Heavy rain soaks the Pacific Northwest as “Juneuary” rolls on

This weekend I was camping (in an RV) in Northeast Oregon. I’ve never seen it so green in June over there and throughout the eastern Gorge and Columbia Basin. So much water in the rivers and creeks in one of the drier parts of the region. Meanwhile, a massive June soaking nailed the Portland metro area Friday and Friday night. I’ve don’t think I’ve seen so much rain in June over such a large area; typically it would be more isolated thunderstorm events with a soaking in one neighborhood, but much drier elsewhere. Regardless, I’ve always liked the term JUNEUARY, a portmanteau of JUNE + JANUARY. It’s a bit dramatic (it’s not really like January), but it works.

Portland picked up .37″ Thursday evening as the rain began, then 1.42″ Friday, .12″ Saturday, and .05″ today. That makes for 1.96″ at PDX out of this system, VERY wet for June and more than we typically see in the entire month. But wait, there was more...a LOT more in some of the surrounding east metro areas. Strong westerly flow in the middle atmosphere pushed subtropical air up into the Cascades. That squeezes out far more rain in the eastern suburbs than west metro. There were spots that picked up 4″ of rain in just 24 hours! Just a few totals here:

This is why, averaged out over time, that hilly areas and east metro picks up far more rain that west metro. I can’t tell you how many times I’ve left home and it’s soaking wet. I get to work (west metro) and it’s been dry all day. The driest parts of the metro area average less than 38″ rain per year, the wettest close to 60″!

Portland NWS put out a statement today that included many other locations: https://www.wrh.noaa.gov/forecasts/display_special_product_versions.php?sid=pqr&pil=pns

The result is mainly full flood control reservoirs throughout the Willamette Basin. A great video of water overtopping Cottage Grove Dam (it’s supposed to do that) for the first time in many years: https://www.facebook.com/watch/?v=3678519672375179

The Columbia River is also experiencing minor flooding in the metro area due to snowmelt upstream and plentiful rain. We saw it near this level in May 2018 and a bit higher in May/June 2011. That year (2011), it stayed near/above flood stage from late May to late June! Before the dams, the Columbia would rise very high (or flood) almost every late spring and early summer

What’s Ahead?

We get a bit of a break this week, more typical mid-June weather. Although temperatures remain mainly below average over the next 7 days. You’ve probably heard about the scorching heat across the middle of America? It’s because we are locked into a pattern with a large area of hot high pressure (a heat dome) over the continent, but a cool upper-level disturbance (low pressure) over the Pacific Northwest.

We haven’t had a single instance of a strong ridge of high pressure lingering for more than a day or so since way back in March. That will continue this week. At midweek (late tomorrow), that upper-level low is gone...we warm up a bit Tuesday-Thursday (like previous weeks)

But then check out this coming Friday. Another deep dip in the jet stream pushes cooler air inland again; that southerly flow along the West Coast can be wet.

Check out that extreme heat across the USA! Yes the rain is annoying here, but I’ll (for now) take the cooler/cloudier weather instead. It’s too early to know how much rain we might see next weekend. I’ve seen this pattern produce areas of heavy rain both west and east of the Cascades, but often it’s not obvious where the heavier stuff ends up until we’re within just a few days. The big message is...

FOR A 4TH CONSECUTIVE WEEKEND, PACIFIC NORTHWEST WEATHER WILL BE UNSETTLED