The 2024 Atlantic Hurricane Season started off hot, with four storms so far from June to early August. But after a bit of a quiet stretch through July, what does the future have in store for the rest of the season? And has our forecast changed? Let's first start off by recapping what we've seen so far:
As mentioned above, we've had quite an active start to the season since it officially began on June 1st. A total of 4 named storms have developed since then; Alberto, Beryl, Chris, and Debby.
Tropical Storm Alberto: The first storm of the season, officially was given the designation "Potential Tropical Cyclone One" on June 17th, eventually becoming a tropical storm two days later. The system formed over the Bay of Campeche, which gradually intensified as it approached the Mexican coastline. It peaked as a mid-tiered tropical storm with maximum sustained winds of 50 mph and a minimum pressure of 993mb before making landfall near Tampico, Mexico on June 20th.
Image Courtesy of NOAA
Impacts: While not a strong system, it brought very heavy rainfall to Mexico, bringing upwards of 12 inches to parts of the area. It also produced 2-4ft of storm surge across Freeport and Galveston, TX, as well as spawning a few tornadoes.
Major Hurricane Beryl: The second storm of the season, and the strongest so far, started out initially as a tropical wave that moved off the Cape Verde Islands on June 25th. The disturbance was eventually given the designation of Tropical Depression Two on June 28th. Given the abnormally warm Sea Surface Temperatures (SSTs) and minimal wind shear in the environment out ahead of the young system, it provided a perfect opportunity for rapid intensification. This is exactly what happened, as the depression went from becoming Tropical Storm Beryl on the 29th to a Category 3 Major Hurricane on the 30th. It cycled between Category 3 and 4 strength before making landfall in Carriacou, Grenada on July 1st with maximum winds of 150 mph. A day later, it ramped up to a Category 5 storm with peak winds of 165 mph before weakening back down to a Category 4 that same day.
Image Courtesy of NOAA
The storm surprisingly held its major hurricane strength well, despite encountering drier air and increasing wind shear to the north. It made a close approach to the southern coast of Jamaica on July 3rd. It weakened even more, becoming a Category 2 storm with sustained winds of 110 mph before its second landfall NE of Tulum, Mexico on July 5th. Beryl managed to escape the mountainous region of the Yucatan in one piece, emerging into the Gulf of Mexico as a tropical storm early on July 6th. While not as ideal as the conditions in the Caribbean, Beryl managed to stay longer over the warm waters of the Gulf, re-intensifying back into a Category 1 Hurricane before making its final landfall near Matagorda, TX with sustained winds of 80 mph. The system weakened as it headed farther inland, with the remnants tracking through the Mississippi Valley and eventually toward the Great Lakes.
Impacts: This was by far, the most memorable storm this season, bringing over 6.2 Billion Dollars in damage to the Virgin Islands, Mexico, and the United States. Beryl caused the worst damage over the Virgin Islands, with Grenada's northern islands seeing the most catastrophic damage. As the storm made it's third landfall in the US it lead to numerous areas of flooding and widespread power outages in and around the Houston Area. Beryl also produced a tornado outbreak from July 8th-10th, producing 67 from Texas to New York State.
Tropical Storm Chris: The third and latest storm of the season formed from a tropical wave that moved into the Gulf of Campeche on June 30th. It was given the designation of Tropical Depression Three, then quickly became Tropical Storm Chris with maximum sustained winds of 40 mph before making landfall in Vega de Alatorre, Mexico.
Impacts: While a quick and weaker storm, it produced very heavy rain for parts of Mexico, causing flooding and numerous mudslides.
Image Courtesy of NOAA
Hurricane Debby: Debby formed from a massive tropical wave that exited Africa during the height of the outbreak of Saharan Dust. Because the wave was so large, it was able to insulate itself from the dry and basically wait until it reached the warmer waters around 60 W to begin to develop. Pre-Debby would then go on to track through Puerto Rico, Hispaniola, and eventually Cuba. Finally, the system was able to become a tropical depression in the Gulf of Mexico, though the strengthening was slow and steady.
