Central California Coast at Risk of Rare Tornadoes Occurring as Severe Atmospheric River Persists in the Same Area

Today's central California Coast faces a rare tornado threat as once again, another severe atmospheric river event takes place there.

From Santa Cruz and Monterey down to areas in Goleta and Santa Barbara, the Storm Prediction Center of the National Weather Service in Norman, Oklahoma, is monitoring the potential for severe thunderstorms as well as isolated tornadoes.

California Forecast

The Storm Prediction Center (SPC) predicts that several mid-level impulses will pass through California today. During the morning and early afternoon, the first upper impulse will pass over California, bringing with it little buoyancy and a chance of widespread thunderstorms.

An occurrence of severe weather cannot be ruled out later in the day when a second, stronger mid-level impulse approaches the California coastline with comparatively more buoyancy and sufficient lift and shear to encourage the development of potentially strong thunderstorms.

The SPC cautions that there may be sufficient atmospheric components present to support the risk of a damaging wind gust or possibly a brief tornado due to the presence of strong low-level and deep-layer shear.

Tornadoes do occasionally occur in California, but they hardly ever affect this region of the state or arrive at this time of year. There are 11 tornadoes on average in California each year; the majority strike the northern half of the Central Valley in the spring and fall.

By tonight, there shouldn't be as much of a risk of damaging thunderstorms and tornadoes, but as atmospheric river events continue to affect the state, more heavy rain is likely in the days to come, according to Weatherboy.

Rare Tornado

In recent weeks, California has experienced an incredible parade of powerful storms, and another storm with even greater potential is expected to hit today. As the latest in a string of Atmospheric River events slams into the US West Coast, parts of California are expected to experience epic rain measured in feet, rather than inches, and snow measured in yards.

Now, there is also the chance of a rare tornado with this severe weather.

The National Weather Service defines a tornado as a rapidly rotating column of air with a circulation that reaches the ground and is typically pendant to a cumulonimbus.

It frequently begins as a funnel cloud and sometimes has a loud roaring sound. It is the most harmful of all atmospheric phenomena on a local level.

Wedge tornadoes are large tornadoes with condensation funnels that are at least as tall (vertically) from the ground to the base of the clouds as they are wide (horizontally) at the ground. Large tornadoes of any size are frequently referred to as "wedges" in a loose sense. But not all-powerful tornadoes are wedge-shaped. It is extremely uncommon to see a true wedge tornado, which has a funnel that is at least as wide as it is tall.

Although violent tornadoes, which are either F4 or F5 on the Fujita Scale, frequently accompany wedges, many recorded wedges were rated lower. And some dangerous tornadoes might not look like wedges. Other than intensity, a tornado's chance of becoming a "wedge" depends on a variety of factors, including the height of the cloud base in the surrounding area and the presence of moisture below it.

Therefore, spotters should not solely rely on visual appearance to determine wind speeds or F-scale ratings. However, it is generally safe to assume that the majority of wedges, if not all of them, can cause severe or violent damage.