Hurricane predictions forecast the position, strength, and timing of a tropical cyclone over several days. These forecasts combine sophisticated technology with the judgment of experienced meteorologists to produce the most likely outcome. The overall accuracy of a hurricane forecast is not uniform, as it depends heavily on the specific factor being measured and how far into the future the prediction extends. Accuracy varies significantly between a storm’s predicted location and its predicted intensity.
The Dual Metrics of Hurricane Forecasting
Hurricane prediction is fundamentally divided into two distinct challenges, measured and reported separately due to their different levels of predictability. The first challenge is forecasting the path or location, referred to as the track. This involves determining the route the center of the storm will follow and where it might eventually make landfall.
The second, more difficult challenge is forecasting the strength, known as the intensity. This involves predicting the storm’s maximum sustained wind speeds, central pressure, and its category on the Saffir-Simpson Hurricane Wind Scale. Track and intensity are measured independently because the physical processes driving each are different.
Reliability of the Forecast Track and Cone
Track prediction has seen substantial improvement over the last two decades, with the average error for a five-day forecast shrinking dramatically. The path of a storm is primarily governed by large-scale atmospheric steering currents, which are well-captured by modern forecasting models. For instance, the National Hurricane Center’s track forecasts achieved record accuracy in the 2024 Atlantic hurricane season at every time interval from 12 to 120 hours.
The public receives track forecasts through the “cone of uncertainty,” which graphically represents the probable track of the storm’s center. This cone is created by enclosing the area swept out by circles of error margins along the forecast path. The size of these circles is determined by the average historical forecast errors over the past five years, meaning the cone constantly shrinks as forecast accuracy improves.
The cone is designed so that the center of the tropical cyclone remains within its boundaries approximately two-thirds of the time (60 to 70% of historical cases). This means there is still about a one-third chance that the storm’s center will track outside the cone, so coastal residents should not view the cone’s edges as absolute boundaries. Reliability decreases significantly as the time horizon extends, with a 24-hour forecast being far more accurate than a 120-hour (five-day) forecast.
Limitations in Predicting Storm Intensity
Predicting a hurricane’s intensity is much more challenging than predicting its track, and improvements have been slower. Intensity is driven by internal storm dynamics and interactions with the immediate environment, occurring on a much smaller scale than the broad steering currents that determine the track. These micro-level factors, such as the organization of thunderstorms around the storm’s core, are difficult for models to resolve.
A major source of error is the difficulty in forecasting “rapid intensification” (RI), defined as an increase in maximum sustained winds of at least 30 knots (about 35 mph) in a 24-hour period. Most major hurricanes undergo this process, often fueled by very warm ocean heat content and low vertical wind shear.
In 2024, the Atlantic basin saw 34 episodes of rapid intensification, nearly double the recent 10-year average, making accurate intensity forecasting difficult. While there has been a gradual reduction in intensity forecast errors, the ability to predict sudden, extreme strengthening remains the greatest hurdle.
The Role of Computational Models in Forecasting
Modern hurricane accuracy is built upon numerical weather prediction (NWP) models that run on supercomputers. These models take observational data from satellites, weather balloons, and aircraft, and use the fundamental equations of physics to simulate the atmosphere’s future state. The outputs from these models form the foundation of the official hurricane forecast.
Two globally recognized models are the American Global Forecast System (GFS) and the European Centre for Medium-Range Weather Forecasts (ECMWF). The ECMWF model has historically held a slight edge in long-term track accuracy, but all models are continually being upgraded. Forecasters do not rely on a single model run but instead synthesize the outputs from dozens of different models.
To better gauge uncertainty, forecasters utilize ensemble forecasting, which involves running a single model multiple times with slightly varied initial conditions. This process generates a family of alternative predictions, or “members,” which helps to capture the range of possible outcomes. Forecasters use this range of solutions and their professional experience to create the final official prediction for both track and intensity.