Surprise Thunderstorm & Evening Thoughts

Thunderstorm just east of Mt. St. Helens this evening

Thunderstorm just east of Mt. St. Helens this evening

Wow…quite an impressive thunderstorm going crazy at this hour.  Check out the cloud to ground strikes…I estimate about 30 in just 15 minutes over the “Dark Divide” area between Mt. St. Helens and Mt. Adams.  That is the divide between the Lewis and Cowlitz river drainages that runs roughly west-east between the two mountains.   You can click on the image to bring up a larger version.  Does anyone think this MIGHT cause a problem tomorrow when the thunderstorm is gone and temps in that area approach 90 degrees?  I don’t remember any significant fires in this area in the last 15 years.

Here are my thoughts at 11pm:

Amazing that we made it to 103 (all airports in the PDX area hit the same temp!) with essentially a flat gradient, or just slightly easterly.  I rode my bike past Crown Pt. around 9am there was just a light easterly breeze.  So with a slightly warmer atmosphere tomorrow, but just a flat/light easterly flow, I figure about 2 degrees warming.    That’s how I ended up with the 105.  As for tonight…whew!  This will probably be the only time I’ll hop into the kids swimming pool when I get home.  At 10pm it’s 90 degrees.  I think even during the bizarre cloudy night during the 2006 heat wave we had dropped to 88 at 10pm.    Looks like a low around 70 will probably be reasonable.

Wednesday and Thursday’s temp forecast is a bit problematic.  It’ll be scorching hot…that much is for sure.  But we get much stronger offshore flow, more like September easterly wind due to a surface high coming down into the northern Rockies.  I think it may actually turn breezy through at least the eastern half of the metro area.  With better mixing one would think it could turn even hotter than that 105.  But the upper-level heights and 850 mb temps drop a bit at the same time.  So do we turn cooler or warmer?  I’m not sure, so I just left it at 105.  I could see a situation where we don’t get much, or any,  atmospheric cooling and then the easterly breezes pick up in the afternoon.  Maybe we’ll get a surprise 107?  This could be fun (and brutal).  Even with an east wind blowing, Thursday’s atmosphere is slightly cooler again, so maybe right around 100 or just under.  Holy cow…we’re talking 4 days at/above 100 degrees if that’s the case.

Beyond Thursday:  I see the 00z GFS has backed off on the trough approaching the Coast, pretty much eliminating the thunderstorm threat and keeping us pretty warm (85 at least) through the weekend and early next week.  Now to give some of you hope, I’m headed into Eastern Oregon starting Friday for a week-long vacation.  So that’s probably when the low will make it’s move, giving us a severe thunderstorm outbreak west of the Cascades.  Stay cool!

Chief Meteorologist – Mark Nelsen

200 Responses to Surprise Thunderstorm & Evening Thoughts

  1. Matthew says:

    91f at my house as of 11:25am.

  2. Not even a full hour later and I’m up to 93.3°…..

  3. Timmy_Supercell (Hillsboro) says:

    168z GFS model indicates an upper level low right over northern California.

    Then it just moves off to the east a little, we may not have storms with this.

    • Timmy_Supercell (Hillsboro) says:

      There may some drifter storms touching areas around Eugene or possibly even just to the south of Salem, but we likely won’t see anything.

    • Andrew Johnson (Silverton) says:

      maybe we can at least get some cloud cover with it.

  4. Jesse-Orchards says:

    PDX is at 88 as of the hour, four degrees ahead of where they where this time on July 21, 2006 ( a day they hit 104) and three ahead of August 10, 1981 (a day they hit 107).

    Granted, though, PDX had a warmer start this morning, at 74, so a 14 degree rise from the min so far.

    2006 had a low of 65 to start from (+19), 1981 had a low of 61 (+24).

  5. muxpux says:

    88 in Longview at 10:55. thats +9 from yesterday!

    so on this pace, well hit 109?! haha.

    i believe Longviews All Time high is 108. that should be safe. 😦

  6. Andrew Johnson (Silverton) says:

    Up to 88 already here.

  7. Michael Goss says:

    The official low this morning at PDX was, sure enough, 74°F. A tie. We’ll have one more shot tomorrow morning I think.

    Sea-Tac, too, tied their all-time record highest low at 69°F this morning.

    PDX is currently +6°F over this time yesterday. Scary to think we actually have the potential to set an all-time record high today.

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

    11:00 AM 90.9F +5 degrees from this time yestreday.

    • Matthew says:

      88f at PDX, which is 6 degree’s warmer then yesterday at this time.

