Summer 2022 dry spell arrives, plus a brief heat wave this weekend

June 21, 2022

10pm Tuesday…

What a change today! On the summer solstice we popped up to 83 degrees this afternoon in Portland. That’s the warmest day of the year so far.

It’s so hard to believe we had only seen ONE 80 degree day this season, back on June 2nd

Now it appears the threat for significant rain is mainly gone for the next 10+ days. Just a quick glance at the next 15 days from both the ECMWF and GFS model ensembles shows less than .20″ rain from both

This is because the endless string of cool upper-level lows dipping down into the Pacific Northwest seems to have “dried up”. These are the disturbances that bring us showers, clouds, and cooler than normal temperatures. It isn’t too unusual to see the “rain faucet” suddenly turn off. I can think of many years in which we’ve gone from regular showers to totally dry. Some years it happens in early-mid June, other years not until early July. I’d say the timing is just about average this year. Soon the complaints about a cool/wet spring will be forgotten…until next spring. 

To summarize:

  • There is no sign of a soaking rain the next 10+ days
  • Unless we get a sprinkle out of the low clouds tomorrow morning, the next chance for measurable rain isn’t until next Tuesday or Wednesday
  • Get ready to start watering those yards and gardens…for the first time this year.
  • We have entered the warmest/driest time of the year in the Pacific Northwest.  It’s time to hit the rivers, mountain lakes, Gorge, & Coast. Time for hiking, camping, bicycling and anything else you wait all fall/winter/spring for…

A weak system IS passing by to our north in Canada tomorrow.

But it only pushes in morning clouds the next two days, plus cooler temps. After that we expect a strong upper-level ridge to build over the western USA. This is THE FIRST TIME we’ve seen this setup all spring and early summer!

Did you notice that we’ve had very few totally sunny days? That’s due to the lack of strong ridging; we’ve only seen brief breaks between organized weather systems and those breaks don’t tend to give us totally sunny days.

WEEKEND HEAT WAVE

It’s been well-advertised (as all heat waves are around here) that we’ve got some hot weather coming this weekend. A combination of that warm ridge overhead, sunshine, and easterly (offshore) wind flow should make temperatures skyrocket. Temperatures up around 5,000′ (850 millibar level) are forecast up in the +21 to +23 range Saturday afternoon through Monday. Each model is slightly different, but their ensemble averages are generally +20 Saturday, +21 Sunday, and +18-19 Monday. That puts high temperatures between 90 and 100 degrees all three days. Heat waves are FAR easier to forecast than any other extreme weather in our area.  In fact I can’t remember screwing up a heat wave forecast in the past 25 years.  Sure maybe a 100 degree day became a 90 degree day because of high clouds. The easy forecasting is because we’re talking sunny skies. and it’s just a matter of HOW HOT IS IT GOING TO GET? And when all models agree, it’s pretty simple. Notice we don’t expect any records to be set this weekend because we saw a similar heat wave back in June 2017, then of course that all-time record heat last year

I don’t see a very humid heat wave this time around, and that should allow overnight temperatures to drop down to at least 65 degrees at night in the urban areas, cooler elsewhere.

That’s it for now…get your air conditioners ready!