Wow, 40-50 degrees. I'd wear a long sleeved jersey over a long-sleeved merino base layer, full-finger gloves and calf to knee length wool socks but that's for 40F. For 50F, short socks would be sufficient but still the double layer top and long gloves (I've always liked long fingered gloves although my most recent acquisition were rather thick and warm for summer riding). At 32-40 degrees, I'd add a thick jersey (or a windproof shell), tights, a buff and maybe a skull.

In your case, given that these are unusual temperatures and likely not to be repeated every year, I'd just add a skull (or a buff twisted into a skull, a buff is a great "tool" to have in your closet as it can be worn in so many ways), a windshell over your jersey (maybe wear a second jersey), tights and wool (thin) socks. Mornings with less sun warmth will be more difficult than the afternoon. Hopefully you won't have to tolerate these abnormal conditions for long.