Welsh Study Explains How Climate Change Increases Hailstorms

The review investigated how climate change will affect hail in the future. The study provides a global summary of hail trends from past and future projections from simulations and models. In summary, the review found that North America and East Asia will see fewer hail storms. Australia and Europe will have more frequent hailstorms, and severe hail weather will increase around the world.

It started with an international collaboration

Researchers from the University of Bern, Central Michigan University, Karlsruhe Institute of Technology, University of Illinois, Colorado State University and Peking University collaborated.

Lead author and postdoctoral researcher at UNSW Sydney Climate Change Research Center Dr Tim Raupach said:

“We concluded that the hail threat is likely to increase in the end in Australia, especially in southeastern Australia, including the Sydney area.”

However, the team says that the current and future climate change impacts of hail storms have a degree of uncertainty. Long-term observations and models remain limited in this area of ​​research.

“There is a lot of uncertainty when it comes to these predictions, and Australia is particularly highly uncertain because there are so few studies that have actually looked at Australia.”

Researchers noted many unknowns with the hail storms. Therefore, the team wanted to do more studies on the impacts of climate change on hail. However, they have uncovered some important data based on current research.

How changes in the atmosphere will affect the frequency and severity of hail

In this study, the team investigated how changes in the atmosphere would lead to more severe weather with hail. Atmospheric instability, wind shear, and melting from falling hailstones will change with warmer weather. Weather hailstorms they will be less frequent in general, their intensity will increase when they occur.

“We know that with climate change we are going to have more humidity in the atmosphere, and that leads to greater instability in the atmosphere, so we expect there will be more tendency for storms to occur due to this unstable atmosphere,” said Dr. Raupach. saying.

He also said that the ice would begin to melt higher in the atmosphere with a warmer atmosphere.

“So as the melting level increases, the hail that forms high up in the atmosphere and falls towards the ground has more time to melt and may actually melt completely before reaching the ground, and you end up no hail on the surface. “

With climate change, overall wind shear (differences in wind by height) will actually decrease, Raupach said. However, the other two factors, instability in the atmosphere and the melting height of hail, will have a stronger impact on hail storms.

“The changes that can be expected from these three properties of the atmosphere lead us to expect that hail will be less frequent because it will essentially melt more in the future,” said Dr. Raupach.

“But the hail will be more severe when it occurs because there will be more instability in the atmosphere that can lead to much larger hail formation. So when the hail survives this additional melt, it will be bigger and more severe when it actually hits the surface. “

However, the review found that this generalized prediction would not apply worldwide.

Dr. Raupach said this:

“Regional variability in atmospheric changes leads to different responses to hail, which is why studies show an increasing frequency of hail in Europe but a decreasing frequency in East Asia, for example.”

Why Scientists Find It Hard to Measure Hail

The study investigated hail storm trends using past data from:

• weather stations
• hail pads (sheets that record hail impacts)
• media reports

Dr. Raupach said that these trends contained great uncertainty due to the difficulty of measuring hail storms. Due to its isolated and relatively infrequent occurrence, the data are minimal.

“If you put an instrument to capture [or] Measure the hail, even in a place where you can expect a lot of hail, you may only get a hit or two on that instrument in a year, “he said.

“If you’re trying to look at climate change and long-term trends where you want decades of information, it’s very difficult to collect that kind of information on hail.”

In the review, the researchers also collected information from simulations and model studies that predict the impact of climate change on future hail storms.

“You can see if the model actually produces more hailstorms or less hailstorms in the future when you change the properties of the model, such as making the temperature higher or increasing the height of the melt level,” said Dr. Raupach.

However, regular weather models do not accurately predict hailstorms due to their isolated occurrences.

“You need to have a very high resolution model to be able to resolve the size of the hail storm,” said Dr. Raupach. “There have been some of these studies, but they are relatively rare and we need more of them to understand how hail will change in the future with climate change.”

Predicting the behavior of hail storms in the presence of climate change

Due to the difficulty of collecting accurate data on hail storms, the researchers recommended changes to the methodology in the future. For example, they believe that the use of hail pads in uncovered hail locations will more accurately record long-term observations. In addition, the team recommends using process-oriented studies. This measurement helps to better understand how hail forms in clouds and then turns into large hail.

“For example, a current research topic is whether an increase in aerosols leads to an increase in hail formation or a decrease in hail formation.”

Finally, they suggested studying the economic impacts of hail, taking into account changes in construction material, population growth, and crop cycles.

In future research, they suggest using more high-resolution computer models that run in high-performance facilities like the National Computational Infrastructure in Canberra.

“As these systems come online, we can perform high-resolution studies that were previously too computationally expensive to run. These models will be extremely helpful in understanding how hail will change in hot weather. “

Final thoughts: study reveals climate change will increase hailstorm severity

A recent study from Wales found that climate change will cause more frequent, severe hailstorms in some parts of the world. However, not all areas will see the same impacts. In East Asia and North America, for example, hailstorms will decrease in frequency. In Australia and Europe, scientists expect more persistent hail storms, while the severity of hailstorms will increase around the world. However, scientists still need more research to better understand how climate change affects hail.