    • Snow-Zone/Monmouth-Elv200' says:

      Do you think 106-107F could still be possible for PDX today?

    • Matthew says:

      If we remain above 6 degrees from yesterday temp through about 3pm, I believe the chances are good.

      I will say if we hit over 94-96f at noon then yes.

  9. K5mitch NE PDX says:

    DP 66.5
    WNW wind @ 4 mph

  10. Matthew says:

    Based on my heat wave scale

    .5 Friday
    1 Saturday
    1 Sunday
    2 Monday
    4.5 cat2 heat wave as of Yesterday…

    My prediction
    2.5 106 Today
    2.5 107 Wed
    2 100 thursday
    94 1 Friday
    92 1 Saturday

    13.5 points or historic heat wave…I believe the highest number was near 13-13.5 based on my heat wave scale going back to the 1950’s. It may not be as hot as 1965 or 1981, but it will rank close to them with its length.

    • Matthew says:

      1981 ranks on my scale a 13.5. So if my forecast thinking is right this should tie it.

    • Matthew says:

      Portland heat wave scale
      Cat1 3 points
      Cat2 4 points
      Cat3 6 points
      Cat4 8 points
      Cat5 10 points

      85-89f .5 points
      90-94f 1.0 points
      95-99f 1.5 points
      100-104f 2.0 points
      105-109f 2.5 points
      110f 3.0 points

    • Timmy_Supercell (Hillsboro) says:

      It may as well tie the 1981 heat wave, I’m sure that will happen.

  11. Timmy_Supercell (Hillsboro) says:

    87F in Hillsboro, and 91F in Aloha already…

  12. Hmmmm….. was over by WA-Square around 9:40 am, wanting to finish up a quick errand before it got too hot…. hahahahahaha….what was I THINKING??? Temp gauge on one of the buildings read 89°….

    My temp here at home is 88.8°…….

  13. Timmy_Supercell (Hillsboro) says:

    Whoa, I feel awfully drowsy this morning. The heat really knocked me one; only ’bout 5 hours ‘o sleep.

    Well, today does look hot. I was looking at the temperatures at PDX until 3 AM, I was impressed. I heard it only went down to 75F? Thats not that low of a low temp. LOL

    • Timmy_Supercell (Hillsboro) says:

      You see, I have an A/C, but I have to turn it off at night so Its not so noisy.

  14. I still think Vancouver’s record temp of 106° could be in jeopardy today, or maybe even tomorrow…..
    If this humidity continues, heat index’s might make it to 110….

    81.2F Td 70.5 RH 70%

    Low this am here was 70.1F

  15. chris s says:

    Well, speaking in terms of my gut feeling, having lived in Salem for 34 years, that these heat waves always end the same way, and that when we least expect it. I know everybody likes to look at the models, but if the models were always right, they wouldnt change every 6 hours to show different things. My feeling is this heat wave will end like almost all do around hear, a nice marine push up the valley, when forecasters are expecting like a high of 95 or so for Eugene, they will top out at like 85 and all the tv mets will say looks like the heat wave is coming to a quick end. These things never last the amount of time the models say they are, either they are a few days longer or shorter, but my honest gut feeling is nobody will see 100 in the valley on thursday and friday will struggle for anyone to see 90. Thats my call and will stick to it no matter what the models are spitting out right now.

  16. Andrew Johnson (Silverton) says:

    So I just saw that Chicago is experiencing their coldest July in 66 years. I am envious, honestly this hot weather has me hating life right now. I decided to wait to move to Oklahoma until September because “summers are so much nicer here.” At least if I was there it’d only be 90 right now, I’d have central air, and would have thunderstorms a couple times a week in the summer… Anyways up to 83 already.

    PS…praying for a strong marine push sometime in the near future!

    • Sean (Lebanon, IN) says:

      Here in Indianapolis this is the coldest July in over 60 years.. Haven’t seen anything close to 90..

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

    Some locations I think will be 90F or just about that temp around the 10:30-10:45 AM time frame.

  18. PaulB/Eugene says:

    Longview 104

  19. Matthew says:

    My pdx hourly forecast

    9am 79f
    10am 83f
    11am 88f
    12pm 93f
    1pm 97f
    2pm 101f
    3pm 103f
    4pm 105f
    5pm 106f
    6pm 106f
    7pm 103f
    8pm 101f
    9pm 99f
    10pm 92f
    11pm 88f
    12am 86f
    1am 83f

  20. muxpux says:

    so, the Seattle AFD talks a lot about the historic aspect of this heatwave.



    and my favorite part:



    what i dont get is why were forecast to be 101 today and tomorrow, almost 4 degrees cooler than PDX (40 miles away) yet only 1 degree warmer than SEA (150 miles away)

  21. PaulB/Eugene says:

    *put* reputation on line.

