4 Ways Hurricane Forecasting Can Be A Headache For Meteorologists

"Uncertainty" is a word you've probably heard many times when it comes to the forecast for a tropical storm or hurricane. While that's frustrating to hear given the thirst to know what will happen, it's sometimes related to multiple forecast headaches meteorologists can encounter.

K​eep these four things in mind as we head through the 2024 hurricane season.

1​. Intensity Forecasts Are A Challenge

Intensity forecasts for tropical storms and hurricanes have improved in recent years, but they remain a big challenge for a variety of reasons. We saw this recently with Hurricane Otis in October 2023, which had a wind increase of 105 mph in 21 hours as it rocketed from a tropical storm to a Category 5 hurricane before slamming into Acapulco, Mexico.

One reason is there can be small-scale changes to the structure of a tropical storm or hurricane that lead to intensification. These subtleties are particularly difficult for forecasters and computer models to predict far in advance, especially when real-time data from inside the storm is lacking, as we saw with Otis.

Smaller storms are notoriously difficult to forecast intensity and 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.

Sometimes the atmosphere and ocean present competing intensification factors, and those can change throughout the lifespan of a hurricane. That's a complicating factor even if the track forecast is more certain.

The bottom line is there may not always be five or more days notice that a powerful hurricane is going to impact an area, so it is important to be ready. It is a good idea to prepare for a hurricane that is one category stronger than forecast.

2​. East Coast Storms And Their Crucial Northward Turn

When tropical storms and hurricanes approach the East Coast, from Florida to Maine, they are often turning in some northerly direction.

I​t can be a teeth-gnashing scenario when trying to predict how close to the East Coast a storm tracks before turning northward. That's particularly the case when a system is still days away from making that forecast turn.

A​ quicker turn north means a storm may stay safely away from the coast to only present a high surf and rip current danger. If the turn is delayed or never happens, the door is open for a storm to pummel the East Coast.

3​. When A Storm Stalls

The forecast for a tropical storm or hurricane to stall can be a headache for multiple reasons.

If the system is located near land, its slow movement can enhance the threat of flooding rain and storm surge. Figuring out how long that stall will occur matters when predicting those types of impacts.

Hurricane Harvey in 2017 is a classic example of a storm that weakened once inland, but dumped prolific rainfall on Texas after lingering for days in a weak steering environment.

I​f a tropical storm or hurricane is predicted to stall over open ocean water, it can lead to complications with predicting the future track of the system once it begins to move again.

F​urthermore, storms stuck in the same area can upwell colder water from below the ocean's surface, which then may affect the intensity forecast of the system.

4​. Unfavorable Vs. Favorable Wind Shear

Wind shear is the change in wind speed and direction with height. It's often a hostile factor that can tilt or even rip apart tropical storms and hurricanes.

B​ut sometimes, wind shear close to a storm that would normally be unfavorable can actually have the opposite effect if it's in the right location. We've seen several cases in the past where wind shear was located just far enough west of a hurricane to not disrupt its core, but instead helped ventilate the storm and allowed it to intensify.

In 2018, Hurricane Michael's rapid intensification into a Category 5 before making landfall along the Florida Panhandle was aided by that type of setup.

As you can see, sorting out whether the wind shear a storm will encounter is an unfavorable or favorable factor is yet another challenge meteorologists sometimes face.

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.