Regional Jet Pilot reported having a MEL for the Right Pack; then when airborne; they received a message that the Left Pack was operating poorly.

Narrative

Today DATE we were the first flight out of ZZZ to ZZZ1. There were about 4 MEL's when we got to the plane. There was weather that just moved through ZZZ and all around and on ZZZ1. They were on a ground stop. The Captain was the one flying this leg and I was pilot monitoring. We had both read through all the MEL's and their procedures associated with each of them. The main one was the R PACK was inop. On climb out; out of ZZZ we were trying to get around some weather; and the turbulence was pretty great. We were thru 1000 feet but below 2500; the Captain did the normal call for flaps up; and set climb thrust. When you only have one operating pack; before you transfer the bleeds you bring the power back. Which he did; I didn't catch the exact number as I was doing my after takeoff duties and talking to ATC. After transferring the bleeds we got the 'L PACK HI PRESS' caution message. The Captain told me to finish my after takeoff flow. He notified ATC and took the radios; and requested I do the QRH (Quick Reference Handbook). We ran the QRH; but the message still persisted; and couldn't do any other QRH procedure due to the other pack being inop. Soon there after we received another caution message 'CABIN ALT'. The Captain immediately made the call to stay at 10;000 feet and let ATC know. The Captain asked me now to run the QRH for this caution message. It was run and completed and both messages still persisted. We notified Dispatch as well. After running through QRH; and having things under control we started to look into the systems manual; and run through some ideas. Before landing we transferred the bleeds back over and the messages went away.