the first time in history that four named storms have formed before July 1

[cyclonebuster]

How many storms went unnamed in 1933 compared to now? That's the whole point of the discussion. We can detect storms now that we didn't earlier in the period.

Where is their proof that wind shear would "Sooner or later wain and all bets are off?"

Landsea et al 2010 shows the bias in observation of TCs do to insufficient observation tools such as satellite and aircraft, and lack of ship traffic in parts of the Atlantic in the early 20th century.

http://www.aoml.noaa...l-jclim2010.pdf

The proof that wind shear wains is in the hurricanes themselves otherwise we would not have them. You can also bet as the oceans warm more and more the hurricane seasons will become longer. This longer time period will mean longer periods of time between wind shear events and more opportunity for cyclogenisis to occur.

[ORH_wxman]

The proof that wind shear wains is in the hurricanes themselves otherwise we would not have them. You can also bet as the oceans warm more and more the hurricane seasons will become longer. This longer time period will mean longer periods of time between wind shear events and more opportunity for cyclogenisis to occur.

Well its not supported in the projections and hasn't happened thus far.

[cyclonebuster]

Well its not supported in the projections and hasn't happened thus far.

How many named storms did we have this year before the season started? 31 storms in 2005 40 storms in 2010 and 2011 combined. I'd say we already started....

[ORH_wxman]

How many named storms did we have this year before the season started? 31 storms in 2005 40 storms in 2010 and 2011 combined. I'd say we already started....

I just linked you to a peer reviewed paper that shows no likely trend in number of Atlantic cyclones. I guess you either didn't read it or completely ignored it. Its really not worth arguing unless you have something that disputes it. Using named storms trends doesn't dispute it because that point was specifically addressed in the paper.

[cyclonebuster]

I'd also say the ACE since 1995 is well above the near normal scale bar. This is just another sign of a warming planet. No need to worry all they have to do now is just change the "Near Normal Scale Bar" upwards. Then everything will be ok..........

[PhillipS]

How many storms went unnamed in 1933 compared to now? That's the whole point of the discussion. We can detect storms now that we didn't earlier in the period.

Where is their proof that wind shear would "Sooner or later wain and all bets are off?"

Landsea et al 2010 shows the bias in observation of TCs do to insufficient observation tools such as satellite and aircraft, and lack of ship traffic in parts of the Atlantic in the early 20th century.

http://www.aoml.noaa...l-jclim2010.pdf

There are a number of assumptions in the methodology of the Landsea et al 2010 paper which should be viewed skeptically. The biggest assumption is that all of the observed increase in the number of TCs is due entirely to underreporting prior to the satellite era. Landsea fails to address the fact that the steepest trendline is during the satellite period, as you can see in Fig 1 of the paper. Another assumption the authors make is that they can quantitatively determine just how many TCs were missed each year - and after they add the missed TCs back into the annual counts, lo and behold the trend disappears. Golly, who saw that coming? But TCs are not my area of expertise so all I can do is shake my head and look for other papers to confirm or refute their findings. And, fortunately, there are a number of recent papers on this topic.

Since you seem to like Landsea let's look at another of his papers (but he wasn't the lead author), also from 2010. Knutson et al 2010 was published in Nature Geoscience and here is the abstract:

Whether the characteristics of tropical cyclones have changed or will change in a warming climate — and if so, how — has been the subject of considerable investigation, often with conflicting results. Large amplitude fluctuations in the frequency and intensity of tropical cyclones greatly complicate both the detection of long-term trends and their attribution to rising levels of atmospheric greenhouse gases. Trend detection is further impeded by substantial limitations in the availability and quality of global historical records of tropical cyclones. Therefore, it remains uncertain whether past changes in tropical cyclone activity have exceeded the variability expected from natural causes.

However, future projections based on theory and high-resolution dynamical models consistently indicate that greenhouse warming will cause the globally averaged intensity of tropical cyclones to shift towards stronger storms, with intensity increases of 2–11% by 2100.

Existing modelling studies also consistently project decreases in the globally averaged frequency of tropical cyclones, by 6–34%. Balanced against this,

higher resolution modelling studies typically project substantial increases in the frequency of the most intense cyclones, and increases of the order of 20% in the precipitation rate within 100 km of the storm centre.