Just like Beryl, the storm was able to intensify into the coast where it made landfall as a Category 1 hurricane with sustained wind around 80 mph. Debby would then go on to produce extremely heavy rainfall amounts in addition to several tornadoes over the Southeast. The storm took a track back over water and briefly strengthened back to a 60 mph tropical storm before its final landfall near Bulls Bay, South Carolina. The storm continued to weaken and head north into the northeast and eventually Canada after becoming a post tropical system.
Impacts: While being a hurricane only during it's first landfall, Debby brought different types of impacts across a wide swath of the United States. Starting in Florida, over 13 million dollars in damage were reported in Manatee County alone, along with taking out power to hundreds of thousands. The worst of the storm was arguably during it's second phase of life, as it moves north and slowed to a crawl off the coast of Georgia and the Carolinas. Catastrophic flooding with over a foot of rain left many places underwater. Debby continued to weaken heading from Virginia into Upstate NY, but brought additional rainfall, gusty winds, and even a handful of tornadoes.
Image Courtesy of NOAA
Overall, our thoughts from the first hurricane season outlook back in May haven't changed all that much. While we haven't seen a tremendous number of storms so far, two out of the four that have occurred have been landfalling hurricanes along the US Gulf Coast. This is an impressive feat for it only being early August and this actually puts us ahead of some of the more active years in terms of landfalling hurricanes. So, how does our observed activity stack up against some of the bigger years?
Even some of the most active years on record like 1933 and 2005 saw relatively quiet periods before returning to an exceptionally active stretch. The point here is that early season activity has little to no correlation with how the remainder of the season will play out. Finally, there's been some chatter that the overall slow development of the La Nina may hinder the season but really doesn't seem like it will be the case. In fact, cool-neutral years, which is where we're at right now are actually on par with La Nina years when talking about landfilling hurricanes.
Figure showing the distribution of landfilling hurricanes based on ENSO phase
So, what's next? Over the next several days, we'll see the pattern across the Northern Hemisphere begin to shuffle around, which will introduce large-scale sinking air over the Eastern Pacific. This will effectively shut the basin down as rising motion moves through the Atlantic and parks itself over Africa. Tropical wave activity over Africa has been above average, though dry air has helped to really weaken these waves in the last few weeks as they splash down into the Atlantic. Once this pattern shift happens, it's quite likely that we'll enter a rather active period, perhaps as early as the third week of August. It's too early to say how long this period may last, but large-scale rising motion over Africa may very well linger deep into September (typical for La Nina years). While you don't necessarily need this setup to have an active peak; this certainly could help provide the boost necessary to sustain elevated levels of hurricane activity for a prolonged stretch of time.
One thing has become clear about this season: we're not seeing the near-constant development of weak tropical cyclones only lasting a short while, like the excessively active years of 2020 and 2021 out in the open Atlantic. While this will likely keep the overall named storm count down a bit (likely lower than 20), it may mean we're in for a dangerous second half of the season similar to 1995, 2010, or even 2017. These years all had back-loaded seasons that were filled with long-track hurricanes (more of a quality vs. quantity situation). Of course, these long-track hurricanes are quite dangerous and garner a ton of attention, though there are "sneaky" threats we'll have to watch for in the coming months.
Loop of sea surface temperature anomalies from recent active hurricane seasons
Something we'll have to keep a very close eye out for are the tropical waves that exit the coast of Africa and don't immediately develop. These waves can fly under the radar for days, with little to no model support until they're close to the United States coast. This is the exact situation we saw with the tropical wave that eventually became Hurricane Debby. As we get deeper and deeper into the season conditions will only become more favorable and coupled with record-warm sea surface temperatures, anything that does happen to find the "goldilocks" spot in the Atlantic will have the opportunity to intensify at a quick pace close to land.
Of course, we'll have to see how things play out, but it's important to remain vigilant as we draw closer to the peak of the hurricane season as things can change in a hurry!
