Our First Heatwave? Possible Early Next Week

Heat Wave

June has been about as “normal” as it gets.  Temperatures here in Portland are running just slightly warmer and slightly drier than average.  We have two more cloudy and cool days ahead with showers at times; we could still end up above average for the month I suppose.

Beyond Wednesday?  Models have been advertising (for many days) strong upper-level high pressure developing over the Western USA.

Here are the key points:

  • The end of this week MAY be the “turning of the summer switch”.  We often start our real summer (abundant sunshine and dry weather) suddenly.  Not always, but more often than not it happens that way.  That may be about to happen.
  • 80+ temps arrive Friday and continue through at least the middle of next week…high confidence in this.
  • 90+ temps are possible Monday-Wednesday of next week…somewhat good confidence with this.
  • Near or above 100 degrees?  It’s looking likely most areas east of the Cascades below 2,000′ this weekend through early next week.  Some models are showing it nearly that hot here in the western Valleys the middle of next week too, very low confidence on this for now.


Here is the 12z ECMWF and 00z GFS 500mb chart for next Tuesday morning.  That is a hot ridge!



Of course there have been variations on the strength of the ridge and location.  The closer to us it ends up the warmer we get.   The 12z ECMWF above was particularly hot with 850 mb temps around +27 for the 2nd of July (next Tuesday).  If so, the weak offshore flow shown (under 595+ heights!) could easily put us over 100 degrees.  Luckily the ensemble chart tseries_850t_000-360_Portland

shows it was at the high-end, with the average more like the 12z GFS’s +22-23.  That’s still would put us well into the 90s Tuesday/Wednesday next week.  Here is the new 00z GFS ensemble chart:


A little warmer than earlier runs, but the hot operational model is still warmer than its ensemble members.  Quite a bit of uncertainty on how far west the upper-level ridge builds.

One thing sticks out on all the model runs…we are headed into a warmer and most likely dry weather pattern as June ends and July begins.

Chief Meteorologist Mark Nelsen

28 Responses to Our First Heatwave? Possible Early Next Week

  1. runrain says:

    KPTV forecast Sat – Mon EXACTLY parallels NWS in temps. A first?

  2. archangelmichael2 says:

    So far the Euro has been right a lot so I put my coins in the Euro slot.

  3. BoringOregon says:

    This is amazing this week it’s been only in the 60’s for the high, then next week it’s going to be in the 100’s. I was looking on the 7-Day forecast it said on Thursday it’s going to be only, 78 then on Friday it’s going to be, 86 that’s still a good Eight Degree temp Change in a day. It’s been kind of funny all the weather channel and the news has been talking about is, Obama’s Climate change. Global warming you thank !?!?

  4. Dave in South Salem (500') says:

    I wonder how warm it will be in Redmond on Monday. Can’t wait to find out!

  5. W7ENK says:

    Good Lord, 113F at PDX on Tuesday according to the 12z. We all know it won’t actually get that hot, but driving up from SFO to PDX that day in a 16 passenger van with no AC is going to suck. 😥

    Looks like some cRaZy thunderstorm threat, too! J/kg values are literally off the chart, maxed at 3000 over almost the whole of Western Oregon right up the Willamette Valley all the way to PDX.

    Could be an interesting time, we’ll see…

    • Timmy_Supercell (Klamath Falls @ 4200') says:

      Usually in this kind of a heat wave, I would see everything start capping in the atmosphere, or at least over the Willamette Valley. I’d say if temps were more like June 2009 into the mid-high 80’s, with dew points over 60, we’d be looking at a decent setup for convection.

    • archangelmichael2 says:

      Don’t do it! Do you know how quickly it can get to 120F in a car without AC and those kind of vans tend to have their engines overheat?

      It happened to Dad in the 70s transporting teachers to a Christian school but the good news is the van broke down right by a Chevron gas station.

