by Fighting a storm for science can be exciting and stressful – we know, because we do it. It was also necessary to develop today’s understanding of how tornadoes form and how they behave.
In 1996, the movie “Twister” introduced storm scientists into the public imagination and inspired a generation of atmospheric scientists.
As the new movie “Twisters” hits theaters, we’re asking questions about storm chasing – or storm intercepts, as we call them.
Here are some answers about what scientists in this type of fieldwork will actually do when they head out after storms.
What does it really matter on a stormy day?
The morning of a chase day starts with a good breakfast, as there may be no chance of eating a good meal later in the day. The team looks at weather conditions, National Weather Service computer forecast models and predictions from the National Oceanic and Atmospheric Administration’s Storm Prediction Center to determine the target.
Our goal is to figure out where tornadoes are most likely to occur that day. Temperature, humidity and winds, and how these vary with height above ground, provide clues.
The end of “hurry up and wait” is before the day of the storm. We want to get into position quickly, but then we are often waiting for storms to develop.
Storms often take time to develop before they can produce tornadoes. So we watch the storm carefully on radar and with our eyes, if possible, stay far ahead of it until it matures. Often, we will watch multiple storms and look for signs that one may be more likely to generate tornadoes.
As soon as the mission scientist declares deployment, everyone scrambles to get into position.
We use many different tools to track and measure tornadoes, and there is an art to determining when to deploy them. Too early, and the tornado might not prove where the instruments are. Too late, and we’ve lost it. Each instrument must be in a specific position relative to the tornado. Some must be deployed well ahead of the storm and remain stationary there. Others are mounted on cars and driven back and forth within the storm.
If it goes well, the team members will focus on the incoming data. Some weather balloons will be launched at different distances from the tornado, while others will place “pods” containing weather instruments directly in the path of the tornado.
A complete network of observation stations will be set up across the storm, with radars collecting data from multiple angles, photographers capturing the storm from multiple angles, and instrumented vehicles traversing the main areas of the storm.
Not all of our work is focused on the tornado itself. We often focus on areas around the tornado or within other parts of the storm to understand how the rotation forms. Theories suggest that this rotation can be generated by temperature variations within the storm’s precipitation region, which could be many miles from where the tornado forms.
Through it all, the teams stay in touch using text messages and software that allows us to see everyone’s location compared to the latest radar images. We are also watching the forecast for the next day so we can plan where to go next and find hotel rooms and hopefully a late dinner.
What do all those tools tell you about the storm?
Weather radar is one of the most important tools of storm chasing. It captures what is happening with precipitation and winds above the ground.
We use different types of radar, usually attached to trucks so we can move quickly. Some transmit with a longer wavelength that helps us see further into a storm, but at the expense of a wider beam width, resulting in a blurry picture. They are good for gathering data throughout the entire storm.
Smaller wavelength radars cannot penetrate as far into precipitation, but provide the high-resolution view necessary to capture small-scale phenomena such as tornadoes. We placed these radars closer to the developing tornado.
We also monitor wind, air pressure, temperature and humidity along the ground using various instruments attached to moving vehicles, or by temporarily deploying stationary arrays of these instruments in advance of the storm. I approach Some of these are meant to be hit by the tornado.
Weather balloons also provide vital data. Some are designed to go up through the atmosphere and capture the conditions outside the storm. Others go through the storm itself, measuring the important temperature variations in the rain-cooled air below the storm. Scientists are now using drones in the same way in parts of the storm.
All this gives scientists an insight into the processes that are happening during the storm before and during the development of the tornado and throughout the lifetime of the tornado.
How do you stay safe while chasing tornadoes?
Storms can be very dangerous and unpredictable, so it is important to always stay on top of the radar and watch the storm.
A storm can cycle, developing a new tornado downstream from the previous one. Tornadoes can change direction, especially when dying out or when they have a complex structure with many funnels. Storm chasers know to watch the entire storm, not just the tornado, and to be on the lookout for other storms that may be moving through. An escape plan is based on the expected movement of the storm and the necessary road network.
Scientists take calculated risks when chasing a storm – just enough to gather vital data, but not put their crews at too much risk.
Driving turns out to be the most dangerous part of storm chasing, especially when roads are wet and visibility is poor – as is often the case at the end of the day. During the chase, erratic driving on other storm trackers and traffic jams around storms can make driving dangerous.
What happens to all the data you collect while running a storm?
It would be nice to have instant eureka moments, but the results take time.
After we collect the data, we spend years analyzing it. It takes time and patience to combine data from all the instruments to get a complete picture of the storm and how it developed. By having data on wind, temperature, relative humidity and pressure from many different angles and instruments we can test theories about how tornadoes develop.
Although the analysis process is slow, the discoveries are often as exciting as the tornado itself.
This article is republished from The Conversation, a non-profit, independent news organization that brings you reliable facts and analysis to help you make sense of our complex world. Written by: Yvette Richardson, Penn State and Paul Markowski, Penn State
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Yvette Richardson receives funding from the National Science Foundation and previously received funding from the National Oceanic and Atmospheric Administration. She is a member of the American Meteorological Society, the National Weather Association, and the American Geophysical Union, and serves on the Board of Trustees of the University Corporation for Atmospheric Research.
Paul Markowski receives funding from the National Science Foundation and previously received funding from the National Oceanic and Atmospheric Administration. He is a member of the American Meteorological Society, National Weather Association, and is affiliated with the University Corporation for Atmospheric Research.
