A system of higher air pressure that has brought summer-like conditions to the Inland Northwest this week is strengthening today and should continue the warm up through at least Saturday, forecasters said. Highs today should reach the upper 70s in the Spokane and Coeur d’Alene areas, and then rise to the lower and middle 80s through Saturday under sunny skies. Highs in Spokane are forecast at 83 on Thursday and Friday and 82 on Saturday. Forecasters believe Coeur d’Alene will be about two degrees warmer, and Spokane Valley maybe one degree warmer. Lows at night will be near 50 through Saturday. The ridge of high pressure begins to subside on Sunday when the high drops to the lower 70s. The weakening of the high continues early next week as the region goes to more seasonal temperatures in the middle to upper 60s by Monday. A 20 percent chance of showers appears in the forecast starting on Sunday night. Tuesday’s high at Spokane International Airport was 81, which was 14 degrees above normal but 8 degrees below the record for the day. The record high for today in Spokane is 86. Winds on Tuesday gusted to 35 mph at the airport with the highest sustained wind speed going to 29 mph. Moses Lake on Tuesday set a record for the warmest overnight low with 55 degrees. That broke the previous record of 51 set in 1979. A record for the warmest minimum temperature is reached over two nighttime periods – the first coming between 12 a.m. and dawn on the first night and the second coming before midnight of the following evening. At 7 a.m. today, it was 53 at Spokane airport, 50 at Felts Field, 52 in Coeur d’Alene, 46 in Deer Park and 47 in Pullman.