Eta weakening over central America, expected to emerge over the western Caribbean Sea later this week and move toward the eastern Gulf of Mexico and FL.
Discussion:
Eta made landfall along the eastern coast of Nicaragua and has continued to move slowly inland and is currently located over NW Nicaragua. While the overall cloud pattern with Eta remains well organized, the low level center is gradually weakening and spinning down and this process will continue.
Track:
Eta continues to move west along the south side of a mid level ridge to its north. This ridge will weaken over the next 24 hours and shift east allowing Eta to move toward the WNW and eventually the NW and N over portions of Honduras and Belize. An upper level trough will begin to develop over the Gulf of Mexico by this weekend and this will impart a NNE to NE steering motion across the western Caribbean Sea and carry Eta in the general direction of Cuba. By early next week, Eta will likely turn back to the N and even NW as the tropical system rounds the eastern and northeast side of the upper trough over the Gulf of Mexico. The track forecast is of fairly low confidence given the various steering factors at play and the likelihood that the low level vortex associated with Eta will dissipate over central America and some sort of new low level center will form over the western Caribbean Sea by Friday into Saturday.
Intensity:
Eta is weakening and this process will continue as the low level center interacts with the high mountains of central America. It is likely that the current low level vortex will dissipate in the next 24-36 hours and that the upper level organization of Eta will be what moves over the western Caribbean Sea by late Friday. A new low level center is expected to form under the upper level circulation over the western Caribbean Sea, but upper level conditions are not expected to be overly favorable for development with the nearby upper level trough over the Gulf of Mexico and dry air likely to the west of the circulation. In fact, what re-develops over the western Caribbean Sea could be more sub-tropical than purely tropical in nature.
Jeff Lindner
Director Hydrologic Operations Division/Meteorologist
Harris County Flood Control District