Is global warming responsible for fewer tornadoes in 2009? Stu
Ostro of the Weather Channel thinks so. Image courtesy NSSL.
Stormchasers across Tornado Alley have been frustrated this spring by what seems to be a lack of tornadoes and severe weather. Indeed, VORTEX2, the largest tornado field study ever, has been running for more than two weeks now and has not seen one twister. Last week, Weather Channel Senior Meteorologist Stu Ostro speculated that global warming was the cause.
In a segment with on-air meteorologist Stephanie Abrams, Ostro explained that the jet stream lingering over Canada and a continual ridge of high pressure were suppressing severe weather. Without the collision of low and high pressure (among other factors), tornadoes and supercell thunderstorms have a hard time forming.
Stu Ostro of the Weather Channel believes these two graphs
show a correlation between atmospheric pressure (top) and
global temperatures (bottom).
Ostro continued his explanation saying that atmospheric pressure in the Northern Hemisphere's mid-latitudes between 30 and 60 degrees has increased steadily since 1970. He then overlaid a chart showing this increase with that of a chart that shows global average temperatures having increased over the same period. As he says in his blog entry, “That parallels remarkably well the trend of globally-averaged temperatures, which has also shown a significant rise since the mid 1970s.”
Previously having considered himself a climate change skeptic, Ostro now believes anomalous weather patterns can be traced to anthropogenic [manmade] climate change. Ostro says, “Up until a few years ago I was convinced that there was nothing out of the ordinary going on. What's convinced me otherwise is the number, nature, and context of the anomalies happening around the world, and changes in circulation patterns associated with them.”
He closed out his blog entry with some rather pointed commentary saying, “There have always been extremes; however, their nature is changing. The large-scale long-term trends are affecting the weather, which is intimately and inexorably linked to climate within the continuum of time scales. Deal with it. We're all gonna have to. If we don't want to get zapped, we must adapt.”
Without entering a greater debate about global warming, what about Ostro’s comments on air that global warming and climate change are responsible for the slow tornado season? Beyond what appears to be a cursory correlation between 500 millibar atmospheric pressure increases and temperature, is there any other empirical evidence to support this claim?
Ostro failed to entirely state his case and the argument he presented left a lot to be desired.
As global temperatures have increased, the number of pirates
has decreased. Is there a relationship similar to the decrease
in the number of tornadoes? Image courtesy Vengaza.org.
Certainly one could take any number of charts, overlay it with the chart of global temperature increases, and seem to establish a correlation. Global warming skeptics are quick to point out that solar activity when overlaid on a temperature chart is remarkably similar. Similarly, one could produce a chart showing the global average temperature versus the number of pirates and find that increased global temperatures are responsible for a decrease in the number of pirates.
Throwing a chart out that apparently correlates air pressures with global temperatures and saying that is the reason behind the decrease in tornadoes in 2009 is not a particularly compelling or convincing argument. Further, the fact of the matter is that if you set aside this one year, the number of reported tornadoes has increased steadily since 1950. That in and of itself would go counter to Ostro’s argument.
Granted it is widely accepted that the increase in the number of tornado reports has as much to do with an increase in population density and technology as anything – there are more people to see and report twisters and radar technology allows us to ‘see’ tornadoes that otherwise would go unreported in rural areas. However, it does speak to the point that oversimplifying the matter does little to make the point.
Lastly, it is very important to note that NOAA’s Storm Prediction Center statistics actually show that the actual number of tornadoes in 2009 is virtually spot-on the 2004 to 2009 average (image at right). Any claim that there are fewer tornadoes than normal simply does not bear out with the facts.
In the end Stu Ostro failed to make his case that global warming is responsible for a decrease in tornadoes this season. His attempt to correlate atmospheric pressure to global temperatures simply showed what on the surface is a cursory correlation between the two. Further, the very basis of his claim that there have been fewer tornadoes is simply untrue.
Comments
Perhaps Mr Ostro's change of opinion came about after Weather Channel global warming cheerleader Heidi Cullen suggested that those tv meterologists who do not toe the global warming party line should have their American Meteorological Society broadcast seals revoked. Only a coincidence i'm sure.
BTW i would think that if global warming is causing a reduction in severe weather that it would be a good thing? Or is it that severe weather occurs over mostly red states and who needs them anyway???
See - this is a fine example if ignorance. Global Warming seems to be the cause of good weather, bad weather, medium weather, low weather, whatever weather. Give me a break. If we have a high tornado season, it's global warming. If the season is slow, it's global warming. If there is a single tornado, it's global warming. If my son lets off two toots instead of one, guess what? It's global warming... This is getting very old, very quickly.
Hi Mr. Hake,
I appreciate your interest in my blog and the on-camera segment.
There is a fundamental relationship between pressure levels and temperatures, by way of what's known as thicknesses. That is discussed and explained in the original blog entry to which I linked in my recent piece.
And I am very sensitve to the issue of cherry-picking one meteorological event and drawing a conclusion, such as the recent tornado-suppressing ridge of high pressure. My point of view has been
[continued] ... reached by observing many, many such cases, which have been documented in the massive PDF to which I linked.
