Extreme Weather Toolkit: Severe Weather
The relationship between severe storms and climate change is an active area of research.
Climate Matters•August 13, 2025
Thunderstorm Straight-Line Winds
KEY FACTS
Severe storms are thunderstorms that produce tornadoes, large hail, or damaging straight-line winds (speeds greater than 58 mph).
Thunderstorm straight-line winds are the most common severe storm hazards.
These destructive and potentially deadly winds put crops, buildings, energy grids, and human safety at risk – especially in the central U.S.
Thunderstorm straight-line winds are complex systems, and their response to climate change is an active area of research.
Recent research shows that thunderstorm straight-line wind speeds in the central U.S. have intensified 7% per °F of warming during recent decades (1980-2020).
With very high levels of future warming, large straight-line wind systems (derechos) are projected to become more frequent, widespread, and intense in the central and eastern U.S.
Severe storms: tornadoes, hail, and wind
Severe storms — thunderstorms that produce tornadoes, hail at least one inch in diameter, or damaging winds (58 mph or higher) — are destructive and deadly.
They cause an average of 200 deaths annually in the U.S. and account for half of all U.S. billion-dollar weather and climate disasters that have impacted the nation since 1980.
The frequency of billion-dollar severe storms has increased dramatically in recent decades, with 2023 and 2024 ranking as the top two years on record.
These trends reflect both the rising frequency and intensity of extreme weather and the growing number of people, homes, and businesses exposed to these hazards. Accelerated development in fire-prone areas, along coasts, and in floodplains can multiply the damage from extreme events.
Partly due to their high frequency, severe storms are the leading cause of weather-related power outages in the U.S.
It’s critical to understand changing risks as heat-trapping pollution warms the planet and alters the ingredients that produce severe storms.
Extreme Weather Toolkit: Severe Weather provides quick facts about climate change and different severe weather hazards — an active area of research.
This brief focuses on the most common severe storm hazard: straight-line winds.
What are thunderstorm straight-line winds?
Thunderstorm straight-line winds are non-rotating winds originating from thunderstorms. Straight-line winds are different from the rotating winds of tornadoes, and they’re classified as “damaging” when their speed exceeds 58 mph.
Thunderstorm straight-line winds are classified in various sub-categories depending on their duration and the area affected (Table 1).
With an average of over 15,000 reported events annually (2010-2024), damaging straight-line winds are the most common severe storm hazard by far — accounting for around two-thirds of all reported incidents.
The number of reported severe thunderstorm straight-line wind events in 2025 is on pace to be the second highest since 2010, with over 14,500 reports by August.
Damaging straight-line winds are a common and dangerous hazard. These winds can be devastating: damaging crops, buildings, energy grids, and threatening safety.
Impacts of damaging winds can range from highly localized, impacting an area just a few miles wide, to widespread, producing a path of destruction impacting up to hundreds of miles with gusts exceeding 100 mph in some cases.
Most thunderstorm straight-line wind impacts occur during May through August. The central U.S. is a global hotspot for damaging winds, although every state in the lower 48 experiences damaging wind events.
Thunderstorm straight-line winds are complex systems, and their response to climate change is an active area of study. But emerging research suggests links between human-caused climate change and increases in the speed, frequency, and area of impact from damaging thunderstorm straight-line winds.
Warming strengthens thunderstorm straight-line winds
Severe storms are localized, short-lived events with limited historical records and multiple driving factors. Despite this complexity, the physics of air movement and phase changes within thunderstorms can help explain their potential response to climate warming.
Damaging straight-line winds happen when a downdraft, or a sinking column of relatively dense, cool air within a thunderstorm, reaches the ground and is forced to spread outward rapidly.
In our changing climate, warming trends could lead to stronger downdrafts and faster thunderstorm straight-line winds. Here’s how:
Compared with cooler air, warmer air can contain more moisture that acts as fuel for stronger updrafts that are important for storm formation. These strong updrafts of moist air can lead to heavier precipitation.
Heavier and more precipitation creates a greater force pulling surrounding air downwards as it falls — intensifying the downward motion that drives downdrafts.
The greater moisture holding capacity of warmer air can also lead to more evaporation of falling precipitation, which then causes greater cooling of the column of drier air that precipitation falls through.
The combination of enhanced evaporative cooling and heavier precipitation makes the air fall to the ground faster, increasing the resulting surface wind speed.
These physical principles are not the only factors influencing thunderstorm straight-line winds. But the enhanced evaporative cooling from increased moisture capacity of warmer air is an important and well-understood factor in thunderstorm straight-line wind speeds.
Faster thunderstorm straight-line winds have the potential to increase the destruction from this already damaging and widespread hazard.
Thunderstorm straight-line winds have already intensified with warming
The central U.S. is already experiencing faster and more widespread straight-line winds from thunderstorms than it was just a few decades ago.
