Rain continues to overshadow Lancashire's season.

The second day of Somerset's visit to Lancashire was dominated by the rain which caused 56 overs to be lost as the visitors progress was halted after they had achieved a daunting first innings total of 420.

Their superiority was compounded by Lancashire's brief response as they stumbled to 22-2 before this pressure was relieved by rain. Alviro Petersen continued to play with fluency and contributed 155 before falling to Simon Kerrigan (3-94).

After toiling in the heat throughout yesterday, the hosts were able to make regular breakthroughs as Somerset lost their remaining seven wickets for 107 runs and it would have been a day that belonged to Lancashire had Petersen not already made such a significant mark on the match.

Wickets continued to fall throughout the morning session, but Petersen resisted the renewed optimism of Lancashire's bowling attack as he reached 150 in 222 deliveries, a score which ultimately means that Somerset will be unable to lose the match with further rain scheduled over the next two days.

Alex Barrow was the first casualty of the day after he was trapped lbw by Glen Chapple without adding to his overnight score of 14 and Craig Kiestwetter (3) soon followed after edging behind off Kabir Ali (2-90).

Lancashire had further success when they removed Peter Trego for 19 off Tom Smith (2-61) but a 39-run stand for the seventh-wicket between Petersen and Craig Meschede (23) prolonged Lancashire's struggle.

But with the score at 404, the hosts were able to claim three wickets as the innings capitulated to give Lancashire something to smile about. The first of these wickets was that of Petersen, who had just registered 150 before he was caught at point by Karl Brown off Kerrigan.

Kyle Hogg (1-59) had been economical, but had to wait a long time for his first scalp before Meschede played a reckless pull shot, with Brown once again called into action in the field.

Brown made a third catch in eleven balls to dismiss Alfonso Thomas for no score, providing Kerrigan with his 200th first-class wicket, before Chapple claimed the final wicket of Craig Overton (9) to wrap up the innings.

Despite spending much longer in the field than they would have hoped, Lancashire could at least take comfort from the fact that this was a pitch where scoring runs was a possibility. However, they had also claimed seven wickets for little more than 100 runs in the morning session and unfortunately followed Somerset's latter example.

After two successive maidens, opener Paul Horton was out lbw, leaving a straight delivery from Thomas (1-3) and Andrea Agathangelou's return to four-day cricket ended in similarly disappointing circumstances when he too was trapped lbw after adding just two runs to the total.

After falling to 5-2 the hosts welcomed the respite of a rain delay, which curtailed the majority of play after a brief recovery by Alex Davies (12*) and Ashwell Prince (8*).