Why so quiet??

[bradjones]

Okay it is May here in Oklahoma and we have had no severe weather this month. Is it just me or has this been a trend for sometime now? Why is the Jet stream in Canada this time of year? And speaking of heat we are cooking in May!! It seems to me that our weather patterns are not what they used to be.

 

[Mark Blue]

It has been quiet as far as Oklahoma and May are concerned and although we haven't discussed Oklahoma specifically, I would recommend reading this thread where we have covered in depth the recent weather trends. It appears there may be upcoming severe weather events in the "Slight" risk category (per current SPC outlooks), but you just never know what each day will bring with happened in KS on 05/19/12. I don't know if you can drive north to chase storms, but it seems to me that's where the action will be in the near term. I've also noticed several days where a "See Text" outlook is upgraded to a "Slight" risk, so it pays to be nimble and ready to go at all times.

 

[Eric Bucsela]

Kinda hesitant to raise this, but I do worry about global warming and long-term trends in tornado activity.

Tornadoes are a small-scale, complex phenomenon and the data record is just not good enough to draw firm conclusions. But a few potential trends have been suggested, e.g. (1) Increase in atmospheric heat/moisture, which could improve instability (but possibly enhance capping?) and (2) northward migration of the jet stream and possible overall weakening of dynamics.

Diffenbaugh et al. have noted a possible decrease in strong/violent tornadoes over the past few decades - but again, not sure how events of 2011, etc would affect their statistics. Anyway, here's their article:

http://www.stanford.edu/~omramom/Diffenbaugh_Eos_08.pdf

Another question is whether the occurrence of "extreme" years has been increasing (e.g. 2008, which was huge for chasing and 2012, which has not been). Any thoughts?

 

[Mike Johnston]

Don't confuse "average" with "normal." Included within "normal" is a range of possible outcomes, which may include some years that appear extreme, but really aren't when you consider the variable nature of weather.

As for global warming; goodness gracious. If severe weather was on the increase, it would be blamed on global warming. If on the decrease, it would also be blamed on global warming. People are so very quick to speculate on cause and effect, to the extent it suits their notions.

 

[Andy Jackson]

There are people who have seen quite a few tornadoes in OK during March/April. If you look at the models the S. Plains is not done yet with severe weather.

 

[Eric Bucsela]

Don't confuse "average" with "normal." Included within "normal" is a range of possible outcomes, which may include some years that appear extreme, but really aren't when you consider the variable nature of weather.

As for global warming; goodness gracious. If severe weather was on the increase, it would be blamed on global warming. If on the decrease, it would also be blamed on global warming. People are so very quick to speculate on cause and effect, to the extent it suits their notions.

Good point re normal vs average. But the frequency of extreme events out on the wings of a normal distribution (bell curve) is affected by small changes in the mean or width of the curve. A once/century event could become a 3-4 times/century event with only a slight broadening of the of the curve or shift of its center.

Also agree that although the media likes to juxtapose images of recent tornadoes with stories about global warming, the data just do not support this. On the other hand, greenhouse gasses ARE significantly affecting other aspects of climate in measureable ways. Hard to imagine that severe thunderstorm/tornado occurrences will not also be affected.

It will be interesting to see how this plays out in nature, especially for chasers. How it is perceived and reported is another matter, since the media view has not always been the scientific view.

 

[Hank Schyma]

The not uncommon May death ridge followed by the killer EML have shunted easily forecast scenarios. Still, tornadoes are occurring... Warren Faidley just bagged a tornado in NM (happy bday dude)... there was the rope-fest in KS May 19th... I myself was treated to my 8th tornado so far this year in South TX on May 10th. The remainder of May looks to be iffy, but watch, chasers will still be reporting tornadoes. If you want to chase this May, you're gonna have to just take a chance and get out there... perhaps drive a little more than usual. You might get a sun burn or two, but if you score you'll be one of the few (unlike April 14th). And then there's June.

 

[Stan Rose]

An interesting question (to me, anyhow...) regardless of your position on AGW, is what would sort of pattern would it take to convince an overwhelming majority that something truly 'unnatural' is occurring. I certainly don't think the current ridiculously warm pattern rises to that level, but what would? Suppose OK didnt see another tornado in Spring for the next 10 years, and the average temperature rose to the (current) 90+ degrees for May. Would people still look at decadal global circulations, longer term patterns in solar activity, etc? Or would they look elsewhere? Hard to say.

 

[mkavulich]

But back on topic, you might be interested in the Oklahoma monthly tornado statistics page. As recently as 2005, when it is doubtful that more than a few tornadoes escaped detection, there was a May with zero tornadoes in Oklahoma. This is smack in between 1999 and 2010, which tied for the most in Oklahoma in the month of May, each having 90 tornadoes. Even if there was an overall trend in the number of tornadoes at a certain time of year, it would be impossible to detect, because the variance is just so incredibly large. Even 100 years of reliable tornado statistics might not be enough. This article by Chuck Doswell does a good job describing the uncertainty problems that come with the small data set that we have.

