Oh I got this...hopefully.
Is this an Auto? To me this sounds like a case of low transmission fluid. Have you checked the level recently?
Remember it is absolutely essential that the Jeep is warmed up, running and in neutral when checking the level on the dipstick. A wise man (Jerry) once told me that was the only way to get an accurate reading, and make sure you are using the correct fluid as well. You can also shift through each gear in neutral to make sure fluid is getting in each area.
I had a similar hard shift into 2nd on cold starts and when warmed up it wouldn't happen but once I checked the fluid in this manner (warmed up, running, and in neutral), I found that my fluid was low, and in fact I needed almost 2 quarts of ATF. Once the fluid was added, the issue simply went away and has been perfect since.
I hope this is the issue with you and not something worse, check your fluid and let us know. Good luck!