Another Round of Hot Weather Sunday-Tuesday

11pm Wednesday…

Today was far more comfortable west of the Cascades with high temperatures only in the low-mid 80s after morning clouds.

Expect more of the same tomorrow and Friday as marine air is in control westside. Nature’s air conditioning will keep us near/below 80 degrees through Saturday. That’s because weak weather systems (upper level troughs) keep moving by to the north in British Columbia. Here’s the view around 18,000′ on Friday from the GEM (Canadian) model showing that “dip” in the upper-level flow:

But see what happens by Sunday? An upper-level ridge pops up directly over the Pacific Northwest

An upper-level ridge this warm (590 dm heights) sitting directly overhead is heatwave material in July and August. So far this season we haven’t seen a hot ridge move right over the top of us. Models are forecasting +22 to +24 degree (Celsius) temperatures at 850mb (5,000′) over us Sunday and Monday afternoon. That’s also heatwave material. Third, a couple models produce easterly flow down off the Cascades Sunday, and to a lesser extent, Monday. The surface pressure map for Sunday shows what we call a “thermal trough” west of the Cascades.

If that develops, we could hit 100 degrees in this pattern. We’ll go slightly cooler and aim for 98 both days. Beyond that time, the ridging weakens and temps go back closer to normal by the middle of next week. Here’s our current Portland forecast:

That’s it for this evening…I’ve got a weekend plus a couple days of vacation coming so no blog post until at least next Tuesday. Enjoy the comfortable weather ahead of the hot weather early next week!

Chief Meteorologist Mark Nelsen

41 Responses to Another Round of Hot Weather Sunday-Tuesday

  1. Mike says:

    The heat wave was supposed to be a S-M event, Tuesday was supposed to be much cooler here in E., more seasonable. By definition, the 94 was unseasonable. Now, “as high pressure rebuilds” (it didn’t ever go away) it will be hot again through Friday. “The ECME MOS guidance has been performing exceptionally well with high temperatures over the past few days”. Hot days to be doing trail work. Got to get it done before the fires close everything down and hope they don’t take out another 50-100K acres of wilderness.

    • Joshua Lake Oswego says:

      The heat is definitely wayyy overperforming. It always does.

      • Gene says:

        It’s interesting how it always seem to work like that in the summer. Too bad we couldn’t get the cold weather to at least occasionally overperform in the winter!

  2. W7ENK says:

    Another decent and sizeable ACCAS field sliding over the area again this morning. At one point it spanned the entire visible sky before clearing off toward the NE. Could bode well for later, but as is usually the case, probably not.

    • W7ENK says:

      And now, some of that has built into towering CU to my SE.

      Official NWS forecast makes no mention of even the remote possibility of thunderstorms tonight, so maybe that’s a good thing?

      • Andy says:

        I noticed the same down here in Albany. But no mention on anything happening from NWS. They did mention we have a dry atmosphere and not much moisture to play with, It would be nice to see a little activity somewhere in the valley.

  3. Paul D says:

    Question for you weather experts: On the NOAA website for PDX yesterday the 24 hour high shows 89 but there’s a 90 at 5:15pm if you look at the 5 minute data. Which is the official high?

  4. Roland Derksen says:

    It’s intresting to compare the first 2 weeks of the month with the last 2, especially, of course with the temperatures: My mean temperature for the 1st-14th was 61.7F (below normal and with 1.15 inches of total precipitation). The 15-28th? 70.0F and just a trace on one day (the 17th). This month will end up fairly close to average here, perhaps a bit drier and warmer than normal.

  5. Grizzly Bear says:

    Nice to see the same old blogger’s and also nice to see KPTV got a new weatherman. A pleasant change from Mark’s other helpers.

  6. Roland Derksen says:

    90F here yesterday, but today is noticeably cooler with some breezes off the water. Could reach 80F. Tomorrow is supposed to be warmer again.

  7. W7ENK says:

    Decent thunderstorm potential for our area late tomorrow night and into the early morning hours on Thursday.

    WRF-GFS CAPE Fcst 2020 07 29 23z

  8. JohnD says:

    Rare back to back 100’ days! Was sceptic when the clouds started to show up yesterday. But finally made it! A true season defining event! And well on our way now to achieving our average 90’+ days!

  9. Evan -- Cedar Mill says:

    Starting to feel cooler west wind kick in.

  10. W7ENK says:

    91 degrees at Noon in Milwaukie, and there’s a pretty serious ACCAS field to the S and E that’s slowly sliding this way.

    That will likely put a cap on today’s peak heating and knock a few degrees off our potential high temperature, but in return it could provide some excitement/entertainment later?

    Probably not the latter, but one can hope…

    • Ken in Wood Village says:

      It says 100 degrees in my area. Also, I got a lightning strike about 62 miles from my location on my lightning detector. I also see a little moisture East of Salem. Maybe we could see a light show over the mountains tonight 😉🌩⛈

  11. Roland Derksen says:

    89F here yesterday. That’s pretty high by our standards up here, but not quite at the late July 2009 level. One interesting fact; the warmest temperature for the day was at 6:24pm, which is pretty late in the early evening.

  12. W7ENK says:

    Wait, what?

    Thunderstorms forming around Eugene?!?

    Mark, how did you miss this one???

  13. tim says:

    Most pesonal weather stations give a false high without a fan and in sun all day so im a bit cautious i do have davis station that’s shaded from 230pm to dark no fan but stil get
    the true high between 3-6pm anyway 89 was the here in belfair southwest of seattle.

  14. runrain says:

    Temps cooling to upper 80’s Tue and Wed. That’s “cooler”?? I call that “less hot”.

    • Paul D says:

      Now it’s 90+. Ugh.

      • Joshua Lake Oswego says:

        Hot weather is always hotter than forecasted and lasts longer. Cold is the opposite. Mark said no extreme heat in his post on July 20th. Back to back 100 degree days 6 and 7 days later. Potentially 5 straight days above 90 now. The Desert NW is in full swing. July will end up above normal even with the very cool start. It’s basically not possible to have a cooler than normal summer anymore.

  15. Kyle says:

    I’m glad this isn’t a full scorcher setup.

    This feels more like a late September kind of event rather than a full on 4 corners July high. A brief spike then a drop. You know a blink it and you’ll miss it event.

    This is one of those early fall warm waves..

    • Patrick says:

      Exactly, with the warm or hot east winds blowing, does remind me of late summer or early fall.

  16. W7ENK says:

    92 at noon in Milwaukie.

    +10 for 5pm high temperature.

    Gonna be a hot one today!

    • runrain says:

      97 at the airport at 2pm. Temp jumped 8 deg as the wind abruptly switched to easterly. Aircraft have now been redirected to Runways 10R and 10L.

  17. Ken in Wood Village says:

    What happened to the weather station for Crown Point? I wanted to see if the warm East Winds were blowing but all I get is “The station ID D6193 does not exist in the database.” Maybe Mark is able to find out for us.

  18. W7ENK says:

    I’m smelling a pretty strong scent of wildfire smoke this evening. That’s not the kind of “real Summer” I was talking about… 😢

    • Jla says:

      There was a brush fire today on Sauvie Island. Out now. That was the source of the smoke in the air in Portland metro.

  19. W7ENK says:

    Looking forward to some real summer heat!

  20. runrain says:

    Ready for 100 next week. Stocked up on hard lemonade. Now, I need some limes.

  21. Roland Derksen says:

    We may get some showers here tomorrow- but after that the heat is on. Could see it reach 90F here next week.

  22. Paul D says:

    Way too hot in a few days. Not enjoyable in the least.

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