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Various degrees of rain fall, from a steady drizzle to a heavy downpour, are demonstrated on the Rain Rate Visualizer. This is 1.5" per hour:
LA Pierce College Weather station indicates, as of 8pm pst, there had been 1.8" of rain in the last 24 hours. Pierce College Weather Station

WeatherUnderground gives historical data - indicating for the past 10 years February and February 13th has had significant rain only thrice, in 2024, 2023, and again in 2019.
Meanwhile, a video captured by local NBC affiliate demonstrate the power of a downpour upon the Los Angeles River system.