Heat Wave Update


Now THIS is a heat wave!  I’ve been wondering for 18 years when we might break the all-time PDX record of 107 degrees.  We’re getting close…I see it’s 100 at 2pm, running 6 above yesterday.  Someone please tell me it’s not going to be 109 at PDX later?

A bit busy right now tracking our historic heat wave, and more important, where we are headed the next couple of days.  I’ll have some thoughts later.  But I’m guessing it may be almost time to bust out the champagne for Portland’s all-time record?  We’ll see…


Looks like we topped out at 106 degrees at PDX, the hottest temp since 1981!  Vancouver also hit 106 which makes it their all-time high temperature.  Combined with the 74 this morning tying the all-time warm low temperature, it’s truly a historic weather day in the area.  Of course the other quirky part of today’s temp is that it’s the first time we’ve had a high temperature of 106.  We’ve hit 105 a few times, and 107 three times, but that’s it…never a 106.  Weather geekery galore today.

Keep in mind that we did this with no obvious easterly flow through the Gorge or over the Cascades.  In fact the pressure gradient was very light westerly this afternoon!  That’s a very hot atmosphere.  More later…


Hmm, that was an uncomfortable TV moment around 10:25…good times.  If you didn’t see it don’t worry, not that big of a deal.  I don’t have any big thoughts about tomorrow that are much different than what I mentioned last night.  Looks like just a notch or two warmer due to the arrival of east wind across the eastern part of the Metro Area.  Maybe it’ll only reach Troutdale and Gresham, but either way the drying of the airmass plus some downslope warming should help.  I’m a bit worried that we’ll get a sudden 2-4 degrees warming…above today!  I hope not.  Seems safe to go with a all-time record-tying 107 degrees for tomorrow.

Beyond that we cool only slightly Thursday…above 100 still a good bet.  There is an obvious weak marine push Thursday night on most models.  So just above 90 the forecast for Friday.  After that models diverge a bit; the ECMWF keeps strong ridging along the West Coast, while the GFS allows an upper-level low to get close to us later in the weekend.  Both keep warm to hot weather around.  If we make it through Saturday with highs above 90, it’ll be the longest stretch of 90 degree weather in Portland’s history.

Time to go home…I may post early tomorrow morning (8am?) since I’m doing some live hits on KXL radio…Chief Meteorologist – Mark Nelsen

295 Responses to Heat Wave Update

  1. Rob "Wrath" S.E. Portland says:

    Be back later.

    Hope for 90F before 10:30AM !

  2. Rob "Wrath" S.E. Portland says:

    Hmmm what is it the SPC is seeing that we aren’t, the NWS service isn’t, and local mets neither?

    Today and Tomorrow in their Convective Outlook they have us under a ‘General Risk’ zone.

  3. Rob "Wrath" S.E. Portland says:

    74.1 now

  4. Rob "Wrath" S.E. Portland says:

    Sure would be nice if there was some more umph to that marine push Friday morning thus ending the heat wave and 100/90F temps. I really doubt it though….

  5. PaulB/Eugene says:

    Area forecast discussion
    National Weather Service Portland or
    237 am PDT Wednesday Jul 29 2009

    Synopsis…very hot record breaking weather will continue for the
    interior portions of the forecast area today into Thursday with a
    strong upper level ridge of high pressure over the Pacific northwest.
    A gradual cooling later in the week as the upper level ridge weakens.


    Short term…through the short term…models in pretty good
    agreement. Little disturbances in the northwest flow out of British
    Columbia will keep a small threat of PM thunderstorms over the
    Washington Cascades this County Warning Area today and less so Thursday.