For all cyclone parameters, projected changes for individual basins show large variations between different modelling studies.

(emphasis mine)

I read that to mean that Landsea and his colleagues expect us to see fewer TCs overall, but a greater frequency of very intense, very damaging hurricanes. Do you read that differently?

And there is another paper I came across, Elsner et al 2008, that was published in Nature. Its abstract:

Atlantic tropical cyclones are getting stronger on average, with a 30-year trend that has been related to an increase in ocean temperatures over the Atlantic Ocean and elsewhere

. Over the rest of the tropics, however, possible trends in tropical cyclone intensity are less obvious, owing to the unreliability and incompleteness of the observational record and to a restricted focus, in previous trend analyses, on changes in average intensity. Here we overcome these two limitations by examining trends in the upper quantiles of per-cyclone maximum wind speeds (that is, the maximum intensities that cyclones achieve during their lifetimes), estimated from homogeneous data derived from an archive of satellite records.

We find significant upward trends for wind speed quantiles above the 70th percentile, with trends as high as 0.3

0.09 m s

^-1

yr

^-1

(s.e.) for the strongest cyclones. We note separate upward trends in the estimated lifetime-maximum wind speeds of the very strongest tropical cyclones (99th percentile) over each ocean basin, with the largest increase at this quantile occurring over the North Atlantic,

although not all basins show statistically significant increases. Our results are qualitatively consistent with the hypothesis that as the seas warm, the ocean has more energy to convert to tropical cyclone wind.

That seems to support Landsea's hypothesis that we'll see an increase in frequency of major Atlantic hurricanes as SSTs increase. What are your thoughts?

[CoastalWx]

I'd also say the ACE since 1995 is well above the near normal scale bar. This is just another sign of a warming planet. No need to worry all they have to do now is just change the "Near Normal Scale Bar" upwards. Then everything will be ok..........

ACE has been at record low levels over the last 3 years. It's not apples to apples to compare it to 1995.

[CoastalWx]

LOL at people trying to be skeptical of Landsea who is one of the premier historians regarding tropical cyclones, yet some alarmist weenie who has little met background can post about longer hurricane seasons because a computer model told him so.

[cyclonebuster]

There are a number of assumptions in the methodology of the Landsea et al 2010 paper which should be viewed skeptically. The biggest assumption is that all of the observed increase in the number of TCs is due entirely to underreporting prior to the satellite era. Landsea fails to address the fact that the steepest trendline is during the satellite period, as you can see in Fig 1 of the paper. Another assumption the authors make is that they can quantitatively determine just how many TCs were missed each year - and after they add the missed TCs back into the annual counts, lo and behold the trend disappears. Golly, who saw that coming? But TCs are not my area of expertise so all I can do is shake my head and look for other papers to confirm or refute their findings. And, fortunately, there are a number of recent papers on this topic.

Since you seem to like Landsea let's look at another of his papers (but he wasn't the lead author), also from 2010. Knutson et al 2010was published in Nature Geoscience and here is the abstract:

Whether the characteristics of tropical cyclones have changed or will change in a warming climate — and if so, how — has been the subject of considerable investigation, often with conflicting results. Large amplitude fluctuations in the frequency and intensity of tropical cyclones greatly complicate both the detection of long-term trends and their attribution to rising levels of atmospheric greenhouse gases. Trend detection is further impeded by substantial limitations in the availability and quality of global historical records of tropical cyclones. Therefore, it remains uncertain whether past changes in tropical cyclone activity have exceeded the variability expected from natural causes.

However, future projections based on theory and high-resolution dynamical models consistently indicate that greenhouse warming will cause the globally averaged intensity of tropical cyclones to shift towards stronger storms, with intensity increases of 2–11% by 2100.

Existing modelling studies also consistently project decreases in the globally averaged frequency of tropical cyclones, by 6–34%. Balanced against this,

higher resolution modelling studies typically project substantial increases in the frequency of the most intense cyclones, and increases of the order of 20% in the precipitation rate within 100 km of the storm centre.

