1939 California Tropical Storm - Meteorological History

Meteorological History

On September 15, a tropical depression formed off the coast of Central America. It moved west-northwest, passing southwest of the Revillagigedo Islands. It then turned north and then north-eastward. For some time, it was a hurricane, and it lost that intensity on or just before September 25. The tropical storm made landfall near San Pedro, California early on September 25 with winds of severe gale strength. It dissipated later that day. The strongest reported wind was of Force 11, reported by a ship, making this system a minimal hurricane. The lowest pressure was reported by the same ship and was 28.67 inHg (971 mb).

Due to the rotation of the Earth, tropical cyclones in the Northern Hemisphere tend to move from east to west. This causes tropical cyclones to approach the West Coast of the United States infrequently. Another inhibiting factor for a California landfall is the water temperatures. Because of the water currents, the waters off California are rarely above 70 °F (21 °C), which is too cold for hurricanes to sustain themselves. This tropical cyclone was rare enough that only three other eastern Pacific tropical cyclones brought tropical storm-force winds to the Continental United States during the twentieth century. The Long Beach Tropical Storm was the only one to make landfall; the other three hit Mexico before moving north.