First heatwave of 2022 will likely feature a 100 degree day in Portland

9pm Friday…

Today was nice with a high temperature of 84 in Portland, but now the heat sets in this weekend.

Our weather forecast models are in agreement that a 100 degree day is becoming more likely in the Portland/Vancouver metro area Sunday. All the factors that can push us to that century mark appear to be in place for just that one day.

For those just wanting the details:

  • Hot weather arrives tomorrow and sticks around through Monday along the I-5 corridor in western Washington and Oregon
  • Expect low 90s tomorrow and Monday, but between 98 and 102 on Sunday. Skies will be sunny all three days
  • Breezy and dry east wind keeps humidity low both tomorrow and Sunday, although it might get a bit more humid (briefly) Monday
  • A breezy west/southwest wind arrives Monday evening along with a major push of cool Pacific air. Tuesday we’ll be in the 70s most of the day!

Our 3 day forecast for Portland looks like this:

Along the northern Oregon coastline, the forecast (as always) is a bit more tricky

That warm/hot easterly wind touches the beaches tomorrow, but then really pushes in Sunday. When that happens, it CAN be just about as hot at Astoria, Cannon Beach, & Tillamook as it would be here in the valleys. Thus the 90 degree possibility.

Here’s the plan for the next 3 days…

A “thermal trough” of low pressure is developing west of the Cascades right now. That’s because low pressure forms on the “lee” (downwind) side of mountain barriers as wind crosses it. Easterly wind has developed over the Cascades and now air is moving toward that blue line west of the Cascades down here at sea level. Easterly wind is blowing at Vista House in the Gorge. This is the classic signature of an approaching heat wave west of the mountains. Notice wind is still weakly onshore at the coastline.

By tomorrow afternoon, a strong thermal trough is in place west of the Cascades, centered over the Coast Range. Temperatures warm a bit at the beaches, but really skyrocket inland. 4 millibars worth of pressure difference between The Dalles and Portland means a gusty easterly wind in the western Gorge. High fire danger…BUT…all the vegetation is very green out there…for now.

Then check out midday Sunday. The thermal trough has broadened and is right over the northern Oregon coastline. Hot east wind is making it to the beaches in that area. 4-5 millibar pressure gradient remains over the Cascade for a continuing easterly wind. But also notice the cooling southwest wind has arrived on the central coastline. It WON’T be a hot day from Lincoln City southward Sunday.

Finally, by late Monday afternoon (5pm) things have really changed. The thermal trough has shifted east of the Cascades with a strong west-southwest push of marine air in progress everywhere west of the mountains. A westerly gradient of 5-6 millibars means a very strong west wind has returned to the eastern Gorge. Big afternoon for kiteboarders out there! It’s possible that from Salem south temperatures remain below 90 on Monday.

These images are all from the high quality WRF-GFS model from the UW. The cross-section product is excellent for showing us the deep easterly flow tomorrow and Sunday (area shown in yellow), then the switch to onshore flow Sunday night. Easterly wind is blowing almost 50 mph over Portland (overhead) tonight and tomorrow night. Note that time goes backward on this graphic

That does keep our humidity low through most of this event. Dewpoints may briefly come up to “normal” for summertime Saturday night, but that’s about it. Dry stuff = good.

Models are now pushing 850 millibar temperatures (temperature in Celsius ~5,000′) to +23 or +24 over Salem Sunday afternoon. There have been two previous events just like this one in late June. Temperatures were similar overhead in June 2006 and June 2017. Both produced 100 degree days in Portland. And the setup Sunday afternoon is “perfect”. Easterly wind dies down to almost calm at peak heating time in the metro area, but cooler southwest wind hasn’t arrived yet. Totally sunny skies uninhibited by high clouds too. This all adds up to a 100 degree day.

That’s it for now, find a place to stay cool this weekend, and be careful on our local lakes and rivers.

Chief Meteorologist Mark Nelsen

37 Responses to First heatwave of 2022 will likely feature a 100 degree day in Portland

  1. tim says:

    Today’s cpc July outlook has us cooler then normal but after reading the discussion it’s only for the first week then we warm up for the rest of the month, that’s a relief.

  2. Roland Derksen says:

    Looking at my rainfall amount for June, i see that 90% of the total (2.97 inches for me) was in the first 10 days. That’s not unusual. I’ve seen similar tendencies in past year Junes for the first part of the month to be wet while the latter half (or more) dries up. Perhaps this will mean a dry summer, but it’ll be hard to match last July: I only had 0.01 inches for that month!

  3. tim says:

    A nice long stretch of 80’s next week and for the foreseeable future.

  4. Weatherdan says:

    Looking to July in Salem I believe our maximums and minimums will both be slightly warmer than average but well below the last few July’s. Precipitation will be close to average. In other words very pleasant. We seem to have left our wet and cool Spring behind us and are headed to a gradually warming Summer. Happy birthday America and peace.

  5. Roland Derksen says:

    Well,it’s all over now, Baby Blue- overcast skies this evening, a few light showers. the temperature at 8pm was over 20 degrees cooler than yesterday at this time. Time to shut off the AC folks- for a little while at least!

