July 08, 2024

The Current Northwest Heatwave: Facts Versus Hype

 We are now in the middle of a heatwave period in which some locations have broken daily temperature records (records for a specific day)

Let me describe what is happening and why.

Below are the high temperatures yesterday (Sunday, July 7).   70s along the coast and over the marine areas of NW Washington.  Lower 90s in Puget Sound, around 100F in Portland, and low 100s over the Columbia Basin.


Why so warm?   

We start with being near the time of maximum sun strength and length of day.   Temperatures can warm until 5-6 PM this time of the year.

But the real secret is the position of high pressure aloft, positioned today and yesterday in the "sweet spot" for Northwest warmth--over southwestern BC.  The map below shows the upper level (500 hPa) map today, with the shading showing the difference of the values from normal (orange and red are above normal).  Perfect for local warnth.


And yes, there is global warming.  You can give credit for about 2F of the heat to increasing greenhouse gases.   For example, a location that reached 93F yesterday, would have been 91F.   

We still would have had a heatwave without global warming.

So what about the future? 

The Seattle Times is up to its old tricks and stating that a "100 Degree Heat Wave" looms for Puget Sound (see front page clip today) and "among the warmest nights in history."   Scary stuff.

And not true.

Let's look at the surface air temperature predictions from the very high-resolution UW forecast model near the time of max temperatures (5 PM)

At 5 PM, most of Puget Sound country is in the upper 80s and lower 90s, but warmer around Portland, and MUCH warmer (over 100F)  at the lower elevation of the Columbia Basin.

 
Tomorrow is much of the same story west of the Cascade crest, except a few degrees warmer south and southeast of Puget Sound.  

Sorry, Seattle Times....no century temperatures predicted near Puget Sound.    But much warmer around the Columbia Basin...over 104F in many places.


But what about Wednesday?  Much cooler in the west, and even eastern Washington starts pulling back. 


Why cooling?  Because the upper level ridge weakens and moves eastward and an upper trough of low pressure moves in (see upper level map for Wednesday).  Marine air starts to push into western WA.


But there is a danger in this change.

As cool air and high pressure build into western Washington, it will produce strong winds over the eastern slopes of the Cascades (see wind forecast for late Wednesday).  Reds, grays, and greens indicate stronger winds.


Winds that can rev up and wildfires.  

Finally, what about the Seattle Times claims about us experiencing one of the warmest nights in history?

Just wrong.

Even at crazy warm SeaTac airport the low temperature last night was not even close  to being a record (see below).  The plot shows the highest minimum temperature each year and the red line is last night at SeaTac.  Many years had warmer minima.

And using a far better station for climatological analysis (Olympia), last night's minimum was nothing unusual.  Most years have had warmer minima.


Stay cool....There is no major heatwave predicted for the next week.






31 comments:

  1. The Seattle Times article you refer to merely said that low last night was 67 which they said is the 18th highest minimum at Sea-Tac. If that is true then I would agree with them that 18th out of ~29,000 nights is one of the warmest. If it is not true that it is 18th, then I agree with you. As far as 100 western WA high temperatures. They merely pointed out that the high in Olympia is forecast to reach 100. The NWS forecast calls for 101, so not sure why you are jumping all over this particular article.

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    1. mike...the headline was not correct It was not one of the warmest nights in "history" at Olympia. You say 18th? 2021 had a low temperature SIX DEGREES WARMER!

      Olympia Airport is substantially south of Puget Sound and much warmer during summer than most PS stations....really not appropriate to use. And it doubtful they will hit 100F tomorrow. The article headline implies that a significant proportion of the PS region would hit 100F...simply not true....cliff

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    2. Did you seriously just say Olympia is "substantially south" of Puget Sound? It's literally ON Puget Sound.

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  2. Great technical analysis. I appreciate your use of facts to highlight issues with current reporting.

    I recently read Bjorn Lomborg's "False Alarm" and "Supercommunicators." Your posts, including this one, often argue with data while others argue with emotions and social connections. While your analysis is solid, it misses the emotional context of others' conversations.

    Here are some actionable suggestions:

    1. Include Stories: Personal anecdotes can break down defenses and change minds.

    2. Steel Man Argument: Start by presenting the opposing view as strongly as possible, then dismantle it to gain credibility.

    3. Acknowledge Emotions: Address the emotional impacts of heatwaves, both immediate (+2°F) and future (+6-7°F by 2100).

    4. Cite Sources: Better citation of your data sources will build trust and transparency.

    Thanks again for your insightful post!

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    1. This is one of the most Seattle-y comments I have ever seen on Dr. Mass's blog. Absolutely brilliant.

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  3. So, the Seattle Times publishes "record heat" without even looking up what the record is. Hmm I wonder what else they fabricate and get completely wrong? Answer: everything else.

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  4. I've got to disagree, Cliff. The NWS pinpoint forecast is showing highs right around 100 in Olympia and places like North Bend. In this case the ST story is accurate.

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    1. This is not correct. The NWS is not going for 100F in Olympia. Just checked the weather channel....95F in North Bend tomorrow....cm

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    2. Wasn't it 99 in Olympia that day?

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  5. Fact checking the Seattle Times on weather/climate articles is sadly a full time job.

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  6. We like to dunk on the Seattle Times, but they cite their sources for the info they publish. So Dr. Mass, which experts should they be asking instead of NWS?

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    1. James...the big problem is the crazy headline, which is not consistent with the article..cliff

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  7. The Weather Channel is predicting high temperatures of 100 or more every day through July 22 for Richland. Average July high is 88 according to the US Climate Data website.

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  8. The high pressure has been detrimental for wind facilities for the past 5 days. Mid-night Tuesday will see the blades turning again near EBRG. Imagine if your favorite coffee or beer pub operated like this.

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    1. Wind turbine generation works exactly as it's supposed to. It contributes to the larger grid as it is able to. Your coffee shop or beer pub does not know the difference whatsoever. You're only showing that you don't understand how power generation across the larger grid works.

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  9. Weather.com has Seattle in the 80's thru the 23rd and probably for the rest of the month.

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  10. You write, "You can give credit for about 2F of the heat to increasing greenhouse gases." Are you saying that the recent increase in global temperatures since exiting the Little Ice Age is entirely from man's increased use of fossil fuels? I was puzzled to read that since our contribution of CO2 compared to what occurs naturally is quite small. Don't dispute a warming planet, do dispute its primary causes.
    Take our shabby, incomplete temperature record (seriously, who was measuring temperatures every day in every country at the same time and same height using the same method while avoiding UHI interference? Think they were religiously measuring temps everyday during both World Wars? Ever seen how much of Africa is actually measured since recordkeeping began?) and that 70% of Earth is covered by water and there's simply no reliable record even including the ARGO buoy system that covers an area equal to about 0.4% of the ocean’s surface (it may be bit higher or lower but you get the point).
    As the old Eagle's song goes, "We paved paradise and put up a parking lot." Dr. Roy Spencer calculated that almost all of the anomalous warming in the historical temp record is from the UHI effect. Blaming greenhouse gases gets activists one step closer to their true goal: ending fossil fuels. Blaming its true causes (both natural and otherwise) doesn't get windmills and solar farms built.

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    1. The band is named the Eagles, not Eagle or Eagle's, and they didn't do that song. And that's the least inaccurate part of your comment.

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    2. Ahem, Joni Mitchell ... not the Eagles. (Big Yellow Taxi)

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    3. You're right, it should have been that Eagles' song, The Last Resort. "You call someplace paradise, kiss it goodbye". Yes, let's focus on a minor error or irrelevant detail in my comment (the wrong song) to distract from or discredit the broader point, rather than addressing the main argument itself. A straw man fallacy.

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    4. Sorry, didn't mean to push your button. Just a music nerd and correcting a detail so it isn't taken as accurate by those who may not know either way. I think it helps with posters' credibility, too.

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  11. John,

    Yes, wind is not reliable here- or anywhere. At least solar is predictable. I say, put solar panels on posts over every parking lot in the country. Two problems solved in one shot: The energy crisis would be well on the way to being solved, and shade for everyone to park in. Covering every parking lot would get us a lot of power without taking any additional land.

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    1. I think that is an excellent idea. I don't think getting the infrastructure in place to move the juice from the panels to the grid would be too bad, either, since parking areas already are served by electricity for lighting. No tearing up streets (too much), no tearing up people's yards or driveways, etc. And as you point out, no additional land needed.

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    2. Ansel, I agree 100% re solar parking lots. And it isn't a deal-breaker if the sun doesn't shine all the time or the wind doesn't blow all the time. In a diversified grid with wind, solar, hydro, nukes, etc, there is always power available and renewables can reduce the costs and emissions over the course of every year.

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  12. I would love to see the formula/logic behind this assertion: "You can give credit for about 2F of the heat to increasing greenhouse gases. For example, a location that reached 93F yesterday, would have been 91F." Is it because the planet has warmed by about that much because of fossil fuels. I can't imagine that it's a straight-line correlation in every heat wave. There must be variable effects from all the warming we've had. Have you seen the oceans lately, Cliiff?

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    1. The global ocean SST has warmed up by a very similar amount. The atmosphere and ocean are slowly warming....

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    2. The global ocean SST has warmed up by a very similar amount. The atmosphere and ocean are slowly warming....

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    3. "I can't imagine that it's a straight-line correlation in every heat wave. There must be variable effects from all the warming we've had."

      Here's my understanding (with the caveat that I'm a mathematician rather than a climatologist): It is certainly not true that every heat wave (or cold wave or other event) is exactly 2F hotter due to climate change. Climate is an incredibly complex system and it is impossible to tie carbon emissions to any particular event. In fact, if emissions (or something else -- the "butterfly effect") were different, last week's heat wave might have been a cold wave or a rainstorm. We simply can't say, and it doesn't matter. Since the world on average has warmed by 2F due to carbon emissions, the best guess in the absence of other evidence is that any particular weather event is 2F hotter. There is lots of work going on to understand what events are more or less affected by climate change and how, but since the average effect is 2F, math tells us that if some are affected more then some must be affected less. There's a lot more we have to learn about that, but the average effect of carbon emissions is pretty clear, just like the average effect of smoking cigarettes throughout your life is pretty clear.

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  13. Cliff - is the tool you use to generate those temp graphs publicly available? Thanks!

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  14. You've mentioned scenarios in this blog previously where the weather modeling programs seem to have trouble and it seems to me one of those is in predicting cool downs following heat dome events like the current one, i.e. the cooler air usually seems to come more slowly than the models predict it will. I don't know if the data supports this or if it's just my perception, but it could be an interesting topic for a future blog.

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  15. The takeaway for me is yet a another example of increasingly sloppy journalism. The part of the headline that reads "100 degree heat wave looms" implies successive days at 100 (not 95 and rounding up). "Hottest night in history" certainly implies something more impressive than 18th hottest (by that logic imagine the spin a professional sports team could put on a losing season). With the responsibility the news media carries for giving us facts they ought to have human eyes proofing these headlines.

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Please make sure your comments are civil. Name calling and personal attacks are not appropriate.

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