MEDICINE LODGE, Kan. (AP) — Meteorologists say the weather conditions could make it hard for crews to make headway against a wildfire that has scorched sparsely-populated areas of Oklahoma and Kansas.

The National Weather Service says wind gusts of up to 30 mph are expected to last from Friday morning through the afternoon.

Meteorologist Bill Turner says the big challenge will be keeping the fire from spreading again once the south wind picks up. He says the wind could blow sparks onto unburnt land.

The blaze has consumed at least 620 square miles since starting Tuesday in Oklahoma and spreading into Kansas. Kansas Incident Management Team spokeswoman Kathleen Fabrizius (FUH'-brish-us) says officials plan to fly over the area Friday to evaluate the damage.