At 11 p.m. EDT on Sunday, the National Hurricane Center upgraded a disturbance in the central Atlantic to Tropical Storm Chantal (pronounced ‘shahn-TAHL’), the third named storm of the season. As of 8 a.m. EDT this morning, the storm has maximum sustained winds of 40 mph, is racing westward at 26 mph, and is about 600 miles east of Barbados. On this trajectory, the center will reach the Lesser Antilles by midday Tuesday.

Visible satellite image of Tropical Storm Chantal from 7:45 a.m. EDT (NOAA)

Chantal developed from a potent easterly wave that left the African coast on July 3, well ahead of the typical start of the “Cape Verde” season (named for the Cape Verde islands off the west coast of Africa near 15N). Usually we don’t see these types of systems for at least another month. But, large-scale signals continue to indicate that 2013 will be a busy hurricane season, and Chantal may be a harbinger.

The official National Hurricane Center 5-day forecast takes Chantal into the eastern Caribbean as a tropical storm on Tuesday, then near or south of Puerto Rico and Dominican Republic on Wednesday, eastern Cuba and/or the southern Bahamas on Thursday, and southern Florida and/or northern Bahamas on Friday (see “Forecast Cone Refresher”). The possible encounter with the mountains of Hispaniola and Cuba substantially increases the uncertainty in the intensity forecast. Some storms can re-organize fairly quickly, and some never do. You can find the most recent forecasts and relevant watches/warnings on the National Hurricane Center website.

Five-day forecast for Chantal. (

If we look for past examples of storms that tracked near Chantal’s current position during the month of July, only Emily in 2005 stands out as significant, with a small handful of weaker storms. But if we extend the criteria to include the entire hurricane season, the list grows dramatically to include some of the most infamous names in Atlantic hurricane history (Dean 2007, Emily 2005, Ivan 2004, Lili 2002, Joan 1988, Allen 1980, Frederic 1979, David 1979, Betsy 1965, Dora 1964, Fort Lauderdale Hurricane of 1947). So, if Chantal ends up becoming a strong hurricane this early in the season, that makes the mega-season of 2005 look a bit more analogous.

Past tracks of July (top) and all (bottom) storms that passed within 200 miles of Chantal’s current position. (NOAA/CSC)

As far as the longer range forecast goes, all options are on the table, from entering the Gulf of Mexico to heading up the U.S. East Coast. Most models (and ensemble members of those models) are presently leaning more toward an East Coast scenario, particularly from Florida into the Carolinas this coming weekend. We’ll keep you updated with the latest information and track scenarios as the time gets closer. As of today, it’s too early to be overly concerned about the U.S. impact, but those with coastal interests should pay close attention as we get deeper into the week.

Brian McNoldy is a senior researcher at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science.