Are we entering a new era of hurricane development!

[x-y-no]

XYNO,

The charts clearly indicate over the long term that overall hurricane intensity and US landfall frequencies have decreased in the long term, period. The charts derived fron the NHC do not lie.

I didn't say they were lying, I said one could legitimately raise the same kind of data quality questions with this data set as skeptics have (legitimately in my opinion) raised with regard to data on worldwide cyclone intensity prior to the 80s.

What happened to all the cat 5 hurricanes at landfall ?? There seem to be a growing trend of tropical cyclones weakening before US landfall in the last 10 years now.

End of story.

Have a nice day.................

There have been a total of three US landfalling Cat 5 storms - the 1935 Labor day storm, Camille and Andrew.

You'll have to explain to me what "growing trend" you see in that because it's a mystery to me.

[kenl01]

XYNO,

The charts clearly indicate over the long term that overall hurricane intensity and US landfall frequencies have decreased in the long term, period. The charts derived fron the NHC do not lie.

I didn't say they were lying, I said one could legitimately raise the same kind of data quality questions with this data set as skeptics have (legitimately in my opinion) raised with regard to data on worldwide cyclone intensity prior to the 80s.

What happened to all the cat 5 hurricanes at landfall ?? There seem to be a growing trend of tropical cyclones weakening before US landfall in the last 10 years now.

End of story.

Have a nice day.................

There have been a total of three US landfalling Cat 5 storms - the 1935 Labor day storm, Camille and Andrew.

You'll have to explain to me what "growing trend" you see in that because it's a mystery to me.

Oh my gosh ! I mentioned a million times already that according to the charts above, derived from the NHC in Miami, that in the last 50 YEARS the overall trend has been weaker. Not in 1935. Camille in 1969 was a strong system, yes. As to Andrew, I would be careful about calling it a cat5 because sustained winds of 140 gust to 165mph at obs time clearly "suggested" a cat 4 at the time.

But overall, especially in the last 10 years, intensity at landfall has been weaker. That doesn't mean you cannot get a cat 4 or 5 ocassionally. But if you look back 120 years ago, they were more frequent and more intense, on average, than they are today.

Have a nice day

[spinfan4eva]

:D How about " Hurricanes gone wild???"

Yeah but I don't like to look at Alberto's naked swirls...I will wait for Debby..

Hmmm-wonder if Debby 2006 will be as threatenning as Debby 2000?

Discussions from Debby 2000 1 day apart.....

HURRICANE DEBBY DISCUSSION NUMBER 15
NATIONAL WEATHER SERVICE MIAMI FL
5 AM EDT WED AUG 23 2000

THE SHIPS
MODEL...WHICH HAS PERFORMED WELL SO FAR...NOW TAKES DEBBY TO 81 KT
BY 72 HR. AN EXTREME OUTLIER IS THE GFDL...WHICH HAS A 926 MB
PRESSURE AS DEBBY REACHES THE FLORIDA KEYS. THIS LOOKS SUSPECT...AS
IT IS ALREADY STRONGER THAN REALITY AND A LOT OF DEEPENING OCCURS AS
THE MODEL STORM MOVES ALONG THE COASTS OF HISPANIOLA AND CUBA.
NEVERTHELESS...DEBBY COULD BE A DANGEROUS MAJOR HURRICANE AS IT
APPROACHES SOUTH FLORIDA.

FORECASTER BEVEN


FORECAST POSITIONS AND MAX WINDS

INITIAL 23/0900Z 19.7N 68.7W 65 KTS
12HR VT 23/1800Z 20.3N 70.7W 65 KTS
24HR VT 24/0600Z 21.0N 72.9W 65 KTS
36HR VT 24/1800Z 22.0N 75.1W 75 KTS
48HR VT 25/0600Z 23.0N 77.0W 80 KTS
72HR VT 26/0600Z 25.5N 80.0W 90 KTS

On second thought............

TROPICAL STORM DEBBY DISCUSSION NUMBER 20
NATIONAL WEATHER SERVICE MIAMI FL
11 AM EDT THU AUG 24 2000

THIS MORNING...A RECONNAISSANCE AIRCRAFT WAS UNABLE TO FIND A CLOSED
LOW LEVEL CIRCULATION SOUTH OF EASTERN CUBA. DEBBY IS DOWNGRADED TO
A TROUGH OR OPEN WAVE. THIS WILL BE THE LAST ADVISORY UNLESS
REGENERATION OCCURS...AND THE GFLD...FSU EXPERIMENTAL...AND
SHIPS...DO FORECAST THE SYSTEM TO MOVE INTO THE SOUTHEAST GULF OF
MEXICO IN 72 HOURS AND REINTENSIFY.

THERE IS STILL AREA OF DEEP CONVECTION WITH HEAVY WINDS AND WINDS TO
NEAR TROPICAL STORM FORCE IN THE VICINITY OF EASTERN CUBA AND
JAMAICA AND THIS WEATHER WILL BE SPREADING WESTWARD TO THE CAYMAN
ISLANDS LATER TODAY.

FORECASTER LAWRENCE

FORECAST POSITIONS AND MAX WINDS

NONE

[x-y-no]

Oh my gosh ! I mentioned a million times already that according to the charts above, derived from the NHC in Miami, that in the last 50 YEARS the overall trend has been weaker. Not in 1935.

You missed my point completely. You asked "What happened to all the cat 5 hurricanes at landfall ??" and I pointed out that in the entire record there have been only three landfalling Cat 5s. That's not enough to derive a trend of any sort at all.

Camille in 1969 was a strong system, yes. As to Andrew, I would be careful about calling it a cat5 because sustained winds of 140 gust to 165mph at obs time clearly "suggested" a cat 4 at the time.

Tell it to the HRD who have classified Andrew a 5.

But overall, especially in the last 10 years, intensity at landfall has been weaker. That doesn't mean you cannot get a cat 4 or 5 ocassionally. But if you look back 120 years ago, they were more frequent and more intense, on average, than they are today.

Have a nice day

Really? Since 2000, we've had 14 landfalling hurricanes, 6 of them majors. That's on a pace to beat the 40s if that rate continues. I fail to see your claimed trend.

[MiamiensisWx]

As to Andrew, I would be careful about calling it a cat5 because sustained winds of 140 gust to 165mph at obs time clearly "suggested" a cat 4 at the time.

The highest winds in a tropical cyclone are almost never recorded. Also, even if Andrew was not a Category Five at landfall, it may likely have had higher sustained winds than the original alleged 145MPH, due the storm's small size, intense eyewall, and tight pressure gradiant (in other words, it likely was more like 150MPH to 155MPH at landfall). Also, the highest sustained winds in Andrew (the estimated sustained Category Five winds) were restricted to a sparsely populated area along Biscayne Bay and over Elliot Key around Coral Gables and southward; thus, although Homestead and many other areas received Category Three to low-end Category Four sustained winds, that does not mean that Andrew was not a Category Five at landfall. All these factors, along with Andrew's exceptionally low pressure at landfall for such a small and tight storm, overwhelmingly support sustained winds likely higher than 145MPH in small areas of Andrew's eyewall; these reasons are why Andrew was upgraded to a Category Five at landfall.

As for Camille, well, Camille's landfall intensity was NOT 190MPH. Camille was not as small as you think. You need to listen to the facts a bit more. Thanks.

[NBCintern]

As to Andrew, I would be careful about calling it a cat5 because sustained winds of 140 gust to 165mph at obs time clearly "suggested" a cat 4 at the time.

The highest winds in a tropical cyclone are almost never recorded. Also, even if Andrew was not a Category Five at landfall, it may likely have had higher sustained winds than the original alleged 145MPH, due the storm's small size, intense eyewall, and tight pressure gradiant (in other words, it likely was more like 150MPH to 155MPH at landfall). Also, the highest sustained winds in Andrew (the estimated sustained Category Five winds) were restricted to a sparsely populated area along Biscayne Bay and over Elliot Key around Coral Gables and southward; thus, although Homestead and many other areas received Category Three to low-end Category Four sustained winds, that does not mean that Andrew was not a Category Five at landfall. All these factors, along with Andrew's exceptionally low pressure at landfall for such a small and tight storm, overwhelmingly support sustained winds likely higher than 145MPH in small areas of Andrew's eyewall; these reasons are why Andrew was upgraded to a Category Five at landfall.

