Ahead: 2nd Long Heat Wave This Summer

9pm Monday…

This weekend was sure refreshing…showers, clouds, and comfortably cool temperatures.  Of course if you had camping reservations for “the driest weekend of the year” you were probably a bit disappointed.


As I mentioned would happen a couple of weeks ago, the last three weeks of July have been significantly cooler than the first week or so.  The average high temperature in Portland the past 18 days has been a very “normal” 81.3 degrees.  Yet in the 18 days before that, the average high was 90.6 degrees!  Quite a swing over the past 5 weeks.

Well now it appears the large/hot upper-level ridge of high pressure is going to nudge back up into the Pacific Northwest from its current position over the offshore waters of California.  This setup causes two significant changes:  First, the atmosphere overhead warms dramatically.  At 5,000′ over our heads, the temperature warms from around 45 degrees earlier today to the lower 70s Wednesday/Thursday afternoons…an almost 30 degree warming.  Then with a strong ridge overhead, the cool marine layer is suppressed to right along the coastline.  The flow overhead turns light east or northeast; we lose ALL marine influence Wednesday-Friday.


How hot?  The setup is almost exactly like what we’ve seen the past few times we’ve been close to 100 degrees this month.  Models would have us believe it’ll be only around 92-95, but all summer the effects of warmer than normal ocean water offshore seem to be showing up in a “model cool bias” during hot spells.  Due to that I went with 96-99-97 for Wednesday-Friday.  Once again this time, it does not appear to be an extreme heat setup.  I would want to see stronger offshore flow for that.

By the way, check out those sea surface temps!


Widespread 62-65 degree water temperatures all along the central/north Oregon Coast.  Wayne Garcia just told me the past few days camping at Yachats they were able to get in the water for a significant amount of time before it felt too icy cold.  Not like the normal 55 degree ice-cream headache cold stuff we are used to.

If we actually stay above 90 through next Monday for high temps, we will tie the all-time record for 90 degree days at Portland Airport.  That record is 24 days in 2009.

I don’t think this will be a LONG heat wave like the bizarre 14 day event early in the summer.  Models are trying to return some sort of weak upper-level troughing later next week.  Take a look at the ECMWF ensemble height anomaly from last night’s run.  First this week:


Then Week #2, just slightly above normal heights.


Week #3, about normal conditions, maybe slightly cooler than normal?  The actual operational run shows much hotter conditions than this.  Remember these maps represent an average of all the ensemble members.


And the last week, Week #4, which takes us into the last week of August


Seems to indicate near normal or slightly above normal conditions.

So August starts scorching hot, then seems to return to closer to normal as we head into the latter part of next week.

Chief Meteorologist Mark Nelsen

34 Responses to Ahead: 2nd Long Heat Wave This Summer

  1. schmit44 says:

    7/28/2015 Oregon (All) Temperature Summary

    High:101 at Brookings (US 10( 149 ft)
    Low: 74 at Brookings Airpor(459 ft)

    High:55 at HOWARD Mt Howard(8150 ft)
    Low: 18 at CROW FLAT (5172 ft )

    Largest Diurnal Change: 58 degrees
    CROW FLAT (76/18 ) (5172 ft )

  2. W7ENK says:

    The Western flanks of Mt. St. Helens are completely devoid of snow, I saw this as I was driving back from Clatskanie this afternoon.

    It’s not even August yet…

    • DBurnett says:

      Yeah, I can the mountain from my living room window and it’s a bleak sight.

      Has anyone noticed that the leaves are beginning to change in the West Hills? Is the early start to the growing season responsible for this, or is it due to the dry weather?

    • Joshua says:

      Dry weather. Trees are stressed. I have seen plenty that have lost their leaves already, or have died completely. Sad.

  3. Boring Oregon says:

    Looks like a little more snow on the very top of Mt.Hood today.

  4. WEATHERDAN says:

    88 so far today with strong North winds to 25 MPH. So since last year was the hottest Summer ever recorded in Salem how do they stack up to this point. in 2014 up until July 28th Salem had 15 days over 90 as compared to 19 in 2015. In 2014 we had 39 days over 80 as compared to 56 in 2015. In 2014 Salem had 77 days over 70 compared to 87 this year. So unless the last 2/3 of Summer is quite a bit cooler than normal we will have a new hottest ever Summer. And 2013 was at that time the 3rd warmest Summer. So what will 2016 or 2017 be like. Stay tuned. How about that snow in Wyoming yesterday. 1 inch in some of the higher mountains. We couldn’t get snow in our mountains in January and they get it in their mountains in July. Hopefully we will get some snow in our mountains come January. Peace.

