Eta nearly stationary over the SE Gulf of Mexico off the western tip of Cuba.
Discussion:
Eta has been drifting to the southwest over the last 24 hours and is now located just off the western tip of Cuba. Overnight extremely deep convection with cloud tops to -90C have developed on the southeast side of the center of circulation. However it appears the low level center is just to the northwest of the blow up of thunderstorms and not directly in the center. Eta has become nearly stationary with the steering currents nearly collapsing overnight.
Track:
Eta is on the western side of a developing mid level ridge over FL and within the circulation of a trough of low pressure over the NW Caribbean Sea. The mid level ridge is forecast to strengthen slightly over the next 24 hours allowing Eta to turn toward the north with a slight increase in forward speed. It appears that much of the forecast track will depend on the intensity of Eta over the southeast and eastern Gulf of Mexico with a stronger system feeling more of a broad trough over the southern US and a weaker system being directed more west by a narrow low to mid level ridge of high pressure over the northern Gulf of Mexico. The models that are showing a stronger Eta bring the storm toward the N and NNE and make landfall along the eastern US Gulf coast where the weaker models bring turn Eta west and WSW and keep the system over the Gulf of Mexico. The official forecast track is down the middle of the large guidance spread and significant changes in the forecast track are likely as one solution becomes more apparent than the other.
Intensity:
Eta is maintaining a deep convective burst on its southeast flank this morning and wind shear is expected to remain generally light for the next 24-48 hours. Eta continues to be surrounded by very dry air and some of this dry air is working into the center of circulation at times. Some models continue to show a more organized and stronger Eta over the eastern Gulf of Mexico, but the majority of the intensity guidance show a weakening tropical system as Eta moves northward over the eastern Gulf of Mexico. The official forecast follows this thinking as wind shear and dry air will likely increase over Eta by the end of the week.
The forecast intensity and track are or lower than average confidence.
Sub-tropical Storm Theta:
The 29th tropical storm of the 2020 Atlantic hurricane season has formed over the far eastern Atlantic Ocean. While this storm is not expected to affect land, it breaks the record of 28 tropical storms from 2005 now making 2020 the most “active” hurricane season in recorded history.
Caribbean Sea:
Another tropical wave over the eastern Caribbean Sea will move westward into the central and eastern Caribbean Sea over the next few days where conditions will become increasingly favorable for development. The general steering is toward the west and in the direction of the western Caribbean Sea and central America somewhat similar to the first portion of the track of Eta. Development chances for this wave are now at 70%.
Jeff Lindner
Director Hydrologic Operations Division/Meteorologist
Harris County Flood Control District