Heavy rain causes the risk of flash floods and mudslides when the rainwater does not soak into the burnt ground.
In the United States, rescuers fighting wildfires outside Los Angeles are preparing for landslides and floods as the storm approaches the fire area. Strong winds are believed to be fanning the fire known as Fairview.
According to the authorities, the fire that started on Monday in the middle of a heat wave continues to spread, and because of this, the evacuation area has also been expanded even further. The authorities have anticipated that with the winds, burning material from the fire area can spread to other places as well, in which case more fires can start.
At least two people are known to have died in the flames, and according to the fire department, the fire is believed to have damaged or destroyed several buildings.
The fire department has said that the fire is raging in difficult terrain for firefighting, for example in deep canyons.
Heavy rain is expected next
Tropical Storm Kay, which hit Mexico on Thursday, is heading north and is expected to bring heavy rains to parts of California and Arizona. The National Weather Service has predicted that up to 18 inches of rain could fall on the area surrounding Fairview.
Heavy rain causes the risk of flash floods and mudslides when the rainwater does not soak into the burnt ground.
Rescue officials have warned that there are difficult days ahead, and firefighting efforts may be replaced by rescuing people from floods and mudslides.
The storm is predicted to ease the heat wave that has lasted more than a week in the western parts of the United States. However, temperatures have remained high in central and northern California.
According to the weather service, nighttime temperatures will remain close to record readings during the weekend. About 29 million Americans are currently in a heat advisory area.
The western parts of the United States are experiencing a historic drought, which experts say is being made worse by human-caused climate change. According to climate scientists, the situation will get even worse in the future.