Heavy rain and thunderstorms drenched much of Southern California on Thursday as a low-pressure system drew moisture from the subtropics up into the region at the tail-end of an otherwise extremely dry winter.

A flood advisory was issued for Los Angeles County as slow-moving storms dropped rain at rates up to a half-inch (1.27 centimeters) an hour.

The National Weather Service also posted lower level flash flood watches and flood advisories for much of the rest of the region.

Knott’s Berry Farm said it was closing early due to inclement weather.

The next weather system is expected to arrive in Northern California during the weekend and reach the south by Monday.

With spring just a week away, California precipitation levels have been running big deficits.

The U.S. Drought Monitor report Thursday showed more than 48% of California now in moderate drought and another 30% characterized as abnormally dry after January and February passed with precipitation far below normal.

Moderate drought covers most of the Central Valley and the Sierra Nevada, extending north to the Oregon border and west to part of the north coast, the San Francisco Bay Area and south to the Los Angeles and Central Coast regions.