50 MPH wind represents a significant force, categorized as a Strong Gale (Force 9 on the Beaufort wind scale). Winds exceeding 50 MPH are often categorized by the National Severe Storm Laboratory as damaging. Understanding the physical power of wind at this velocity requires looking beyond simple weight to the fundamental physics of how moving air transmits energy to stationary objects.
How Wind Force Works
Wind exerts force through dynamic pressure, which is the kinetic energy of moving air molecules impacting a surface. This pressure is directly proportional to the air’s density and the square of the wind’s velocity.
The relationship between speed and pressure means a small increase in velocity results in a much greater increase in force. For example, if wind speed doubles, the dynamic pressure exerted on an object quadruples. This non-linear scaling explains why 50 MPH winds are significantly more powerful than a 25 MPH breeze.
When moving air hits a stationary object, it slows down or changes direction, converting kinetic energy into a pushing force. This force must overcome the object’s inertia and is influenced by the object’s ability to resist airflow, known as aerodynamic drag.
Objects 50 MPH Wind Can Move
A 50 MPH wind is capable of moving and damaging many common household and outdoor items. Unsecured objects like plastic patio furniture, grills, and trash cans will be pushed or tumbled across the ground. Temporary outdoor signage or barricades will be blown over, potentially creating flying debris.
This wind speed is also sufficient to cause light structural damage to buildings. Poorly attached roofing materials, such as shingles or tiles, can be peeled away from the roof deck. Television antennas and chimney covers are susceptible to being damaged or blown off entirely.
The wind’s power is evident in its effect on vegetation and infrastructure. Small, weak trees can be blown over or uprooted completely. Large, mature trees can have limbs and small branches broken off, creating dangerous projectiles. 50 MPH gusts have been known to snap large trees in half or topple light poles and commercial signs.
The Factors That Determine Movement
The amount of weight 50 MPH winds can move depends on several interacting factors, not weight alone.
Surface Area
The most significant variable is the object’s surface area presented to the wind. A large, flat object, such as a 50-pound sheet of plywood, will experience a much greater total force than a solid, dense object of the same weight, such as a 50-pound boulder.
Anchoring and Friction
The degree of anchoring and friction is equally important in determining movement. A heavy object sitting on a slick surface, like a metal shed on frozen ground, will move more easily than a lighter object embedded in the earth, such as a well-rooted shrub. Friction acts as a resisting force the wind must overcome before movement can begin.
Aerodynamic Profile
An object’s shape, or its aerodynamic profile, also plays a role in movement. A streamlined object allows air to flow smoothly around it, minimizing the drag force. Conversely, a bluff, non-aerodynamic shape, like a flat-faced billboard or a square-sided storage unit, maximizes the drag force and is more likely to be moved or damaged.