    • High Desert Mat says:

      I believe in 2016 our weather returns to near normal conditions and then a little cooler than normal in 2017. Its in the cards but its also a hunch. Mark my words, I posted this on July 28th 2015.

    • Boring Oregon says:

      At 7:00 pm pacific time

    • High Desert Mat says:

      Yes I meant to say that lol

    • Joshua says:

      Pretty sure we got 1″ of snow at 9,000 feet during January.

  5. what do I have to do to get the Kelso station fixed? The thermometer keeps going out and it’s very aggravating.

  6. runrain says:

    Looks like the NWS has taken the expected heat down a notch and moved the hottest day from Thursday to Friday.

  7. WEATHERDAN says:

    Delightful day outside today. 81 degrees now headed for 90. Nice night for a baseball game or a barbeque. I will remember this day come January. Peace.

  8. tygrrlilley says:

    Right?!! I need to keep telling myself that it’s temporary, else I’ll lose my mind completely…and not in a good way. 😉

    • tygrrlilley says:

      Oops, this was in response to Paul D’s response to my response to the post. lol

    • Paul D says:

      I’ve quit riding my bike to work because I’m tired of feeling like a roasted piece of meat when I get home. By the time this heat wave is past, it’ll be too dark in the morning when I commute, and I don’t ride in the dark. I miss riding…… Blasted heat wave!

  9. ockman says:

    Brandon Bockman in Portland area Says’
    Hi Mark Nelson we are having a hot hot hot summer like 2014 last year Im staying cook with the aircondishing on and swimming.
    I Would like to know how long will it last? and when is the cooler weather going to come? also what will September weather will bring? when fall comes.
    Have a good day stay cool

  10. Looks like we’ll have a fairly normal August, once we get past the first weekend of the month.

  11. Tyler Mode in Battle Ground says:

    A nice cool 49 here in Battle Ground this morning.

    PDX only dropped to 58.

  12. alohabb says:

    I love this weather!!!! Keep it coming!!!!!
    Just returned from Hawaii where the tradewinds died and the temps were 85-90 with 90 percent humidity! Never spent so much time in the water!!!! The ocean temps over there have to be in the upper 80’s close to 90. It rained a ton in the upcountry, but by the beaches it was sunny and hot. This hot is going to feel refreshing!

  13. Paul D says:

    Just what we don’t need……

  14. schmit44 says:


    Here is the link to enter your guesses

  15. schmit44 says:

    7/27/2015 Oregon (All) Temperature Summary

    High:85 at DW5789 Eagle Poi(1463 ft) & EW1735 Central P(1285 ft)
    Low: 63 at Roseburg Regiona(525 ft) & PATSY Eddyville/(1210 ft) & Bradley Wayside(650 ft)

    High:43 at HOWARD Mt Howard(8150 ft)
    Low: 25 at KIRK (4519 ft )

    Largest Diurnal Change: 46 degrees
    MAZAMA (73/27 ) (4596 ft )

    Heaviest Rainfall:
    0.20″ at MT. HOWARD(7910ft)
    0.14″ at SUMMIT(6113ft)
    0.14″ at EW4395 Milton Fr(3454ft)



  17. Boydo3 N. Albany says:

    The bad part of the bad part is, the rivers around here look like low tide at the coast. Like a minus tide at Newport. And they feel like the swampy Bayou, you know, catfish country. Warm, warm slow moving water. Slow, slow water. Like an irrigation ditch in Texas.
    I was born and raised on the west side of the mtns. Lived in P-town, Olympia, Corvallis, Ashland, Albany…this is as crispy dry as I’ve ever seen it in my 63 years… dry and crispy is all I can say…dry and crispy 🙂 🙂

  18. Doesn’t sound too bad. I am hoping this is the last really hot blast before we sneak into fall.

  19. tygrrlilley says:

    Sonofabiatch!!!! I was hoping we wouldn’t get another one of these. At least the weekend was wonderful!! =D

    • Paul D says:

      This is one of the most depressing posts I’ve ever read. More 90+ weather – UGH!!!!!

%d bloggers like this: