By Reginald Stanley. Posted February 21, 2020, 6:03 PM.

A low pressure system began spreading increasing clouds across the region Friday afternoon, along with sharp drops in temperature and windy conditions.

Showers and a slight chance of thunderstorms are forecast to impact the region shortly after midnight and throughout the day Saturday. Precipitation totals are not expected to be particularly significant, mainly between 0.2 and 0.3 inches across the valleys. Locally heavier amounts may result from orographic lift or thunderstorms. The chance of thunderstorms first becomes evident late tonight near the coasts, spreading inland by Saturday afternoon as the cold center of the low passes over the region. According to the National Weather Service, lightning is already being detected near the center of the low about 400 miles west of San Diego this evening. Snow levels are forecast to start around 7,000 feet above sea level tonight, lowering to roughly 5,500 feet by Saturday afternoon.

Weak offshore flow is expected to develop Monday, strengthening throughout next week under high pressure building over the Great Basin.