Hijacking Harvey: It’s High Pressure Meets Low Pressure, Not Climate Change
As surely as night follows day, a large hurricane causes the usual suspects to harrumph that this MUST END THE DEBATE OVER CLIMATE CHANGE. Interesting that those who claim to be all about Science® argue that you should base your conclusion on a single data point, or a small number of data points.
This is happening now, as the rain continues to fall in Houston, as I can affirm by looking out my window. There is effectively a pump in the Gulf that is pushing massive amounts of moisture into central Houston, and dumping it on my head.
But as Dr. Wayne Spencer points out, attributing this effectively local event to global climate change is a huge stretch. There are those who hypothesize that greater warmth leads to greater ocean temperatures which leads to more frequent and intense hurricanes. There are those who hypothesize that this mechanism is too simplistic. Further, the evidence that there has been an increase in hurricane frequency and/or intensity is equivocal at best. The nearly nine year pause in major hurricanes in the western Gulf is certainly hard to square with this explanation.
And reading this Texas hurricane history (produced by NOAA) or this Louisiana hurricane history makes it plain that hurricanes are a fact of life in this region, and were long before consumption of oil, or even coal in significant quantities. (They also make me ask myself WTF was I thinking when I moved down here :-P) Scan those publications and you will find numerous monster storms, many of which date widespread use of the internal combustion engine, or even the steam engine.
No, what is making Harvey so horrible is something that I feared when I first saw the forecasts of the track before it made landfall: that it would stall over the coast and drop huge amounts of rain, like Allison did in 2001. And that’s what’s happened, but occurring later in the year and being more powerful (as later storms typically are), Harvey is outdoing even Allison in inundating Houston.
It’s the combination of the track and the economic development of eastern Texas that is producing the current catastrophe: those two things are intersecting in Harris county and the surrounding region. Harris county has grown dramatically over the years, and that creates a bigger target. Further, more development is more pavement and built up area, which doesn’t retain water: there is controversy here, but it is quite plausible that due to the political economy of development, takeaway and retention capacity hasn’t kept up with the runoff, leading to more flood risk for a given amount of rainfall. The Tax Day Storm of 2016 could be another illustration of this.
So what kept Harvey from going inland? A high pressure area in central Texas that moved east and has pushed Harvey back into the Gulf, where it can drink heavily and then relieve itself over Houston. This is a chance intersection of weather events and circulation patterns, not a signal of long term climate change.
This is not unique. Consider Racer’s Hurricane of 1837. It was a huge storm, probably Cat 4 like Harvey–illustrating that global warming is not a necessary condition for the development of such storms. Moreover, it wreaked havoc on the entire Texas coast, then the Louisiana, Alabama, and Florida coasts, before petering out in North Carolina (where it also did considerable damage). If you look at the track it did a sharp u-turn, almost certainly because it hit a high pressure area coming in from the north. (Sound familiar?)
What would have happened had Harvey not hit the high pressure, and continued inland from Corpus Christi? Likely a repeat of the 1921 San Antonio Great Flood, which led to flash flooding in the city, with up to seven feet of water in the downtown area. (No margaritas on the River Walk when that happened, I’m wagering.) Harvey is worse because by stalling over the Gulf, instead of moving inland (as the 1921 storm did) it can continue to replenish its moisture.
So this is about weather and circulation, not climate.
It should be noted that many other extreme weather events used to flog the global warming cause are also attributable to circulation, and in particular, the impact of high pressure systems. The great French heat wave of 2006, and the great Russian heat wave of 2010 were attributed–not by climate “deniers” (whatever the hell that is–who denies there is such a thing as climate?) but by NOAA and others who are sympathetic to the warming hypothesis–to high pressure systems that stalled, creating thermal inversions and extended periods of hot weather.
To attribute what is going on outside my window to climate change would require a credible model, with evidence to support it, showing that the probability of the collision of a major tropical depression and a high pressure system over the Texas coast is higher when the average surface temperature is a degree or so warmer than it was in the past. I’m not aware of any such theory, and reading Spencer, he’s saying there isn’t one.
