Hurricane Bud over the Eastern Pacific rapidly intensified overnight into the second major hurricane of the 2018 Pacific hurricane season. Bud is now a Category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale, and some Dvorak estimates suggest it may be even stronger. To the west of Bud, Tropical Storm Aletta has degenerated into a post-tropical remnant low. In the Atlantic basin, there is a disturbance in the Western Caribbean Sea that has a low chance of tropical development by this weekend when it reaches the southwestern Gulf of Mexico.

As of 3:00 p.m. MDT (5:00 p.m. EDT) Monday, Hurricane Bud was centered near 17.0°N 107.4°W, and was moving northwestward at about 7 mph. Maximum sustained winds were 105 knots (120 mph), with an estimated minimum pressure of 955 mb. Bud is a well organized hurricane with a ring of very deep convection surrounding a clearing and warming eye. Bud should reach its peak intensity during the next 12 hours or so, and could become a Category 4 hurricane during this time. Although wind shear is expected to remain fairly low, a weakening trend should begin by late Tuesday as Bud moves over cooler waters. In about 48 hours or so, Bud is expected to cross the 26°C (78.8°F) isotherm, and this should accelerate the weakening trend. Aside from rough surf along the Pacific coast of Mexico, Bud is currently no threat to land. However, Bud may make landfall along the southern tip of the Baja California Peninsula late Thursday or early Friday, most likely as a tropical storm. The quickly cooling waters should weaken Bud significantly by the time it approaches the Baja California Peninsula. Bud is expected to degenerate into a post-tropical low by Sunday due to land interaction and its passage over even cooler waters. No watches or warnings are currently in effect with Bud, but this likely will change during the next day or two.

Bud is unusually early for the second eastern Pacific major hurricane, which does not form on average until August 19. After Bud, the eastern Pacific should quiet down, with no new tropical cyclones expected to form for at least the next five days.

An Atlantic disturbance to watch: weak development possible in western Gulf of Mexico this weekend

The Atlantic basin is showing some signs of activity as well. A trough of low pressure, associated with a tropical wave, is producing a large area of disorganized showers and thunderstorms over the western Caribbean Sea. The National Hurricane Center (NHC) gives this system a 10 percent chance of development within 48 hours, and a 20 percent chance of development within five days. While environmental conditions are not particularly conducive for development, conditions could become favorable enough for some slight development by Saturday after it enters the southwestern Gulf of Mexico.  It does not appear likely this system will become anything more than a weak tropical storm at most. Global models are not particularly excited about development, with the GFS and CMC models showing weak closed lows and the UKMET and ECMWF models showing little to no development. It should be noted that the Bay of Campeche, where the disturbance will likely emerge into on Thursday, is a common location for tropical cyclogenesis during the latter half of June. The concave shape of the Bay can enhance spin and help tropical lows close off a circulation.  While it appears likely an area of low pressure will be over the western Gulf of Mexico by Sunday, it is not clear if the system will be able to acquire sufficient organization to be classified as a tropical depression or storm. If this system does develop into a tropical storm, it would be named Beryl.

I will be back with an update on Bud and the Caribbean disturbance tomorrow.