Meteorology

Storm-chasing for science can be exciting and stressful – we know, because we do it. It has also been essential for developing today’s understanding of how tornadoes form and how they behave. In 1996, the movie “Twister” with Helen Hunt brought storm-chasing scientists into the public imagination and inspired a generation of atmospheric scientists. With the new “Twisters” movie hitting theaters, we’ve been getting questions about storm-chasing – or storm intercepts, as we call them. Here are some answers about what scientists who do this kind of fieldwork are really up to when they race off after storms. Scientists with the National Severe Storms Lab ‘intercepted’ this tornado to collect data using mobile radar and other instruments on May 24, 2024. National Severe Storms Lab What does a day of storm-chasing really look like? The morning...

When tropical meteorologists peer at satellite images, they often catch sight of subtle cloud formations hinting at something more ominous brewing. The first signs of a potential hurricane can be detected days before a storm gains its fierce momentum. Wispy cirrus clouds radiating outward, the appearance of curved banding low-level clouds and a drop in atmospheric pressure are all clues. These early clues are crucial for predicting the onset of what might develop into a catastrophic hurricane. I am a meteorology professor at Penn State, and my research group uses satellites and computer models to improve forecasting of tropical weather systems. With an especially fierce Atlantic storm season forecast for 2024, being able to detect these initial signals and provide early warnings is more important than ever. Here’s what forecasters look for. Hurricane Harvey entered the Gulf of Mexico as a tropical wave before reorganizing into a tropical storm a...

As the weather warms, people spend more time outdoors, going to barbecues, beaches and ballgames. But summer isn’t just the season of baseball and outdoor festivals – it’s also lightning season. Each year in the United States, lightning strikes around 37 million times. It kills 21 people a year in the U.S. on average. For as often as lightning occurs – there are only a few days each year nationwide without lightning – there are still a lot of misunderstandings about nature’s largest spark. Because of this, a lot of people take unnecessary risks when thunderstorms are nearby. I am a meteorologist who studies lightning and lightning safety, and a member of the National Lightning Safety Council. Here are some fast facts to keep your family and friends safe this summer. What is lightning, and where does it come from? Lightning is a giant electric spark in the atmosphere and is classified based on whether it hits the ground or not. In-cloud li...

It’s been a warm day, maybe even a little humid, and the tall clouds in the distance remind you of cauliflower. You hear a sharp crack, like the sound of a batter hitting a home run, or a low rumble reminiscent of a truck driving down the highway. A distant thunderstorm, alive with lightning, is making itself known. Lightning flashes in thunderstorms at least 60 times per second somewhere around the planet, sometimes even near the North Pole. Each giant spark of electricity travels through the atmosphere at 200,000 miles per hour. It is hotter than the surface of the sun and delivers thousands of times more electricity than the power outlet that charges your smartphone. That’s why lightning is so dangerous. Lightning kills or injures about 250,000 people around the world every year, most frequently in developing countries, where many people work outside without lightning-safe shelters nearby. In the United States, an average of 28 people were killed by lightning ev...

Hurricane Helene caused deadly and destructive flooding when it swept through the Southeast on Sept. 26-29, 2024. Across a broad swath of western North Carolina, where the worst flooding occurred, the amount of rainfall exceeded levels that would be expected on average only once every 1,000 years. But this wasn’t the first 1,000-year rainstorm in North Carolina this year. In mid-September, an unnamed slow-moving storm produced more than a foot of rainfall closer to the Atlantic coast. This storm inundated areas that had already been drenched by Tropical Storm Debby in August. As atmospheric scientists and state climatologists, we believe it’s important for the public to understand the risk that extreme events may occur. That’s especially true as climate change alters the conditions that create and feed storms. Here’s how scientists calculate storm probabilities, and why events like a 1,000-year storm can happen much more frequently in some places than tha...