In 2021, we watched several thunderstorms march across the Valley, and numerous storms bubble up in the Sierra. We even had a funnel cloud report and a couple of cold air funnels. Along with lightning that accompanies every storm, we had flooding rain, hail, and gusty wind. With storms likely at some point in 2022, it’s always a good idea to brush up on severe weather safety.
First, let’s get familiar with the terms used to alert you of potentially dangerous weather.
Watch vs. warning
A watch can be issued for either severe thunderstorms or tornadoes. A watch means conditions are favorable for severe storms or tornado formation. You should be keeping an eye on the weather and be prepared for the development of storms.
A warning means there are signs that a severe storm or a tornado is occurring. This can happen either by looking at radar signatures that point to severe weather or by a confirmed report from someone. At this point, you need to take action to keep yourself and your family safe.
A tornado emergency is an intense version of a tornado warning. This is issued when a large and catastrophic tornado will have a high impact and will likely cause multiple fatalities. The first tornado emergency was issued on May 3, 1999, when an F5 tornado was moving through Moore, OK.
How do meteorologists decide if a storm is severe? There are criteria for that, and it changed in 2021.
First, a thunderstorm by definition is a rain-bearing cloud that also produces lightning. Lightning is dangerous, which means all thunderstorms are dangerous. However, damage to life and property can occur with stronger thunderstorms, earning them a “severe” title.
A severe thunderstorm used to be classified as a storm with at least one of the following:
- Hail of at least .75″ in diameter (1″ threshold for areas more prone to hail)
- Wind of at least 58 mph
- A tornado
The new criteria is divided into three categories of damage: base, considerable, and destructive.
Base damage threat is a relatively unchanged version of the severe thunderstorm warning criteria we are used to. Either 58 mph wind, and/or 1″ hail (quarter size) is required to issue this warning.
Considerable damage threat is the next category. These storms will be capable of wind of 70 mph and/or 1.75″ hail (golf ball size).
And the strongest category is destructive. These storms will potentially have 80 mph wind and 2.75″ hail (baseball size). This category requires urgent action, as the storm may be life-threatening. This destructive category will activate a Wireless Emergency Alert (EAS) on your smartphone
How to stay safe
If you hear thunder, you are close enough to be struck by lightning. Lightning can strike over 10 miles away from a storm. This means the sky over you could be blue, but you could be in danger. Being outdoors is unsafe when there’s lightning. Move indoors, and brings pets with you.
Once you’re indoors, stay away from windows. Avoid plumbing, including showers and toilets. Lightning can travel through plumbing. Lightning can also travel to electrical outlets. Avoid using plugged in electronics during storms. Landlines are also unsafe to use. However, cell phones are safe.
If you are caught outside without an enclosed building, a hardtop vehicle is the next best option. If that isn’t available, get to the lowest elevation you can find. Crouch down into a ball with only your feet on the ground. Never lie down flat on the ground. Don’t use an isolated tree for shelter, and stay away from rock caves or rocky overhangs.
And finally, tornadoes aren’t unheard of in Central California.
If a tornado warning is issued for your area, you need to take shelter immediately indoors. If you have a basement (not a crawl space), this is the best option. In most homes, however, you’ll need to find an interior space away from windows and outside walls. Think about putting as many walls as you can between yourself and the outdoors.
Under stairs, or an interior hallway or bathroom are the next best options after a basement. If you have blankets or helmets, put them near your tornado safe place before the storms develop so they’re ready to be used if you need to take shelter.
Please take severe thunderstorm and tornado warnings seriously, and stay safe.