The third tropical depression of the 2021 Pacific hurricane season, Tropical Depression Three-E, developed Saturday afternoon over the open eastern Pacific far from any land areas, and is likely to become a moderate to strong tropical storm without affecting any land. In the Atlantic, Invest 92L has been designated over the Bay of Campeche, which has a medium chance to develop over the next five days.

A long-tracked disturbance (Invest 92E) over the eastern Pacific that was given a 90% chance of development nearly a week ago has finally developed into a tropical depression. As of 2:00 p.m. PDT (5:00 p.m. EDT), Tropical Depression Three-E was centered near 11.8°N 123.6°W, and was moving westward at about 9 mph. Maximum sustained winds were 30 knots (35 mph), with an estimated minimum pressure of 1006 mb. The depression is gradually becoming better organized, and is likely to become a tropical storm tonight. The 00z Sunday run of the SHIPS model indicated that environmental conditions will be favorable for the next 48 hours, with sea surface temperatures near 28°C (82.4°F) and wind shear less than 10 knots. Despite this, the hurricane models and statistical guidance are somewhat bearish with intensification, but it cannot be ruled out that 03E becomes a short-lived minimal hurricane on Monday. If Three-E becomes a tropical storm as expected, it will be named Carlos.

An elongated trough of low pressure, associated with a central American monsoon gyre, has developed over the southern Bay of Campeche. The National Hurricane Center (NHC) has designated this disturbance Invest 92L, and gives it a 10% chance of development within 48 hours and a 40% chance within five days. As of 00:00 UTC Sunday, Invest 92L was centered near 20.0°N 94.5°W. Maximum sustained winds were 20 knots (25 mph), with an estimated minimum pressure of 1008 mb. Weak steering currents are likely to keep 92L nearly stationary for the next few days, but it is possible that 92L’s vorticity maximum could approach the Bay of Campeche coast of Mexico. The 00z Sunday run of the SHIPS model suggests that 92L will be in a marginally favorable environment for tropical cyclogenesis, with shear less than 15 knots, and sea surface temperatures warmer than 28°C (82.4°F). The global models are much less enthusiastic, as the GFS and ECMWF models both show a broad, messy low that potentially qualifies as a sheared tropical storm over the northern Gulf of Mexico by next weekend. This remains a complicated setup, as it remains uncertain as to if we will see short-term cyclogenesis or whether we see a lingering area of low pressure for several days. At the moment, tropical cyclogenesis does not appear imminent, as 92L remains very elongated and disorganized at this time. Arguing against significant development is climatology. June hurricanes in the Atlantic basin are uncommon, with the last such occurrence being Chris in 2012. Regardless, interests along the Gulf Coast of Mexico, as well as over the Northern United States Gulf Coast, should continue to monitor the progress of 92L. If 92L develops into a tropical storm, it will be named Bill.