* WHAT...West winds with gusts of 50 to 70 mph possible. Locally higher gusts are possible. * WHERE...Portions of central and south central Montana and north central Wyoming. * WHEN...From late tonight through Thursday evening. * IMPACTS...Damaging winds could blow down trees and power lines. Power outages are possible. Travel could be difficult, especially for high profile vehicles. The warm and windy conditions could cause rapid fire spread in grasses. * ADDITIONAL DETAILS...The strongest winds are expected during the day Thursday. Mountain wave activity may bring strong and erratic winds to the immediate foothills overnight tonight.