  6. Joshua Lake Oswego says:

    26 degree negative departure at 3pm for PDX today compared to yesterday. Just glorious. We should end up close to a negative 45 degree departure compared to this day last year.

    65 days until meteorological autumn and daylight will be decreasing by over a minute a day starting a week from today.

  7. Weatherdan says:

    72 and partly cloudy at 2:10PM. Should see more Sunshine Wednesday then 3 days of mostly sunny with highs 80-85 before a brief downturn over July 4th, of course. Then a nice warmup and back to Summer. Fireworks are better seen under a cloudy sky anyway. Peace and happy birthday America.

  8. tim says:

    Another warmup around the 10th this time it won’t cool down until next fall it’s finally summer the way it should be.

    • icydaze says:

      For someone who bragged about turning your AC on when your house was 73deg I find it hard to believe you like hot weather

  9. JohnD says:

    After last years “once in forever” event, typical 3 day 90’s heat is like—meh—whatever! Take it as it comes, of course.
    For me—and a lot of us, I think—last years event was a definite positive in many ways.
    I mean seriously—as someone noted last year—our PDX 116’ set an official high temperature record behind only Phoenix @ 122’ and Las Vegas @ 117’ among all the big cities of the US.
    Pretty darn amazing to say the least.

  10. Roland Derksen says:

    Around 90F here this late afternoon, but there are bands of Ac Castellanus moving in. Looks like tomorrow could be an intresting day- some showers or possible thundershowers coming.

  11. Weatherdan says:

    90 currently in Salem. Of course it will rain on the Independence day weekend. It is Natures final insult. Warm and dry after that. Peace.

  12. JERAT416 says:

    Raindrops are making their way into the weekend forecast….NO. Definitely not ok, assuming somehow we could change that. There is lots of time for change as we get closer…..

    • West Linn 200 says:

      I wouldn’t worry too much just yet. These things tend to fall apart the closer we get to it. Most of the Euro ensemble members give us less than 0.2in over the weekend at best. You’ll probably have some fine mist or a small episode of drizzle Saturday night into Sunday.

  13. Jim says:

    Climate change is fine by you? What are you talking about?

    • tim says:

      the fact we don’t get cooler than normal summers anymore due to climate change which is fine because I like warm/ hot summers and this summer most likely be warmer than normal again. 2012 for Seattle was our last cool one.

  14. tim says:

    Even during a la Nina summer supposedly like this one we can’t get cool summers anymore like 2010-2012 or any other ones for that matter thanks to climate change which is fine by me.

    • Zach says:

      It is too early to call this summer “hot” or “cool”. I would say if we end up with less than 10 90F+ days that qualifies as cool in my mind.

      • Mike says:

        I would like to cancel summer and have extended spring and early fall. That would be perfect. And nothing but rain during fireworks so that fires don’t happen any longer.

  15. West Linn 200 says:

    No more heatwaves in sight for now 🥳

    I sincerely hope it was the last one, but I know that’s very unlikely.

    • tim says:

      Our real summer heat usually starts mid July and onward so yes we will have more heatwaves , we’re just getting a preview now.

  16. Patrick says:

    Perfect summer weather coming up this week, with highs in the mid 70’s to low 80’s, fresh northerly breezes afternoon and evenings.

  17. Joshua Lake Oswego says:

    PDX is hanging at 99. Nail biter.

  18. tim says:

    Who’s ready for heatwave #2? gfs has another big warm up around the 11th, the very idea of a cool summer is absurd it’s not happening thank goodness.

  19. Joshua Lake Oswego says:

    70 degrees here. Should be the low for the day. 100, here we come. I see some mid-70s readings near Gresham, some foothill locations, and near McMinville

  20. Lucky Hoquiam! The Bowerman Airport beat everyone yesterday with a 91 degree reading on the west side of Washington thanks to offshore winds. Olympia and Shelton Airports were close behind with 90 degree readings.

    Here in my area in Port Orchard it reached 87 and at the Bremerton Airport made it to 88 degrees.

  21. West Linn 200 says:

    I was right earlier about going over 95. We hit 96 degrees around 1PM here in West Linn. Car thermometer hit 99 degrees on Hwy 217 around 3:30 PM, but not sure how accurate that one is.

  22. Weatherdan says:

    After all is said an done it looks like June will be a little warmer and wetter than average. So no Juneuary this year. I believe July-September will also be a little warmer than average. Precipitation will most likely be close to average. So by 2022 standards a pleasant Summer. But by the Standards of say 1962 a hot Summer. 94 at 2:30PM. Peace.

  23. Paul D says:

    I was outside this morning ripping apart my ancient deck and it was brutal in the direct sunlight. I gave up at 11:30.

  24. Joshua Lake Oswego says:

    Heatwaves always overperform. Already 90.

  25. JERAT416 says:

    We will live. This happens every summer a time or two. After last year, I’m thankful we aren’t gonna see anything unprecedented. Stay cool !

  26. West Linn 200 says:

    Ugh it was already 79 degrees here at 9am. I’m guessing I’ll top 95 today

  27. Joshua Lake Oswego says:

    Disgusting that we can’t get through June without hitting 100 these days. Brutal for flora, fauna, and humans to have this heat near the solstice when the solar energy is the most intense. Thankfully, there is no sign of heat after Monday.

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