July 29, 2009

Update III (Updated 10:45 PM)

The 5 pm observations are in. Sea Tac got to 103F. Thunderstorms have developed and the clouds are spreading over the crests and foothills...beautiful anvils from space (see image). And low clouds have spread to the coast.

Temperature Readings

Several of you have been sharing temperature readings, which I and others really appreciate! But keep in mind the following:

(1) Bank thermometers are notoriously inaccurate. (I will refrain from generalizing this to the reliability of banks in general)

(2) Temperatures measured in cars driving over asphalt during the day are often too high and not representative of the true air temperatures. Air temperature should be measured in the shade over a vegetated surface. Roads can heat up to 120-140F and thus can inflate car temperature readings. So drive your car over grass or vegetated surfaces if you want a dependable reading.

That said, there have been a number of reports of western WA temps over 110F. Here is a report from Mark Albright, research scientist at the UW:

The highest temperatures in western Washington today (29 Jul 2009) seemed to be between Portland and Olympia. Check out this map for 2009073000 UTC:

High temperatures reported today: Chehalis MS (CHHLS) reported 111F, Winlock (WINLK) 110F, and the Chehalis RAWS site reported 2 hours at 114 F (someone should check this thermometer for accuracy before we believe this one):


  1. Plus lots of down strikes!!

  2. Are we going to get any thunder moving over the lowlands (especially the eastside)?

  3. Nice interview on the Weather Channel. Too bad super bald guys has that interrupting problem. ;)

  4. Oh I'm glad you mentioned the anvils - I've been watching them build up every afternoon over the last few days and I was wondering if you would talk about them a little bit? It's a shame we don't get the storms over Seattle...

  5. Upper reaches of the Middle Fork of the Snoqualmie was getting about 6 strikes a minute around 1630 today. Some were in the valleys but most along ridges. Sad thing is all the rain evaporated before hitting the ground. Very dry out here in the Cascades, soil moisture and forest fuel moisture are near what we usually see around the first of September. Please spread the word, it is a tinder box out here in the woods!

  6. Very strange-- 10,000 in Tacoma are without power due to a supposed lightning strike sometime around 5 pm PDT. Yet radar showed no rain, even in the composite, IR satellite showed only marginally cool cloud tops in the vicinity, and none of the lightning locators that I can find show a strike any where near Tacoma. Either this is the strangest stray strike I've ever seen or it wasn't lightning at all.

  7. Professor Mass,

    Some months ago I turned on my TV to watch an entire hour where you discussed our weather on one of our 3 local channels (don't remember which) but I think it was about the I-5 closure because of flooding.

    I watched in vain for any mention of the words Global Warming, Global Climate Change or, better yet, Global Climate Disruption. Nothing.

    Is there any serious question in your mind that this phenomenon is real and is caused in a major way by human behavior on the planet?

    If so, don't you think you have a responsibility to speak about this -- beyond the technical aspects of reporting the weather -- when you are arguably the most well-known "weather man" in this area?

    I welcome your reply -- here or by direct email. And I apologize if you've dealt with this question elsewhere. Just point out where.

    Sincerely, Bert Sacks

  8. It reached 111 degrees in Sammamish today. Please Cliff, tell me it will cool down!

  9. Bert,
    I did talk about the effects of global warming in the last third of that show (on KCTS). If you want to watch, you can order the DVD from them.

    111F !!! Where did that happen. 106 I could believe...but 111? Anyway, it will be cooler tomorrow..perhaps as low as 103...cliff

  10. Autumn, Autumn, wherefore art thou, Autumn?

  11. Cliff, I have a picture of my car thermometer reading 110 degrees near Factoria around 4:05-4:10pm... if I can get it off my phone I'll send it to you.

  12. Cliff,
    My car thermometer went to 111 and stayed for the duration of my drive and a friend was down in Redmond today and the thermometer posted at Brwonn Bear car wahs registered 111 as well. Only 103 tomorrow, gee, how nice!

