Meteorologists at Colorado State University think as many as four major hurricanes with winds exceeding 110 mph will form in the Atlantic Basin during an active 2013 hurricane season. And they think it’s likely that at least one of those catastrophic storms will make landfall somewhere on the U.S. coast from Maine to Texas.
CSU meteorologists think the stormy summer will be fueled by unusually warm waters in the Atlantic Ocean, Gulf of Mexico and Caribbean Sea. Hurricanes and tropical storms — the seeds from which hurricanes grow — draw their energy from seawater that has been warmed to at least 80 degrees Fahrenheit.
Meteorologists Phil Klotzbach and co-author William Gray don’t think a hurricane-suppressing weather event known as an El Niño is likely to occur this year.
“The tropical Atlantic has anomalously warmed over the past several months, and it appears that the chances of an El Niño event this summer and fall are unlikely,” Klotzbach said.
An El Niño occurs when waters in the eastern Pacific Ocean off the coast of South America are warmer than usual. When this happens, it can cause upper level winds — known as wind shear — to form over the tropical Atlantic. The wind shear makes it more difficult for tropical storms to form, and when they do form, the vertical winds can disrupt their momentum and prevent them from developing into more powerful storms.
The overall CSU forecast predicts that 18 named storms with winds of at least 35 mph will form between June 1 and November 30. Nine of those storms will develop into hurricanes with winds exceeding 74 mph.
Other predictions in the forecast include:
• A 72 percent probability that a major hurricane will make landfall somewhere on the U.S. Gulf or Atlantic coasts. The average probability for U.S. landfall for the last century is 52 percent.
• A 48 percent chance that a major hurricane will strike the U.S. East Coast. The average likelihood for the past 100 years is 31 percent.
• A 47 percent chance that a major hurricane will come ashore somewhere on the U.S. Gulf Coast from the Florida peninsula to Brownsville, Texas near the U.S.-Mexico border. The average for this region for the past 100 years is 30 percent.
• A 61 percent probability that a major hurricane will strike land somewhere in the Caribbean Sea. The average for the Caribbean for the last century is 42 percent.
If the forecast for the 2013 hurricane season is accurate, it will continue a trend of active hurricane seasons that started in 1995. Meteorologists think hurricane activity is influenced by cyclical fluctuations in the salt content of seawater. When the salt content is higher — as it is now — water temperatures are warmer and more hurricanes tend to form.
These cycles can last 20 years or more.
The CSU meteorologists will update their forecast on June 3. The full preseason forecast by Klotzbach and Gray can be viewed at CSU’s Tropical Meteorology website.
Willie Drye has been writing about hurricanes and other topics for National Geographic News since 2003. He is also writing a book about the Florida land boom of the 1920s.