Volcano-Caused Cool May?

A viewer emailed yesterday, wondering if the volcanic eruption in Iceland is what caused our cool and wet May.  Probably not.  Now I just point at a green wall for my career, but  I do have a degree in meteorology.  That doesn’t make me a volcano/climate expert.  Cliff Mass up at the UW had a great write-up about the possible effects of that eruption back in April.  You can read all about it, but it sounds as if it won’t (or didn’t) have any effect on our weather.

It’s a normal human tendency to only care or focus on areas right around us.  If it was a chilly May it must have been everywhere else too!  Not true…take a look at the chart from NCDC.  It was cool in the West, but very warm in the East.  Basically May was perfectly normal temp-wise when averaged across our nation.  I saw an email today from a local radio celebrity actually implying the lack of 80 degree weather so far this spring is an indicator of global cooling!  I absolutely hate it when people use data like that (also called cherry-picking data).  Um…how about the extreme heat last summer???  You can’t take either one of those incidents and use it to prove a point.  But some people love to argue…I’ve even worked with a few.  And some have found a great way to make money doing so, while dragging you down into the argument.

Chief Meteorologist Mark Nelsen

67 Responses to Volcano-Caused Cool May?

  1. Kyle says:

    Mark. I emailed you some questions about the Letter post on your previous blog thing.

    When you get time will you please look at it or did it dissapear in cyberspace? 😕 😕

  2. W7ENK says:

    It really hasn’t stopped raining in Sellwood all day, and now it’s coming down fairly hard again… Looking out the door, I was just reminded of something.

    Do any of you remember watching a short film in Grade School called “All Summer In a Day”? I believe it was based on a story by Ray Bradbury. If I remember correctly, it’s supposed to be set on Venus where the idea is that it rains ALL THE TIME, except for once every like 100 years or something, when the sun comes out for only a few minutes. It follows a group of school kids, and one girl who’s waited her whole life for her one chance to see the sun, but she gets locked into a closet by some mean kids just before it happens and she misses it while all the other kids go out to soak in their few minutes of sun.

    Anyway, my point is I feel like I’m trapped in that film. 😦

    Found it!

    Part 1: http://www.youtube.com/watch?v=-QWmahMdeGU

    Part 2: http://www.youtube.com/watch?v=DI8A1LOLdkA

    Part 3: http://www.youtube.com/watch?v=XQfWno_DuB0

    • Kyle says:

      I try to stay away from tragedy films but whatever floats your boat. 😉

    • W7ENK says:

      Yes, it was sad, but it was something they made us watch in Elementary School.

    • pgiorgio says:

      I don’t remember seeing that. The snotty boy that locked her up should be locked up for life at the end. That would be a better ending.

  3. Cherie in Vernonia says:

    Mark thanks for posting that graphic. It makes things so much easier to grasp.

  4. Joshua says:

    Hello everybody! Can somebody please tell me how many days with measurable precipitation Portland has had for the following months: April 2010, May 2010, June 2010 so far?

    Thank you!

  5. Garron near washington square says:

    We should be really close to breaking the rain record TODAY! 3.61″ BY 11 am, it should happen today…IMO

    • W7ENK says:

      Well, there’s little under a half inch left to go…
      If not today, then possibly the end of next week???

      Man, I really hope it’s nice up North next weekend.

  6. Jesse-Orchards says:

    I don’t, to be perfectly honest. I think it’s silly to set a global average temp, basically the temperature we think the planet “should” be, and then get really freaked out when it varies by .5 or so. Especially when, as you said, data collecting around the world is anything but reliable. There are huge blank spots where no temperature data is collected for hundreds of miles, ie Siberia, much of Africa, parts of the Arctic, the Amazon, etc. The IPCC will “extrapolate” temps across these vast regions though, usually favoring warmer over colder.

    The US isn’t much better, though. Many of our urban stations are made falsely warmer due to the urban heat island. PDX is a great example of that. One would think that would have a marked effect on temperatures from the late-19th century or so until now.

    That said, there’s no doubt the globe has warmed over the past century, there are natural signs (glaciers, changes in ecosystems, etc) that can attest to this much more convincingly than our often erroneous measurements of temperature. I basically just don’t trust the data, or even worse the predictions as to where the climate is heading long term based on that (potentially faulty) data. The global warming predictions made a dozen years ago have basically fallen flat on their face (there has been no net warming since 1998, and counting…you never hear about that). Then there are those out of our control factors like solar cycles and volcanism. Long story short, we basically have no idea what’s going on, so enjoy the ride!

  7. Gidrons says:

    Due to the controversy around cherry picking data to prove/disprove global warming, I’m skeptical of most non-US temperature data. My personal barometer is the arctic ice cap.

    Beside releasing all that volcanic ash, didn’t the volcano pump out enormous amounts of greenhouse gases?

