* AFFECTED AREA. Fire Weather Zone 658 West Slopes of the North Cascades Generally above 1500 Feet and Fire Weather Zone 659 West Slopes of the Central Cascades Generally above 1500 Feet. * THUNDERSTORMS. Scattered chance of thunderstorms over the Cascade mountains with LAL 3 during the afternoon and evening hours. * OUTFLOW WINDS. Gusty and erratic winds are possible in the vicinity of any thunderstorms that develop. * IMPACTS. Scattered lightning in dry fuels can cause multiple fire starts. Thunderstorms can also bring sudden sharp wind shifts on existing fires, causing rapid changes in a fire's rate of spread and direction of spread. Thunderstorm outflow winds can be a threat for several hours following the start of a new lightning-caused fire. If a fire were to begin, air quality may diminish in the surrounding area.