NHC Monitors Three Atlantic Systems as Development Chances Rise

The National Hurricane Center is tracking three disturbances across the Atlantic basin, with the most closely watched being a tropical wave off the coast of Africa that could develop into a tropical depression. Forecasters are also monitoring two other systems, though one is expected to dissipate.

The tropical wave, forecast to move off Africa's west coast on Aug. 24 and continue west through the week, has seen its development odds increase. According to the NHC's tropical outlook for Aug. 23, "Environmental conditions are forecast to be marginally conducive for development, and a tropical depression could form by the middle to latter portions of the week."

Reports vary on the exact odds for the African wave. Several outlets, including the Gainesville Sun and Herald-Tribune, cite a 48-hour chance near zero percent and a 7-day chance of 50 percent. The Norfolk Virginian-Pilot similarly reported a 50% chance within seven days, up from 40% on Saturday, with the disturbance expected to move west at 15 to 20 mph. Newsweek, however, placed the seven-day odds at roughly 40 percent.

The two other systems under watch include one near Portugal that is expected to fizzle due to unfavorable conditions, and Invest 95L, located southeast of Bermuda, which may see some development as it moves north this week. The Portugal system carries a 10% chance of development over both 48 hours and seven days, according to the NHC. Invest 95L has a 20% chance within 48 hours and a 30% chance within seven days, as reported by the Virginian-Pilot and others. Newsweek described the Portugal-area system as a non-tropical low northeast of the Azores with a 20% seven-day chance, and the Bermuda-area system as having a 10% chance in 48 hours and 20% in seven days — slight differences from the figures cited by other sources.

None of the three systems currently pose a threat to the United States, as reported by Newsweek. If a named storm develops, it would be called Dolly.

The Atlantic hurricane season has been relatively quiet so far, though the Pacific has been extremely busy, with Hurricane Lala battering Hawaii and Tropical Storm Moke forecast to bring heavy rain and dangerous surf. The contrast between basins is linked to an active El Niño phase, which according to NOAA lowers vertical wind shear and elevates sea surface temperatures in the Pacific, while suppressing Atlantic activity through enhanced upper-level wind shear.

Forecasters emphasize that the Atlantic is entering its most active stretch. Over 60% of the basin's total hurricane activity occurs between Aug. 20 and Sept. 30, according to Ryan Truchelut of WeatherTiger. The traditional peak of the season is Sept. 10, with most activity between mid-August and mid-October. Historically, the fourth-named storm of the season forms Aug. 15, the first hurricane Aug. 11, and the first major hurricane Sept. 1, per NOAA. A major hurricane is Category 3 or stronger, with winds of 111 mph or greater.

AccuWeather, in an updated forecast released Aug. 19, lowered its prediction for named storms this season but warned of three to five direct impacts on the United States. Colorado State University's final outlook also calls for a "well below-normal season," with nine named storms total, including Arthur, Bertha, and Cristobal, meaning six additional named storms are expected.

The season runs from June 1 through Nov. 30, with 97% of tropical activity occurring during that period, according to NOAA. As part of a Trump order, the Gulf of Mexico is now referred to as the Gulf of America in U.S. usage.

Forecasters continue to urge preparedness, noting that it is too early to tell whether the African wave will affect Florida, but the timing aligns with the season's busiest weeks.