  6. Narda Ward says:

    Yuck, too hot, bring on the snow…..hahahaha

  7. Harrison says:

    Is this high heat a recipe for thunderstorms and wildfires to likely start up in the cascades then?

  8. umpire says:

    Ugh, hope it cools a bit for the Blues Festival, which starts on the 4th next week.

    Mark, if you’re biking out of Lewiston Idaho in August, figure on about 90 degrees IF it’s cool. Otherwise, 105 would be about right. I loved the travelogue – I grew up in northern Idaho (St. Maries, then Coeur d’Alene and enjoyed many family camping trips in the area. Also, if I recall correctly, Farragut St. Park used to be the site of a huge annual gathering of Boy Scout troops every summer.

  9. dharmabum says:

    I think we will have the hottest & driest July since 1967

    • WEATHERDAN says:

      In August of 1967 Salem averaged 91.0 degrees for a maximum. 19 of the 31 days exceeded 90. !0 were consecutive. The consecutive rainless days reached a record 79 days. So if you are correct we will have one long hot and dry summer.

  10. 300game says:

    Here is the 12z operational GFS. The wishcasting fountain has arrived with its off the wall temps for July 1 and 2

  11. HAHA..The GFS text output spits out a 113 for PDX on July 2nd…I don’t think I’ve seen it do that before.


  12. WEATHERDAN says:

    The Death Ridge cometh. The NWS has in this morning’s AFD called fot the potential of record breaking temps for Western Oregon next week. That would be in the 100-105 degree range.. Later this week we should see highs in the 80,s with DP,s in the 60-65 degree range. So Thursday through Saturday may be rather humid. Here’s to Summer. So enjoy this mild rain while you can. Go Dodgers and Go Volcanoes.

  13. schmit44 says:

    6/24/2013 Oregon (All) Temperature Summary

    High:77 at ALKALI FLAT(2495 ft) & LAKE OWHEE AND O(2400 ft) & Rye Valley(I-84(2230 ft)
    Low: 63 at RUFUS(185 ft) & BLALOK(277 ft)

    High:41 at Rim(7050 ft)
    Low: 32 at CW1038 Sumpter (4321 ft )

    Largest Diurnal Change: 28 degrees
    CW1038 Sumpter (60/32 ) (4321 ft )

    Heaviest Rainfall:
    1.10″ at RED MOUND(1753ft)
    0.93″ at POINT PROM II(6607ft)
    0.92″ at QUAIL PRAIRIE LO(3183ft)

  14. Greg Carstens says:

    Oh joy, there goes the water bill I was saving on. Hopefully the heat wont be coming with a lot of humidity. If so I may have to sleep on a mattress full of ice cubes while it is around…

    • Jesse-Stevenson says:

      I’m with you Greg! Nice to see someone who’s not in the heat fanatic crowd.

    • I hate the heat! 75 during the day, 40 at night? Perfect!

      The only part I like about the hot days is driving around at night with the windows down.

      The worst time I can remember here was July 2009. Those back to back hot days and humid nights were horrible! I had two lows of 70+ and that’s no fun. I know that’s fairly common east of the Rockies, but that’s one of our claims to fame here, a nice, comfortable summer.

    • jakeinthevalley says:

      Warm, comfortable evenings seem to only really happen after we approach triple digits during the day.

      I wish we could have 75 degrees extend from noon to midnight!!

    • Timmy_Supercell (Klamath Falls @ 4200') says:

      I only like heat under certain circumstances, like if its for 3 days and it goes back into the 70’s, I’m in heaven. But IF this turns out to be anything like 2009, count me out. Several days of 90+ and a couple 100’s is not my way of enjoying heat. 😉

      Not that I can’t “handle it”.. But I just don’t prefer that.

  15. Sifton says:

    I’m so in!!

  16. Josh in Sherwood says:

    Uh oh. Jesse is about to get upset at you “warm bias” and call you out. And then cower when it comes true. Which would be par for the course.

  17. I’m ready for summer heat!

%d bloggers like this: