Over the last day, the area of potential development in the western Caribbean has become much more organized and has been designated as Invest 97 by the National Hurricane Center. This designation means the disturbance has become well-enough established to provide meaningful data about where the storm might go, although there is still a lot of uncertainty until the storm becomes better organized. The current guidance shows that the storm, which is likely to be named Helene in a day or two, is expected to move north from its current position and approach the northern Gulf Coast by Thursday or Friday this week. Note that the timing has moved up so the impacts from the storm may also start to occur a little earlier than previously thought. Here are some things to note:
- The storm could make landfall anywhere from Mobile east to Tampa, but the place with the highest probability at the moment is Apalachicola in the western Florida panhandle. This could still change over time. In 2022, Hurricane Ian was predicted to take a similar path before swerving to the right and hitting Fort Myers, FL instead. We don’t expect that to occur this time, but significant changes in the path are still possible. The skill of the computer models is limited as long as there is no closed low and they don’t have dropsonde information from hurricane hunter planes to get the vertical temperature structure and winds in the developing storm.
- The largest impacts will be along and to the right of the track that the storm eventually takes, so any change in the predicted path will mean changes in the impacts at any spot in that area. Impacts include gusty winds potentially up to hurricane strength, storm surge along the coast, and some brief tornadoes, especially associated with the spiral bands of convection. Some paths bring rain of up to several inches over parts of Georgia and Alabama, including Atlanta in at least a few projections.
- The timing of when the storm makes landfall depends on how quickly it develops. If it develops quickly, it will move more to the right, which would mean the west coast of Florida would be in play. If it develops slowly, then a more westward path is more likely. In some scenarios it could reach the Gulf Coast as soon as Thursday, although many hold it back until Friday. Impacts will start to occur a day or so before landfall, so I expect to see the outer rain bands from the storm start to affect the coast by Wednesday night. There will be non-Helene rain falling in northern Georgia and Alabama and points north of that associated with frontal activity earlier in the week, not from the hurricane.
- The Gulf of Mexico has a loop of very warm water right where the storm is expected to move, which could enhance the storm development and make it strengthen quickly as it approaches the coast. Now it is expected to be a Category 1 or 2 hurricane but rapid intensification is possible and some models show it as a category 3 or 4 at landfall.
Farmers and others in the Florida Panhandle, southern Alabama and Georgia, and the northwest coast of the Florida Peninsula should now be preparing rapidly for the storm to impact their area, since it has become much more clear that the storm will hit somewhere in their area. By the time the storm becomes named, it may be only a day or two before landfall. It should be dry in those areas until Wednesday afternoon, but after that rainfall will increase and could become heavy in some locations. It will start raining earlier if the storm speeds up. There may be some dry conditions after the storm passes, but more rain is now expected after that, although at lighter levels. There is still quite a bit of uncertainty about the path, strength, and timing of the storm, but by the time the track becomes clear it may not provide enough time for the producers to take care of harvesting cotton and peanuts ahead of the storm. You can ask your local Extension agents for help in determining the best course of action in the days leading up to the approach of the storm.
If you are planning an event or a vacation along the Gulf Coast, you should watch the forecasts carefully to see what the likely weather will be at the time of the event and make appropriate changes if the risk of dangerous weather is too high, but that will differ for each situation and location. Some of the paths take the center of the storm over Atlanta and NW Georgia so even if you are not near the coast you could be affected by bad weather, especially if the storm intensifies before landfall. I am sure that some of you are wondering about the Georgia-Alabama game on Saturday (and I will be in Birmingham that day for the UAB-Navy game), but James Spann, the Birmingham meteorologist, says that so far he thinks they will not be affected. Also note that a wave coming off the coast of Africa this week is expected to become a Cape Verde hurricane in less than a week and could affect us in a couple of weeks, so the tropical season is definitely not over yet.
Pam Knox
Director, UGA Weather Network