RED FLAG WARNING IN EFFECT THROUGH THIS EVENING FOR DRY AND UNSTABLE CONDITIONS, AND THUNDERSTORMS. .Low pressure in the area is increasing instability and producing thunderstorms within the area. Instability will be highest within the Lane and Linn County Cascades. High probability for pyrocumulus development. Within thunderstorms, outflow winds may cause rapid fire spread. * AFFECTED AREA. In Oregon, Fire Weather Zone 689 Northern Willamette National Forest and Fire Weather Zone 690 Southern Willamette National Forest. * THUNDERSTORMS. Isolated to scattered thunderstorms. 15-25% chance of thunderstorms after 1 PM. * DRY AND UNSTABLE. Very unstable conditions with elevated mixing heights may promote pyroconvective activity. * OUTFLOW WINDS. Outflow wind gusts up to 35 mph. * IMPACTS. Conditions may be favorable for rapid fire spread which may threaten life and property. Thunderstorm outflow winds may result in unanticipated erratic fire spread. High instability may result in fire growth. Frequent lightning and critically dry fuels may result in fire starts.