Forecasters have warned California residents that unsettled weather through Thursday is likely to bring heavy rains, strong winds and mountain snow as another atmospheric river moves down along the West Coast. Another storm will threaten the region early next week.

While forecasters warned on Tuesday to begin preparing for inclement weather, the National Weather Service’s San Francisco Bay Area office said that the heaviest rainfall will begin around the Wednesday morning commute for some areas and toward the afternoon farther south down the coast. Flooding and downed trees will be the most common hazards.

Flooding concerns, like overwhelmed storm drains that can lead to road closures, will be widespread, and the heavy rain that falls could create localized areas of flash flooding, with urban areas, roads, small streams and burn scars the most vulnerable, forecasters said.

The storm is predicted to be a moderate atmospheric river, and nowhere near the strength of an “Ark storm,” as has been making the rounds on social media in the past few days. Nor is the forecast likely to be anywhere near as severe as the series of back-to-back storms last winter that led to widespread flooding and historic amounts of snow in the region.

This midweek storm, while still having the potential to produce flash flooding and heavy mountain snow, is expected to move quickly, which would reduce the amount of rain that falls over any one location.