NEW ORLEANS — Tuesday morning, by the time Stump Mitchell left the main lobby of the Mercedes-Benz Superdome and headed out toward Poydras Street, the weather outlook in this grand old city was fairly bleak.

The temperature hovered in the mid-to-low 70s. It was lukewarm. Low-lying, fast-moving clouds covered the sky. The whole town was gray.

The inside of the Superdome had offered a very different picture. On the floor level, the annual Bayou Classic news conference — designed, as always, to build up buzz for the grudge match at 1 p.m. Saturday between Southern and Grambling — was an explosion of lights and sound.

A jazz band strolled across the field. In the background, workers set up bunting and end-zone paint in the schools’ familiar colors: black and gold for the Tigers, blue and gold for SU.

Then there was Mitchell. The shortest man to approach the lectern, he had a demeanor that stood taller than usual.

With each punch line, each joke, each verbal jab between the Southern and Grambling camps, Mitchell broke out a smile and a laugh that’s practically been in hiding since he arrived in Baton Rouge.

Who was this guy? And what had he done with the scowling, all-business coach who’s often as cheery as a left upper cut?

Who knows?

“New Orleans is a spectacular place, so let’s all come out and have a great time. It’s going to be very competitive,” Mitchell said, referring to Saturday’s game. “But you know ...”

He smiled, then walked away, perhaps stopping himself from going too far.

Maybe it was all a show, a good salesman’s face for the cameras. Or maybe, this time around, Mitchell really feels better about his team.

And maybe he should. More on that in a moment.

In three days, Mitchell and Southern (4-6, 4-4 Southwestern Athletic Conference) will square off against archrival Grambling (6-4, 5-3) in a slightly renamed and reconfigured stadium, with a national audience on NBC watching along.

The Jaguars, and their fans, have to hope it turns out more pleasantly than Mitchell’s debut in the Bayou Classic.

Three hundred sixty-one days ago, Mitchell took his first Southern team into the same Superdome. It was his first game against Grambling. It was the less-than-grand finale in an ugly 2-9 debut season. And it wasn’t pretty.

In a game that served as a microcosm of the entire season, the Jaguars were largely uncompetitive in the second half of a 38-17 rout.

It was the Tigers’ third straight victory in the Bayou Classic.

So much has changed since then. For both teams.

Up in north Louisiana, Rod Broadway bailed out of Grambling after four years and one SWAC title, leaving for a job in his home state at North Carolina A&T.

Re-enter Doug Williams, the Grambling legend, ready for his second stint as the Tigers’ coach.

His team got off to a gruesome start, losing four of its first five games.

Now, after a five-game winning streak, Grambling only needs a victory against Southern to clinch the Western Division championship and a berth in the SWAC title game.

“They wanted to pull the plug on us,” Williams said with a grin. “I think they called the family around and said, ‘Just stay where we are. It’ll cost us a lot more.’ And we refused to let them pull the plug. The guys have really rallied around what we’ve wanted them to do. It showed a lot of character.”

Southern, for that matter, showed more mettle than its fans might have expected.

Two weeks ago, toward the end of a promising season that had been marked by so many close losses — SU dropped four games by a combined 13 points — the Jaguars pulled a fast one on Alabama State.

Having blown yet another fourth-quarter lead, Southern rallied to score a touchdown with nine seconds left, clinching a 26-23 upset and the most stirring victory of the Mitchell era.

“We went into their home, and we beat them, and I think if you’re going to be a good football team, you have to win games on the road,” Mitchell said. “We found a way to do that, and I think we’re going to find a way to win this one.”

The coach, obviously, has a bright outlook on the Classic.

Saturday’s forecast for New Orleans, on the other hand, calls for a 30-percent chance of showers and thunderstorms.

Of course, that hardly matters.

What really matters is how things look inside the Superdome.