It’s the biggest day of women’s college volleyball all year: eight matches between the 16 teams still vying for the national championship. Regional semifinal day is a smorgasbord of talent stretching across the country.

It starts Thursday at noon ET, and by early Friday morning we’ll know which programs are one step away from the national semifinals in Tampa, Florida.

With the conference realignments next season, including the demise of the Pac-12, volleyball like every other sport will look notably different. But for one more NCAA tournament, we have volleyball’s two traditional “power” conferences — the Pac-12 and the Big Ten — with four teams from each still alive. Two rising powers, the ACC and SEC, have three teams each. The Big 12 and the Big East have one each.

Six of the teams remaining have won the NCAA title, led by nine-time champion Stanford. Three of the regional semifinal matches will pit conference foes: Kentucky vs. Arkansas, Wisconsin vs. Penn State, and Stanford vs. Arizona State.

Matches will be held at regional sites hosted by the No. 1 seeds: Nebraska, Pittsburgh, Wisconsin and Stanford.

All matches will be televised by either ESPN2 or ESPNU, and are available on the ESPN App. Regional finals are Saturday.

Here are the biggest storylines in each region heading into the Sweet 16.

Lincoln Regional: How does overall No. 1 Nebraska look so far?

Semifinals: No. 1 Nebraska vs. No. 5 Georgia Tech (2 p.m. ET, ESPN2), No. 2 Kentucky vs. No. 3 Arkansas (4:30 p.m. ET, ESPNU)

Admittedly, the first two rounds against Long Island and Missouri were pretty much a formality for Nebraska. Even so, the Huskers looked good in winning both sweeps. Merritt Beason led Nebraska in kills both matches, but this team can spread out its offense.

The Huskers’ next opponent, Georgia Tech, upset Florida on the Gators’ home court in the second round. So it’s quite the contrast: the five-time national champion Huskers, who’ve made it to at least the Sweet 16 for the past 12 years, vs. a Georgia Tech team that has made it this far just four times in program history.

Still, Yellow Jackets standouts Tamara Otene and Bianca Bertolini are experienced and complete players, and Georgia Tech did win 11 road matches this season.

Incidentally, the Huskers had “Volleyball Day in Nebraska” on Aug. 30 when they set the attendance record for a women’s sports event with 92,003 at Memorial Stadium in Lincoln. Thursday will be another big day in the state for volleyball as both the Huskers and Creighton (located in Omaha) will be playing Sweet 16 matches. The Bluejays meet Louisville in the Pittsburgh Regional.

Pittsburgh Regional: Collision course for Pitt and Louisville?

Semifinals: No. 2 Louisville vs. No. 3 Creighton (noon ET, ESPN2), No. 1 Pittsburgh vs. No. 4 Washington State (2:30 p.m. ET, ESPNU)

Not so long ago, the national semifinals seemed to be an unattainable dream for much of the ACC. The Panthers and Cardinals have changed that narrative: They have made it that far the past two seasons.

They both won’t get to do that this season, since they’re in the same regional. But one could make it to Tampa and be looking to win the ACC’s first national championship in women’s volleyball.

First, they will have to get past two challenging semifinal foes. Creighton has won 17 matches in a row, including a sweep over Minnesota in the second round. Washington State has won seven in a row, including against fellow Sweet 16 team Arizona State near the end of the regular season.

If the Panthers and Cardinals do make it the regional final, it will be their third meeting this season. They split in the regular season, each winning at home.

Madison Regional: Can Penn State pull off another road upset?

Semifinals: No. 1 Wisconsin vs. No. 5 Penn State (7 p.m. ET, ESPN2), No. 2 Oregon vs. No. 3 Purdue (9:30 p.m. ET, ESPNU)

The Nittany Lions played one of the most exciting early-round matches, upsetting No. 4 seed Kansas in five sets on the Jayhawks’ home court in the second round. It gets even tougher now as they go to one of the hardest places for opponents to win.

Wisconsin has lost just three matches at home over the past four seasons, none of them this year, as the Badgers are 15-0 at UW Fieldhouse. That includes a Nov. 24 sweep of Nebraska, plus sweeps over their NCAA tournament early-round foes Jackson State and Miami.

However, the Nittany Lions did hand the Badgers one of their three losses this season: 3-1 at Penn State on Nov. 11.

Stanford Regional: Are the Cardinal vulnerable?

Semifinals: No. 2 Texas vs. No. 3 Tennessee (9 p.m. ET, ESPN2), No. 1 Stanford vs. No. 5 Arizona State (11:30 p.m. ET, ESPNU)

The Cardinal were the only No. 1 seed to go to five sets in the early rounds; Stanford defeated Houston 3-2 in the second round. Next up is an Arizona State team that split matches with Stanford this season: The Cardinal won 3-0 at home on Sept. 29, and the Sun Devils won 3-0 at home Oct. 29. That was Stanford’s only Pac-12 loss.

This is Arizona State’s third regional semifinal appearance and first since 1995. The Sun Devils are 28-6, the second-highest win total in program history. Their 14 conference victories and 20 matches won by sweep are both program records. Arizona State’s JJ Van Niel was named Pac-12 Coach of the Year.

Still, Stanford lost just two matches at home this season: to Florida in August and Nebraska in September. It would be a very big deal for the Sun Devils to knock off the most successful program in the sport’s history. But San Diego did it last year at Maples Pavilion in the regional final.