Thunderstorm Information

Damaging thunderstorm wind events are more common than tornadoes in Longview. In a typical year, Longview is likely to experience 10 to 20 times as many wind events as tornado events.

Not only can severe thunderstorms produce injury and damage from violent straight-­line wind and hail, but tornadoes can and sometimes do develop very quickly from these storms.

The term severe thunderstorm refers to a thunderstorm producing hail that is at least quarter size, 1 inch in diameter or larger, and/or wind gusts to 58 mph or greater, and/or a tornado. Although lightning can be deadly, the NWS doesn't use it to define a severe thunderstorm. If it did, every thunderstorm would be severe, by definition. Also, excessive rainfall may lead to deadly flash flooding, but heavy rain is not a severe criterion either. The flood threat is handled through a separate set of watches and warnings from your local NWS forecast office.

Severe thunderstorm wind can gust to more than 100 mph, overturning trailers, unroofing homes, and toppling trees and power lines. While dime size hail denotes a severe thunderstorm, hail as large as grapefruit has occurred. The danger of serious injury from hail is not hard to imagine when you consider that a good­-sized hailstone may fall at speeds near 110 mph.

The best defense against thunderstorms is to stay inside a substantial building. Thunderstorms do not usually last for a long time and will generally pass in less than an hour. When thunderstoms are expected, be sure to pick up loose objects around your home or business. Small items can become deadly in strong wind, and flying debris can cause serious damage to other property.