As for Camille, well, Camille's landfall intensity was NOT 190MPH. Camille was not as small as you think. You need to listen to the facts a bit more. Thanks.

Good analysis, but this comment "You need to listen to the facts a bit more." really screwed your argument. When you attack the person your logical reasoning goes down the tubes...

[MiamiensisWx]

Good analysis, but this comment "You need to listen to the facts a bit more." really screwed your argument. When you attack the person your logical reasoning goes down the tubes...

OK, I didn't intend to sound mean. However, can you please try to be a little more positive to others, too? Thanks.

[NBCintern]

Good analysis, but this comment "You need to listen to the facts a bit more." really screwed your argument. When you attack the person your logical reasoning goes down the tubes...

OK, I didn't intend to sound mean. However, can you please try to be a little more positive to others, too? Thanks.

Hey, I gave you Kudos on your analysis. I just didn't want your analysis to go down the tubes with your last statement.

[MiamiensisWx]

Hey, I gave you Kudos on your analysis. I just didn't want your analysis to go down the tubes with your last statement.

Oh, OK. Thanks!

[kenl01]

Hurricane intensity and frequency is decreasing in the last 50 years, period. Look at the charts please.


One example in the last 10 years:

Alberto will join a growing list of named tropical systems to weaken before landfall before moving into the northeast Gulf of Mexico area of Florida. Gordon in September of 2000 was a hurricane at one point but by the time it came ashore near Cedar Key it was only a tropical storm. In August of 2004, Bonnie came ashore at Saint Vincent Island as a minimal tropical storm. Even Hurricane Earl back in September of 1998 was showing signs of becoming extra-tropical as it approached the coast near Panama City. Although each of these storms had different factors influencing them, a southwest steering flow is necessary in the atmosphere for a storm to get drawn into this part of the Gulf of Mexico. Unfortunately, this also induces shear on a system. In addition, the cooler shelf waters of the northeast Gulf of Mexico do not have nearly the heat content that is found farther out in the Gulf of Mexico.

[NBCintern]

Hurricane intensity and frequency is decreasing in the last 50 years, period. Look at the charts please.

Ken, we know. I think you have engraved your point.

[x-y-no]

Hurricane intensity and frequency is decreasing in the last 50 years, period. Look at the charts please.

I've looked at the charts you offered and I've raised my issues with what you claim that they show. Telling me to "look at the charts please" again doesn't do anything in terms of addressing the issues I've raised.

One example in the last 10 years:

Alberto will join a growing list of named tropical systems to weaken before landfall before moving into the northeast Gulf of Mexico area of Florida. Gordon in September of 2000 was a hurricane at one point but by the time it came ashore near Cedar Key it was only a tropical storm. In August of 2004, Bonnie came ashore at Saint Vincent Island as a minimal tropical storm. Even Hurricane Earl back in September of 1998 was showing signs of becoming extra-tropical as it approached the coast near Panama City. Although each of these storms had different factors influencing them, a southwest steering flow is necessary in the atmosphere for a storm to get drawn into this part of the Gulf of Mexico. Unfortunately, this also induces shear on a system. In addition, the cooler shelf waters of the northeast Gulf of Mexico do not have nearly the heat content that is found farther out in the Gulf of Mexico.

Yeah, storms regularly weaken in that area. What's your point? There's no data I'm aware of that indicates this is a recent phenomenon. You think there wasn't shear and cool shelf waters 50 years ago?

[curtadams]

I *have* looked at the charts. First, for long-term analysis you need to look at pressure, because wind estimates are questionable as recently as Camille, because of wind reduction and estimation issues. Pressure reads are absolutely spot-on as long as we've been doing aerial recon and quite good even before that. By pressure, 5 of the 10 strongest Atlantic hurricanes occured in the past three years. That is INSANELY statistically significant - even if you just consider the past 50 years, that's a chi-square p value of 1 in two hundred MILLION. There is absolutely no way hurricanes are getting milder or even staying the same - they are getting worse, and rapidly. I have no idea why Mayfield would say that, but he's flat wrong.

