KANSAS CITY, Mo. — Kansas and Missouri drivers should prepare for a steep price increase at the pump, experts say.

Gas Buddy, which monitors gas prices around the United States, Canada and Australia, predicts gas prices in the Midwest will spike anywhere from 50 cents to $1 per gallon over the next several days.

There are few details on what’s leading to the increase, but Gas Buddy says a refinery outage could be to blame.

Patrick De Haan, head of petroleum analysis at GasBuddy, said the price hike could be limited if the EPA switches to the winter blend of gasoline early.

“The spike in gas prices may be relatively short-lived, but the situation remains volatile,” De Haan said in a news release.

As of Thursday, wholesale gas prices in the Midwest were already up nearly $1 per gallon from one week ago, and AAA reports a gallon of gas is up 7 cents in Missouri and 3 cents in Kansas.

But AAA did note on Thursday that the national average for a gallon of gas was down two cents since last week, falling to $3.80. Missouri remains one of the top 10 least expensive states with an average gas price of $3.55, as of Friday. Kansas isn’t far behind at $3.59 per gallon.

Gas Buddy expects stations will start raising their prices significantly soon and advises drivers to fill up now before prices spike.