For all cyclone parameters, projected changes for individual basins show large variations between different modelling studies.

(emphasis mine)

I read that to mean that Landsea and his colleagues expect us to see fewer TCs overall, but a greater frequency of very intense, very damaging hurricanes. Do you read that differently?

And there is another paper I came across, Elsner et al 2008, that was published in Nature. Its abstract:

Atlantic tropical cyclones are getting stronger on average, with a 30-year trend that has been related to an increase in ocean temperatures over the Atlantic Ocean and elsewhere

. Over the rest of the tropics, however, possible trends in tropical cyclone intensity are less obvious, owing to the unreliability and incompleteness of the observational record and to a restricted focus, in previous trend analyses, on changes in average intensity. Here we overcome these two limitations by examining trends in the upper quantiles of per-cyclone maximum wind speeds (that is, the maximum intensities that cyclones achieve during their lifetimes), estimated from homogeneous data derived from an archive of satellite records.

We find significant upward trends for wind speed quantiles above the 70th percentile, with trends as high as 0.3

0.09 m s

^-1

yr

^-1

(s.e.) for the strongest cyclones. We note separate upward trends in the estimated lifetime-maximum wind speeds of the very strongest tropical cyclones (99th percentile) over each ocean basin, with the largest increase at this quantile occurring over the North Atlantic,

although not all basins show statistically significant increases. Our results are qualitatively consistent with the hypothesis that as the seas warm, the ocean has more energy to convert to tropical cyclone wind.

That seems to support Landsea's hypothesis that we'll see an increase in frequency of major Atlantic hurricanes as SSTs increase. What are your thoughts?

Mine are more like Kerry Emanuel's:

ftp://texmex.mit.edu/pub/emanuel/PAPERS/free_etal2004.pdf

[PhillipS]

Mine are more like Kerry Emanuel's:

ftp://texmex.mit.edu/pub/emanuel/PAPERS/free_etal2004.pdf

Kerry Emmanuel was a co-author with Landsea on the Knutson et 2010 paper I linked to above. The paper you linked to is older, 2003, but still relevant.

[cyclonebuster]

Kerry Emmanuel was a co-author with Landsea on the Knutson et 2010 paper I linked to above. The paper you linked to is older, 2003, but still relevant.

It reminds me of turning up the heat on a pot of boiling water. The more you increase the temperature on the burner the more steam or water vapor is created. Increasing the GHG blanket is like turning the heat up on the burner it is going to make more water vapor,an essential for cyclogensis......... Even more water vapor in areas of lower pressure which is what hurricanes are.

[ORH_wxman]

There are a number of assumptions in the methodology of the Landsea et al 2010 paper which should be viewed skeptically. The biggest assumption is that all of the observed increase in the number of TCs is due entirely to underreporting prior to the satellite era. Landsea fails to address the fact that the steepest trendline is during the satellite period, as you can see in Fig 1 of the paper. Another assumption the authors make is that they can quantitatively determine just how many TCs were missed each year - and after they add the missed TCs back into the annual counts, lo and behold the trend disappears. Golly, who saw that coming? But TCs are not my area of expertise so all I can do is shake my head and look for other papers to confirm or refute their findings. And, fortunately, there are a number of recent papers on this topic.

Since you seem to like Landsea let's look at another of his papers (but he wasn't the lead author), also from 2010. Knutson et al 2010was published in Nature Geoscience and here is the abstract:

Whether the characteristics of tropical cyclones have changed or will change in a warming climate — and if so, how — has been the subject of considerable investigation, often with conflicting results. Large amplitude fluctuations in the frequency and intensity of tropical cyclones greatly complicate both the detection of long-term trends and their attribution to rising levels of atmospheric greenhouse gases. Trend detection is further impeded by substantial limitations in the availability and quality of global historical records of tropical cyclones. Therefore, it remains uncertain whether past changes in tropical cyclone activity have exceeded the variability expected from natural causes.

However, future projections based on theory and high-resolution dynamical models consistently indicate that greenhouse warming will cause the globally averaged intensity of tropical cyclones to shift towards stronger storms, with intensity increases of 2–11% by 2100.

