Missouri natural gas prices already jumped in November and they may increase again this winter. Sheila Lumpe with the Missouri Public Service Commission says the utility company’s can revise the prices they requested in November if their costs outrun what they’re bringing in by more than 15%. Each company does it individually, and can file its request anytime. Gas prices this month are more than double last December’s rates. By January, they’re expected to be more than triple last year’s rates.