So rather than try to hijack Harvey to advance a political cause, it’s better to accept it as one of those things in the category of “stuff happens.” In this case, “stuff” is high pressure meets low pressure over Houston. Further, that stuff like this will happen regardless of government policy–imagine the havoc that Racer’s Storm would do today, and it occurred a quarter century before the drilling of the first oil well in the US.
Rather than making this another opportunity for political theater, it would be far better if energies were directed to helping out those devastated by the storm. Texans (with a strong assist from those in neighboring states, especially Louisiana) are coping heroically. We gladly welcome assistance from others, and you know that help will be reciprocated (as it has been in the past). To those attempting to exploit Houston’s misery, shut your pie hole and pitch in. Or don’t pitch in–but shut your pie hole regardless.
Technical quibble: I read someone yesterday arguing that Harvey isn’t Cat 4, at least not while it was at its most destructive, because it doesn’t have the necessary sustained wind speeds measured at the right altitude. Apparently meteorologists don’t categorise using gusts. Maybe the bloke’s complaint was that people kept reciting category 4 long after it had ceased to be one. (I’m assuming that it had once been category 4 but I’m old enough to have often seen journalistic excitement quietly corrected months after the event.)
Not that it matters if the damage is being done by downpours rather than the breeze.
I grew up in a town which would have a tidal flood about once a year when the Spring tides were at their highest. No problem: the Victorians had designed the buildings around the harbour accordingly and more recent buildings had been sited prudently. The other advantage we had is, in the words of a Chinese acquaintance, “your climate is so reasonable”.
Anyway, best of luck to you and your fellow citizens. Except the antifas, obs. .
Comment by dearieme — August 29, 2017 @ 3:27 am
I can’t find the bloke I read so here’s someone else saying much the same thing.
‘As reported by satellites, Harvey peaked at a sustained speed of 115kt, or 132mph, just before landfall.
However, this appears to be at odds with the land based data, where the highest PEAK GUST was 132 mph. Wind gusts are typically about 1.3 times as high as 1-minute sustained speeds, according to NOAA, which suggests that Harvey’s sustained speeds at landfall were about 100 mph, making it a Cat-2 hurricane.
Note that hurricanes like Carla and Celia were much more powerful at landfall. Once more, this raises questions about the current practice of comparing satellite data with historical land data. This often results in claims that storms these days are more powerful than in the past.’
I suppose the sheer amount of rain means that considering using permeable surfaces for roads and car parks would be fruitless. What else might it be economic to do to lessen damage from a future event like this, or is the economic thing to do just to take it on the chin?
Comment by dearieme — August 29, 2017 @ 4:26 am
@dearieme, I believe Harvey had sustained cat4 winds *offshore* when it made landfall. You’re right that there probably weren’t any sustained cat4 winds that affected land, although there certainly were strong cat2 to weak cat3 affects on land.
Comment by Sam — August 29, 2017 @ 8:12 am
Climate change is the divine revelation that leads to the religion of world Communism.
Comment by Thomas Jefferson — August 29, 2017 @ 8:54 am
In a previous post the Prof said there were no basements in Houston.
This suggests to me the water table is naturally high. If that’s the case the more tarmac the better, as water will eventually run off rather than create more property damage from heave.
Comment by james — August 29, 2017 @ 9:10 am
Yes for Texas just a soft summer zephyr with a light sprinkling of rain. ”’Tis but a scratch.
Comment by pahoben — August 29, 2017 @ 1:13 pm
Hi Prof, hope you are well.
A few remarks re climate change.
1. Extrapolating local extreme events to the globe is idiotic. In fact, hurricane activity has been fairly low in the past decade.
2. Has anyone done a rigorous cost / benefit analysis on increased CO2? Roman and MWP were periods of growth. Increased rainfall in the Mahgreb and the Sahel is surely a good. CO2 below 180 ppm kills all plants, having twice that is a safety buffer.
3. The Gaia hypothesis – whether you belive it or not – works both ways. More CO2, more plant growth.
Comment by james — August 29, 2017 @ 2:49 pm
Sorry, prof. Maybe not be the best moment to recommend more rain, even in the Sahara a continent away. I apologise.