  22. PaulB/Eugene says:

    OK…It is time to reputation on the line….

    Forecast high temps for today

    Eugene 108
    Salem 109
    Portland 107 (Portland will speed up temp rise later this morning)
    Hillsboro 109
    Troutdale 106
    Roseburg 110
    McMinnville 108
    Vancouver 107
    Seattle 99

  23. Matthew says:

    My thinking

    Today 106
    Wednesday 107/77
    Thursday 100/71
    Friday 94/65

    Ull appears to be just far enough away to keep the southly flow away for Friday, but that could change this weekend. Today and tomorrow very hot with 850 mb temps around 26c,,,possible eastly wind, which has been reported within my area the last few hours. I believe Wednesday has a chance to tie the all time record.

  24. PeteyJ - Uptown Village Vancouver says:

    81.1 at 8:53am. +6.6 from yesterday.

  25. Michael Goss says:

    Taking a quick peek at the 12z GFS, it’s hotter all around for today through at least Thursday. Incredible stuff.

    • Rob "Wrath" S.E. Portland says:

      Imagine if we were to develop some offshore/downslope…. 110 attainable? Not sure, but 107 sure would be.

    • Michael Goss says:

      Yeah, 107°F seems suddenly reasonable, doesn’t it?

      The 12z GFS also brings 850s back above 24°C for Thursday, so a four-day 100°F streak also looks reasonable.

      Records? We don’t need no stinkin’ records.

  26. N3EG says:

    Low here in Longview was 67, currently 75F and as Rob Wrath said +7. The 102 for us (as seen in the newspaper) was bogus – Kelso was 100, Longview 99, and far west Longview 98. Our “water treatment plant” is known to be a few degrees hotter, where Kelso’s airport (while warming faster) is in a flat grassy plain.

    That’s my only gripe for today – this is my favorite kind of weather!

    • muxpux says:

      ya, ie never believed the temps in the daily news, always wrong.

      where are you located? im right behind Keslers school, and i only got down to 68.9 at the house. up to 74 now.

      NWS Kelso at 75, with the fog yesterday AM i didnt think wed benearly as hot as everyone else that had wall to wall sunshine…but wow. with 24hr. sunshine today id say 102 is a low-ball number.

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

    Temp 78.1F….. +5 from yesterday this time.

  28. geo says:

    not sure the wind direction, but starting to blow a bit here in sw gresham.

  29. Christiana--Forest Grove says:

    84.5 right now
    low temp 72

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

    Good morning all

    HEAT WAVE 2009

    Currently a ridiculous 80.7F at my house. DP 61

    Surface Gradients
    As of 8 AM-Current | Hourly Change
    AST-PDX: +0.1mb | 0.1mb Increase
    PDX-DLS: -0.7mb | 0.1mb Decrease
    TTD-DLS: -0.8mb | 0.3mb Decrease
    OTH-GEG: -2.7mb | No Change
    *Surface flow is even slightly improved from yesterday with even less onshore flow shown and a bit more OTH-GEG cross cascade downslope. Of course we would need that to get over 5mb to do much of anything and PDX/TTD-DLS to exceed 3mb to see truly explosive heating.

    Current Temps
    As of 8 AM-Current | 24Hr Change
    Kelso: 70F +7
    Scappoose: 76F +6
    Hillsboro: 77F +4
    McMinnville: 75F +6
    Corvallis: 75F +3
    Eugene: 74F +3
    Salem: 81F +6
    Aurora: 82F +7
    Portland: 77F +5
    Vancouver: 78F Unknown
    Troutdale: 75F +4
    *All locations are 3-7F warmer, especially Salem northward. 850mb temps are warming slowly yet progressively all day today. I feel locations stand an excellent chance of exceeding 105F today!

    • Rob "Wrath" S.E. Portland says:

      I did not get more than 1 1/2 hours of sleep, so I am not sure I can provide hourly updates each hour.

    • Jesse-Orchards says:

      It’s fine Rob, most of us know how to check on the NWS website.

      Even Mark Nelsen’s site has a nice link.

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

    Morning all, update.

    Currently no wind. Low today was 66.9F at 6 AM which is +3.5 from yesterday. Now current temp is 74.1F +4 from this time yesterday.

