Registration for Class AA will begin Thursday at 11 a.m., with practice from 11:45 a.m.to 2 p.m.
The PIAA also announced changes in the basketball playoff schedule.
A storm bringing inclement weather to much of the state prompted changes in the PIAA basketball playoff schedule for this week.
All games will be played Thursday, and all semifinal games will be on Saturday.
The girls' championships will be held from 4-6:30 p.m., with the boys' races to follow from 7:30-10 p.m.
The diving competition back to March 25 and 26 at Bucknell. The Lady Terrors' start at 6 p.m. against Kennedy Catholic on Thursday with Coudersport and Greensburg Central Catholic afterward.
The local teams competing in the swimming championships include (2A) St. Joseph's, Bellefonte and (3A) State College.
In Class AA girls, Minersville's game with Sacred Heart was moved to a 6 p.m. start at Penn Manor High School in Millersville.
Class 4A - Strong Vincent will face Beaver Falls at Sharon High School, at 8 p.m., and Grove City will face Quaker Valley at North Allegheny High School, in Wexford, at 8 p.m. They are now set to tip off at 7:30 p.m. Thursday at UPJ.
Both teams are playing in the first game of a doubleheader.
At Bethlehem Liberty High School: Boys, GAR vs.
Class 2A - West Middlesex will face Bishop Guilfoyle at Hempfield Area High School, at 6:30 p.m.