Existing modelling studies also consistently project decreases in the globally averaged frequency of tropical cyclones, by 6–34%. Balanced against this,

higher resolution modelling studies typically project substantial increases in the frequency of the most intense cyclones, and increases of the order of 20% in the precipitation rate within 100 km of the storm centre.

For all cyclone parameters, projected changes for individual basins show large variations between different modelling studies.

(emphasis mine)

I read that to mean that Landsea and his colleagues expect us to see fewer TCs overall, but a greater frequency of very intense, very damaging hurricanes. Do you read that differently?

And there is another paper I came across, Elsner et al 2008, that was published in Nature. Its abstract:

Atlantic tropical cyclones are getting stronger on average, with a 30-year trend that has been related to an increase in ocean temperatures over the Atlantic Ocean and elsewhere

. Over the rest of the tropics, however, possible trends in tropical cyclone intensity are less obvious, owing to the unreliability and incompleteness of the observational record and to a restricted focus, in previous trend analyses, on changes in average intensity. Here we overcome these two limitations by examining trends in the upper quantiles of per-cyclone maximum wind speeds (that is, the maximum intensities that cyclones achieve during their lifetimes), estimated from homogeneous data derived from an archive of satellite records.

We find significant upward trends for wind speed quantiles above the 70th percentile, with trends as high as 0.3

0.09 m s

^-1

yr

^-1

(s.e.) for the strongest cyclones. We note separate upward trends in the estimated lifetime-maximum wind speeds of the very strongest tropical cyclones (99th percentile) over each ocean basin, with the largest increase at this quantile occurring over the North Atlantic,

although not all basins show statistically significant increases. Our results are qualitatively consistent with the hypothesis that as the seas warm, the ocean has more energy to convert to tropical cyclone wind.

That seems to support Landsea's hypothesis that we'll see an increase in frequency of major Atlantic hurricanes as SSTs increase. What are your thoughts?

It is known that there is a good correlation between the multi-decadal phase of the Atlantic (AMO) and TCs in the Atlantic. Landsea mentions a large multi-decadal variation in the Atlantic basin in his conclusions and warns of using short term trends to make assumptions about longer term variability of TCs. The satellite era starts in the negative phase of the AMO and we are currently in the positive phase having flipped around 1995.

His reconstructions when taking into account the observational biases show a pretty clear cycle with peaks in the late 1800s, again in the 1930s-1950s and now from the late 1990s-present....about 60 years apart. Even the unadjusted graph shows this cycle pretty clearly, with just a bias of higher numbers late in the period due to the reasons outlined in his paper.

And yes, most research has supported about a 1-3% increase in the intensity of TCs in the Atlantic basin with a warming world that goes with fewer TCs overall.

[cyclonebuster]

It is known that there is a good correlation between the multi-decadal phase of the Atlantic (AMO) and TCs in the Atlantic. Landsea mentions a large multi-decadal variation in the Atlantic basin in his conclusions and warns of using short term trends to make assumptions about longer term variability of TCs. The satellite era starts in the negative phase of the AMO and we are currently in the positive phase having flipped around 1995.

His reconstructions when taking into account the observational biases show a pretty clear cycle with peaks in the late 1800s, again in the 1930s-1950s and now from the late 1990s-present....about 60 years apart. Even the unadjusted graph shows this cycle pretty clearly, with just a bias of higher numbers late in the period due to the reasons outlined in his paper.

And yes, most research has supported about a 1-3% increase in the intensity of TCs in the Atlantic basin with a warming world that goes with fewer TCs overall.

Fewer TC's overall? Not so evident in 2005 with 31 or in 2010 with 21 or 2011 with 20 is it? The hot ocean has already proved him wrong in just 6 years of history. You can't argue,the statistics are already in........ BTW if you don't believe me let's see what 2012 brings.

[ORH_wxman]

Fewer TC's overall? Not so evident in 2005 with 31 or in 2010 with 21 or 2011 with 20 is it? The hot ocean has already proved him wrong in just 6 years of history. You can't argue,the statistics are already in........ BTW if you don't believe me let's see what 2012 brings.

