Localized hail, strong winds and even tornadoes are possible in central North Carolina ahead of a cold front expected to arrive Friday, forecasters say.

The greatest risk of severe weather is late Wednesday through late Thursday, according to the National Weather Service. Storms are possible from Friday morning to Friday night but are expected to be less severe.

Forecasters issued a hazardous weather outlook for 21 counties including Wake, Orange, Durham, Johnston, Chatham, Franklin, Lee and Harnett beginning Wednesday.

What are the potential hazards?

According to the National Weather Service, multiple rounds of showers and thunderstorms are expected beginning after 5 p.m. Wednesday. A few storms could be severe, with strong straight-line winds and large hail possible.

On Thursday, sustained winds of 9 mph to 15 mph are expected through central North Carolina, with gusts of up to 25 mph possible. Thursday night, winds should drop to 7 to 10 mph with gusts up to 18 mph.

“An isolated tornado is also possible,” the outlook says.

In addition, forecasters warned of high temperatures expected to reach the upper 80s to low 90s Wednesday and Thursday, about 10 degrees higher than average for this time of year. Coupled with high humidity, that could be an issue for people with low heat tolerance.

What’s causing the instability?

Meteorologists say a cold front making its way across the country – and creating the potential for tornadoes and bigger-than-golfball-sized hail in Midwestern states – will interact with the unseasonably moist air mass that’s over North Carolina as it pushes into the state on Friday.

What’s the forecast for Mother’s Day weekend?

Thunderstorms are possible in central North Carolina through Friday night, but Saturday conditions will improve.

Cooler, drier air should make for a pleasant weekend; as of Wednesday, forecasters say Saturday will be sunny with a high near 76 degrees and a low near 55 degrees. Mother’s Day on Sunday will be sunny with a high of 78 degrees and a low of 53 degrees.

How to protect yourself during a tornado

North Carolina gets an average of 31 tornadoes per year. “Tornado season” is March through May but they can happen any time.

The National Weather Service offers these tips:

▪ Be ready: Listen to local news or a NOAA Weather Radio to stay updated about tornado watches and warnings.

▪ At home: If you are in a tornado warning, go to your basement, safe room, or an interior room away from windows. Gather pets if time allows.

▪ At work or school: Follow your tornado drill and proceed to your tornado shelter location quickly and calmly. Stay away from windows and do not go to large open rooms such as cafeterias, gyms or auditoriums.

▪ Outside: Seek shelter in a sturdy building immediately if a tornado is approaching. Sheds and storage facilities are not safe. Neither is a mobile home or tent.

▪ In a vehicle: Being in a vehicle during a tornado is not safe. The best course of action is to drive to the closest shelter. If you are unable to make it to a safe shelter, either get down in your car and cover your head, or abandon your car and seek shelter in a low-lying area such as a ditch or ravine.