Climate change has been a major factor in increasing the risk and extent of wildfires in the western United States
Wildfires in the western United States can lead to more severe hazardous weather conditions in the central US, increasing incidences of heavy precipitation rates and large hail, according to a new report.
This is because forest fires in the western United States build up surface high pressure and increase westerly and southwesterly winds producing stronger moisture and aerosol transport to the central US, the analysts mentioned.
Heat and aerosols from forest fires can lead to a rise in severe storms and weather hazards downstream, according to research published in the journal PNAS October 17, 2022.
Western United States wildfires increased the occurrences of heavy precipitation rates by 38 per cent and severe hail by 34 per cent in the central United States, the analysis showed. Both heat and aerosols from forest fires played an important role in this, it added.
Climate change is the main driver of this increase in fire weather in the western United States, according to a November 2021 PNAS study.
The local wildfires in the central US also enhanced the severity of storms, but their impact was notably smaller than the impact of remote wildfires in California and Oregon, the authors observed. This was because of reduced severity of the local wildfires.
The researchers looked at the large and destructive wildfire events in the western US during the week from July 23 to 29, 2018. These forest fires were located mainly in northern California and southern Oregon, they noted.
Forest fires which occurred during this period included:
Some of those fires, such as the Carr Fire, produced fire-triggered thunderstorms in a phenomenon called pyrocumulonimbus clouds.
Among the four storms during July 26-29, the July 29 supercell thunderstorm was the strongest, causing widespread damage over eastern Colorado, the analysts observed. Widespread damage occurred due to damaging straight line winds and hail to the size of baseballs said the National Weather Service, Goodland Kansas, the report stated.
The United States National Interagency Fire Center site stated that as of October 19, 2022, 71 large fires have burnt 580,241 acres. Two new large fires were reported, one in Washington and one in Florida.
The 2017 wildfire season was well above average, with deadly fires in California and throughout the west, including Montana, Oregon and Washington states. according to the analysis. “The 2018 wildfire season was also one of the deadliest and most destructive seasons on record in California.”
The total costs of wildfires in 2017 and 2018 was more than $40 billion, the National Oceanic and Atmospheric Administration (NOAA) stated. In 2019, wildfires caused an estimated $4.5 billion in damages in California and Alaska.
In 2020, five of the six largest fires on record in California and Oregon saw historic levels of spread and damage. Wildfires across the west led to week-long periods of unhealthy air quality levels for millions of people, the researchers said.
We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.
.png)
Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.