I don't know if you've read both items to which I'm referring in these comments and in the blog, but if not I'd be interested in your thoughts after doing so.
Thanks again,
Stu Ostro
Global temperatures have been falling steeply for the past 8 years ... probably caused by global warming of course.
Tony,
Way to go! Unfortunately I am not currently writing on Examiner in Baltimore, but I will share your thoughts with Tony Pann. As a meteorologist with an AMS CBM and over 5 years of college teaching experience I have come up with one certain conclusion. We don't know everything! That is why the skeptics are gaining ground and the science is losing the credibility that was gained in the 90s with expanding WSR-88D, the super computing power at NCEP, advances to the NAM, etc. They all s
continued...
...They all still make mistakes, miss data. Tony Pann; Baltimore Weather Examiner just wrote about how the National Hurricane Center missed the call on a tropical storm last week. So, to throw any blanket statement such as AGW for every weather event brings back the hype of El Nino in the 90s. Learn from the mistakes of past hype, and move forward. That is scientifically responsible. Discuss other reasons for severe weather. Lord knows we will have it every year in some shape
Man, the whacko global warming alarmists have it all covered. First they make up this man-made theory for the miniscule warming we experienced last century and then they blame every weather event that occurs on it as the cause. Here is your link for another whacko's that blame MORE TORNADOES on global warming. http : / / www. foxnews. com/story/0,2933,295272,00 .html . Scientists, my butt, they are all just liberal idealogues!
People still watch the Weather Channel?
The increase in the (reported) number of tornadoes since the mid-20th century always used to be taken as evidence of the consequences of global warming. Now that the numbers--over a statistically meaningless period of time--seem to be headed in the opposite direction,THAT is supposed to be a consequence of global warming. So the rel point here is, WHATEVER happens, it's caused by global warming. Of course the people who expected personal gain from spreading alarmism used to have enough sense to attribute only bad things to global warming. The "throw anything and see if it sticks" mentality is here on full display, indicating a movement flailing in desperation.
It's important to understand what Stu is saying here, which is the rise in temperature which is a virtually certain fact, cannot exist independently of other atmospheric variables. It would be unreasonable to think we would not see a change in day to day weather because of it.
Teasing the climate change signal from the day to day swings in weather is very difficult, but it should be possible. New attribution techniques developed in the last 10 years (See Santer's work), and the NOAA re-analysis project that makes it possible to look back at the past state of the atmosphere, will be very helpful.
Dan Satterfield
Chief Meteor.
WHNT TV
Mr. Ostro,
Thanks for taking a look at the article and posting your comments. I apologize for the slow reply – just not enough hours in the day. :-)
My article was more referring to the on-air segment than anything. I know of course it is impossible to make a compelling argument for anything in 2 minutes but as I say, throwing out the overlapping charts without a more thorough explanation was kind of tough to swallow and came across (to me) as a good bit of hype.
[continued] Certainly climate (and any associated change) and weather are interrelated and your research does make a compelling case that one is impacting the other. As Justin Berk commented though, I think a lot of what we see put out there goes to show just how little we know about how everything meshes together.
It was just in recent years the public was told that AGW would bring cataclysmic storms and other significant major weather events – ala Al Gore in an Inconvenient Truth? Just recently President Obama repeated that claim.
And yet research has shown that isn’t happening and in fact it is just the opposite. Tropical cyclone activity is at some of the lowest levels on record. Then of course your research seems to indicate that AGW is responsible for a decrease in severe activity, contrary to what has been said before.
[continued] Again, I really think the conflicting statements and evidence that goes back and forth highlights that maybe we just don’t know what the heck is going on. How do we reconcile saying climate change is causing fewer tornadoes when empirical data shows the number of tornadoes increasing and last year was near a record year? As I say in the original story, a lot of that increase is because of technology and wider spread population however it is hard to reconcile the two.
I am going to sit down and thoroughly analyze your research in the coming days and perhaps do a more details write-up on it. I will drop you a note when I do to get your comments prior to publishing.
Thanks again!
Tony
[continued from above]
With tropical cyclones in the Northern Hemisphere (not just the Atlantic) there have been wildly conflicting signals - a case of “all-or-nothing.” While that and the other odd and/or extreme weather that’s been happening in recent years represent a very complex issue, that doesn’t mean we shouldn’t try to get our arms around it, and I think progress is being made in understanding it.
Let me know if you get a chance to dig deeper into my stuff!
Stu
Tony,
Thanks for the follow-up!
Yes, it was impossible to adequately address this in a short on-air segment; that’s why Stephanie and I referred viewers to my blog(s).
In regard to your comments about tornadoes and hurricanes, there’s no compelling evidence that tornadoes overall are either increasing or decreasing (I was only highlighting the recent weather pattern). As you will see in my PDFs, what *is* evident during this decade is a series of outbreaks unusually intense and/or far north for the October-February period, and that makes sense in the context of the warming.
[continued below]
How about a link between less tornadoes and gifting orgonite?
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