LOS ANGELES (CBSLA) — The torrential rain hitting Southern California after a week of already heavy rainfall has forced two theme parks to close Thursday.

Six Flags Magic Mountain in Valencia and Knott’s Berry Farm in Buena Park both announced on Twitter that they would close Thursday due to inclement weather.

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The Santa Ana Zoo also said it would close Thursday due to the rain.

The heavy rain also forced Santa Anita Park in Arcadia to cancel today’s eight-race card, which had been set to happen at 1 p.m. The racetrack’s superintendent says Santa Anita has taken on 3.5 inches of rain since Monday, and that two more inches of precipitation were forecast for Thursday afternoon.

Santa Anita will remain open for simulcast wagering.

Disneyland and California Adventure in Anaheim, and Universal Studios in Universal City remain open.