Somewhat unexpectedly, a non-tropical area of low pressure off the United States east coast rapidly developed into Tropical Depression Two – the second tropical cyclone of the 2021 Atlantic hurricane season. In addition to TD Two, two other systems are currently being monitored in the Atlantic for tropical development: Invest 92L over the Bay of Campeche, and an early-season tropical wave over the far eastern tropical Atlantic. Tropical Storm Carlos remains active over the eastern Pacific, but poses no threat to land and has weakened.

As of 11:00 a.m. EDT, Tropical Depression Two was centered near 35.0°N 73.7°W, and was moving northeastward at about 21 mph. Maximum sustained winds were 30 knots (35 mph), with an estimated minimum pressure of 1006 mb. Tropical Depression Two formed from a non-tropical area of low pressure along a frontal boundary, and has acquired sufficient organized convection to be classified as a tropical depression. The depression is likely to intensify into a tropical storm by tonight, but only has a short life ahead of it as it moves away from the United States east coast. Within less than 24 hours, the depression will be moving over sea surface temperatures cooler than 25°C (77°F) while wind shear increases to more than 40 knots (45 mph). As a result, the depression should become a remnant low or extratropical low by tomorrow afternoon. Since the depression is not expected to bring tropical storm conditions to any regions, no watches or warnings are in effect.

There are also two disturbances being monitored for development in the Atlantic basin. The first, Invest 92L, is a broad trough of low pressure over the Bay of Campeche. 92L remains poorly organized with minimal shower and thunderstorm activity, and development does not seem imminent. The National Hurricane Center (NHC) gives 92L a 20 percent chance of development within 48 hours, and a 60 percent chance within five days. As of 12:00 UTC Monday, Invest 92L was centered near 19.8°N 95.8°W, and was nearly stationary. Maximum sustained winds were 20 knots (25 mph), with an estimated minimum pressure of 1009 mb. Global models suggest that 92L could develop into a broad, disorganized tropical cyclone before moving inland to the northern United States Gulf Coast by the weekend. Considering the environment, it appears unlikely that 92L will become a strong tropical cyclone, but even if 92L remains weak, there will be a rainfall threat.

In addition to 92L, there is a strong tropical wave over the eastern tropical Atlantic that is unusually potent for so early in the season. The NHC gives this wave a 10 percent chance of development within 48 hours, and a 20 percent chance within five days. 92L has a narrow window for potential tropical cyclone development before conditions become less favorable by the weekend. Although this tropical wave is very unlikely to become a significant tropical cyclone, even a weak tropical cyclone in the Atlantic’s Main Development Region this early in the season could be an ominous warning sign for the peak of the season.