An early taste of summer is expected to return to a large part of the eastern United States in the final days of April.
Rain continued to plague NASCAR drivers and fans at Bristol, Tennessee, on Sunday as officials were forced to postpone the Food City 500 to Monday.
The potential for damaging thunderstorms and flooding downpours will target parts of the South into Saturday evening.
Concern is mounting for a significant severe weather event to threaten the south-central United States in the final days of April.
Arlene formed over the Atlantic Ocean on Thursday afternoon and became the first tropical storm of 2017.
Snow caused travel chaos in parts of Europe this week, while an asteroid named after celebrity Dwayne "The Rock" Johnson made a close approach to Earth.
Dangerous thunderstorms and flash flooding will focus on portions of Oklahoma, Texas, Kansas, Missouri and Arkansas through Friday night.
A potent storm will threaten parts of Michigan, Indiana, Ohio and Pennsylvania with dangerous and damaging weather conditions into Thursday night.
The American Lung Association’s annual “State of the Air” report found that 125 million Americans live in counties with unhealthful levels of either ozone or particle pollution.
Wildfires can ignite and spread suddenly, as high winds can fan flames, so being prepared to evacuate at a moment's notice could be the key to survival.