Dorian has brought twisters to the Carolinas. Why do tornadoes form during hurricanes?
As if strong winds and heavy rain weren’t enough, Hurricane Dorian also brought tornadoes to the Carolinas coast on Thursday.
At least two tornadoes touched down near Myrtle Beach, South Carolina, and another was reported in Pender County, North Carolina, on Thursday, McClatchy news group reported. A waterspout also came ashore in Emerald Isle, North Carolina, damaging an RV park.
This isn’t unusual: At least one tornado usually forms during tropical storms in the United States, the National Ocean Service says.
So why do hurricanes and tornadoes go hand in hand?
Because a hurricane’s “strong vertical shear” — change in wind speeds and direction, according to AccuWeather — and its instability are favorable conditions for a tornado, the National Ocean Service says.
Hurricanes are considered unstable because they bring with them warm, moist air that wants to rise above a layer of cooler, less-moist air, LiveScience says.
Tornadoes brought on by hurricanes often form in the system’s rain bands, which are far away from its center, the National Hurricane Center says, but they can also form near the eyewall.
Although these tornadoes are usually relatively weak and don’t last very too long, they can do serious damage, the National Hurricane Center says.
Tornadoes are smaller than hurricanes but produce much stronger winds, according to FEMA.
Hurricane Dorian’s maximum sustained wind speeds were 110 mph as of 4 p.m. Thursday. Meanwhile, tornadoes produced by hurricanes or tropical storms are usually EF0 or EF1 intensity but can reach up to EF3, with maximum wind speeds of 165 mph, according to The Weather Channel.
To stay safe during a tornado, the National Weather Service recommends moving to the lowest level of your home and into an interior room that doesn’t have windows. If you’re in an apartment or dorm, go to the lowest floor and into a central room.
The National Weather Service also recommends covering your head and neck to protect yourself from debris.
This story was originally published September 5, 2019 at 4:32 PM with the headline "Dorian has brought twisters to the Carolinas. Why do tornadoes form during hurricanes?."
