Portland logged a high temperature of 81 degrees Thursday, reaching the first 80+ degree day of the year. But that’s the last we’ll see of those sorts of temps at least through the weekend.
The National Weather Service says a broad upper level trough is setting up over the northeast Pacific and will keep showers and rain moving through the region through Sunday.
Friday will start off showery in Portland, but rain is likely to become steadier during the afternoon. Skies will remain mostly cloudy, and the high will reach 70 degrees.
Heavier rain is possible in the central and southern Willamette Valley south of about Salem as that area takes the leading portion of an atmospheric river moving inland from the coast.
Showers continue into Saturday morning before a stronger portion of the jet stream carries some deep subtropical moisture into the region by the afternoon or evening. Saturday night could bring some of the strongest rain of the weekend. The daytime high will only reach near 65 degrees.
Sunday will have showers, heavy at times, and a 25-35% chance of thunderstorms in most areas east of the Coast Range. The high will be about 69 degrees.
The weather service isn’t too concerned with any main river flooding issues, but small streams and low-lying areas could see some minor flooding over the weekend. Rainfall totals will range from 0.50-1.00 inches in the inland valleys and 1-3 inches along the coast, and in the mountain ranges.
Longer rang forecast are showing lingering showers Monday, but Tuesday looks like it will be dry through most of the day before another wet system approaches by Wednesday. Highs will be in the lower 70s.