You are doing exactly what people say not to do...use a short term trend to make a conclusion about long term. Why was there a decrease in TC activity in the Atlantic in the 1980s and early 1990s from the high that occurred in the 1950s? We were definitely warmer than the 1950s...how come it didn't show up in the hurricane frequency?

Why was there a decline in storms between the late 1800s and the 1920s? We were definitely warmer in the 1920s than we were in the late 1800s.

[cyclonebuster]

You are doing exactly what people say not to do...use a short term trend to make a conclusion about long term. Why was there a decrease in TC activity in the Atlantic in the 1980s and early 1990s from the high that occurred in the 1950s? We were definitely warmer than the 1950s...how come it didn't show up in the hurricane frequency?

Why was there a decline in storms between the late 1800s and the 1920s? We were definitely warmer in the 1920s than we were in the late 1800s.

Because it is just like Kerry Emanual says. It is all about potential. The potential is there for this to happen but it doesn't mean it will happen sort of like playing Russian Roulette. It's all good if the hammer falls on a empty cylinder but watch out if the firing pin finds the primer. The heat content is there,one only needs to track the ACE......

[ORH_wxman]

Because it is just like Kerry Emanual says. It is all about potential. The potential is there for this to happen but it doesn't mean it will happen sort of like playing Russian Roulette. It's all good if the hammer falls on a empty cylinder but watch out if the firing pin finds the primer. The heat content is there,one only needs to track the ACE......

Well we have been tracking it and it doesn't look like your theory holds up:

[cyclonebuster]

Well we have been tracking it and it doesn't look like your theory holds up:

Why doesn't that chart match this NOAA chart? Also your chart reads Knots not Joules.Even if it is typo they should still be somewhat the same.

[ORH_wxman]

Why doesn't that chart match this NOAA chart shouldn't they be the same?

Your chart is OHC which is Oceanic Heat Content. ACE is Accumulated Cyclone Energy.

[cyclonebuster]

Your chart is OHC which is Oceanic Heat Content. ACE is Accumulated Cyclone Energy.

Yours reads knots mine reads joules of energy?

[ORH_wxman]

Yours reads knots mine reads joules of energy?

Here is what ACE is via wikipedia

http://en.wikipedia.org/wiki/Accumulated_cyclone_energy

[cyclonebuster]

Here is what ACE is via wikipedia

http://en.wikipedia...._cyclone_energy

Correct and I had ACE confused with SST's. My bad. I know better than that. Anyways,OHC is greater which means more available heat for the storms. I never should have used ACE as an example it has more to do with Oceanic Heat Content.

[ORH_wxman]

Correct and I had ACE confused with SST's. My bad. I know better than that. Anyways,OHC is greater which means more available heat for the storms. I never should have used ACE as an example it has more to do with Oceanic Heat Content.

Well the ACE is relevant since it shows how the TC's are reacting to this new found heat...and so far they aren't. The argument you seem to be presenting is that increased OHC will fuel the storms into much higher numbers and higher intensity and ACE is a good measure of the combo....thus far we have seen little to no response which is consistent with peer review science.

[cyclonebuster]

Well the ACE is relevant since it shows how the TC's are reacting to this new found heat...and so far they aren't. The argument you seem to be presenting is that increased OHC will fuel the storms into much higher numbers and higher intensity and ACE is a good measure of the combo....thus far we have seen little to no response which is consistent with peer review science.

Except for the past six years. Perhaps,there is a lag in such responses or perhaps the new found heat is going to melt the Arctic Ice?

[ORH_wxman]

Except for the past six years. Perhaps,there is a lag in such responses or perhaps the new found heat is going to melt the Arctic Ice?

ACE is way down since the 2005 peak...look at the graph again.

[cyclonebuster]

If the heat did go to melt more Arctic Ice then that may be the reason why we don't see an increase in tropical activity. Any thoughts on that? But even so that doesn't make sense either because the oceans have still warmed 1.5 degrees since the industrial revolution.

[ORH_wxman]

If the heat did go to melt more Arctic Ice then that may be the reason why we don't see an increase in tropical activity. Any thoughts on that? But even so that doesn't make sense either because the oceans have still warmed 1.5 degrees since the industrial revolution.

