The broad center of Tropical Storm Eta has passed the Florida Keys, but the bands of heavy rain and gusty winds wrapping around the back side of the circulation will continue to affect southeast Florida and the Keys.
Obviously, we can’t stand much more rain in South Florida. But the main band of rain will only slowly move out of Miami-Dade. Heavy rainfall will continue for at least part of today. And even after the band moves out, the moisture and gusty breeze will remain, so more heavy showers could pop up when the sun comes out.
Eta is shaped like a big comma with the center being at the head. The main tail of the comma is a thick moisture feed with gusty cells of tropical downpours embedded in it. There are other more minor bands – mini tails in effect – rotating across the Keys. As Eta slowly moves away to the west and southwest, all of the moisture tails should move west with it. This means that the thickest, strongest tail will slowly move down the Keys, although it shouldn’t be as intense as it is now.
Over time, there should be more and more space between the bands as dry air rotates into the system, but it’s impossible to predict exactly how that is going to play out. In addition, Eta’s track a few days from now is a big open question.
The official National Hurricane Center forecast calls for the center of circulation to loop and/or stall over the Gulf west or southwest of the Keys, and then take a slow track to the north staying west of the Florida peninsula. The NHC forecasters acknowledge, however, that this is a low-confidence forecast.
As we have seen this year, when the steering currents are light and systems drift around, forecast errors are much higher. In this case, the computer forecast models are all over the place, but there is a general trend for the storm to eventually weaken and move northward in the Gulf over time.
South Florida will continue to be on the moist side of the storm, so bands of showers will continue to be possible until Eta weakens enough, moves far enough away, and/or enough dry air wraps around the circulation to soak up the moisture. The likelihood is that that will slowly happen over the next couple of days, but it could take longer.
It will likely take longest in the Keys, but the rain will be in narrow bands with sunshine in between. Be aware that the downpours will be quite gusty, which could be dangerous on the water.
Eta is forecast to reach hurricane strength over the Gulf over the next few days, but it is unlikely to suddenly strengthen into the super-strong storm, as we saw earlier in the hurricane season. If, however, Eta does track north through the Gulf and arc toward the northern peninsula as indicated by the National Hurricane Center cone, we will be concerned about storm surge flooding on the west coast of the state, including in Tampa Bay. Everybody along the west coast needs to stay in close touch with local instructions and information.
And by the way, there are two other areas to watch – one well out in the Atlantic and one in the Caribbean. Both have a good chance of getting named. The next two letters in the Greek alphabet are Theta and Iota. It doesn’t appear that either would threaten the U.S., although, obviously, we’ll have to watch the one in the Caribbean to be sure it doesn’t misbehave.