Why do tornado wind speeds fluctuate during a storm event?

Understanding Wind Shear

Wind shear plays a crucial role in determining the strength and behavior of a tornado. When wind shear is low, the wind speed and direction change little with height, resulting in a relatively stable environment for the tornado to form and maintain its rotation. Conversely, high wind shear can cause the tornado to weaken or dissipate.

Factors Contributing to Wind Speed Fluctuations

Several factors contribute to the fluctuations in wind speed during a tornado event. Updrafts and downdrafts within the storm system can cause the tornado’s rotation to weaken or strengthen. For example, a strong updraft can increase the wind speed and cause the tornado to strengthen, while a downdraft can decrease the wind speed and cause the tornado to weaken. Additionally, changes in the storm’s mesocyclone can also affect the wind speed and direction of the tornado.

Sheltering Strategies

When preparing for a tornado event, it’s essential to understand the factors that contribute to wind speed fluctuations. By monitoring wind shear, updrafts, and downdrafts, you can make more informed decisions about sheltering and evacuation. In a shelter, it’s crucial to stay away from windows and exterior walls, and to seek shelter in a basement or storm cellar if possible. If no basement is available, go to an interior room or hallway on the lowest floor, and get under a sturdy table or desk. Stay informed about the storm’s progress and be prepared to adjust your sheltering strategy as needed.