Second round action was halted at 4:13 p.m. (ET) and will resume Monday morning at 7:45 a.m. A total of 131 players have yet to complete their rounds.
The first round of match play is still slated for Monday once the stroke play portion is completed.
The tournament is using the par-72 Plantation Course as well as the par-70 Seaside Course. Players will play each course once during the stroke play portion of the event.
Paul Simson posted a 4-under 68 on the Plantation Course Sunday to stand atop the leaderboard at 5-under-par 137. Patrick Carter played the Seaside Course on Sunday and carded a 2-under 68. He stands alone in second place at 4-under-par 138.
'I'm pretty comfortable with the driving even though there are a lot of visual problems,' Simson said. 'There's really a lot of room, but visually, it's pretty intimidating on some of those holes. The dunes make it look like the marsh is a lot closer than it is. It's a wonderful golf course. It will be interesting if the wind picks up there.'
Bryan Norton is finished his two rounds at 3-under-par 139. He is joined at minus-3 by Douglas Clapp and Gary Wolstenholme, who are through nine holes of their rounds.
Gary Havro has completed two rounds at minus-2 and is tied there by Jeffrey Wilson, who still has holes to play. Barton Goodwin and Trip Kuehne finished the stroke play portion at 1-under-par 141.
The U.S. Mid-Amateur is one of 13 national championships conducted annually by the United States Golf Association, 10 of which are strictly for amateurs.