The Gulf's first tropical system of the season has arrived, and after almost a full day of having a center to hone in on models seem to be coming together (although plenty of uncertainty exists).
Louisiana's primary threat from this system remains the potential for dangerous rainfall along a narrow corridor that will likely occur between I-49 and Mississippi.
Exactly placing where that corridor will occur will remain almost impossible until we start to see where those showers are setting up, and while trends have been to keep this east of the Atchafalaya it's still too close to rule out east Acadiana.
Generally speaking the further west you are the less rainfall you'll encounter and it will be a very tight gradient from simple rainfall to potential life-threatening flooding.
While the GRAF has a tendency to run a little hot when it comes to tropical showers it does do a good job highlighting how narrow some of these corridors can be, as well as how small shifts with the low change the location of the greatest impacts.
So while most of Acadiana will receive 1-4" of rain there's going to be the possibility of 12"+ east of the center, with a bulk of that rain falling late Wednesday night into early Thursday morning.
We do give the GRAF a lot of credit for the way it handles tropical weather, but for transparency sake it's not the only model we trust and some others have the showers way less intense although still capable of producing flooding.
The HRRR, another short range model prone to large fluctuations, seems way too low so will wait to see how it trends this morning but I did want to show that there's still some disagreement from the models.
Still though, there's value in comparing the two as both pick up on narrow corridors of heavier rain in the eastern half of Louisiana and the truth likely sits somewhere between the two models.
Keep a close eye on both of these models over the next 12 or so hours to see how they evolve through the day and hopefully we can narrow the area we'd expect to see the heaviest rain.
It'll be important to keep an eye on the radar both this evening and into the overnight, as it will start to become apparent where the flooding may occur once we start to see it.
Of course there's going to be other impacts that come along with a system like this, although rains will be far and away the biggest threat.
Tides will be running higher than normal and some coastal flooding is to be expected.
The stronger storms will have the possibility for some isolated tornadoes that spin up.
As mentioned earlier the thing to be the most mindful of will be the possibility of major flooding occurring Thursday morning, and the trends have shown that areas east of the Atchafalaya are more likely to see it.
Given the potential impact and how close it will be to Acadiana, however, you want to make sure that you're prepared in case those storms nudge eastward.
