By Paul Yeager, author of Weather Whys: Facts, Myths, and Oddities
Tropical Storm Emily was slower to become organized than the experts at the National Hurricane Center originally expected, but now that it has the focus has shifted to whether Emily will become a hurricane and will it make a direct landfall.
The initial forecast track by the National Hurricane Center is for Emily to become a hurricane as it approaches Florida on Saturday afternoon, possibly making a landfall on the east coast of Florida.
The forecast track is, as I said above, preliminary, and questions about the intensity and track remain.
Emily is not yet well organized, and it’s predicted to move directly over the rugged terrain of the Dominican Republic on Wednesday, which has been known to weaken more organized storms than this. So, the first question is how much intensity will Emily lose with its land interaction and how quickly will it re-strengthen once it returns to open water.
The second question, as it relates to a possible Florida impact, is the uncertainty of the track during the latter part of the forecast period, something that’s been specifically noted in the NHC discussion. The models vary considerably on the path, mainly because of a difference in the models on the strength of an upper-level high pressure system predicted to develop to the north of Emily.
Remember, it’s typically high pressure systems, which generally have weak flow over tropical regions in the summer, that direct tropical storms and hurricanes. This weak flow is subject to change more quickly than a strong flow.
The moral of the story is that Florida needs to monitor Emily closely in the next couple of days.