The transition toward a wetter weather pattern began across south Louisiana and SW Mississippi today. While rains have been pretty manageable around metro Baton Rouge through late afternoon, radar estimates show widespread totals of 1 to 4 inches in our coastal parishes and a band from northern W. Feliciana Parish extending into parts of Wilkinson and Amite Counties in SW Mississippi where 2 to 5 inches or more of rain has fallen today!
Given the impressive totals we’ve seen in some locations today and the expectation of more rainfall to come this weekend, it’s easy to see why a Flash Flood Watch has been posted for parts of the WAFB viewing area. The Flash Flood Watch currently includes areas along and east of I-55, along with Terrebonne, Lafourche, St. John the Baptist and the parishes surrounding metro New Orleans. While I do agree that these are the areas most likely to see some heavy rainfall, the band from W. Feliciana in to SW Mississippi this afternoon serves as evidence that heavy rains could fall outside of the watch as well.
We’ve been talking about it for days…the increasing rains this weekend will be compliments of a deep surge of tropical moisture moving in from the Gulf. It’s a rather complex setup, but suffice it to say all of that moisture plowing inland will result in widespread showers and t-storms.
Loosely tied to all of this mess is a weak area of low pressure in the SW Gulf of Mexico. The National Hurricane Center gave development chances a slight bump this afternoon, now listing them at 20% over the next 48 hours. As you can see, the odds of development appear to be fairly low and the primary threat from this system will be heavy rainfall along sections of the Gulf Coast. In perhaps a small bit of good news for us today, most of our guidance has trended a bit farther south and west with the track of the low into Texas, which means it should have less of an influence on our already wet weekend forecast.
So how much rainfall can we expect? Honestly, I think most of our guidance has been running too low. Including today, rain totals by the end of the weekend will likely range from 2 to 4 inches around metro Baton Rouge. Closer to the coast, I think 4 to 6 inches is a good bet, with the potential for some much higher totals. And as we saw today, there can also be some localized bull’s-eyes with higher amounts farther inland as well.
And while I don’t think rains will be quite as widespread next week, our extended outlook does feature rain chances near or slightly above-normal through the balance of next week. Keep those umbrellas handy!