George Richardson bowled Nepal opener Asif Sheikh for 16 in the seventh over to see Nepal on 26-1.
But his fellow opener Kushal Bhurtal and Bhim Sharki impressed with a second-wicket stand of 122 before Sharki was bowled by Ben Ward for 39 to leave the visitors on 148-2 off 28.3 overs.
Nepal added a further 10 runs before rain stopped play after 31 overs, but when they returned Jersey took two quickfire wickets.
Rohit Paudel was caught off Dan Birrell’s bowling for 16 while Ishan Pandey was stumped for one to leave the Nepalese on 177-4 off 36.1 overs.
Bhurtal reached his century off 113 balls and went on to make 105 before being trapped lbw by Nick Greenwood at the end of the 40th over.
Eight balls later Greenwood took the wicket of Aarif Sheikh for 11 as Nepal slipped to 200-6 off 41.2 overs.
Ward took another wicket as Henamt Dhami ended on 19 not out for the Nepalese when their innings ended.