    • Jesse-Orchards says:

      Not the best barometer, IMO. It’s vulnerable to way to many fluctuations. Wind patterns can cause ice to shrink or grow drastically regardless of temperature.

    • Gidrons says:

      Hadn’t thought of that. What do you use Jesse?

    • SilentReader says:

      As I have said before: The planet has been here 5 billion years. We have been keeping records, of any value, maybe 100 years of that 5 billion. So we are supposed to get excited about any change in even 100 years? really? I think the problem that we have is forgetting that this rock has been here far before any of us. So when talking about normal or averages at 10 or 100 year periods is really not enough data to really conclude anything. We have no data to suggest what the ups and downs are. We only have data for the past 100 years. Seems silly to draw any “certain” conclusions from that. For all we know we are in a up period from a 10,000 year interval. As far as how much do we contribute to offsetting the natural order of the atmosphere and climate? well that is the debate and not what I am talking about.

  8. Battle Ground Brian says:

    Bah!!! the 06z GFS was much cooler and cloudier than the previous run. Hope for improvement in the 12z.

    Another 0.15″ since midnight here

    4.42″ of rain in June so far.. Ouch!!

    • Jesse-Orchards says:

      12Z GFS is about the same. The window for warmth keeps shrinking on the models. Now it appears PDX may barely top 80 Saturday, then fall back into the low 70s Sunday, then even cooler Monday/Tuesday.

      Looks like we could be flirting with record lows by early next week! It will be sunny, but the flow will be out of the North or NNW for a few days, with ridging retrograding offshore. Really unusual setup for this late in the season.

  9. I can’t remember a time in recent memory when the first time I wore shorts was in mid June, but it looks like that is what’s happening this weekend for me, and probably some of you as well, long live the sunshine!

    • pappoose in scappoose says:


    • umpire says:

      I grew up in Boise, and wore shorts (when I was much younger 😉 ) much of the time.

      I’ve worn shorts three or four times this year, despite the cold, rain, etc., just because I refused to let the weather fully dictate my fashion choices! Of course, I had a rain coat and down vest on as well.

    • W7ENK says:

      I wore shorts once last month, on the one day it reached up into the upper 70s. I seem to recall it clouding up and raining that evening, so maybe since I put the long pants on before the end of the day, it doesn’t actually count?

      At any rate, @umpire I could imagine you’d look awfully silly in that get-up! :snicker:

  10. Kyle says:

    Fun Viewer Letters
    June 8, 2010

    I emailed you a serious question on that blog topic:

    Back to weather!!!

    51.8F outside.

  11. Kyle says:

    Mark. About the letter from your previous blog post:

    I emailed you an important question in it and you never read it and I want to know what you find funny in taunting me?

    Are you trying to get me mad so I’ll say something that will get me banned?

    Please be honest with me Mark.

    I can see thru lies.

    • Ryan (Walnut Grove) says:

      You are a big ol’ can of crazy dude.

    • W7ENK says:

      Kyle, Mark’s a busy guy, I’m sure he’ll get to your e-mail when he gets a chance. It may take some time, but he always does, doesn’t he?

      Ryan, c’mon. Uncalled for, man.

  12. Battle Ground Brian says:

    Just uploaded my rain gauge totals for today

    Had 0.65″ and now have a 4.27″ monthly total.

    Also today was the 4th day below 60 for a high this June at my weather station.

    I am glad this epic period of bad spring weather is coming to an end in about 24 hours.

  13. muxpux says:

    about .81″ of rain in Kelso/Longview today, man, its gonna be a shock come saturday

  14. W7ENK says:

    65.1°F High
    52.2°F Low
    SW 18.8 mph at 3:25p


    Here’s my breakdown on rainfall for the first 9 days of the month…

    ~* My June Rainfall *~

    Date Daily Total

    6/1 0.17″ 0.17″

    6/2 0.79″ 0.96″

    6/3 0.29″ 1.04″

    6/4 0.75″ 2.00″

    6/5 –

    6/6 0.83″ 2.83″

    6/7 –

    6/8 0.08″ 2.91″

    6/9 0.29″ 3.20″


  15. Tyler in Hazel Dell says:

    More pics and video from today:


    I like this one of the clouds in the gorge around 8 this evening:


  16. Jake-(Gresham) says:

    I might come across as crazy but I say let it rain some more we’re already up to our eye balls in water…might as well break a record in the process of drowning. 😀

  17. Kyle says:

    I actually I was joking at the global warming comments I made and I DON’T recall you making any comments Mark about my commonts.

    And Mark did you get my email on your letter?

  18. Tyler in Hazel Dell says:

    Here is a vid from this morning near Gresham at the tail end of that thunderstorm…


  19. rain-a-dazer says:

    I can’t mow my lawn now… >> It’s floating…

  20. W7ENK says:

    God, it’s pouring out there right now! I was going to go for a walk this evening, but nix that idea.

