CRJ700 flight crew reported the autopilot disconnected and the navigation systems on the captain's and first officer's Primary Flight Displays became unreliable after takeoff in night IMC. After entering VMC; the flight crew diverted using their magnetic compass and ATC vectors; and landed safely.

Narrative

For a departure from ZZZ to ZZZ1 the Captain and myself were preparing for the RNAV departure off of runway XXL. During taxi we were informed that we were #20 for takeoff. As we slowly approached the departure runway we got an EFIS COMP MON annunciation. At ZZZ this is a common place; to get this annunciation; so we did the rapid realignment procedure. After this alignment all instruments appeared normal. Once we were cleared for takeoff off of runway XXL we were assigned a heading; and after a non-eventful takeoff we encountered IMC weather conditions; and moderate turbulence. In these IMC weather conditions; we got a ROLL flag; PITCH flag; and a HDG flag along with the autopilot disconnected. I was Pilot flying; and maintained aircraft control; as the Captain ran the QRH. Our navigation system on both PFDs (Primary Flight Displays) became unreliable; and the QRH did not solve the issue. We entered VMC flight conditions and decided to stay VMC due to our unreliable instruments. We then determined the safest course of action was to divert to ZZZ2 because the weather was deteriorating at ZZZ. As we approached ZZZ2 we advised ATC; and got vectored as best we could off of the magnetic compass. once we got ZZZ2 in sight we did a normal visual approach; except we were unable to back the visual approach up with an instrument approach due to our navigation failure. We had a safe landing and an uneventful taxi to the gate in ZZZ2.Equipment failure caused this event.Avoiding this event is difficult as it is a equipment failure; but the best course action to avoid this event is to be acutely aware of impending instrument or equipment failures