Why Blame the Models for the Devastation of Hurricane Helene and Milton?
Flooding from extreme rainfall is the deadliest direct cause of tropical cyclone fatalities in the U.S. over the past decade.
The devastation from the 2024 hurricane season cannot be overstated. Over 90 people are dead in western North Carolina from Hurricane Helene, and over 90 are still missing nearly a month after the storm. However, less than a week after the storm, the rumor that forecasters were not using the most accurate model available crept into the national conversation. The article discusses the fallacy that models are to blame for hurricanes is discussed more in this article.
I Hate This Quote
Let’s start with the most famous quote about modeling.
“All models are wrong, but some are useful.” George E. P. Box
Box intended to emphasize that while no model can perfectly represent reality, models can still provide valuable insights. He highlighted how models should be judged based on utility rather than absolute correctness.
The trouble is that most modelers use this quote as a crutch, especially when doing post-forecast reviews.
I am from the school of thought that the Box quote is unhelpful. If the quote is true, why do we take time and effort in selecting and purchasing a model? If you adhere to the Box quote, we simply waste our resources.
Models simplify reality. He emphasized that statistical models, like other scientific models, aim to capture important aspects of systems through idealized representations.
NOAA Reviews Forecasts Annually
NOAA reviews its forecasts annually. This includes a comprehensive evaluation of their hurricane forecasts, which is detailed in the National Hurricane Center’s (NHC) annual verification reports. These reports assess the accuracy and performance of various forecast models and the official forecasts issued by the NHC.
Strengths and Weaknesses of Hurricane Models
Hurricane models generally perform well in predicting hurricanes’ overall path and intensity as they move inland. However, the accuracy decreases due to the complex interactions between the storm and land features (including inland flooding). The path and intensity over land are often well-forecasted, but local variations pose challenges.
The models do not do well at predicting rainfall amounts or rate of movement at specific locations over land.
Hurricane models are intended to forecast the overall path and intensity of the storm and do a good job of it within 48 hours of landfall.
NOAA Uses All of Its Models to Forecast
A national press article received widespread attention a week after the storm. The contention is that NOAA cannot reveal weather forecasts from a particularly accurate hurricane prediction model because of a public-private partnership agreement used to develop the model.
The model at issue is called the Hurricane Forecast Improvement Program (HFIP) Corrected Consensus Approach (HCCA). In 2023, it was deemed in a National Hurricane Center (NHC) report to be one of the two best performers in the 2023 Verification Report.
That’s good news for the public. We’re getting value for our investment.
But the core contention concerning the model is wrong. NOAA uses the HCCA model in its publicly available forecasts. The bottom line is the benefits of the HCCA model’s accuracy are reflected in the forecasts that the public receives.
What’s more, all of the models predicted the inland path of the storm with good agreement. The disaster, or its prediction, was not caused by inadequate models or a model under a public-private development agreement.
NOAA’s Special Notification Before Helene
NOAA released the following special notification the day before the storm made landfall. It is noted that the leading edges of this massive storm would already have been inland.
“UPDATED: September 25, 2024. Reporters: This is a rare news release from NOAA for an operational weather event. We urge the news media to continue focusing the public’s attention on the major impacts from inland flooding expected along the path of Helene well after landfall.”
More from NOAA’s Special News Release
Bad Weather Predicted Inland
“Hurricane Helene is predicted to make landfall Thursday evening along Florida’s northwest coast as a major hurricane, but NOAA’s National Weather Service is alerting communities that Helene’s flooding rainfall and high winds won’t be limited to the Gulf Coast and are expected to travel hundreds of miles inland.
Heading for the Southern Appalachians
“Helene is an unusually large storm whose wind field extends as far as 275 miles from its center. Even well before landfall, heavy rainfall will begin in portions of the southeastern United States [download these forecast graphics], and will continue to move northward into the southern Appalachians region through Friday where storm total rainfall amounts are forecast to be up to 18 inches.
A Major Flood Risk for Western NC
“The major flood risk includes the urban areas around Tallahassee, metro Atlanta and western North Carolina, including Asheville. Recent rainfall in these areas, especially the southern Appalachians, have left the grounds saturated and the river tributaries running high. Additional rainfall from Helene will exacerbate the existing flood risk. Extreme rainfall rates (i.e., torrential downpour) across the mountainous terrain of the southern Appalachians will likely inundate communities in its path with flash floods, landslides, and cause extensive river and stream flooding.
“Gusty winds, combined with saturated ground, will also raise the risk of falling trees that can cause loss of life, property damage, blocked roads, and lead to power outages.”
How Did the Hurricane Models Perform?
Several hurricane models predicted Hurricane Helene’s track, which included significant impacts over North Carolina. The National Hurricane Center (NHC) and other forecasting agencies use a variety of models to predict hurricane paths and intensities. These models provided forecasts that closely matched Helene’s actual track.
Don’t Blame the Models
There’s been talk about models being to blame for the recent devastation and slow recovery response. Nothing could be further from the truth. Blaming a model is just a cover for the slow response in other areas of recovery. The one thing we have is accurate models of where and how intense a hurricane will be within 48 hours of landfall.
References
JD Solomon resides in the Carolinas, where he fishes, sails, and coaches baseball. Professionally, JD Solomon is the founder of JD Solomon, Inc., the creator of the FINESSE fishbone diagram®, and the co-creator of the SOAP criticality method©. JD has weathered many storms, both on land and at sea.
