Hurricanes Matthew (2016), Irma (2017), and Michael (2018) were three of 10 storms that grew into Category Five Hurricanes since 2015. Those ten monster storms represent 53 percent of all the Cat Five storms in the last 30 years and nearly a quarter of all such storms on record.
2025 Atlantic Hurricane Season Fast Approaching
The countdown to the 2025 Atlantic Hurricane Season has begun. Yesterday marked a month until the first day of the season. Typically, the Atlantic season begins on June 1st and lasts until November 30th. Statistical peak is on September 1st. There has been a great deal of chatter on the outlook for the season, especially since government cuts to NOAA and the NWS may have an impact on how these storms are tracked and forecasted. Hurricaneville’s Tracking the Tropics takes a look at seasonal forecasts, ENSO, rainfall across Africa, and sections of the Atlantic Basin for any signs of trouble.
2025 Seasonal Forecasts
There have been several seasonal forecasts issued already. NOAA’s annual forecast will most likely be issued later this month. The first and most significant forecast was issued by Colorado State University. The trailblazer of Atlantic Hurricane Season forecasts is calling for an above-normal season in 2025 with 17 named storms, 9 hurricanes, and 4 major hurricanes.
Researchers at North Carolina State are a bit more pessimistic with their outlook. The NCSU forecast is calling for a more average season with anywhere from 12 to 15 named storms, 6 to 8 hurricanes, and 2 to 3 major hurricanes. Accu-Weather is calling for a “dynamic” season for the Atlantic Basin in 2025. The tropical forecast team at Accu-Weather expects anywhere from 13 to 18 named storms, 7 to 10 hurricanes, and 3 to 5 major hurricanes.
The Weather Channel’s forecast is even more enthusiastic. The TWC team indicates that there will be 19 named storms, 9 hurricanes, and 4 major hurricanes. WeatherBELL shares similar optimism. The WeatherBELL forecast projects there will be anywhere from 15 to 19 named storms, 7 to 9 hurricanes, and 2 to 3 major hurricanes. Tropical Storm Risk, based in the United Kingdom, is more constrained in its outlook, which matches the current 30-year average of 14 named storms, 7 hurricanes, and 3 major hurricanes.
| Seasonal Forecast | Named Storms | Hurricanes | Major Hurricanes |
| Colorado State University | 17 | 9 | 4 |
| North Carolina State University | 12-15 | 6-8 | 2-3 |
| Accu-Weather | 13-18 | 7-10 | 3-5 |
| The Weather Channel | 19 | 9 | 4 |
| WeatherBELL | 15-19 | 7-9 | 2-3 |
| Tropical Storm Risk | 14 | 7 | 3 |
| 2024 Season | 18 | 11 | 5 |
| 10-Year Average | 18 | 8 | 4 |
| 30-Year Average | 14 | 7 | 3 |
| 70 Year Average | 11 | 6 | 2 |
Category Five Storms More Prevalent
In addition to these forecasts, the Mann Group out of the University of Pennsylvania is calling for an average year with 14 named storms. Last year, this team, led by Dr. Michael Mann, called for 33 named storms. It is very important to remember though that all it takes is one storm.
Looking at the 10-year average, there have been 18 named storms, 8 hurricanes, and 4 major hurricanes. A grave concern is the increasing number of Category Five Hurricanes. Over the past 10 years, at least one Cat 5 storm has developed in seven seasons with an average of one per year.
Going further back to when this most recent active tropical cycle began in the Atlantic, Category Five Hurricanes became more prevalent during the 2000s. Going back to 1995, there have been 19 major hurricanes that have reached this optimum level.
So, approximately 53 percent of all Category Five Hurricanes over the last three decades have occurred in 7 out of the last 10 years. Since records have been taken, there have only been 42 storms that have grown into Cat Five intensity. Therefore, nearly a quarter of all Category Five Hurricanes on record have happened in 7 out of the last 10 Atlantic Seasons.
A Look at ENSO
For those, who may not be familiar, ENSO stands for El Niño-Southern Oscillation. According to NOAA, ENSO “is one of the most important climate phenomena on Earth due to its ability to change the global atmospheric circulation, which in turn, influences temperature and precipitation across the globe.” ENSO consists of three phases: El Niño, La Niña, and Neutral.
During El Niño, sea surface temperatures become warmer in the Central and Eastern Tropical Pacific. The impact of an El Niño is significant on tropical weather not only in the Central and Eastern Pacific but also in the Atlantic.
While there are more tropical storms and hurricanes in the Central and Eastern Pacific, there are fewer in the Atlantic. The reason for this is because storms in the Eastern Pacific come ashore into Western Mexico and Central America, and create hostile upper level conditions that hinder the formation and development of Atlantic storms.