Comment by james — August 29, 2017 @ 4:28 pm
Take it from someone who has lived through 45 years of Gulf coast storms – natural disasters are inherently unpredictable because of the large number of variables involved.
Take the four storms that caused the most damage during my time in Houston — Hurricane Alicia in 1983, Tropical Storm Allison in 2001, Hurricane Ike in 2008 and Hurricane Harvey this year.
Alicia was a seemingly innocuous low pressure system that dithered around the northern Gulf for awhile before intensifying over a few hours. It came in quickly on Galveston’s west beach as a weak Cat 3 and then proceeded up the Gulf Freeway directly through downtown Houston, blowing out hundreds of skyscraper windows in the process. Most of the enormous damage was the result of wind, not flooding. Several areas of Houston were without power for weeks.
On the other hand, Allison never became a hurricane, but was – similar to Harvey – a slow-moving storm that caused enormous flooding damage. Having said that, Allison’s initial damage wasn’t bad at all. The problem was that, after it went through Houston and moved north toward the Texas-Arkansas border, atmospheric conditions forced it to return to Houston. As a result, it sat over Houston for the better part of two days, causing enormous floods throughout the already saturated area.
Then, Ike was a classic monster hurricane that intensified over the Gulf after causing huge damage in the Caribbean and Cuba. As with Alicia, most of its damage in Houston was the result of wind, not rain. It moved through the eastern part of the Houston metro area quickly.
Which brings us to Harvey, which had characteristics of both Allison and Ike. It was a powerful hurricane (Cat 4) when it came ashore and caused tremendous wind damage initially (although not much flooding damage) in Port Aransas, Rockport, and Corpus Christi. Then, as we all know, Harvey stalled about 100 miles inland on the South Texas coastal plain and dumped – as the slow-moving Allison did – incredible amounts of rain over four days on Houston, which unfortunately was on its “dirty” or primary rain-making side. Wind damage in Houston from this Cat 4 storm was non-existent.
Had Harvey moved like Ike did, Houston would not have had damage at all. But – as Craig noted – both San Antonio and the Texas Hill Country would have experienced devastating flash floods, which probably would have killed more people than will be lost in Houston.
The bottom line is that there is a degree of randomness to natural disasters that people resist confronting because of our instinct to gravitate toward control and predictability. The better approach is to embrace the randomness and do your best in adjusting behavior to changing circumstances.
Having said all that, I do agree with the point that my friend Bill King made today in this Houston Chronicle op-ed: http://www.houstonchronicle.com/opinion/outlook/article/If-we-want-better-flood-control-it-must-be-a-12113906.php&cmpid=twitter-premium
There is a special place in hell reserved for local politicians who recklessly spend enormous amounts of public money on uneconomic light rail systems and obsolescent sports stadiums rather than using a portion of those funds to help protect citizens from the inevitable floods that occur on the Gulf coast.
Comment by Tom Kirkendall — August 29, 2017 @ 5:44 pm
Not just the politicians. I understand the Corps of Engineers has faced opposition from environmentally concerned citizens to even clean out let alone upgrade Buffalo Bayou. As I remember it was impossible for them to even clean it out through Tanglewilde as an example. The management team at Barker Reservoir have been very concerned about the state of Buffalo Bayou for some years but were prevented from making reasonable efforts to even reestablish previous throughput capacity. I am sure that will change now.
Comment by pahoben — August 29, 2017 @ 6:54 pm
Pahoben:
Never underestimate the Greenies, the Environmentalist Fundamentalists or the committees comprised of elected officials or bureaucrats that will vote to decide fate of public policy on matters like Buffalo Bayou. The voting members of the councils will all go home to air conditioning after the chaos in the chambers. Witness what happened in Charlottesville (populated by liberal Dems) when it was overtaken by boisterous BLM protesters & SJW. They abandoned the chambers. Law enforcement did nothing.
Don’t put faith in them.
The #MSM only took notice of how violent anti-fa is when they repeatedly attacked, beat & destroyed cameras & iPads of reporters & photographers in Berkley last weekend.
Vlad has little faith in sensible folk standing up to the violent minority. He fears it will only end when met with force. And ONLY when a majority of the media stops coddling these hard core leftists in sheep’s clothing. They don’t even wear the sheepskins anymore. Only masks & hoodies. But the media portrays them as ‘anti-racist’ protesters. How noble.
