Isaias spawned tornadoes when it hit NC. Here’s why twisters form during hurricanes
Hurricane Isaias brought tornadoes to Eastern North Carolina on Monday night and early Tuesday — which is common for tropical systems.
The National Weather Service confirmed a tornado touched down in Northampton County near the Virginia state line at about 2:30 a.m. Tuesday, and at least five other suspected tornadoes have been reported in the state: two in Brunswick County, two in Bertie County and one in Hertford County.
At least two people died and more are missing or injured after a tornado tore through a mobile home park in Bertie County, The News & Observer reported.
Trees were downed and buildings sustained damaged in other areas.
At least one tornado usually forms during tropical storms in the United States, according to the National Ocean Service.
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, according to LiveScience.
Tornadoes spawned by hurricanes often form in the system’s rain bands, which extend far away from its center, the National Hurricane Center says. But they can also form near the eyewall, which is the ring of clouds that surround the storm’s eye.
Although these tornadoes are often relatively weak and don’t last long, they can do serious damage, the National Hurricane Center says.
Tornadoes are smaller than hurricanes but produce much stronger winds, according to NASA.
Isaias made landfall in North Carolina with 85 mph winds and gusts up to 87 mph.
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 August 4, 2020 at 12:41 PM.
