Trenberth speculates the latest high-resolution weather models over-intensify tropical systems that assume a constant sea-surface temperature, not fully taking into account their cold wake. Accurate prediction of hurricane eyewall replacement cycles and intensification may require near-real-time, high-resolution data from the upper oceans and Gulf of Mexico.
“The European Center for Medium-Range Weather Forecasts is probably leading in terms of doing coupled weather forecasts,” Trenberth admitted, adding that the U.S. National Centers for Environmental Prediction “has been playing with this and making some progress.”
So, the challenge remains: How can we accurately predict the future when we can’t get an accurate snapshot of what’s happening right now, both atmospheric and oceanic?

Left: An Argo float. Right: An ALAMO float, a cousin of the Argo float, diving. (Coastal Studies Institute, left; Robert Todd, WHOI)
Data from the Argo network of nearly 4,000 drifting floats in the world’s oceans could be programmed to provide deep-sea temperature data more frequently, close to real time during hurricane scenarios. Right now, Argo data updates roughly every 10 days.
“In places like the gulf and East Coast, they could program those to come up and down more frequently,” Trenberth speculated. “The result would be a more comprehensive understanding of upper-ocean water temperature profiles, giving forecasters the ability to gauge whether a hurricane’s cold wake may be resupplied with additional warming at the surface, thus prolonging the storm.”

Global Argo array. (Argo Information Center)
Accurate prediction of increasingly powerful (and wet) hurricanes requires increasingly sophisticated and coupled models combining atmospheric measurements with regional hot spots of unusually warm and deep-ocean water. Hurricanes don’t follow identical tracks, because the next hurricane can “feel” where a previous hurricane has been. Trenberth’s take: “Until we properly put those kinds of factors into our models, we’re not going to quite get those tracks right.”
But regional hot spots of unusually warm, deep water may have implications beyond fueling hurricane strengthening and rainfall prediction. Nontropical cyclones, the bread-and-butter low-pressure systems that parade across our daily weather maps, also may be affected, especially the redevelopment of East Coast storms, feeding on tropical warmth and moisture.
“This can lead to some intensification, but it’s also apt to lead to development out ahead of the storm, so it affects the actual track of the storm,” Trenberth said. “It may also lead to some increase in the size of the storm.”

The aftermath of Hurricane Michael in Mexico Beach, Fla., on Feb. 24.
Weather data and high-resolution mapping are more accessible; weather model physics continues to advance and improve, but Hurricanes Harvey, Florence and Michael are reminders that the most accurate forecasts of track, intensity and rainfall require extensive, real-time analyses of ocean heat content, and not just at the surface. With rising carbon dioxide levels in the atmosphere, warming oceans fueling increasingly potent hurricanes makes real-time, deep-ocean data a necessity, not a luxury.
Tropical researchers are making great strides, but Hurricane Michael’s remarkable, last-minute intensification into a catastrophic 155-mph monster, just 2 mph shy of Category 5 strength, before leveling parts of the Florida Panhandle in October, underscores the urgency of removing biases in coupled air-sea models. Such advancements will provide meteorologists the tools necessary to improve tropical cyclone track and intensity forecasts — and save lives.
Paul Douglas is co-author of “Caring for Creation: The Evangelical’s Guide to Climate Change and a Healthy Environment” and co-founder and senior meteorologist at AerisWeather, located in the Twin Cities of Minnesota.