Weather

What is an eyewall replacement cycle, and what does it mean for Milton?

Milton completed an eyewall replacement cycle Tuesday morning

NBC Universal, Inc.

It is common for strong and powerful storms to undergo eyewall replacements, which allow for a brief period of weakening, like we saw with Milton going from a Category 5 to a Category 4 early Tuesday.

As hurricanes strengthen, the eyewalls, which consist of "a ring of tall thunderstorms that produce heavy rains and usually the strongest winds," according to NOAA, become tighter and more intense until they reach maximum strength in their environment.

Watch NBC6 free wherever you are

Watch button  WATCH HERE

A new eyewall may then begin to form on the outside of the previous inner eyewall, which cuts off the energy for the intense inner eyewall. This causes it to collapse and weaken.

Get local news you need to know to start your day with NBC 6's News Headlines newsletter.

Newsletter button  SIGN UP

As the outer eyewall regains organization, the storm will often re-increase in intensity.

This can take several hours (around 12 to 18) to complete.

The forecast models have extreme difficulty with predicting an eyewall replacement cycle.

Although an eyewall replacement cycle can reduce the category of a hurricane, we can also experience the expansion of the wind field. This means the hurricane force winds and tropical storm force winds begin to reach out over a larger area.

We are expected to see an expansion of the wind field as this weakens and approaches Florida.

But don’t forget: it will still be a major and dangerous storm at landfall.

Contact Us