Understanding the Four Major Inhibitors of Tropical Weather

As the tropical weather season starts to heat up, meteorologists are keeping an eye on the factors that could inhibit the development of named storms. Whether it be within the ocean waters or up in the atmosphere, four primary factors determine if a cluster of rain showers and storms develops into a named feature. Here are four factors that tend to limit tropical development.

Wind Shear

Wind shear is defined as the change in the wind speed and direction. This atmospheric factor is known to break apart features as they churn through the ocean. Regardless of how warm the ocean waters are at the time that the storms begin to come to life, they will not be able to intensify if excessive amounts of wind shear make an appearance.

The exception to this is when wind shear can have the opposite effect due to the precise location. For instance, there have been areas of wind shear located far enough to the west of a storm that it does not serve as a mitigating factor. Instead, wind shear in this direction can provide the extra ventilation that the storm needs to strengthen. This happened in 2018 when Hurricane Michael went through the process of rapid intensification, sending it to the status of a monster Category 5 storm before it came ashore along the Florida Panhandle. An area of wind shear located to the west of Michael in the Gulf breathed more life into the feature as it churned over the especially warm ocean waters.

Areas of Dry Air

A budding tropical storm needs persistent thunderstorms within the core to stay alive. A surge of dry air will tear apart the storms as it strengthens the downdrafts, leading to weakening of the overall feature.

However, dry air can typically inhibit a storm for a finite period of time. Depending on the timing of the arrival of the dry air, a developing storm can often fend off the intrusion and go on to become stronger.

Interaction with Land

Tropical storms and hurricanes feed on warm ocean waters. This is why a storm naturally weakens when it moves over land. The natural weakening can happen quickly in some cases. There are other times when the storm retains its intensity for some time over land.

One of the most influential factors in how long a storm will survive on land is the general topography of a region. Tropical weather makers break up at a faster rate when they move over mountainous terrain. This is why storms tend to dissipate quickly when moving over the mountains of Haiti, Mexico, and other areas with a more varied landscape.

However, the weakening does not always last for long. Last year's Hurricane Beryl showed that just because a storm breaks apart when interacting with land, it still may have enough juice to come back to life if the right conditions are in place. In addition, the parts of the land that trigger the weakening often see the worst of the impacts.

Cooler Ocean Water Temperatures

Just as hurricanes and tropical storms get their strength from warm ocean water temperatures, they also weaken when they meet up with cooler water. A feature that moves over an area of the ocean with a lower heat content is less likely to intensify. Cooler sea-surface temperatures also promote more stable atmospheric conditions, promoting greater levels of weakening.

It is also more likely for a tropical weather feature to stall out and produce its own well of cool water. This is a process known in meteorological circles as upwelling. The strong winds circulating within a tropical event churn up the ocean water, bringing the cooler water from below to the surface.

Forecasting the development, intensification odds, and track of tropical weather features is not an exact science. However, the absence or presence of these four factors gives the experts a guide as they release their forecasts and alert the public of potential dangers.

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