As a Goodyear mechanic for 20 yrs, I saw this many times. As described here already it is the classic symptom of an under inflated tire. The heat generated while running in a low inflation mode is surprising. The rubber right at the "bulge" melts away and lets the tread take off on its own. I see lots of tread sections, for all kinds of tires not just low profiles along side the roads here in CA.

How many here remember a "service station" ? I learned as a gas jockey to check tires at least once a week. It has paid off. No flats or blow outs in 30 years !! Thank heavens I haven't needed my spare like around Bakersfield or Fresno!! (See my signature for my spare) If your TPMS comes on......go put air in the tire! It's getting hot if your driving at freeway speeds.

BTW.....HOORAY GIANTS!!!!!