What meteorologists look for in the early warning signals of a future hurricane: A new storm is coming toward the Caribbean.

What meteorologists look for in the early warning signals of a future hurricane: A new storm is coming toward the Caribbean…see more

Tropical meteorologists frequently see tiny cloud formations on satellite photos that suggest something more sinister is about to happen.

Days before a storm intensifies into a hurricane, the initial warning indications can be seen. The emergence of curving banding low-level clouds, a decrease in air pressure, and wispy cirrus clouds radiating outward are all indicators.

These early indicators are critical for anticipating the beginning of a storm that could turn into a devastating hurricane.

As a Penn State meteorology professor, my research group improves tropical weather system forecasting with satellite data and computer models. It is more crucial than ever to be able to recognize these early signs and issue early warnings because 2024 is predicted to be an exceptionally violent Atlantic storm season.

favorable conditions for a hurricane
Usually, atmospheric tropical waves—zones of low pressure connected to thunderstorm clusters—form the precursors of hurricanes. Some of these tropical waves have the potential to become hurricanes as they travel over tropical waters toward the west.

A hurricane’s ability to form depends on several key factors:

Tropical cyclones typically form at least five degrees away from the equator. This is a result of the Coriolis force being weaker close to the equator, which is essential for the cyclonic system’s initial spin-up. The rotation of the Earth creates the Coriolis force, which causes flowing air to twist and swirl.

Warm sea surface temperatures: For a hurricane to form, the sea surface temperature must be at least 26.5 degrees Celsius, or roughly 80 degrees Fahrenheit.

Moisture and unstable atmosphere: An unstable atmosphere is necessary for the formation of tropical cyclones. This means that heated surface air rises and continues to ascend because it is warmer than the surrounding air, which causes thunderstorms to occur. Additionally, there must be an abundance of moisture since dry air can lead to cloud evaporation, which reduces the strength of thunderstorm upward motion. The formation of clustered thunderstorms within the tropical waves depends on these elements.

Low vertical wind shear: A forming storm can be ripped apart by strong vertical wind shear. Variations in wind direction or speed at varying heights are known as vertical wind shear. It messes with the development and growth of storms and makes it difficult for hurricanes to maintain their vortex alignment.

In order to forecast early, more than