Breakdown: Why wind determines where tropical systems travel

Why Winds Determine Where Tropical Systems Travel

MEMPHIS, Tenn. (WMC) - Have you ever wondered what drives a hurricane to move in a specific direction? In this Breakdown, we will discuss what elements play a role in where 'canes go and why.

The short answer is that hurricanes are steered by global winds, but the journey starts with the trade winds. The trade winds, in the tropics blow from east to west, which is why many hurricanes will form just west of the African coast and then move from the African coast toward the Caribbean and United States. The direction of hurricanes can get pretty tricky when the trade winds are are weak.

High and low pressure systems within these global winds also have big impacts on where tropical systems end up. The Bermuda High that sits over the Atlantic plays a big role in direction. Other areas of high pressure can control the direction based on the strength and position. Tropical systems get carried by the trade winds to start but once it reaches the influences of high and low pressure, storms can get pushed northward along the periphery these system pressure. The Bermuda High that sits over the Atlantic Ocean will often times steer hurricanes around it, and based on location this pushes tropical systems northwestward, which would mean landfall on the east coast. Other times if the Bermuda High’s influences are penetrating far enough south, that would allow for a landfall in Florida, Caribbean or along the Gulf Coast.

Beta drift is a process that causes tropical systems to move toward the poles and westward.

Coriolis Effect is the spinning of the earth, which causes objects to get deflected, and with cyclone we see this as storms curve. Storms moving north will curve east while storms that move south will curve west.

Once a tropical system is out of the influences of the tropics, the winds are sometimes not as strong and as big of an influence. The environment following the tropics can sometimes be weaker which can cause a storm to move slowly or move in unusual ways especially if a strong low or high is not present. When tropical system track north into the mid-latitudes, some systems will accelerate due to the jet stream. Most storms won’t survive for long north because of the colder waters. The movement of any tropical systems can be difficult to predict.

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