SEATTLE — The Seattle area is likely to exceed 90 degrees Saturday for a fifth straight day, continuing a heat wave that has triggered an excessive heat warning through Sunday from the National Weather Service. The record high for July 30 in the Seattle metropolitan area is 96, set in 2009, according to meteorologist Samantha Borth. Forecasts show Saturday’s high temperatures hovering in the lower 90s, but Borth said it was possible that the record could fall. Normal for this time of year is upper 70s, said Borth, although in a changing climate and on the heels of last year’s heat dome, area r…