To draw a parallel from a fairy tale, Hurricane Milton, which may become quite dangerous, is about to face the weather equivalent of a big, bad wolf — wind shear — as it approaches Florida.

This situation presents a mix of outcomes. The storm’s strength, wind speeds, and the extent of storm surge will rely on whether the winds coming over the Gulf of Mexico are strong enough to disrupt its internal structure.

According to James Franklin, a retired branch chief at the National Hurricane Center, if the winds Milton faces as it nears Florida are strong enough to interfere with its central core, the hurricane’s peak wind speeds might somewhat decrease. However, it could also expand in size, pushing a greater volume of water ashore, resulting in a more substantial storm surge, Franklin explained.

Regardless of these factors, forecasts indicate that Milton is likely to be a menacing and formidable storm.

Understanding Hurricane Mechanics

A hurricane fundamentally operates as a heat engine, Franklin shared with YSL News on Monday. “It absorbs heat from the ocean, which is then released in thunderstorms surrounding the eye of the storm. Additionally, descending air in the eye also produces heat as it lowers.”

“In and around the eye, there’s considerable heat being generated and released in a tightly compact vertical column,” he continued. This heat decrease in pressure is essential as it maintains the hurricane’s energy, enabling it to develop and intensify.

Impact of Wind Shear on Hurricanes

Wind shear is when the winds around a storm come up against winds that are moving at different speeds or in various directions.

If the wind shear disrupts the hurricane’s heat release, spreading it over a wider area, it can halt the pressure drop in the storm’s core. Franklin noted that strong wind shear could effectively “blow the top off the hurricane,” inhibiting it from functioning as an efficient heat engine.

Benefits of Low Wind Shear

Milton’s swift increase in wind speed and reduction in pressure on Monday exemplifies how hurricanes thrive in environments with low wind shear.

Over ample warm waters with minimal wind shear, Milton’s wind speeds surged by 85 mph in just 12 hours, while its pressure decreased dramatically by 64 millibars. (A lower air pressure usually indicates a stronger storm.) This makes Milton one of the storms with the lowest pressure recorded in the Gulf of Mexico in recent times.

The low wind shear permitted the heat to concentrate, allowing for a drop in pressure, Franklin said.

Since 1979, only three hurricanes in the Gulf of Mexico had lower pressure than Milton saw on Monday, according to Phil Klotzbach, a climatic research scientist at Colorado State University. These were Allen in 1980, Katrina in 2005, and Rita in 2005.

The Importance of Size in Hurricane Strength

Smaller storms like Milton can escalate in intensity more rapidly, Franklin noted. “Yet they also can diminish faster because small storms don’t resist wind shear as effectively.”

Starting Tuesday, meteorologists are predicting that Milton’s strength will be affected by eyewall replacement cycles, which may result in gradual weakening but increased size, Eric Blake, a hurricane specialist at the center, mentioned in his forecast discussion on Monday.

These cycles happen when a secondary eye wall develops further from the storm’s center, diverting heat generation from the core. As this occurs, the winds expand to align with the areas where heat is being expelled.

This scenario mirrors what transpired shortly before Hurricane Idalia struck land in August 2023. Its “effects were likely moderated because Idalia’s inner core was in rapid decline due to an eyewall replacement cycle just before making landfall,” as reported in an after-storm review by the National Weather Service in Tallahassee.

In the next 36 hours, Milton is “predicted to meet a far less favorable environment characterized by strong shear and dry air,” Blake indicated. “Thus, some weakening is expected before the hurricane reaches the Florida coastline.”

Nonetheless, if the replacement cycles result in Milton expanding before arriving at shore, it might better withstand wind shear, as Klotzbach explained.

Larger, more powerful storms, including Hurricane Helene, find it more challenging to be disrupted.

“In general, smaller intense storms tend to be preferable for various reasons,” Franklin remarked. Compact storms are more prone to quickly weakening and don’t generate the same storm surge as larger ones.

Ultimately, Milton is expected to be “a large and powerful hurricane upon reaching Florida, bringing potentially life-threatening risks to coastal areas and extending far inland.”