"I've lived here for 30 years and this is unprecedented," Kerry Vincent, the world-renowned, West Australian-born cake designer, nuskin told AAP from her home in Tulsa, Oklahoma on Monday.
"My heart bleeds for my friends who I can't find.
"There's so many dead folks, it is just unbelievable."
Ms Vincent said Oklahoma City, hit by a tornado packing 321 km/h winds, is home to some Australians, but she was unaware if they escaped injury.
Phone lines are down and mobile coverage is sketchy.
The terror is not over for locals, with more twisters forecast in coming days.
"We know it's not over," she said.
Ms Vincent, 67, born in Wyalkatchem, WA, nu skin hk is known as the "The Simon Cowell of Cakes" in the US for her acid-tongue while judging US TV cooking competitions and will soon be seen in Australia on the Nine Network's reality cooking show, The Great Australian Bake Off.
She has lived through many tornadoes since marrying her American husband, Doug, and moving to Oklahoma three decades ago.
"Everything suddenly turns to teal," Ms Vincent, describing an approaching tornado, said.
"It is the most incredible thing to look at nuskin group, but it's also the moment you know you need to get out of the way.
"I can't tell you how many times I've spent curled up in cupboards and wrapped around toilet bowls because that is where they say it is the safest place in the house.
"My best friend is the toilet bowl."