by Monday morning that will continue throughout the day and Tuesday, according to the National Weather Service. Showers are predicted to lighten on Wednesday, though they’ll still be intermittent.

Total rainfall could exceed 4 inches, according to the NWS’ Los Angeles office.

A drying trend is expected for the latter half of the week.

In the mountains, snow accumulation was possible Monday night at 6,500 to 7,000 feet, where forecasters predicted 6-12 inches, with local amounts up to 20 inches.

Wind gusts of 40 mph are expected Sunday night and Monday in the mountains and high desert, increasing to 55 mph Tuesday. The weather service advised motorists to “prepare for slick roads and wintry travel in the mountains,” as well as potential issues along the Grapevine on Tuesday night.

The wet weather will be accompanied by chillier days and nights.

Daytime temperatures are expected to drop into the low 60s in the valleys and the downtown Los Angeles area Monday through Wednesday, with lows in the 50s Monday and Tuesday and the lower 40s Wednesday, Thursday and Friday.

Wednesday’s highs are only expected to reach 58 in Pasadena and Santa Clarita and 53 in Lancaster.

The Antelope Valley will see overnight temperatures below freezing level later this week, with lows of 33, 30 and 31 degrees expected Wednesday through Friday.