  32. Rob Martin says:

    We possibly broke the warmest low temp record tied back in 2006 of 74. This morning so far looks to be 75 at the coolest point at PDX?

  33. Andrew Johnson (Silverton) says:

    71 here after a ridiculously warm low of 68.

  34. Aleta-West Gresham says:

    Got the inside my house down to a whole 77 last night….wonder if there’s anymore window fans in the stores!? It got down to about 73 outside.

  35. Currently 61.8° in my small rural town. Windows are wide open, bringing that cool air in.

  36. Eternal Yamcha (SE Milwaukie) says:

    Portland bumped down to 75 during the 4am hour… By the time the 4:53 recording came, it was back to 76. Something tells me that 75 is gonna be it. It all comes down to the 5:53 observation… No matter what, I think we’re tying the 74 at the very least.

    As of right now, it had temporarily reached “comfortable” in my AC-less apartment around 5am and is once again getting “mild”. Don’t have a thermometer in my room so it’s kinda hard to tell the exact temperature.

    Today’s record high is going to get replaced. I think we’re poised to crack 105 and be right on the heels of the 107 record… Especially if we don’t get any cooler tonight than 75.

    • Michael Goss says:

      I have a feeling the official low is going to be something like 74°F or 73°F since the hourly temperature values were hovering in the 75°F to 76°F range for so many hours. We’ll have to wait ’til 11 to know for sure.

  37. K5mitch NE PDX says:

    oh yes a nice cool 74.4

  38. PaulB/Eugene says:

    Hourly prediction of temps in PDX:
    6AM 75
    7AM 77
    8 AM 80
    9 AM 83
    10 AM 87
    11 AM 91
    12 PM 96
    1 PM 100
    2 PM 103
    3 PM 105
    4 PM 106
    5 PM 106
    6 PM 105
    7 PM 103
    8 PM 101
    9 PM 97
    10 PM 93
    11 PM 89

  39. Sean (Lebanon, IN) says:

    With temps at 105 and a dewpoint in the middle 60s, there will be a heat index around 110. In all seriousness everyone needs to make sure and drink plenty of water. Doesn’t take long for heatstroke to set in.

    Oh BTW – it’s only suppose to be in the 70s here the next few days.. 🙂 I’ll be sure to enjoy it for you all..

  40. Karl Bonner says:

    I was really not expecting this much heat myself. It was interesting to note that the hottest conditions were mostly on the west side of the mountains this time. That is very Septemberesque. If we were to get a little downsloping wind tomorrow then my oh my could things get interesting.

    There have been a few times when the compressing breezes threw a curve ball at the Valley. Late last October, I believe the last Sunday of the month, it got all the way up to 75F in Eugene. That’s not something you normally expect so close to Halloween. And in the middle of November we had one day where the chilly fog layer was broken up by some kind of storm brushing to our north. With the sunshine and mixing of the air we got slightly over 70 that day.

    Actually there were several days over the past year or two when Eugene got an unexpected puff of warmth. Usually during late fall and winter dry spells, the south valley gets more fog and chill than almost any other place west of the mountains. It happened again in late January and early February when the stagnant air in the valley got shunted aside at the extreme south end and we warmed up to the middle and high 50s right in town.

  41. K5mitch NE PDX says:

    77.0 @ 4:00 a.m. OMG

    • Chris in Beaverton says:

      Yep…my thoughts exactly, although I would add “ridiculous”. It’s 76 here. At 4am, it’s about 5 degrees cooler than a normal high temp.

  42. Timmy_Supercell (Hillsboro) says:

    I got an observation image from UCAR weather if anyone wants to keep this for the records:

    This is going on my fireplace mantle. (Sarcasm)

    • Matthew says:

      It went down to 78f at 2am, but raised to 79f at 3am at PDX. If we can make it another 3 hours we could have a new all time maximum for PDX. We will see.

  43. PaulB/Eugene says:

    An official weather station somewhere in the Willamette Valley will register 108F tomorrow…I can just feel it…….S L E

  44. PaulB/Eugene says:

    ULL gets close enough to NoCal coast to bring convection to area…6-7 days from now, followed by retrogression and rebuildng heights.

    Tomorrow will be definitely a scorcher in PDX area: It will get to 73 tonight, then 80 F by 9 AM, 90F by 11 AM, break 100F by 1 pm….

    • Matthew says:

      Personally it would not suprize me if we hit 100f for Thursday, Friday and topped the 1981 for number of hundred degree days in a roll. That is about as sure as we are about any break down.

    • Timmy_Supercell (Hillsboro) says:

      100 by 1 pm hasn’t happened a while.

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