  13. Down in Centralia earlier..when we left Oly it was 107, and was 103 when we arrived in Centralia. At about 7pm a wind came up and the temp dropped to 95. I see the NOAA has updated the forecast and Oly is supposed to be 95 instead of 101 tomorrow...that is a great start!

  14. I would be disappointed if Cliff became a global warming crusader during his weathercasts. A conservative approach is prudent.
    Didn't he point out some time ago how the proliferation of parking lots at universities during the past few decades was accompanied by an increase in recorded temps?
    You can imagine how much effect hot pavement has if you look at ground and road temps today (WADOT web site), many of which are over 110 deg.
    This human-caused "warming" has fed directly into the global warming theory.
    Hey, we'll cool the planet if we rip up all the parking lots!

  15. Still 94 in maple valley on the shores of Lake Wilderness.

    I saw 109 with the warm wind about 14:00, in the shade.

  16. Jeff, I know there's a bias on the pavement - but my car's thermometer seems to be adjusted for that, or something. I've compared - on several occasions - my car's reading to official observations taken at the same times when I'm driving past airports, and they are nearly always within a degree of the official observation, sometimes a degree lower even in the summer. Today, its reading driving through downtown Bellevue (105) was very similar to the downtown Bellevue observation at the time. And it was reading 98 in Bothell, which I thought was a bit low honestly based on posts I saw here from Woodinville. When I arrived to Renton, it was very similar (changing between 105 and 106) to the observation at the Renton airport at the time (105, with a high of 106 there today). So I believe the reading I have is quite accurate.

  17. Sedro-Woolley topped out at 103.3 this afternoon.

    It was simply amazing at how fast the temps climbed this morning.... Wow!

  18. Cliff -- You wrote "Bert,
    I did talk about the effects of global warming in the last third of that show (on KCTS). If you want to watch, you can order the DVD from them."

    I am positive it was not KCTS since there were commercials and it was a station I almost never watch except that I was looking for a discussion about Global Climate Disruption.

    From one other comment on your blog today, I have the impression that entering into this area is considered "political" and "controversial" ... and you don't go there.

    However even if you do not hold that 100% of the clearly demonstrable heating of the planet is due to human activity, the Precautionary Principle demands of us to use caution. And not to say, Well I'm not 100% positive. The future of our children and the planet is potentially at stake.

    Or don't you think so? I'm still waiting to hear your scientific opinion on this question.


  19. I wouldn't get too caught up in the global warming-climate change hysteria because we've had a heat wave on the West Coast for a few days.

  20. You were sure popular today. More power to you! Thanks for all you do to keep us informed.

    I almost didn't want to leave work.

  21. I'm looking at what I think is the official NOAA observation (http://www.wrh.noaa.gov/mesowest/getobext.php?wfo=sew&sid=bfi&num=60&banner=on) and it looks like the temp did go up to 104, just as you'd speculated it might. But the max temp for today is listed as 103. Shouldn't it be 104? Am I just misinterpreting the way the chart works? Or where our official high temps come from? Thanks!

  22. Bert, you post is coming across a bit too...just not very Cliff Mass Weather Blog like. It's a pretty relaxed atmosphere in here. I'm not saying you can't bring up climate change. It's all about the approach baby!!!

  23. Bert,
    I talk about global warming issues all the time. Anyway, this one event doesn't prove anything about global warming.

    Shalimar and others:
    Car temps taken on asphalt roads are not really valid. The asphalt heats up and a car riding on it will have an enhance temperature. Temps should be measured in the shade over a vegetated surface. And bank and other such thermometers are notoriously in error.


  24. Did the weather station CW-5022 (Kirkland) really reach 112 degrees today? That would be 7 degrees off our all time record high for the whole state of Washington if I'm not mistaken.

    Also worth looking at might be Chehalis "CLSW1" which registered 114.

    In any case the heat and the records set are truly astounding.

  25. Hi Cliff, I've noticed that some of the cumulonimbus buildups that have popped up over the mountains the past few days have had a peculiar form. Instead of developing into typical broad-shouldered thunderheads, they've risen rapidly in very narrow vertical columns - shaped like 30,000 foot-tall tree trunks - that quickly dissipate. I suspect that they're caused by intense localized uplift that for some reason cannot be sustained. Your thoughts?

  26. A miserable...but amazing weather day!

  27. Ooof! Not a fun afternoon/evening at work. It was a busy night and the A/C in the dining room just didn't quite seem to make it all the way back to the kitchen.
    Where is our cool ocean air? Our birthright?

  28. Here in my area of Woodinville atop Hollywood hill, my high temp for the day reached 106 with a morning low of 69.

  29. I am feeling "puffs" of cooler air. Low temp on our (in-shade) digital thermometer has gone down from 71 at 6 am to 69 now at 7:10 am.

  30. I believe we were coming off a strong El Nino when the last record was set--1998

  31. This is an amazing weather time we live in, huh? Just eight months ago we had record setting cold and more snow than anyone around here could recall. As I was shoveling a couple of feet of snow in December not many were commenting that it was a Global Cooling trend. Ha, ha.

    No one can say we haven't had four distinct seasons during the last twelve months. And that, my Cliff Mass friends is some sort of a record!

  32. Thanks for posting the temperature map around Thurston County! My mom lives in that area (Lawrence Lake) and frequently experiences a lot of our extremes of weather, 12" of snow when everyone else gets a dusting, the biggest wind gusts, most frequent power outages and the highest temperatures. Does this have to do with the Chehalis Gap? I've heard that mentioned on several severe weather warnings in the past, but I haven't really figured out what geographic region it refers to.

  33. I live out near Duvall.
    My reliable thermometer indicated 107F at 2:30 Wed. Yikes!!
    I was sceptical, so I checked the Stillwater Elementary online weather station; it indicated 107.3F at the time. It later reported 108F at about 3pm.

  34. I suppose then that if my car's thermometer was at least 6-7 degrees too high because of faulty readings due to pavement, then it was only 91-92 degrees in Bothell at 3:45pm taking away this effect. From temperatures I've seen in Woodinville and everywhere else, 91 to 92 just doesn't make any sense.

  35. Shalimar, Nicholas, and any others - Don't worry about what Cliff says about your car temperatures "not really [being] valid." They are perfectly valid readings, unless something is wrong with the thermometer itself. If you're standing on an asphalt road with the sun beating down on you, it's definitely going to be hotter than you'll see at the airport (never mind that you may be in danger of being hit by a car), so it is in fact a true, actual temperature.

    The issue comes in being able to compare them to the official readings, not whether they are valid. We know they are valid. But can they be compared to the official readings? Maybe, maybe not. In order to get a good reading, your car should at least be moving fast enough to have air rushing past it and not just sitting on top of one spot on the pavement, or else you'll get erroneously high readings. Nicholas, from your message it sounds like your car was measuring fairly accurately compared to the unofficial downtown Bellevue station and the official measurement at the Renton airport, as well as in Bothell, where there aren't any official readings as far as I know, but 98 is on the low side of what I've seen here so I can't say it was reading high there. When you were in Factoria, was your car moving or mostly stopped? Shalimar, it sounds like your car was surely moving, as you said "for the duration of my drive," so the reading is probably fairly accurate. The East Side can be 5-10 degrees warmer than Seattle and the airport as well, particularly when there are easterly downslope winds involved, as there were at times yesterday close to the Sound, and even more so close to the Cascade foothills. Given all this, and the dramatic warming that took place yesterday morning partly due to easterly downslope winds (though mostly due to mixing out the surface inversion), I am not surprised to hear of pockets of areas that were 110-112 degrees in the eastern part of the area. These seem like perfectly valid readings to me.

  36. In my unscientific contest, the most accurate Internet weather sites (of the 7 I checked) for the heatwave were Intellicast.com and AccuWeather.com. I looked at the forecasts from Friday morning only...


