Wow, what a difference a week makes! May 15th ended with PDX total rainfall for the month reaching .20 inches. We were still talking about the driest May in recent memory and parts of the metro were continuing to see the driest 5 month start to a year in recorded history.
This week's upper level low has dropped 2.43 inches of rain over the past three days. The total is just shy of 2.47 inches, which is considered normal for the entire month of May. PDX began today with 2.94 inches of total May rainfall. The much needed moisture has returned our grass to the expected deep green color this time of the year. Widespread moisture this week and more than a foot of Cascade snowfall will also help delay the start of wildfire season.
As a forecaster, it is frustrating to realize the lack of skill, modern meteorology still has in foreseeing a sudden change in weather pattern. Forecast outlooks did correctly call for below normal spring rainfall but did not offer a clue to this week's heavy rain and change to wet, cooler weather pattern now expected through the first 10 days of June. To be clear, this past week's weather was correctly projected on the 7day forecast, but the fact that we would shift into a long stretch of cooler, wet weather was not picked up.
KGW Meteorologist, Rod Hill