The active period in the eastern Pacific continues. Tropical Storm Bud is approaching Baja California Sur this evening, and is expected to make two landfalls (one in Baja California Sur late tonight and a second along the coast of Mainland Mexico late Friday night as a tropical depression). To the east of Bud, a new tropical depression has developed, the fourth of the season for the eastern Pacific basin. In the Atlantic, Invest 91L is little threat to develop, but will likely bring heavy rainfall to southeastern Texas.

Bud still a tropical storm as it nears Baja California Sur

As of 3:00 p.m. MDT (5:00 p.m. EDT) Thursday, Tropical Storm Bud was centered near 22.2°N 109.8°W, and was moving north-northwestward at about 7 mph. Maximum sustained winds were 40 knots (45 mph), with an estimated minimum pressure of 1000 mb. Bud should maintain its strength or weaken slightly as its center passes over Baja California Sur late tonight, and the rough terrain of the peninsula should disrupt Bud’s circulation. Bud is currently producing tropical storm force winds over Baja California Sur, where a Tropical Storm Warning remains in effect. On Friday morning, Bud is expected to emerge into the Gulf of California as a tropical depression. Bud is expected to make its final landfall along the western coast of Mainland Mexico late tomorrow night as a tropical depression, but it is not out of the question Bud loses its status as a tropical cyclone before then. Bud should become a post-tropical remnant low by Saturday as its circulation moves over the mountainous terrain of central Mexico. Even though Bud should lose its status as a tropical cyclone by Saturday afternoon, Bud should spread tropical moisture throughout the Southwestern United States this weekend.

Tropical Depression Four-E forms south of the Pacific coast of Mexico, may make landfall as a tropical storm this weekend

To the east of Bud, an area of low pressure developed into the fourth tropical depression of the 2018 Pacific hurricane season Thursday afternoon. As of 4:00 p.m. CDT (5:00 p.m. EDT) Thursday, Tropical Depression Four-E was centered near 15.5°N 100.1°W, and was moving northwestward at about 6 mph. Maximum sustained winds were 30 knots (35 mph), with an estimated minimum pressure of 1008 mb. The depression should not be as strong as Aletta or Bud due to the circulation being close to the coast of Mexico. Four-E is expected to be in a somewhat favorable environment for the next 48 hours or so, with wind shear light (less than 10 knots), sea surface temperatures above 30°C (86°F), and a fairly moist mid-level environment. The official National Hurricane Center (NHC) forecast calls for Four-E to strengthen into a tropical storm, though hurricane intensity is currently not forecast. Given the favorable environment and SHIPS model calling for hurricane strength, It is not out of the question that the depression becomes a minimal hurricane before landfall. It is also possible that Four-E may be significantly weaker if it makes landfall sooner. A Tropical Storm Watch is in effect from Tecpan de Galeana to Punta Maldonado. As noted by Eric Blake of the NHC, Four-E is the second-earliest fourth tropical cyclone on record in the eastern Pacific basin. If Four-E strengthens into a tropical storm, it will be named Carlotta.

91E not expected to develop, but heavy rainfall likely for the Texas coast

Invest 91L over the Bay of Campeche is very poorly organized, and chances of it developing into a tropical cyclone appear very slim at this time. The NHC gives 91L a near 0 percent chance of development within 48 hours, and a 10 percent chance within five days. As of 12:00 UTC Thursday, Invest 91L was located near 20.2°N 90.7°W and was moving generally west-northwestward. Maximum sustained winds were 20 knots (25 mph), with an estimated minimum pressure of 1012 mb. Although tropical cyclone development appears highly unlikely, heavy rainfall is expected in eastern Texas regardless, with amounts of about 5 inches possible in some areas. However, these rainfall totals should not be anywhere close to what occurred with Hurricane Harvey last year.

I will be back with another post tomorrow.