San Diego County residents were surprised and alarmed by a rare tornado warning issued by the National Weather Service (NWS) on February 6th. The warning, which expired at around 12:15pm, covered parts like El Cajon, La Mesa and Santee.
It was triggered by a rotating column of air in a thunderstorm detected by radar. The storm also brought heavy rain, snow, and gusty winds to the region, causing flooding, power outages, and road closures.
A tornado warning is issued when a tornado is imminent or occurring, based on radar or eyewitness reports. It means that people in the affected area should take shelter immediately in a sturdy building, away from windows, doors, and outside walls. If no shelter is available, people should lie down in a low, flat area and cover their heads with their hands.
Tornadoes can be unpredictable and dangerous, especially when accompanied by other severe weather conditions. They are very rare in San Diego County, but not unheard of. The last time a warning was issued was in August 2023.
The storm that triggered the tornado warning on February 6th, 2024, was part of an atmospheric river, a long and narrow band of moisture that transports water vapor from the tropics to the mid-latitudes. Atmospheric rivers can produce heavy rainfall, snowfall, and strong winds, leading to flash floods, landslides, and debris flows.
The NWS advised residents to remain alert for possible hazards, such as downed power lines, flooded roads, and rockslides. The agency also urged residents to report any storm damage or flooding to their local authorities.