Thunderstorm straight-line winds during June, July, and August have intensified in the central U.S. by a rate of about 7% per 1°F (13% per 1°C) of warming (1980-2020). This is based on observed data, and is an even larger increase than what theoretical models predict.
The area of the central U.S. affected by thunderstorm straight-line winds faster than about 45 mph during June, July, or August increased nearly fivefold during the same time period.
Looking to the future, it’s uncertain how damaging thunderstorm straight-line winds will change in the U.S. as the climate continues to warm. One limitation is the need for high-resolution models that come with high computational costs.
However, recent research suggests that large and long-lived straight-line wind events called derechos (Table 1) are projected to become more frequent, widespread, and intense by the end of the century for most of the central and eastern U.S. in scenarios with intermediate and very high levels of warming.
Another study suggests that the second most costly U.S. severe storm on record (a 2020 derecho with more than $13 billion in damages), could affect an area up to twice as large if it were to occur at the end of this century with very high levels of heat-trapping pollution.
Destruction from straight-line winds
Damaging thunderstorm straight-line winds are strong enough to knock down trees, power lines, and crops. When people, cars, or buildings are in the way, these winds can be deadly. Wind from thunderstorms is especially dangerous for people living in mobile or manufactured homes.
Especially large and long-lived thunderstorm straight-line wind events such as derechos (Table 1) are particularly dangerous because they are difficult to forecast and can form and move quickly, leaving little time to prepare.
A 2020 derecho in the central U.S. had wind speeds equivalent to those in a Category 4 hurricane. This was the second most costly severe storm on record, with more than $13 billion in damages and nearly 20 million people impacted.
It’s not just the most intense severe wind storms that have destructive consequences; a typical thunderstorm with damaging winds was found to reduce income growth in affected counties. And areas at high risk of damaging straight-line winds include major and growing population centers.
Despite the frequency and extreme destruction from damaging winds in the U.S., they are the least studied type of severe weather. Emerging research, however, shows connections between human-caused climate change and increases in damaging thunderstorm straight-line winds.
Table 1. Types of thunderstorm straight-line winds.
Type | Definition |
|---|---|
Thunderstorm straight-line winds are non-rotating winds originating from a thunderstorm. Thunderstorm straight-line winds are also referred to as damaging winds when they reach a certain speed, usually 58 mph. | |
A downdraft is a small column of air that sinks rapidly within a thunderstorm. | |
A microburst is a small but strong downdraft (less than about 2.5 miles across) lasting only 5-10 minutes, that produces high wind speeds sometimes exceeding 100 mph as the downdraft reaches the ground. | |
A macroburst is a larger (more than about 2.5 miles across) strong downdraft that produces high wind speeds. | |
Derechos are the largest and longest-lived of thunderstorm straight-line wind events, consisting of many downbursts with wind speeds greater than 58 mph. Wind damage from derechos extends for at least 240 miles. These storms present additional challenges since they can be difficult to define and forecast, even for experts. |
Other wind trends related to climate change
Thunderstorm straight-line winds are just one type of wind that scientists are working to understand. There are projections of future decreases in global average wind speeds, called “global stilling.”
At the same time, maximum wind speed (not only from thunderstorms) are projected to increase in some areas of the globe and decrease in others.
In general, less is known about future wind speeds and their connections to climate change compared to other climate impacts such as extreme heat.
Changes in both average and extreme wind speeds driven by human-caused climate change can impact infrastructure, including changes in wind energy generation. A recent study suggests that future warming could cause longer low-wind periods, called wind droughts, in northern mid-latitude countries including the U.S., potentially limiting future wind power generation.
Both increases and decreases in wind speed can have negative consequences spanning agriculture, wildfires, air travel, air pollution, and weather patterns.
LOCAL STORY ANGLES
Rolling storm damage reports in the U.S.
Using data from the National Weather Service (under NOAA), USA TODAY maintains an interactive map dashboard of reports of storm damage from tornadoes, hail, and high wind across the country. Explore the tool to see any recent occurrences in your area.
CONTACT EXPERTS
Andreas Prein, PhD
Professor
Department of Environmental Systems Science, ETH Zurich
Relevant expertise: changes in extreme events in a warming climate, modeling changes in wind
Contact: andreas.prein@env.ethz.ch
Walker Ashley, PhD
Professor
Department of Earth, Atmosphere, and Environment, Northern Illinois University
Relevant expertise: changes in extreme weather and societal impacts
Contact: washley@niu.edu
FIND EXPERTS
Submit a request to SciLine from the American Association for the Advancement of Science or to the Climate Data Concierge from Columbia University. These free services rapidly connect journalists to relevant scientific experts.
Browse maps of climate experts and services at regional NOAA, USDA, and Department of the Interior offices.
Explore databases such as 500 Women Scientists, BIPOC Climate and Energy Justice PhDs, and Diverse Sources to find and amplify diverse expert voices.
Reach out to your State Climate Office or the nearest Land-Grant University to connect with scientists, educators, and extension staff in your local area.