VP VVP
Comment by VP Vlad — August 30, 2017 @ 7:34 am
@Vlad
Yes. If you look at Buffalo Bayou on Google Earth you will see it meanders back and forth back and forth. Even if you just took out the meanders and made it straight in the long runs the capacity would increase dramatically. Just something as simple as that would have a large impact. But no can’t disturb the sacred breeding grounds of the alligators or some such nonsense. Sorry don’t want to ruin the view of the gators from my kitchen window.
Comment by pahoben — August 30, 2017 @ 8:52 am
Oops
No sooner do I suggest more rainfall in the Sahara than you get this
http://www.cbc.ca/news/world/niger-niamey-deadly-floods-1.4266384
Comment by james — August 30, 2017 @ 8:30 pm
The good news–Niamey is pre-destroyed, no significant loss expected.
Comment by The Pilot — August 30, 2017 @ 9:31 pm
It’s Dr ROY Spencer, not Wayne.
The alarmists have been attributing natural weather events to CAGW since the early 90’s.
Also, it’s the air pressure level that determines the strength of a hurricane (cyclone etc) not water temperature. Alarmists claiming Harvey was strong due to warmer Gulf waters are lying, purely and simply lying.
Comment by Baa Humbug — August 31, 2017 @ 4:52 am
Good point, Professor.
This was an astute article pointing out the economic development in the Houston metropolitan over the years has significantly contributed to the magnitude of area flooding, which is central.
But then the authors regressed to their stupidity and arrogance by slowly invoking their climate change ideological vomit into the article mid-way through the piece.
https://www.bloomberg.com/news/features/2017-08-31/a-hard-rain-and-a-hard-lesson-for-houston
This type of journalism, if one wants to call it that, has become part of an ever increasing structural change of our social norms, and turns it my stomach.
Why can’t the journalist/writers report the facts, like they once use to? Because they think they know everything and want to indoctrinate people with their flawed, delusional purported facts.
Another case in point: A majority of the “business journalist” seem to think they know economics and its supporting statistics just because they talk and write about it. Now they are all experts. Wrong! They don’t know half of what they think they know–they just don’t know that they don’t know. ?
Now, back to the main premise. For those that partake in the chimera this hurricane and others like it is climate change, I ask the simple and rhetorical question: Where are the data to support such irresponsible claims? News flash: we don’t have nearly enough timeline– not even close. We would need multiple hundreds of years of weather data to debunk the notion that our modern-day climate is nothing more than normal, cyclical random events.
One can make any data set say what they want it to say. But to interpret data cleanly in an unbiased fashion, that’s for another time on the Streewise.
Comment by EconMaestro — August 31, 2017 @ 6:02 am
My opening comment is directed to the attached article, not towards the good professor. My apologies, as I don’t believe that is conveyed clearly.
Comment by EconMaestro — August 31, 2017 @ 6:09 am
…speaking of “heroically.” Beldar also is posting from Houston. He took a long hiatus from his blog, but felt compelled to resume posting (however briefly) by what he’s observed happening in Houston.
I noted one of the coomenters said that Harvey didn’t create heroes, it revealed them.
http://beldar.blogs.com/beldarblog/2017/08/harvey-has-created-untold-heroes-from-ordinary-people-responding-magnificently.html
Comment by ColoComment — August 31, 2017 @ 4:14 pm
Craig (if I may) – my sympathy and admiration goes to Texans. What a courageous people! Got a list of charities that work directly onsite, and will send some (payday!). One of my vendors, flooring company, emailed an offer this morning: go thru your closets, send us your clean clothes we’ll deliver it down to Houston.
So not all NYkers are bubbling idiots, I wanted you to know…
Comment by ETat — September 1, 2017 @ 6:06 am
@EconMaestro–No worries! I knew that you were referring to the article, not me.
@ETat–You may!
It is very kind of you to contribute. Thank you! I know that there are many good people in NY. I am pleased that one of them is a reader–and sometime linker ;-)–with whom I am glad to be on a first name basis.
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