2025 Atlantic hurricane update

 

Keeping an eye on the tropics at the shore

The peak of the Atlantic hurricane season in September is quickly approaching. That's when atmospheric and environmental conditions are the most favorable for tropical storm and hurricane development. Earlier this week NOAA updated its seasonal hurricane forecast to reflect the tropical activity over the first two months of the season.

NOAA's updated forecast currently expects a seasonal total of 13-18 tropical storms, of which 5-9 could become hurricanes, with 2-5 major hurricanes. This includes the four tropical storms that have already developed. An "average" hurricane season features 14 tropical storms, 7 hurricanes and 4 major hurricanes. The two primary reasons NOAA scientists expect an average to slightly above average season are warmer ocean water over the tropical Atlantic and the lack of El Nino or La Nina conditions.

One of the trademarks of La Nina conditions in the tropical Atlantic is a reduction in the amount of wind shear. Wind shear refers to winds that change in both speed and direction at different levels of the atmosphere. Less wind shear means conditions are more favorable for tropical development. El Nino conditions often produce more wind shear in the tropical Atlantic that creates less favorable conditions for tropical development. The absence of both are expected to continue into the fall.

The four tropical storms that have already developed this season have been relatively weak and short-lived. Only Chantal made landfall in the United States as a 60 mph tropical storm in South Carolina on July 6. No hurricanes have developed anywhere in the Atlantic Ocean since last November.

The National Hurricane Center doesn't expect any other tropical storms to develop in the Atlantic over the next few days. However, they’re watching the tropical Atlantic for a disturbance that could become Tropical Storm Erin next week.

As recent seasons have shown, things in the tropical Atlantic can ramp up in a hurry. The 2017 Atlantic hurricane season, for example, got markedly more active in late-August, starting with Hurricane Harvey. September 2017 saw four major Atlantic hurricanes, including two Category 5 powerhouses (Irma and Maria). 

The 2020 Atlantic hurricane season had more named tropical storms than any season on record.  It was a back-loaded season with four major hurricanes after October 15. That’s not to say this season will feature similar trends as 2017 or 2020, but atmospheric and environmental conditions are the most conducive for tropical development in September.

August storms can be catastrophic

 

Hurricane Charley, August 2004 (Source: NOAA)

The hurricane season often gets much busier during the month of August. Below are some of the high-impact August hurricanes that made landfall in the United States in recent decades.

Ida (2021): Ida reached peak intensity over the northern Gulf of Mexico as a powerful Category 4 hurricane with sustained winds of 150 mph. It made landfall at Category 4 intensity in Port Fourchon, Louisiana on August 29. It caused widespread damage not only along the U.S. Gulf Coast, but inland areas as well. 

The D.C. Metropolitan Area had heavy rain and severe weather due to the remnants of Ida. A September 1 rainfall record of 4.13” was reported at BWI Airport. Several tornadoes were reported in the DMV (D.C., Maryland and Virginia), including an EF-2 in Anne Arundel County that caused a lot of damage in suburban Annapolis, Maryland. Ida ranks as the sixth costliest hurricane in U.S. history with $84.6 billion worth of damage (2024 dollars), according to NOAA. Ida also claimed nearly 100 lives in the United States.

Harvey (2017): Harvey was a Category 4 hurricane with sustained winds of 130 mph at peak intensity. When Harvey made landfall in Texas late on August 25, it was the first major hurricane to make landfall in the United States since Wilma in 2005. Unfortunately, Harvey was a slow moving storm that left widespread damage both at the coast and inland. 

Devastating flooding ensued with four-foot rainfall totals in spots. Harvey remains the second costliest hurricane on record in the United States, having caused approximately $160 billion in damage (2024 dollars). Dozens of fatalities resulted from Harvey, according to NOAA.

Katrina (2005): A powerful Category 5 hurricane over the Gulf of Mexico less than 48 hours before making landfall, many feared Katrina was the doomsday scenario for the U.S. Gulf Coast. Fortunately, Katrina weakened to a Category 3 hurricane before making landfall east of New Orleans on August 29. However, because Katrina was such a large and intense hurricane, its storm surge was commensurate with a stronger hurricane. 

Katrina became the costliest hurricane in U.S. history, according to NOAA. Katrina caused approximately $201.3 billion in damage (2024 dollars), with a death toll of more than 1,800 in the United States.

Charley (2004): Just a year earlier, the west coast of Florida saw another very powerful hurricane. After making landfall in Cuba as a Category 3 hurricane, Charley entered the Gulf of Mexico where it became even stronger. Initially, it was feared that it would make landfall in the major urban area of Tampa-St Petersburg. However, Charley’s path shifted and it came ashore near the town of Punta Gorda (south of Tampa) as a Category 4 hurricane on August 13 with sustained winds of 150 mph. 

It was the strongest hurricane to make landfall in the United States since Andrew in 1992. Charley left roughly $26.7 billion in damage (2024), with an estimated death toll of 15.

Where did the summer go?

NOAA's August 2025 temperature outlook

Following the tenth hottest July in the nation’s capital, a major shift in the weather pattern has temperatures feeling more like September. That's especially welcome news, since August is traditionally the second hottest month of the year. 

Average daily high/low temperatures in Washington, D.C. range from 89°/72° on August 1 to 86°/69° on August 31. D.C.’s hottest August temperature was 106° on August 6, 1918, and is also tied for D.C.’s hottest overall temperature. Meanwhile, the coolest August temperature of 49° has occurred three times, most recently on August 29, 1986.

On rare occasions, August is the warmest month of the summer. There have been four such instances over the last 20 years, most recently in 2018. Triple-digit heat is also less common in August than in July. And, there’s been 100-degree heat in only two of the last 10 August’s. Since official weather records began in 1871, the nation’s capital has seen 34 August days of triple-digit heat, down from 68 in July, but ahead of June (17) and September (4).

August is one of the drier months of the year in Washington, D.C. with NOAA’s updated rainfall average of 3.25”. There have been three August’s since 2010 that were significantly drier than average (2019, 2015, 2013). In an average year, August is wetter than only four other months (January, February, April and November). Unlike August, those months see essentially no rainfall from decaying tropical systems.

August's comfortable weather will continue for the short term, but NOAA’s Climate Prediction Center expects this month to be warmer and wetter than average for the D.C. Metropolitan Area.