Summer Weather Heating Up

9:30pm Monday…

I’ve seen quite a bit of complaining about Summer 2020 so far. A wet June was followed by a cool July start. In fact this month is running 2.5 degrees below average; the coolest start to summer in 8 years. Summer is defined by June 1st through July 12th in this case. We have seen 5 days of very pleasant weather with temperatures near normal though.

Today’s 80 degree high under mainly sunny skies was about as “normal” as it gets for July 13th.

A clear shift into the dry season arrived right on schedule though. We have seen less than .10″ rain in the past three weeks! And I see very little in the next 1-2 weeks. Check out the very dry ensemble rain forecast from the ECMWF model. It shows 51 different ensemble members as horizontal lines through the next two weeks. Only TWO of those members produce any significant rain over Salem (Portland is similar) and it’s brief. Most likely attempting to bring thunder up from the south.

So what’s ahead? A quick summary:

The next two weeks will feature the weather some of us wait for. Expect reliably dry and warm weather with near to above normal temps…plus abundant sunshine. This is it folks!

What has changed? All models are, in general, keeping upper-level heights quite high over us the next two weeks. A hot ridge of high pressure doesn’t seem to want to sit directly over us for a major heat wave, but heights remain high. Here’s the GFS ensemble 500 millibar chart for tomorrow

The cool trough that brought us sprinkles/showers Sunday morning is over the Rockies and northern Plains. A warm upper-level ridge is sitting just to our west over the Eastern Pacific. It’s not right over the West Coast, but heights are above average for mid July (the warm colors) over us. Then look at Thursday night; a fast moving upper-level wave rides over the ridge. In summer this means a strong marine push of cooler ocean air, but typically no rain.

By this Sunday (the 19th) the ridge is rebounding and moving closer again. Notice heights are up to 588dm. That means the 500 millibar pressure level is way up over 19,000′; a warm/hot airmass is pushing overhead with the core of the warm air offshore.

By Tuesday the ridge offshore is a bit weaker and farther away. But the main thing to see here is that upper-level heights are above average all across the region. This is a warm weather pattern through these 10 days, but not excessively hot.

With that ridge nudging a bit closer to us next Sunday-Tuesday, we may turn hot for a brief period. It’s not real tough to see a few 90-95 degree days in late July in Portland! This is what we’re thinking right now for Portland:

Enjoy the dry and warm summer weather!

Chief Meteorologist Mark Nelsen

17 Responses to Summer Weather Heating Up

  1. Roland Derksen says:

    Finally- another 80+ temperature maximum- the first since May!. It happened yesterday here with 81.6F. A bit of a return to cloudier conditions today and tomorrow, but by early next week, we could see afternoons in the high 80’s (30C ).

  2. Lurkyloo says:

    Happy summer everyone!

  3. JohnD says:

    Lifelong—as a weather nerd like all of us—EVERY season—amid our generally moderate “marine” climate—I’ve always pulled for “season defining events!” Also records!
    As we all know, these are typically harder to come by during most winters; easier to occur in many summers— including maybe in the coming days!
    Time to think about breaking out the bedroom A/C!

    • MasterNate says:

      My interest is definitely more in extreme winter events being wind storms, rain events and most of all snow/brutal cold weather events. Hard to come by in the great PNW.

  4. W7ENK says:

    Finally, my tomatoes can ripen and my corn can stop struggling!

  5. Summer is finally here!

  6. Roland Derksen says:

    I love the summer weather the way it has been yesterday and today: Sunny skies, nice breezes, temperature in the mid to upper 70’s. If someone else prefers clouds and showers, take a trip north to Alaska.

  7. WEATHERDAN says:

    I was born in Salem in 1954 and have lived here all of my life. I also love hot and sunny weather. Some native Oregonians love cooler Summers. Many of us love the heat. Please do not attempt to speak for all of us. Thank you. Peace.

  8. JohnD says:

    It was 128’ @ Furnace Creek in Death Valley, California on Sunday. I read that their record is 129.2’ recorded in 2013–which may also be the all time world record. Apparently the 134’ record reading from 1913 has basically been shown to have been unreliable.
    My wife and I went to Furnace Creek during a heat wave one time. The high that day was 121’. It was fun to experience (well, sort of.)
    The day before that we had climbed Mt. Whitney. The highest elevation and the lowest elevation in the lower 48 both within a 100 miles or so from each other!

  9. Finally had to break out the lawn sprinkler yesterday. The less than .10 of an inch of rain these past three weeks might explain why things looked a bit parched. No excuses other than I am a Scot and suffer from a well-known Scottish condition – we tend to have short arms and deep pockets. A clever way of saying we are a wee bit thrifty! And water is a wee bit expensive!!
    I think St. Swithin is going to come through for us tomorrow and the rest of summer will be lovely.

  10. Paul D says:

    I’m loving it so far. Keep it below 90!!

  11. Gene says:

    Wrong. It’s the long-termers who are complaining. We’ve lived here long enough to know that the window for sunny, warm/hot weather in the Portland area is small, and losing even a part of that to cool, cloudy, rainy weather can be maddening (not to mention, our gardens hate it). That’s why most Oregonians, I’m guessing, are looking forward to seeing sun, blue skies and warmth for a few weeks

    • Anomynous says:

      Sounds like your opinion, man. All the true local I have talked to are so happy to have our normal summer weather back, after the last several years of scorchers.

      • Gene says:

        True, the last few have been scorchers, but I still contend that most lifelong Oregonians (like me) enjoy sunny, warm summers — mostly because our summers are so short (compared to the rest of the country) and the rest of the year is so cool/cloudy/wet. I’ve lived here since the early ‘60s, so I think I’m safely in the “true locals” category. And today is an example of what I think most Oregonians would call a beautiful, sunny summer day.

      • MasterNate says:

        I second that Anomynous

  12. tim says:

    12z gfs has a 3 day 90-95 streach for seattle 24th to 27th so this first heat wave early next week is the
    just prelude to main event later in the month i suspect pdx will be much hotter then seattle.

  13. Anomynous says:

    Most locals have loved this summer so far. Probably the disgruntled California transplants flooding your inbox Mark.

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