The second named storm of the 2021 Atlantic hurricane season, Tropical Storm Bill, is beginning to lose tropical characteristics as it moves northeastward away from the warm waters of the Gulf Stream. In addition, Invest 92L over the Bay of Campeche is likely to become a tropical depression by late this week over the western Gulf of Mexico as it begins to lift northward.

As of 11:00 a.m. EDT Tuesday, Tropical Storm Bill was centered near 40.5°N 62.0°W, and was moving northeastward at about 38 mph. Maximum sustained winds were 50 knots (60 mph), with an estimated minimum pressure of 998 mb. Bill underwent a fascinating evolution from a frontal low to a tropical cyclone, and earlier this morning the cyclone was relatively well organized. Since that time, the circulation has become increasingly separated from the convection, and Bill appears to be losing tropical characteristics. Bill should become post-tropical either tonight or early Wednesday morning.

As of 18:00 UTC Tuesday, Invest 92L was located near 19.0°N 95.0°W. Maximum sustained winds were 20 knots (25 mph), with an estimated minimum pressure of 1009 mb. In their 2:00 p.m. EDT Tropical Weather Outlook, the National Hurricane Center (NHC) gave 92L a 40 percent chance of development within 48 hours, and an 80 percent chance within five days. The next name on the Atlantic naming list is Claudette. 92L is likely to remain nearly stationary for another two days or so, before moving northward into the northwestern Gulf of Mexico. Even if 92L does not develop into a tropical cyclone, the threat for heavy rainfall over the Gulf Coast of the United States will be significant. Interests along the United States Gulf Coast from east Texas to the western Florida Panhandle should closely monitor the progress of 92L. Right now, it appears as if the most likely landfall location will be near the Texas-Louisiana border, but with a system like this, the greatest impacts will likely be well east of the center. Global model runs continue to suggest that 92L will likely develop into a disorganized, east-weighted tropical cyclone that may even have some subtropical characteristics. 92L is likely to struggle with multiple vorticity maximums, making significant intensification unlikely. It appears as if rainfall, not wind, will be the primary threat with 92L. The 18z GFS-based SHIPS model indicates that conditions will be marginally favorable for development, but wind shear moderate (around 15 knots) for the next 5 days and sea surface temperatures warmer than 28°C (82.4°F). An Air Force Hurricane Hunter aircraft is scheduled to visit 92L on Thursday afternoon, if necessary.