Severe Weather Awareness Week continues across the Mountain State today. A mix of rain, sleet, and snow is in the forecast so winter is still hanging on. However, spring and summer severe thunderstorms will be here before we know it.
Some of those severe thunderstorms may produce hail. Those strong storms contain powerful upward-moving and downward-moving columns of air called updrafts and downdrafts, respectively.
Raindrops within the cumulonimbus or storm cloud are then carried into cold parts of the atmosphere. As temperatures dip below freezing, the raindrops freeze into small ice pellets called hailstones.
Hail is carried up and down inside the cumulonimbus cloud as they are constantly moving. The hailstones grow by colliding with supercooled water droplets within the storm cloud.
As the hailstones grow larger, they fall out of the cloud when one of two things happen. They either fall when the hailstones are too heavy for the cloud to contain them or when they stop moving within the cloud due to a weakening updraft.
Hailstones come in many sizes. Pea and dime/penny size hail are most common. Within a stronger thunderstorm, nickel size hail can be seen falling from the cumulonimbus cloud.
Severe thunderstorms may produce hailstones one inch in diameter or greater. Quarter size hail or greater is considered “severe.”
Here are some safety tips from the National Weather Service on what to do when hail comes during a severe thunderstorm if you are in a specific location:
- Stay Weather Ready: Continue to listen to local news or a NOAA Weather Radio to stay updated about severe thunderstorm watches and warnings.
- At Your House: Go to your secure location if you hear a severe thunderstorm warning. Damaging wind or large hail may be approaching. Take your pets with you if time allows.
- At Your Workplace or School: Stay away from windows if you are in a severe thunderstorm warning and damaging wind or large hail is approaching. Do not go to large open rooms such as cafeterias, gymnasiums or auditoriums.
- Outside: Go inside a sturdy building immediately if severe thunderstorms are approaching. Sheds and storage facilities are not safe. Taking shelter under a tree can be deadly. The tree may fall on you. Standing under a tree also put you at a greater risk of getting struck by lightning.
- In a Vehicle: Being in a vehicle during severe thunderstorms is safer than being outside; however, drive to closest secure shelter if there is sufficient time.