Yesterday on my Facebook page, I posted about the limitation of just looking at the radar to see when it will rain. I had gotten stuck behind three farm tractors for about ten miles on a country road on my way home from work and had time to really look at the sky while I was driving. It’s something I don’t really do while going 55 mph on a two-lane road, but I will do it while going well below 20 mph. I was watching storms grow to the south of the Triangle and noticed one cumulonimbus cloud had developed a nice anvil top by the time I arrived home. I parked in my driveway, looked at the radar and saw nothing.
The situation inspired me to post a reminder that the radar only shows you where the rain is at that moment – or at least, within a 6 minutes span of time containing that moment. The radar can’t show you where a storm cloud has developed but has not started precipitating.
Fast-forward to my drive into work this morning when I heard a news report on the radio about the storm on Lake Norman yesterday. Twenty-six people had to be pulled from the water after a “sudden storm” capsized their boats. Thankfully, all survived.
Now, I am sorry they experienced a dangerous situation on the water, but I have a problem with phrases such as “sudden storm” and “it hit without warning,” when used to explain weather-related mishaps. I need to remind myself as I feel my hackles rise that not everyone studies the sky the way weather geeks do. In fact, it often surprises me how the people around me respond to my reactions to what I see.
Instead of being defensive of the great job that meteorologists do in trying to prepare the public for the possibility of storms, which I admit is my normal reaction, I’ll take this moment to provide a little basic weather education. Let’s face it, if more people understood what they were seeing when they looked at the sky, we might have fewer news reports of capsized boats and lightning casualties.
First, I’d like everyone to take a moment to accept that no storm just materializes fully formed. It’s science, not magic. Every storm, whether severe or not, goes through the same basic life cycle stages. They all start as cumulus clouds and are created by warm, moist air rising from the earth’s surface.
With enough energy, those puffy clouds grow taller and become towering cumulus clouds. Around here, the tall, thin ones are sometimes referred to as “turkey towers.” These clouds consist mostly of updraft – that warm, moist air rising from the surface. The edges of the storm at this stage have a cauliflower look to them.
As the storm cell matures, it produces precipitation because what goes up, must come down. With the rain – and possibly hail – cooler air from the top of the cloud also drops from the storm. In a non-severe storm, you feel it as the cool breeze coming out of the cell. In a severe storm, that air can rush out at over 100 mph! The damage it can cause is worse that a small, weak tornado. A mature storm may have what we call an anvil top – a flattening out – if it’s powerful enough for the top of it to reach the tropopause.
At some point, the amount of air flowing out of the storm exceeds the amount of air flowing into the storm. In fact, the outflow can cut off the inflow. At that point the storm is dissipating, or weakening, and will soon die. Dying storms have softer edges as if an artist took a brush and blurred them a little.
For those who can’t quite visualize the lifecycle from my description, take a look at the graphic below from weather.gov, NOAA’s National Weather Service website.
Now that you can identify a threatening storm – meaning one that is reaching the mature stage, you can consider other factors in deciding what action to take.
- If you hear thunder, seek shelter. As the saying goes, “If thunder roars, go indoors.” If you are close enough to hear thunder, you are close enough to be struck by lightning.
- If the storm is moving toward you but you don’t hear thunder, seek shelter. There has to be a first lightning strike somewhere, and it might be too close for comfort.
- If the storm is moving away from you and you don’t hear thunder, you could still take the better-safe-than-sorry approach and head inside for a bit. The other option is to appreciate the beauty and energy of it while also putting your head on a swivel to look for signs of other storms in the area. Sometimes a storm is truly isolated – a single pop-up storm. More often, there is a forcing mechanism that is providing the energy for multiple storms – such as a leeside trough, a cold front, or a sea breeze. If you see one storm, be aware that there may be more forming.
I’m not concerned for my job security in sharing this information. Meteorologists can’t be everywhere, and we need an educated public in order to achieve our goal of protection of life and property from the weather. So, please, share this information with others. The more people who have a situational awareness of the weather and can identify a potential threat, the fewer news stories we’ll have with disastrous endings.