B737 Captain reported receiving an Oil Filter Bypass indication for the left engine during climbout. The crew decided to return to the departure airport after receiving a second warning.

Narrative

Upon resuming climbout of ZZZ after a brief level off; at 15;000 feet we got the Oil Filter Bypass indication for the left engine. I continued flying and worked ATC as I assigned the FO to start the QRH procedure. When we were able to extinguish the indication per the QRH procedures; I then transferred control and ATC duties to the FO as I attempted to contact Dispatch and Maintenance Control (per QRH procedures). As we were flying at a reduced thrust (about 74% N1 on the left engine) I stopped climb at FL250. It seems this altitude was too low to facilitate communications as the transmissions were unreadable. We were flying towards inclement weather throughout the eastern U.S. so I made the decision request priority handling to return to ZZZ. During the course reversal turn we got a 2nd Bypass indication which required thrust to reduce to about 63% to extinguish indication. After having notified Dispatch; briefed FA's; PAX; and briefed the approach; I resumed PF duties. During final approach course intercept we got a 3rd Bypass indication requiring thrust to reduce to about 33% N1 on the left engine. We proceeded to land without incident.