Schmid, who came into the FedEx Cup Fall portion of the season trying to secure a full PGA Tour card for next year, had a bogey-free 65 in windy conditions at the TPC Summerlin, though not nearly as strong as the other half of the field faced.
Wind gusts that approached 80km/h early Friday led to a four-hour delay to start the second round and left the tournament in catch-up mode the rest of the week.
It was unlikely all 66 players who made the cut would finish on Saturday.
Poston is playing for the first time since the BMW Championship in August. He chose to take a few months off as a new father and didn't appear to have much rust, particularly at the end of his round. He took advantage of enough scoring holes and helping wind.
He two-putted from about 35 feet on the reachable par-4 15th, holed a 25-foot eagle putt on the par-5 16th and then made a 35-foot birdie putt on the par-3 17th.
Poston was at 13-under 129. Schmid joined him with four birdies on the back nine.
Rico Hoey, who returned in the morning one shot behind first-round leader Taylor Pendrith, had a 66 and was one shot behind along with Norman Xiong (65). Ryan McCormick had a 66 and was two shots back.
Pendrith and everyone else who had to finish the second round had the easier side of the draw than those who faced 40 mph gusts for much of their round. Pendrith didn't take as much advantage, having to settle for a 71 that left him three shots back.
The cut was at three-under 139. Among those who missed was Tom Kim, the two-time defending champion who was trying to become the first player since Steve Stricker at the John Deere Classic (2009-11) to win the same PGA Tour event three straight years.
Australians Aaron Baddeley (four over) and Cam Davis (11 over) were also well outside the cut line after finishing on Friday.
