NOAA forecasts a much stronger than normal 2024 hurricane season. This official U.S. government forecast of a very active season is consistent will all of forecasts by experienced hurricane specialists. However, the forecast number of storms does not reflect the potential severity of the situation this year. The heat content in the main development region for Atlantic hurricanes is at unprecedented levels for June and models predict it will continue to increase to a record high in September. The heat content in the Caribbean and the Gulf of Mexico has risen to extremely high levels over the past sixty days. Oceanic conditions are already very favorable for major hurricanes in the Caribbean and Gulf of Mexico. Early season high wind shear is the one thing that has been holding the hurricane season back atmospheric conditions has become more favorable for tropical storm development this week near the continental U.S. An atmospheric vortex, called the Central American gyre has formed and one or more tropical storms may develop in the Gulf of Mexico from this large region of low pressure centered around Central America.
The ECMWF, the European Centre for Medium-Range Weather Forecasts, predicts the 2024 Atlantic hurricane season will end with 200% the average accumulated cyclone energy (ACE). ACE is a better estimate of the severity of a hurricane season than the total number of storms because it is based on the maximum wind speed of storms over the series of 6 hour increments of the life of the storm. It’s not a perfect measure because it does not consider the size of the storm. The most active year for total number of storms was 2020, but it only had 150% of average ACE. Technological improvements have increased the number of observed weak storms. An ACE of 240 would place 2024 as one of the most active years on record based on ACE calculations made for storms in both the modern record and less well documented historical record.
The combination of atmospheric conditions (not considering wind shear) and water temperatures in the North Atlantic is already capable of supporting hurricanes as intense as category 5 across a wide area from Africa to the Caribbean to the Gulf of Mexico. Wind shear and early season dry air and dust makes an intense storm very unlikely in June but the water is warm enough. When wind shear and Saharan dust drops in August and September, models show extremely favorable conditions for major hurricanes. I will show those model results as the hurricane season progresses.
The first storms forming from the Central American Gyre are unlikely to cause any major problems except for possible flooding in Mexico and southern Texas, but this is just the beginning to what could be one of the strongest hurricane seasons on record. In future posts I will look at possible storm tracks and impacts.