PORTLAND, Ore. — Portland is expected to see cloudy skies with only a possible trace of rain for this weekend's Rose Festival Starlight Parade and Timbers home match, but it's a good thing both events are happening on Saturday, because Sunday is forecasted to kick off a three-day round of wetter weather that will soak the city with an unusually large amount of rain for early June.
"Our big story continues to be this push of widespread soaking rain with hours of good, moderate rain rates developing Sunday, raining all of Sunday night into Monday — the type of soak that we don't get that often this time of year," said KGW meteorologist Rod Hill.
The culprit is a strong jet stream moving in across the ocean toward the Pacific Northwest, Hill explained, which will arrive in the Portland area on Sunday and then continue to drive strong rain over the following 24 hours. The rain should transition to showers Monday afternoon as a new front moves in, he said, but another system will bring more rain on Tuesday.
Portland will pick up about 1.15 inches of total rain from Sunday morning to Tuesday evening, Hill said, and most coastal cities will get about a half inch more than that. The rest of the Willamette Valley will get a bit less, but still close to an inch in some places.
"Remember that the entire month of June, 30 days, the average is 1.63 , I think is the exact number out of Portland," Hill said. "So if we get more than an inch, that puts us in really good shape as the young month starts off."
Snow levels have risen quite high, Hill added, so the system is expected to bring purely rain even at Timberline Lodge, which is 6,000 feet above sea level. Rhododendron could see as much as 2.15 inches, he said, with as much as 2.54 inches in the Columbia River Gorge at Skamania.
The rainy days will be accompanied by lower temperatures, with highs only in the 60s Sunday, Monday and Tuesday. Temperatures will warm up rapidly after that as the sunshine returns, Hill said, with a high of 78 on Wednesday and 85 on Thursday.
The forecast for the Grand Floral Parade next Saturday, June 8 is still a bit unclear, Hill said, with disagreements among the weather models — as of Friday morning, some of them were predicting continued sun with temperatures getting into the 90s, while others were showing falling temperatures and possible rain showers that day.
"So that's weather models going opposite directions," he said. "Now at some point they'll come together, but that has not happened yet, so we are waiting to see."