    The thermal trough will be along the coast today…shifting a little
    inland Thursday and east of the Cascades on Friday. So excessive heat
    to continue in the interior today and Thursday but cooling some
    Thursday. Will continue with the hot weather along the north coast
    today with a big drop in temperatures Thursday as onshore flow
    returns. Look for some marine clouds to push the coastal gaps and
    move up the Columbia Friday morning. Starmer

    Long term…the GFS model appears to be bringing the upper low west
    of California to the coast too quickly and will follow the European model (ecmwf) for
    later in the period. This limits convection/precipitation to the Cascades
    and temperatures probably a little above guidance. Starmer

  6. Rob "Wrath" S.E. Portland says:

    Up to 72.4 now….

  7. What happened to my bird’s eye view of area temps?
    I see the map, but no temps are posting.
    Anyone know what is going on?

  8. Aleta-West Gresham says:

    I’m seeing a tree movement here now. Has picked up to a slight breeze just within the last few minutes.

  9. Rob "Wrath" S.E. Portland says:

    And so it begins!

    I now have a very light E-NE wind developing….
    My temp which had dropped to 70.5F is now up to 71.0 and I expect rapid warming east of I-205 initially, then overspreading the entire metro area mid-morning.

  10. Snow-Zone/Monmouth-Elv200' says:

    I am going with 108-110F for me today… in an extreme case maybe 112F… still cant believe we will be calling mid 90s for this weekend cool after these highs.

  11. 63.4° this morning, a +2.2 from yesterday. Very light SSE breeze.

  12. Rob "Wrath" S.E. Portland says:

    I’m still going with 109 PDX today. The entire metro area 106-110.

    • Snow-Zone/Monmouth-Elv200' says:

      Think we will be 100F from around 12-1pm today?

    • Rob "Wrath" S.E. Portland says:

      100 my noon is possible…. The only potential real fly in the ointment situation today would be too strong of offshore flow…. If that occurred we may not hit our all-time high…. 5-15mph, nothing stronger.

    • Rob "Wrath" S.E. Portland says:

      By noon*

  13. Rob "Wrath" S.E. Portland says:

    Rob, just give it another 20-30 minutes…. It will develop slowly in Troutdale, Gresham, and places above the Columbia River. I already have some puffs of E-NE wind here.

  14. PaulB/Eugene says:

    I was a tad too high on temps yesterday…still think there is an upside to temps

    PDX 108
    SLE 108
    HIO 109
    Corvallis 110
    EUG 108
    Vancouver 108
    Longview 107
    Seattle 100
    Olympia 104

    • Snow-Zone/Monmouth-Elv200' says:

      Still not bad though only off by 1-2 degrees and no ones complaining, yesterday was hot no matter how you look at it….

  15. Snow-Zone/Monmouth-Elv200' says:

    Beautiful sunrise by the way….. anyone with there most recent thinking on high temps today?

    • sds says:

      It was the hottest that I’ve seen at my farm 6 mi. E of Woodland and I’ve lived here for over 40 yrs.!! It was 100 in the shade and I live in a shady canyon–got to go bale hay this AM–fun on the farm!!

    • Snow-Zone/Monmouth-Elv200' says:

      Have fun I guess if you can..Lol… you should be just as hot if not slightly warmer.

  16. Rob Martin says:

    Wheres the wind? We have a decent gradient that would give is 10-15 mph in Sept. What gives?

  17. Eternal Yamcha (SE Milwaukie) says:

    First the NWS goes down, now Comcast is messing up?

    …..I think the Matrix just imploded and thrust us all into Bizzaro-Oregon where it’s muggy and obscenely hot for many days. Where beavers no longer exist, Mt. Hood is actually made of wood like the Matterhorn and the Marionberry grows in vast colonies across the time-space continuum!

  18. Snow-Zone/Monmouth-Elv200' says:

    Morning all… low so far 65.5F about -1 degree from yesterday…. wont effect temps though…

  19. Rob "Wrath" S.E. Portland says:

    Ah great! A real possibility at a historic day unfolding and Comcast e-mail is giving me errors!

  20. Rob "Wrath" S.E. Portland says:

    During the morning hours temps are going to literally soar due to the impending offshore flow.