In a La Niña episode, the opposite happens. Sea surface temperatures become cooler in the Central and Eastern Tropical Pacific. As a result, fewer storms form in those basins. Fewer storms make landfall in Western Mexico and Central America, which benefits the Atlantic Basin. When there are less storms coming in from the Eastern Pacific, there is less wind shear or upper level hostility to tropical formation and development in the Atlantic.
When there is a neutral phase, the sea surface temperatures in the Central and Eastern Pacific are just right. Not too warm, or above normal, and not too cool, or below normal. Consequently, tropical development in the Central and Eastern Pacific is normal or similar to the long term average. The upper level winds in the Atlantic will be normal.
As the 2025 Atlantic Hurricane Season approaches, ENSO is currently in a neutral state. However, ENSO is expected to transition later this summer, and there is uncertainty on which direction it will go. So, we will need to look at other factors such as sea surface temperatures around the Atlantic Basin as well as rainfall in the Sahel region of Africa.
Rainfall in the Sahel
One of the key factors in the lack of storms during August and the early part of September in 2024 was the storms across Africa. These storms traverse the African continent east to west through the Sahel region. When these storms move into the Eastern Atlantic near the Cape Verde Islands, they become tropical waves that could develop into the tropical depressions, storms, and hurricanes you hear about year after year.
Going back to last year’s peak season period, these storms were traveling further north than normal and even bringing rainfall to the Sahara. As a result, many tropical waves embarked into the Eastern Atlantic further north along the West Coast of Africa, which made them more likely to turn out to sea rather than effect the United States, Bermuda, and the Caribbean. Could this happen again this year? Perhaps.
Taking a look at what is happening in the Sahel region of Africa right now, rainfall is expected to be average to above normal according to the Regional Climate Centre for West Africa. From Senegal to Chad, “average to high cumulative rainfall (total amount of rain observed over a given period) is expected during the months of June-July-August 2025.”
Therefore, expect a normal tropical conveyor belt to develop this season.
Sea Surface Temperatures in the Atlantic Basin
Looking at the ocean surface across the Atlantic Basin, the sea surface temperatures are still above normal, but not as much as they have been over the past year or two. More importantly, the SST’s in the Central and Eastern Atlantic have cooled down.
Keep in mind though that although last year’s SSTs in these regions were above normal, there still wasn’t a lot of activity during peak season. One instance, where the SSTs proved to be a huge factor was during the historically explosive development of Hurricane Beryl in June 2024.
The Western Caribbean and Gulf of Mexico still remain quite warm. These two portions of the Atlantic Basin played pivotal roles during the tracks of both Hurricane Helene and Hurricane Milton. Areas in the Gulf such as the loop current play a significant role in the explosive development of hurricanes. The monster storms of 2005 such as Katrina, Rita, and Wilma are prime examples.
Currently, the temperatures around the Gulf and Northwestern Caribbean range from the upper 70s to the low 80s. In order to have tropical formation and development, sea surface temperatures must be at least 80 degrees. So, the western portion of the Atlantic Basin is already well on its way to being conducive towards development.
The Bermuda High
One key player in the Atlantic is the subtropical ridge in the Western Atlantic known as the Bermuda High. Over the last month or so, it has made quite an impact on the weather over the Eastern half of the United States.
At Greg’s Weather Center in South Plainfield, NJ, there have already been 7 days with high temperatures of at least 80 degrees. The southwesterly flow around the Bermuda High has had a lot to do with that as well as the severe weather that has been occurring in the Upper Mississippi and Ohio Valleys.
This vast area of high pressure in the Western Atlantic also impacts tropical storms and hurricanes. Tropical systems in the Atlantic look for areas to exploit between ridges and troughs. Hurricanes use subtropical ridges as a steering current to guide them westward.
Remember, tropical storms and hurricanes move east to west, which is why subtropical ridges are so important because their clockwise flow help steer the storms. The stronger the ridge is, the more likely a tropical storm or hurricane will be suppressed to the south and move across the Caribbean, South Florida, and into the Gulf rather than up the Eastern Seaboard.
Indications thus far this spring show that there could be more systems going into the Western Caribbean and the Gulf come this tropical season.
Today’s Look at the Tropics
Currently, there are no storms expected in the Atlantic Basin for the time being. Back in March, there was a flare up of activity that drew the attention of the National Hurricane Center. The NHC was monitoring an area of disturbed weather to the northeast of the Leeward Islands on March 17th. Fortunately, the chances for development were very low, and it eventually fizzled out.
Overall, the Tropical Atlantic is quiet and tranquil. There are a couple areas of high pressure off the East Coast of the United States including our Bermuda High. There is a trough of low pressure in the Central Atlantic about a few hundred miles to the east of the Lesser Antilles. There is a minor trouble spot in the extreme Southwestern Caribbean near Colombia and Panama thanks to the eastern portion of the Pacific monsoon trough.
No development is expected at this time.