The final round at the 7,011-yard Red Course at Eisenhower Park was scheduled to begin in the late morning, but the same weather system that caused three delays and finally suspended the round Saturday was still in the area.
A Champions Tour event is official after 36 holes, so the first prize of $225,000 from the purse of $1.5 million would be awarded if the third round wasn't completed.
Jenkins was 8 under through 16 holes when play was stopped Saturday, and was three shots in front of Haas, who is looking for his fourth straight Champions Tour win, which would match the record set by Chi Chi Rodriguez in 1987.
Jenkins had a par and then bogeyed the par-4 18th to complete his 7-under 64 in a light rain and was at 9-under 133 for the two rounds.
Haas sandwiched a birdie on the par-5 17th around two pars as he completed a second-round 65 on Sunday. Morgan had two birdies -- both on par-5s -- in the seven holes he played Sunday to finish with a 69.
First-round leader Allen Doyle (71), David Eger (65), Bruce Fleisher (67) and Tom Wargo (68) were at 7-under 135.
Defending champion Ron Streck had a second-round 70 and was at 139.
The last Champions Tour event to be reduced to 36 holes by weather was the Bayer Advantage Classic in Overland Park, Kan. last year. The Bank of America Championship in Concord, Mass., was a total washout earlier this month because of heavy rain.