 

[Jesse Risley]

ADMINISTRATIVE NOTE

Administrative Note:
Since this is the Advanced Weather and Chasing sub-forum, discussions here should seek to remain on topic. As such, a protracted discussion about the merits of anthropogenic global warming (or lack thereof) is best suited to the Bar and Grill, where off-topic discussions are permitted so long as they remain civil. However, any further discussion here should be focused specifically on why the pattern has been arguably "quiet" lately, with any references to global warming (or ancillary responses) specifically tied to the recent pattern itself (if such an argument can be made), rather than a political debate over the merits of the argument as a whole. A few off-topic posts have been removed, so hopefully we can carry on with an otherwise excellent discussion about the seemingly torpid synoptic pattern as of late.

Thanks,

ST Management Team

 

[Dan Robinson]

This season doesn't seem all that unusual to me. A slow May (less than 3 good chase days) in the southern Plains seems to come along every 3-4 years. Peak season is April-June, sometimes the peak is early, sometimes late. I look at the season as a whole - considering April, 2012 is the best season I've had. If you're constrained to chasing only Oklahoma in May, I'd agree that it's not a good year so far. The big May tornado days so far have been low-potential setups that only those who can afford to chase every setup from TX to ND and back many times will score.

 

[Joshua Cowan]

Tornadoes WRT Global Warming/Weirding

Kinda hesitant to raise this, but I do worry about global warming and long-term trends in tornado activity.

As for how warming affects tornado patterns, there doesn't appear to be a consensus on the subject. There is, generally speaking, the tendency to believe it will all be somewhat of a wash, with overall greater energy in the atmosphere increasing instability but reducing wind shear. In any case, we're talking climate here, it may very well take decades for a pattern to emerge (if at all).

 

[Rick Schmidt]

This season doesn't seem all that unusual to me. A slow May (less than 3 good chase days) in the southern Plains seems to come along every 3-4 years. Peak season is April-June, sometimes the peak is early, sometimes late. I look at the season as a whole - considering April, 2012 is the best season I've had. If you're constrained to chasing only Oklahoma in May, I'd agree that it's not a good year so far. The big May tornado days so far have been low-potential setups that only those who can afford to chase every setup from TX to ND and back many times will score.

Dan:

I have been chasing storms for more than 30 years, and I have NEVER seen such a low-tornado May, at least in Kansas, as this year. And, going hand-in-hand, Topeka has .95 of an inch in rainfall for the month, and we average over 3 inches. This May is most certainly a very unusual dry, non-tornado month for Kansas. I will usually chase 7-10 times in May, and I have not gone on a chase yet in may this year.

 

[Joshua Nall]

Okay it is May here in Oklahoma and we have had no severe weather this month. Is it just me or has this been a trend for sometime now? Why is the Jet stream in Canada this time of year? And speaking of heat we are cooking in May!! It seems to me that our weather patterns are not what they used to be.

People have been coming to this same conclusion for ages. For good reason I guess, because the weather is always changing. 7 years of drought will be followed by 7 years of floods. Or maybe the pattern is 3 years or 10. Or maybe for 50 years there is no pattern. Then for 50 years there is observable pattern.

I realize I think differently than most, but what seems strange to me is when a bad tornado hits a big town and tears it up, everyone wonders why. And they immediately start assuming there is something unnatural going on. What would really be odd, what would be absolutely strange and unnatural is if no bad tornado every hit a big town. Sometimes I wonder if we are not more superstitious than were the American Indians who also endured tornadoes.

Tying this in to your specific question, what would be really different, odd, unnatural… is if every May there was abundant severe weather in Oklahoma. Or if there were never 3 Mays in a row with minimal severe weather. Now, that would be strange.

As has already been mentioned extremes are normal. Concerning Global warming which has been mentioned later in your thread, it’s normal and global cooling is normal also, both will continue to occur. Instead of rationally looking into every possibility though, it seems we are quick to choose sides concerning AGW. The majority of the population does not know the difference between GW and AGW. With out a doubt these would effect the overall weather pattern, the question is are we smart enough, or have we had the smarts for long enough to accurately measure it and compare it against anything.

A well known religious book I am familiar with has a bit in it about the end of time. It says something about earthquakes and wars and this and that, then I believe it says, “and the end is not yetâ€.
But what do 99% percent of folks of this particular faith (which I hold to also) believe?… that wars and rumors of wars and earthquakes signal the end of time. That is the opposite of what that book teaches. It teaches don’t be alarmed, it’s not the end… these are natural.

I have come to conclude that rational thought is not natural to many, rather it is emotion, and personal belief, etc... that guides them. I guess you could sum it up by saying it is human nature that we are quick to believe something without much thought, and it cause us to say, “OMG!… what’s happening. This is so unnatural. It’s for sure the end", etc…. when the fact is the same old thing is happening that’s always been happening. Everything is changing. If the average life span of a human were 1000 years with perfect memory, we would come to much different conclusions concerning weather patterns and such.

 

[Andy Jackson]

This graph reminds me that things may seem out of place but they may not actually be:
WCM count
Yes, summer might start a little earlier this year, but that happens. How many tornado days do you need in OK in May for everything to be ok?