Weather permitting, BART travelers Sunday morning and afternoon will experience 15- to 20-minute delays between the Rockridge and Orinda stations as crews trim trees near the Berkeley Hills Tunnel, BART officials said.

The delays will start at 6 a.m. and last to 4 p.m.

The trimming is safety work that must be done as soon as possible, but will be canceled and rescheduled if it rains, according to BART officials.