ASK THE METEOROLOGIST
How do thunderstorms develop?
Laura C., South Medford High School
There are three ingredients that go into building a thunderstorm & that are responsible for any severe weather for that matter. First and foremost, moisture must be present in the atmosphere. Typically moisture filters into the Northwest when a southwesterly wind is positioned over the region because the air originates from the tropics and from over the ocean.
When moisture is present, and the sun is high and strong, a lot of surface heating can help to start mixing the air. Air near the ground is heated by the sun; when this air becomes warm, parcels will start to rise. This is know as instability and the perfect example of a real life scenario is a pot of boiling water. The burner helps to heat the pot & as a result bubbles of water begin to bubble and rise. The same thing happens with warm air in our atmosphere.
These parcels will rise, cool and condense to form a cloud if water vapor is in the air. If enough moisture and enough lifting is present, these puffy cumulus clouds will start to vertically grow. When I say lift, I am referring to some type of lifting mechanism …usually this is a cold front, or some type of front. This can help to raise these warm rising parcels of air enough to build clouds into thunderstorm clouds.
A thunderstorm cloud is otherwise known as a cumulonimbus cloud.