How bad is May? Can June continue?

May 2022 will be one of the wettest and coolest times in the Northwest’s history, setting the stage for a delayed wildfire season in the region.

To provide some perspective, here’s the difference in lower-than-normal (°C) atmospheric temperatures for the month, said Dr John Christy of the University of Alabama at Huntsville. An apparent cold pink eye over the Pacific Northwest (medium blue, more than 1.5 degrees below normal). There is only one place colder: eastern Russia (I could make a comment here, but won’t).

The eastern US was warmer than usual in May. The yin and yang of the weather.

The snow cover in our area is amazingly deep (see below). For example, the snow cover southeast of the WA Cascades has an INCREASE rate of one hundred hundred percent above normal. Yes, 18 times normal. Snow and ice east of central Puget Sound was 319% above normal. Just crazy.

And if that doesn’t impress you, Seattle had its wettest May since 1948 (see below). You’ll notice that Seattle’s rainfall tends to be very little over the long term.

The entire region has been cold for the past month, with temperatures across much of the Northwest averaging four to six degrees below normal for the month. The cold extends eastward into Idaho, Montana, Wyoming….and beyond.

Why so cold and wet?

Because a more persistent low-pressure gully is already circling the area.

To illustrate, below is a map of the difference from normal (abnormality) of altitude at a pressure of 500 hPa (you can think of it as the difference from normal of pressure at 18,000 ft) over the last 30 days Blue and purple indicate a much lower pressure/altitude than normal – known as a bottom.

A very large and sturdy chute is above ours – and that creates wet/cool conditions. In contrast, there is altitude…well above normal altitude and pressure – in the eastern US, where temperatures are higher than normal. There is a very similar pattern of alternating low and high pressure. Not an unusual pattern.

Now the frustrating part.

Latest model runs suggest June will resume cool/wet mode. Sorry.

For example, the UW model’s latest forecast for cumulative precipitation for the next week shows heavy rainfall in the area, with many mountainous areas more than 2 inches high. That’s a lot for June. Even northern CA gets a piece of the steamy action.

And the predicted temperature is basically cooler than usual for the next week (see Central Europe’s overall forecast for temperature difference from normal below). The entire Northwest will be cooler than typical (in blue).