June is the first month of the Atlantic hurricane season, and is on average the least active of the six months that make up the season. According to NOAA, the month of June has seen 92 total tropical cyclones since reliable records began in 1851. Of these 92 tropical cyclones, just 33 (35.9%) of them became hurricanes. This means that, on average, a named storm forms in June in slightly over half of all years. In uncommon cases, two or more named storms form in June, such as in 2016 with Tropical Storms Colin and Danielle. It should be noted, however, that 8 of the last 10 Atlantic hurricane seasons have had a named storm form or active in June. Major hurricanes in the Atlantic (category 3 or stronger) in June are very rare, with the most recent occurrence being Hurricane Alma in June 1966, which made landfall in the Florida Panhandle as a category 1 hurricane.

June tropical cyclones most commonly form in three areas: the Northwestern Caribbean Sea, the Gulf of Mexico and off the east coast of the United States. Perhaps the area that is most likely to have Atlantic activity in June, especially early June, is the Northeastern Gulf of Mexico. A large amount of June tropical cyclones impact the United States, with a total of 19 June landfalling United States hurricanes since 1851. June tropical cyclone impacts in the U.S. have been fairly common in recent years, with a recent example being the very disorganized Tropical Storm Colin in early June 2016, which made landfall in the Big Bend region of Florida. There are no indications of a classic early June tropical cyclone in the Northeastern Gulf of Mexico on the models, so the United States might just get lucky this June. June activity in the Atlantic Main Development Region (MDR) in the deep tropics east of the Lesser Antilles is extremely rare, but has happened (such as Tropical Depression Two in June 2003).

June Atlantic storms are known to be “big and messy.” While sea surface temperatures in June are warm enough for tropical cyclones to form in most of the Atlantic, wind shear is typically higher in June that at the peak of the Atlantic hurricane season. As a result, June storms tend to be very sheared and disorganized. It is somewhat uncommon for June hurricanes to form in the Atlantic, with the most recent example being Hurricane Chris in June 2012.

I will be back for another post tomorrow.