  37. Cliff, it seems as if this heat wave was unusual in more than just its intensity. Not a lot of flow across the mtns. from 509-land...and eastern WA was generally cooler than Puget Sound! High dewpoints...felt more like upper Midwest in summer when air has moved in from Houston. High 500 mb hts., to be sure, but maybe not record levels. What happened? Once-in-a-century fluke, or likely to recur?

  38. This was the worst heat I have felt in my entire life. :(

    Lacey hit 104, I walked outside from the air-conditioned room I was staying in...and BAM!

    It felt like walking inside a giant hair dryer...literally. I couldn't breath right, the air felt "thick" in my lungs etc...

    And my heart goes out to those in Tacoma and Monroe who went through power outages yesterday (and anyone else that went through a power outage for that matter). That had to be the worst experience ever.

    What is your opinion on this type of even Cliff? Is it something that over the next 10 years we'll have to slowly get used to? Or, is it one of those "once a decade" events in some sort of cycle of weather?

  39. On another note, to the power outages - I noticed when I came home in Renton yesterday that our power had gone out at some point during the day and came back on around 3pm (all the clocks were flashing, etc.). I assume it could be traced to the heat. Does anyone know how long it was out (even if an average length of time from other places around the area)?

  40. @Joseph, I think my nine year old has likely called this one... "in twenty years when we have our first 120-degree day, I'll be able to say I remember the first day that it went over 100." I hope she's wrong, but given the reliable 107.4 (shade and vegetation) we recorded at our house in east Bellevue yesterday...

    I honestly was surprised at how bad it WASN'T. Yes, it was hot. But my lungs and heart didn't stop or anything. I felt a little bit like panting a few times, as if somehow that would help, but otherwise, I just broke a sweat without doing anything.

    The hardest part for me was that our fish tank got so hot that all the fish save one died (our favorite, an exotic pleco). We'd been floating ice in the tank but it wasn't enough to keep it below 100 in there. :-(

    The air did cool off nicely last night after 2 am, though it was fairly sticky until about then, with the midnight reading standing at 88 and today's low at 74... amazing how lovely 74 felt after 107!!

  41. Tacoma only at 70. I'm really wondering if 90s are in the offing for at least the southern (and western) part of the Seattle-Tacoma area.

  42. @JewelyaZ
    Sorry to hear about your fish :(

    I woke up to 63.9 degrees this morning, walked outside and WOW it was amazingly different. :)

    The house is aired out now...and today the high is "only" 95 according to Probcast...but one weather tool (KOMO's) is saying like mid-high 80's...but I can't believe I am going to be relieved to feel that.

    Just unbelievable this whole heat wave.

    Two days in a row over 100 for Lacey, and in the 90's since Sunday.

    Add today to that...and that's 5 in a row at or over 90. Whew!

  43. My low dropped down to 72 this morning. right now at 10:26am, I have 82 with DP at 62. So with that said, I`m pretty sure we`ll be in the high 90`s or maybe even hit 100+ again. Maybe.

  44. Professor, I watched the Weather Channel last night when you were talking to the hosts, and from what you said, this sounds pretty anomalous and it would be impossible to speculate that this could recur under the exact conditions. Very interesting all the same.

  45. the noaa said chehalis was 114. now is the thermometer asphaly somewhere or was it at a spot where it could get a reliable reading?

  46. TrickyCJ, the Chehalis Gap refers to the area South of the Olympics and North of the Willapa Hills along the course of the Chehalis River. The extremely broad valley was the drainage for the Puget Sound lowlands during (at least) the most recent ice age and acts as the funnel for the Southern winds that meet with the Northern in the Seattle/Everett area as the Puget Sound convergence zone.
    These winds then carry all their precipitation into the Cascades where it turns into feet of sweet, sweet snow, waiting for my skis or snowshoes to pound out some tracks.

    Alright, I'll quit my whining about the heat. It WAS a bit like breathing through a paper sack yesterday, but back to norm today. I did enjoy that welcome scent of salt air when I walked out after my shift. I don't mind the heat as long as I get a bit of a break at night.


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