    This weekend can’t come soon enough. 😕

    • W7ENK says:

      Not to mention it’s FREAKIN’ COLD out there! I just had to crank the heat on… in the middle of June! I haven’t even pulled the window A/C down from the attic yet.

      Don’t you even dare tell me this is normal – it’s not, and you know it! It’s ridiculous, is what it is.

    • Kyle says:

      Apperantly here it dropped to 54.3F.

      If this were a calm clear night I would hit the low 40s.

  21. David B. says:

    As of this evening, PDX has recorded 3.41″ of rain this month. The record is 4.06″ (I think).

    Seeing as how hard the showers are coming down out there right now, and as how the forecast beyond the weekend is calling for more chances of rain, it looks like we have a good shot at breaking the record.

    One or two heavy showers tracking just the right way and it might happen before the weekend!

  22. RobWaltemate says:

    One more thought; what about all the volcanic activity of the “Ring of Fire?” Alaska alone has quite a few volcanoes. What about the giant dust storms in China? That adds to the particulate in the upper air. There is just a lot of things that have a small part in the big picture, but the goofy birds on the roof next door don’t seem to mind? They are still getting bussy! LOL

  23. RobWaltemate says:

    I think the average person just likes to have a name for a cause of the weather. El Nino, La Nina, Sun spots, etc… Either way it was hard to work outside this last month and stay dry. If I put on rain gear, then the sweat was as bad as the rain! LOL

  24. W7ENK says:

    New lightning strike just East of Salem…

  25. BrandonInNWSuburbia says:

    A direct effect to the US…probably not. But unless we have parallel universes…one w/ the eruption, one without, no one can definitively say what affected what.

    Now the May snowfalls in the UK and France do seem like a bit too much of a coincidence.

    • pgiorgio says:

      how about we take a global average of the temps in May to find something more useful

    • Mark Nelsen says:

      Yeah, I was looking for that too, but it’s not out yet. Someone still needs to run those temps in from the Khalahari Desert and Amazonian uplands? April WAS the warmest on record for the globe, and so was the January-April period. As of April it’s the warmest year on record so far…

  26. Gidrons says:

    How about this one — gfs 18z has Tuesday’s low in Troutdale at 32 degrees?!!

  27. Kyle says:

    IceKeg I agree: That was remarkable to have so many “snow days” up in the hills that winter.

    Mark was very right in his forecastings that year and I think that winter really was the *whatchamacallit* that caused Mark to be more accurate.

    What was I’m typing again? 😕 I’ve completly lost it.

  28. Kyle says:

    Does that mean the global warming alarmist 86-90F weather is out to lunch for the weekend? 😕 🙂

    • Mark Nelsen says:

      Kyle, so what does a forecast in the 80s this weekend have to do with global warming alarmism? I think that’s what I was referring to in my comment to the four of you last night.

    • PDX Weather Nut says:

      I tend to think of anything above 85 degrees as hot. An 87 degree high isn’t too abnormal for here this time of year.

  29. Jake-(Gresham) says:

    Big black clouds are coming in like periodic dive bombers over here haha! At least there’s sun breaks between the bombings! 😛

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

    Yeah we would need a seriously large eruption to occur to truly alter are typical weather.

    • W7ENK says:

      Just wait for the day the Yellowstone Super-Volcano lets go… I wanna watch that from space! 🙂

    • Snow-Zone/Monmouth-Elv200' says:

      Do you believe we are far enough west from yellowstone, that when she blows we would not get affected by the immediate blast and huge ash cloud? I know we would suffer the long term effects.

    • RobWaltemate says:

      I would bet Mt. Hood is more likely to erupt than Yellowstone or even the West hills. If I remember right almost all of Portland’s srounding hills are volcanicly formed; you just can’t see the cinder cone under all that green and top soil.

  31. Jesse-Ochards says:

    Yep, May was average across the country when all was said and done. Definitely very cool out west though. Surprised to see that Oregon, Idaho, Montana, Wyoming, Utah and California all had top ten cold Mays. Idaho had it’s second coldest ever!

    Looking at the models, there seems to be a definite trend toward ridging this weekend being quickly squashed by yet another cool system for early next week, then the pattern becoming cool/progressive again for awhile after that. Definitely won’t be as murky and wet as the past couple weeks though, IMO.

    In any case, looks like any ideas of extended summer weather starting this weekend were premature!

    • W7ENK says:

      But of course… Just bEcauSe we See a light at thE end of the tunnel, doesn’t mean that we should all get our hopes up, rIght? I mean, thiS is the PNW After all.

      I guess it’s just too much to ask for some normal or more seasonable weather. We woulDn’t want tO Upset the weather gods by Crying for some mucH nEeded mercy.

      :sly grin:

  32. W7ENK says:

    I have to say, the thought did cross my mind…

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