With heavy rain and winds pounding the Inland Empire this week, many have taken to social media to express their concern about so-called tornado weather.
But how likely are tornadoes in the Inland Empire?
Tuesday, the National Weather Service did receive reports of a funnel cloud over San Bernardino, but tornadoes — when a funnel cloud makes contact with the ground — are not a common occurrence in Southern California.
“They are rare and they don’t happen very often,” said Mark Moede, a meteorologist with the National Weather Service.
All the ingredients — moisture and instability — were in place Tuesday and Wednesday to allow funnel clouds to form, however a funnel cloud touching down and becoming a tornado is sparse.
Even when funnel clouds do reach ground and become twisters, like the brief tornado that touched down in the Victorville and Apple Valley area May 7, Moede noted California is lacking in several elements that would allow the tornado grow to Tornado Alley proportions.
“We’re lacking in certain atmospheric parameters that prevent tornadoes from becoming as huge and destructive as in the plains,” he said. “Nevertheless, although the tornadoes here can be weak, they can briefly reach wind speeds of 80 mph. An 80-mph wind is enough to damage poorly constructed buildings and do some damage to homes.”
There is an area in Riverside County, though, that is known for damaging storms.
The Elsinore Convergence Zone, as it’s been called, stretches from the eastern slope of the Santa Ana Mountains near Lake Elsinore through Perris toward the San Jacinto Mountains and is prone to violent storms.
In 2008, a large storm in the convergence zone spawned four tornadoes, golf-ball-sized hail, raging winds, heavy rain and flooding that damaged 28 homes. One tornado crossed I-215 north of Perris, knocking over a tractor trailer and badly injuring its driver.
Despite the factors being ripe for birthing a funnel cloud and potentially a tornado, Moede said a bigger concern for residents in the Inland Empire is flash flooding.
“So yes,” Moede said Wednesday morning, “today there is a small potential for a brief tornado, though the biggest threat will be thunderstorms and rain heavy enough for street flooding to occur. That will be the biggest concern today.”
Authorities advise residents to be prepared and to keep checking weather reports if they notice a significant change in the weather. They also warn people not to walk or drive through moving water.