  21. Rob "Wrath" S.E. Portland says:

    Good Morning

    It is disgustingly humid outside. Offshore flow has increased above 2,000′ and is less than an hour surfacing/developing at Troutdale and Gresham. My temp seems to have stalled at 71.2 DP 66.

  22. Tyler in Hazel Dell says:

    PDX sits at 75 still as of 5 AM…We’ll see if it can maintain that temp to break the record!

  23. K5mitch NE PDX says:

    Good morning all,

    It is a balmy 76.2 with a DP of 62.3.

  24. Rob "Wrath" S.E. Portland says:

    Current Temps
    As of 3 AM
    Portland: 78
    Kelso: 71
    Hillsboro: 73
    Salem: 73
    Eugene: 68
    Vancouver: 76
    Troutdale: 72

    By the way, thanks for the link, Matthew.

  25. Rob "Wrath" S.E. Portland says:

    Hmmmm NWS and Mesowest observation sites are still down.

  26. Rob "Wrath" S.E. Portland says:

    We have a wall unit A/C which does nicely to keep the living room, kitchen, and dining room below 80F, but the South facing bedrooms earlier were over 90F…. My computer room was 94.4F earlier…

  27. Rob "Wrath" Far S.E. Portland says:

    We have a wall unit A/C which does nicely to keep the living room, kitchen, and dining room below 80F, but the South facing bedrooms earlier were over 90F…. My computer room was 94.4F earlier…

  28. Eternal Yamcha (SE Milwaukie) says:

    It’s brutal. Seriously, brutal.

    It’s unbelievable that I have to look to Phoenix and the Inland Empire to find temperatures that make our temps look “warm.” It’s unbelievable I have to look at Las Vegas for comparable temperatures.

    I’m trying not to get my hopes up that the record will fall. I’m telling myself it’ll hit 105. But deep down I want to hit 108 and really want 110+

    By the way; no AC = FUN FUN FUN.

  29. Eugene says:

    What is everybodys take on thunderstorms when the heatwave finally breaks? Also, how are your tomato plants holding up?

  30. Rob "Wrath" S.E. Portland says:

    I was kind of surprised to see that Hillsboro is still 75F.

    • Yevgeniy says:

      Rob I am at 75 with DP at 66 and RH at 66% in Hillsboro
      since its becoming more humid and muggy out wont that give us a decent chance at tstorms tommorow???

    • Rob "Wrath" S.E. Portland says:

      Nah we don’t have any trigger such as a shortwave, vort max/lobe… That I believe could change by the end of the weekend into next week.

  31. Matthew says:


    80f at PDX as of 2am. Had to find another way for information.

  32. Snow-Zone/Monmouth-Elv200' says:

    Well I have to go to bed so I can stay up for tomorrows heat blast.

    72.5F… hopefully wont drop below 64F.

    • Cherie says:

      Well, finally got cool enough to do housework. Been a while since I was seen vacuuming at 2am LOL

  33. Rob "Wrath" S.E. Portland says:

    Surface Gradients
    As of 12 AM-Current | Hourly Change
    AST-PDX: +2.0mb | 0.1mb Decrease
    PDX-DLS: -0.2mb | 0.2mb Increase
    TTD-DLS: -0.3mb | 0.1mb Increase
    OTH-GEG: -4.6mb | 0.9mb Increase
    A large scale pressure pattern change is underway in which onshore flow across Oregon will cease entirely. Pressure is now rising sharply in Spokane, across eastern Washington and northern Idaho.

    This is in response to a surface high moving down out of the Canadian Prairies into Montana. Generally I’ve noticed a OTH-GEG Cross-Cascade gradient of 5mb is sufficient to develop downsloping E-NE flow across the North Cascade Foothills, Foothills of the Gorge, South Washington Cascades, and places such as Brightwood, Sandy, Larch Mtn. (A few examples).

    You can see the PDX/TTD-DLS easterly gradient is much slower to respond, but it will overnight. I’m thinking E-NE winds develop in the Gorge by 3-4 AM, then Troutdale and Gresham near/before Sunrise.

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