Jan 24 (Reuters) - Shell on Tuesday said it was experiencing an incident at its Deer Park chemicals facility south of Houston, Texas, following severe weather, according to a company tweet, after a tornado was reported in the area.

Pemex, which owns the oil refinery at Deer Park, also reported operational upsets resulting in flaring due to the weather events, according to a company alert. (Reporting by Arathy Somasekhar, Erwin Seba and Marianna Parraga in Houston; Writing by Liz Hampton in Denver)