A tropical cyclone outbreak is likely to begin in the eastern Pacific very soon. Tropical Storm Daniel has degenerated into a post-tropical remnant low, but two systems to the east of Daniel are expected to develop into tropical depressions by late this week, but should remain far from any land areas. In the Atlantic, we are continuing to watch the potential for a non-tropical low to gain tropical characteristics off the east coast of the United States later this week.

96E expected to develop far from land as it moves west-northwestward

Invest 96E over the Eastern Pacific is likely to develop into a tropical depression by Thursday as it moves west-northwestward. As of 18:00 UTC Tuesday, Invest 96E was located near 10.2°N 102.0°W, and was moving generally west-northwestward. Maximum sustained winds were 25 knots (30 mph), with an estimated minimum pressure of 1008 mb. 96E is gradually becoming better organized, and should become a tropical depression within the next two days or so. The National Hurricane Center (NHC) gives 96E a 70 percent chance of development within 48 hours, and a 90 percent chance within five days. All reliable global models develop 96E into at least a tropical depression. Although wind shear is currently moderate, wind shear is expected to drop below 15 knots on Wednesday and remain low through the weekend. Sea surface temperatures are fairly warm at about 29°C (84.2°F), and 96E is currently embedded in a very moist environment with relative humidity values above 75 percent. However, 96E only has about 4-5 days to develop and intensify before sea surface temperatures drop below 26°C (78.8°F) and 96E moves into a drier and more stable environment. 96E is likely to be weaker than the system to its east, which is likely to become a strong hurricane. The next name on the Eastern Pacific naming list is Emilia.

Tropical wave over Central America expected to develop in the Eastern Pacific, likely to become a powerful hurricane

A tropical wave currently located over central America is expected to emerge into the eastern Pacific by tomorrow, and will likely steadily organize into a tropical cyclone by the weekend. The NHC gives this tropical wave a 10 percent chance within 48 hours, but a 90 percent chance within five days. Models are in very good agreement that this system should develop into a powerful hurricane by the middle of next week as it tracks generally westward to west-northwestward over the open eastern Pacific. Like 96E, this system should not pose any threat to land areas. It is possible that if this system – likely a hurricane – remains far enough south, it could be the first Eastern Pacific tropical cyclone of the season to reach the Central Pacific basin. After Emilia, the next name on the eastern Pacific naming list is Fabio.

Watching the Western Atlantic for weak development late this week

In the Atlantic, a poorly organized non-tropical area of low pressure is beginning to develop near the coast of North Carolina. This system could gradually acquire some tropical characteristics over the next few days as it moves east-northeastward to northeastward out to sea away from land. The NHC gives this system a 10 percent chance of development within 48 hours, and a 20 percent chance within five days. Today’s 12z global models have trended weaker with this system, and the 12z ECMWF, GFS, CMC and UKMET models now all show no significant development with this system. Even though models have trended weaker with this system, some slight development is still possible, since models often struggle with this type of genesis. It is unclear if the system will be able to lose its frontal characteristics, and it will need to do so in order to be classified as a tropical cyclone. It should also be noted that systems like this commonly develop into weak tropical storms during El Niño years, most recently Tropical Storm Claudette in 2015. The next name on the Atlantic naming list is Beryl.

I will be back with another post on the tropics tomorrow.