The reason TC activity has likely not increased is because it isn't supposed to. The Atlantic has seen an increase in named storms but that is well documented by Landsea et al for the reasons. But even their ACE hasn't shown much long term increase at all which supports Landsea's paper on the bias of observation because ACE should be way larger in the present in the Atlantic versus the past if we are truly seeing more storms...more of them should be long lived and intense, but they aren't which says we just missed the short lived weak storms and a few recurving ones in the early part of the century.

Most storms of any significance were usually documented so that's why Atlantic ACE looks much more like his adjusted graph than just the unadjusted named storms graphs.

[cyclonebuster]

ACE is way down since the 2005 peak...look at the graph again.

Yes I saw that. 2005 most active season with 31 when the ACE was high...... Perhaps a correlation between the two. Two years later in 2007 was lowest North Arctic Ice extent since 1979. Perhaps a two year lag with all that tropical heat moving poleward transported by cyclones in 2005 and 2006.

[aslkahuna]

Cyclonebuster is making one basic mistake-he's using the ATL TC frequency which is assuredly up as a proxy for the GLOBAL frequency which is not going to fly because for one reason the ATL seems to have an inverse relationship to activity occurring in certain other basins WRT to frequency. AGW is GLOBAL Warming so if you want to study the effects of GLOBAL warming on Tropical Cyclones then you must look at the storm activity that occurs GLOBALLY NOT just one basin. In fact GLOBAL TC activity has been down in recent years though we have begun to see some interesting intensity trends (like 10 hurricanes/6 majors out of 11 named storms in EPAC last year).

Steve

[ORH_wxman]

Cyclonebuster is making one basic mistake-he's using the ATL TC frequency which is assuredly up as a proxy for the GLOBAL frequency which is not going to fly because for one reason the ATL seems to have an inverse relationship to activity occurring in certain other basins WRT to frequency. AGW is GLOBAL Warming so if you want to study the effects of GLOBAL warming on Tropical Cyclones then you must look at the storm activity that occurs GLOBALLY NOT just one basin. In fact GLOBAL TC activity has been down in recent years though we have begun to see some interesting intensity trends (like 10 hurricanes/6 majors out of 11 named storms in EPAC last year).

Steve

On top of that, the ATL basin is expected to be near peak right now anyway...slowly declining through 2020-2025 if the past multi-decadal cycles are to be followed. 2005 was probably the peak andwe should still see some active seasons for now, but it should begin to show a more notable decadal decline as we go through the next couple decades.

[icebreaker5221]

It reminds me of turning up the heat on a pot of boiling water. The more you increase the temperature on the burner the more steam or water vapor is created. Increasing the GHG blanket is like turning the heat up on the burner it is going to make more water vapor,an essential for cyclogensis......... Even more water vapor in areas of lower pressure which is what hurricanes are.

Unfortunately, (or probably fortunately) there are a couple of problems with this idea.

1) Moist atmospheric convection is not the same as what you get when water vapor rises from your pot of boiling water. When your water boils, it is much hotter than the air above it and rises quickly. The air in you kitchen is also about the same temperature near the top of the stove as at the ceiling. In the atmosphere, the air above the ocean surface is roughly the same temperature as the ocean below it. Even tho the air at the tropopause is much colder, the actual stability of an air parcel depends up the potential temperature difference between the two, and lapse rates come into play. In a warmer world, the ocean warms, but the upper atmosphere also warms comparably. So there is little net thermal imbalance associated with a warming ocean. (I won't get into the fact that you don't have latent heating of fusion as that steam rises in your kitchen, a significant factor in deep tropical convection.)

2) It is true that warmer air can support more total moisture content than cool air, meaning higher dewpoints or higher mixing ratios. However, the occurrence of tropical cyclogenesis is dependent upon (near) saturation of the core of the system, which is more closely related to relative humidity. Saturation deficit increases at higher temperatures. Having a larger saturation deficit results in more dry downdrafts in a system, thus weakening it. While its true that regions of ascent and moisture convergence could potentially be more moist in a warmer scenario, regions of subsidence would be even drier (RH) at higher temperature.