By Jay Grymes & Steve Caparotta
For the third day in a row, the biggest rains of the day arrived in metro Baton Rouge arrived by or before noon, helping to “settle down” the atmosphere and keeping the afternoon relatively quiet weatherwise for the Capital City.
Today’s main rains were the result of a long-lasting outflow boundary that began in southeast Texas (around Houston in the pre-dawn hours) and then marched east at about 20 mph through the morning and afternoon. Although the boundary has weakened throughout the day as it continued east, evidence of it is still very apparent on Titan9 Doppler at 4PM, extending southward from eastern Mississippi into the northern Gulf.
With the line of storms “stabilizing” the atmosphere earlier in the day, most of us will remain rain-free through the evening and into the overnight. But as we’ve seen each of the past few days, a “quiet” evening and overnight will allow the very-moist air over southern Louisiana to begin to “de-stabilize” once again by Thursday morning. Look for isolated to scattered showers to return for the morning commute.
Although the pronounced upper-level “closed” low that has prompted our recent run of “wet” weather over the past several days has lost much of its structure, an upper trough (a “weakness”) still lingers over the central Gulf Coast and lower Mississippi Valley. That trough looks to stay around for at least another two or three days, keeping our weather unsettled right into - - and possibly through - - the coming weekend.
Rain in the form of showers and a few t-storms is likely for Thursday, with the clouds and rain keeping highs in the 80°s once again. For now, we’re going with a 50-50 rain chance for Friday, but that may still be on the low side. Even the weekend is currently posted with a 50% rain chance for both days, so keep the umbrella within reach.
The upper trough should start to relax by Saturday, allowing for a bit more sunshine and a return of highs at or even just above 90° for the weekend. At this point, the guidance suggests that we should expect more typical summer days for next week, with lows in the 70°s, highs in the low 90°s, and scattered, mainly-afternoon rains.