* WHAT...Today, southwest winds 15 to 25 mph with gusts up to 40 mph expected. Tonight and Friday, north-northwest winds 15 to 25 mph with gusts up to 45 mph expected. * WHERE...Portions of northwestern Arizona, southeastern California, and south-central and southern Nevada. * WHEN...From 11 AM PDT / MST this morning to 5 AM PDT / MST Friday. * IMPACTS...Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result. Winds this strong can make driving difficult, especially for high-profile vehicles, particularly along east-west thoroughfares including Interstate 15 and Interstate 40.