The National Weather Service summary for the weekend calls for cooler weather in western Oregon from an offshore low pressure system. West of the cascades, the air is fairly moist but clear, with humidity in the seasonal range; as the air moves over the Cascades, central and eastern Oregon will see dryer air and breezy conditions that could increase fire potential until Sunday.
The Medford NWS office is calling for increased thunderstorm potential Friday around Crater Lake and Diamond Lake. Concern has also been expressed about breezy conditions in the Columbia Gorge and the crest of the Cascades this weekend.
A Fire Weather Watch has been issued by the Pendleton NWS office for much of northeast Oregon into the weekend. The low pressure moving over the Cascades could turn into lightning storms by the time the system reaches the NE part of the state.
Kevin Weeks – Oregon Department of Forestry