IMHO -
At 49deg's ... I'd start looking for them around brush or fallen trees ... along the Northern shorelines ... mud flats or weed beds ... and in water depths of 12ft or less ... especially on a sunny day, during a warming trend.
Find where the baitfish are spending their time ... and the Crappie won't be far from them. As water temps continue to rise, and breach the 55deg mark, expect them to be in these shallow areas more often & for longer periods. They should be starting to put on the feedbag, in preparation for the spawn ... if not right now, then move out from the known spawning banks & look for creek channels &/or deeper wood cover. They'll be staging & waiting for the temps to get more to their liking.
The simplest method to "finding" them, if you're not sure where they are, is to slow troll/longline with jigs ... starting at the mouth of creeks/coves & working your way back to the shallow flats. Vary the depth you troll over and the depth your jigs run. If no hookups, move to the shoreline & look for stump beds, fallen trees, and cast or jig around them.
... cp