Tropical Storm Ida has formed in the Caribbean, and will likely make landfall along the U.S. Gulf Coast as a major hurricane this weekend, before ultimately dumping appreciable rainfall across much of Tennessee.
We’ve been watching this system for a few days and highlighting its potential impact on Tennessee. Of course, the impact to the Volunteer State will be nothing like what the Gulf Coast will experience. Life-threatening impacts are expected along the Louisiana coast, which is currently under a Hurricane Watch.
The National Hurricane Center expects Ida to reach hurricane status tomorrow after crossing Cuba later today. This is a fast moving storm that will be absolutely trucking across the open waters of the Gulf. Unfortunately, the fast movement of the storm isn’t going to prevent it from intensifying. Even though it’ll be over the open waters of the Gulf for less than two days, it’s expected to become a category 3 hurricane, with winds in excess of 110 mph. Several models show it reaching even greater intensity before landfall, so that will have to be monitored closely over the next day or so.
Surprisingly little has changed with regards to expectations for this storm. Landfall along the Louisiana coast just to the west of New Orleans is very consistent, and an inward track that eventually brings the remnant tropical depression into Tennessee is also very consistent.
One interesting twist, though, is that the GFS model — which was the first to show the remnants of Tropical Storm Ida tracking directly over the Cumberland Plateau — now shows the storm never getting much further north than the Tennessee-Alabama border before turning east, and even sliding a little south. This is due to a frontal boundary that’s expected to be pushing southward by the latter part of the weekend. If that comes to fruition, it wouldn’t stop us from receiving rainfall from the system here on the northern plateau, though it might hold down rain totals somewhat.
The ECMWF model, too, is slowly pushing the tropical depression further south, though it still brings the core of the system a little closer to our neck of the woods. But the ECMWF reduces rain totals even more than the GFS, showing less than an inch of rain for most of the northern plateau region.
For now, the Weather Prediction Center is still showing quite a bit of rain for the plateau region, though the greatest rains are likely to be further west.
As for the timing of these impacts, it’s likely we will see rain chances start late in the day on Tuesday and continue through Wednesday.
Along with increased rain chances, we should also see cooler temperatures. The GFS is currently projecting temps in the mid 70s for several days next week. That will be a nice taste of fall, on Wednesday especially.
The bottom line: The remnants of Tropical Storm Ida will be expected to interact with a frontal boundary to bring appreciable rainfall to much of Tennessee, including the northern Cumberland Plateau, on Tuesday and Wednesday of next week. Currently, anywhere from 1 to 4 inches of rain appear possible, with 2 to 3 inches being the best bet. Cooler temperatures are also likely. Whatever the impacts to Tennessee, the far greater impacts will be along the Gulf Coast, where Ida is expected to strike as a major hurricane with life-threatening impacts. More than a foot of rain is expected for parts of the Louisiana coast, which could lead to major flooding threats for some areas.