The tropical disturbance over the western Caribbean Sea is organizing and could become a tropical storm by Monday.
Recent data Saturday morning indicates a very broad system. Showers and thunderstorms are increasing, and upper level winds are gradually becoming more favorable for continued development. A tropical depression could happen over the next 24 hours.
This disturbance is likely to track northward. Our suite of recent computer forecast simulations have been consistent in indicating a track toward the north, entering the southern Gulf of Mexico by Monday afternoon. Forward motion of this system will be fairly slow through Monday, then it will accelerate and move faster Tuesday and Wednesday as a cold front approaches from the northwest. The image below (from tropicaltidbits.com) shows many forecasts on a track heavily favoring the Florida Panhandle. The tracks further west toward Louisiana, Mississippi and Alabama are possible. The actual track of the system will be dependent on exactly where the developing storm's circulation develops. That means these tracks can shift as the system grows better organized.
The bottom line right now is that anywhere from Louisiana to the Florida Panhandle. Landfall can happen as early as Tuesday night or as late as Wednesday evening.
What about intensity? A few computer forecasts suggest this system can become a hurricane. That may be possible, but it's a slim possibility. More likely this system will be limited in how much it intensifies by its fast forward motion. The previously mentioned cold front that will speed up the forward motion of this system will also increase the upper level winds, which is another factor that may limit the intensity and even cause some weakening prior to landfall.
The Simple Verision
A track toward the north is likely. The system will enter the southern Gulf of Mexico by Monday afternoon, then it will track toward the northern Gulf of Mexico through Wednesday morning. Landfall can happen anywhere from Southeast Louisiana to the Florida Panhandle.
Impacts are to be determined at this point. How quickly this system intensifies will play a huge factor in impacts on the coast. Landfall tropical systems often bring heavy rain, coastal storm surge flooding, flash flooding, tornadoes, deadly rip currents along the coast and destructive winds. These impacts can be felt well away from the center, so don't focus on the forecast of the center of the storm. The impacts may be limited in time, since this system will likely be moving quickly.
Impact In The Tennessee Valley
Widespread heavy rain will increase on Wednesday and end by Thursday morning. Rain will likely be the biggest impact for us, but some gusty 20-30 mph winds will be possible. Based on recent forecast tracks, the heavy rain and gustiest wind locally will be over Sand Mountain. The biggest rain and wind and even the biggest tornado threat will likely pass east of us, though this can change if the forecast track changes.
We will closely monitor the progress of this system and encourage you to stay informed with updated information, especially if you have interests in the Northern Gulf Coast. Don't look at one forecast one day and assume it will not change.