Portland will stay warm and dry on Wednesday, then experience a shift on Thursday to a bit cooler weather. Sean Meagher/The OregonianPortland will see another warm and dry day Wednesday as high pressure continues to dominate the region’s weather pattern, according to the National Weather Service. Temperatures are expected to reach the low to mid-80s across the metro area, with clear skies and very low humidity. Overnight lows will remain seasonable, with temperatures dropping into the low to mid-50s in the Portland area. The warm and dry pattern is expected to hold through Wednesday night, but a shift begins early Thursday as the ridge of high pressure starts to weaken.