What is wind shear and how does it affect a hurricane?

News 6 meteorologist Samara Cokinos explains


ORLANDO, Fla. – Wind shear: This term comes up a lot when hurricane season rolls around, but what does it mean?

Don't worry, the meteorologists with the News 6 Pinpoint Weather Team are here to help. 

By definition, the National Oceanic and Atmospheric Administration says wind shear is the variation of the wind's speed or direction in the atmosphere over a short distance.

This is an important player for tropical cyclones. Try to picture looking a storm vertically through the atmosphere. Tropical storms occupy a large part of the atmosphere and, once they get going, sometimes exceed 40,000 feet in the air in the summer.

That's a lot of room for changes to happen.

The ideal conditions for a tropical system to form are over water that's 80 degrees or hotter, there needs to be substantial moisture in the low and mid levels of the atmosphere, and low vertical wind shear. There's that word again -- wind shear. 

Tropical systems need to spin. If there's a strong wind going against the storm, it's less likely to form. That wind just eats away at the system down to its core. Basically, it disrupts the flow of the heat and moisture it's sucking in from the surrounding atmosphere.

The perfect scenario would be little to no wind shear so the spin within the system becomes uniform, making it stronger and allowing for it to build in strength. 

Wind shear is not equal. It varies from place to place. So any storm that develops could go through pockets of little to no wind shear and strengthen and then move into heavy wind shear and weaken little by little.  

Wind shear is also not the only variable.

Water temperature and moisture content also vary from place to place, hour to hour, day to day, which leads to the changes in the forecast that we see so much until landfall or until the system fizzles out. 

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