Hurricane Beryl Was An Example Of How Small Storms Have Uncertain Intensity Forecasts

H​urricane Beryl's rapid intensification into a Category 4 over the weekend is another example of how tricky intensity forecasting can be for smaller storms.

Beryl intensified much more quickly than its initial forecast: In the first forecast for the storm, released Friday afternoon by National Hurricane Center, Beryl was predicted to reach Category 1 hurricane status by Sunday, and then strengthen into a Category 2 by Monday. Instead, it quickly intensified, with winds increasing from 75 mph late Saturday afternoon to a Category 4 with 130 mph winds by late Sunday morning.

Beryl's wind field illustrated how small the hurricane was during that time: Beryl's hurricane-force wind field extended out just 15 miles from its center early Sunday morning as it was rapidly intensifying. For comparison, Hurricane Ian's hurricane-force wind field reached up to 45 miles from its center when it was approaching landfall in Florida in September 2022.

T​he expansiveness of the hurricane-force winds did grow to 30 miles outward from Beryl's center later Sunday, and then 35 miles by Monday morning, partially due to what's known as an eyewall replacement cycle.

Why smaller storms like Beryl can introduce additional forecast difficulties: For one, smaller storms can rapidly strengthen or weaken due to small changes in their environment because they contain less mass (air, water vapor, clouds) to spin up or slow down.

Another example of a storm that was able to spin up quickly because of its small size was Hurricane Humberto in 2007. Humberto first became a tropical storm on the morning of Sept. 12. It then rapidly intensified and made landfall near High Island, Texas, as a Category 1 hurricane about 19 hours later.

S​mall size can also mean a quick demise: There are other cases when the fragile nature of smaller storms contributes to a quick demise, especially if the circulation center is poorly defined.

Wind shear is a change in wind speed and/or direction with height that can rip apart a tropical storm or hurricane.

Dry, sinking air disrupts tropical storms by suppressing thunderstorms and strengthening downdrafts of storms that are able to form. That prevents thunderstorms from persisting long enough near a surface low-pressure center in order to keep the storm healthy.

Danny in August 2015 was a small hurricane that quickly succumbed to wind shear and dry air. After becoming a Category 3 hurricane with 125 mph winds in the central Atlantic, it dissipated about 72 hours later near the Caribbean.

Land interaction is another trap that smaller storms must avoid to survive: The tall mountains of Hispaniola (Haiti/Dominican Republic) are one of the more notable features in the Caribbean that are capable of quickly shredding a small circulation.

While large and more intense hurricanes are not immune to the obstacles mentioned above, they are better suited to fend them off.

Sometimes, larger hurricanes will battle one or more of those hostile factors for a period of time and eventually reorganize. Other times, they can fall apart, just like their smaller counterparts.

Chris Dolce has been a senior meteorologist with weather.com for over 10 years after beginning his career with The Weather Channel in the early 2000s.