[x-y-no]

By the way, here is the "Easterling et al (2000)" paper referenced (it sure would be nice if one were supplied with full cites so that one doesn't need to do so much hunting around).

The quoted passage in context reads:

Overall, occurrences of Atlantic hurricanes do not
show a statistically significant long-term trend over the
twentieth century. However, Landsea et al. (1999)
found a statistically significant decrease in intense
hurricanes—those that cause the most damage. From
1944 to the mid-1990s the number of intense and
landfalling Atlantic hurricanes has declined (Landsea
1993; Landsea et al. 1996). Furthermore, large variations
of hurricane activity on interdecadal timescales
have been observed in this century (Gray et al. 1997).
Since the majority of coastal settlement occurred in a
period of relatively low hurricane landfall frequency,
the potential societal impacts of hurricane landfall in
more active decades have yet to be realized (Pielke and
Landsea 1998).

I note this references a '96 paper and thus neccesarily omits the most recent decade, which has shown a marked increase in landfalling majors. I doubt the quoted statement is still true if applied to the last 50 years.


I still have not found the original of that quote attributed to the WMO.

[kenl01]

Hurricane intensity and frequency is decreasing in the last 50 years, period. Look at the charts please.

I've looked at the charts you offered and I've raised my issues with what you claim that they show. Telling me to "look at the charts please" again doesn't do anything in terms of addressing the issues I've raised.

One example in the last 10 years:

Alberto will join a growing list of named tropical systems to weaken before landfall before moving into the northeast Gulf of Mexico area of Florida. Gordon in September of 2000 was a hurricane at one point but by the time it came ashore near Cedar Key it was only a tropical storm. In August of 2004, Bonnie came ashore at Saint Vincent Island as a minimal tropical storm. Even Hurricane Earl back in September of 1998 was showing signs of becoming extra-tropical as it approached the coast near Panama City. Although each of these storms had different factors influencing them, a southwest steering flow is necessary in the atmosphere for a storm to get drawn into this part of the Gulf of Mexico. Unfortunately, this also induces shear on a system. In addition, the cooler shelf waters of the northeast Gulf of Mexico do not have nearly the heat content that is found farther out in the Gulf of Mexico.

Yeah, storms regularly weaken in that area. What's your point? There's no data I'm aware of that indicates this is a recent phenomenon. You think there wasn't shear and cool shelf waters 50 years ago?

Dude, read it again. More and more tropical cyclones have "weakened" before landfall in the last 10 years. This has been the trend elsewhere too since about 1996. Those are the hard facts, even last year.

Bye

[x-y-no]

Ahhh ... found the source of the WMO quote here.

Note, this is from 1997.

Here's the whole thing in context:

There is little evidence to support any significant long-term trends in the frequency or intensity of tropical storms, or of hurricanes in the North Atlantic during the past several decades. Although the hurricane frequency was high during 1995 and 1996, an anomalously low number of hurricanes occurred during the 1960s through the 1980s, including those hitting the United States during that period (Figure 8.2). Reliable data from the North Atlantic since the 1940s indicate that the peak strength of the strongest hurricanes has not changed, and the mean maximum intensity of all hurricanes has decreased. There is also some evidence for a decrease in the frequency of cyclones in the Indian Ocean during the past two decades relative to earlier records and an increase in the frequency of typhoons in the western Pacific. Wide variations in the total number of tropical storms including hurricanes, typhoons, and cyclones occurring per decade have been observed, with no apparent long-term trends in most ocean basins. There is little consensus about how global warming will affect the intensity and frequency of these storms in the future.

(original quoted portion in italics)

So again, this omits the recent active decade, and interestingly the author thought it worthwhile to obscure the fact that the quoted sentence referred to the North Atlantic only.

Also, contrary to the implication, the overall gist of this passage is to indicate no particular trend, as evidenced by the highlighted portion indicationg an increase in the western Pacific counterbalancing the decrease (through 1997) in the Atlantic.

[NBCintern]

Ahhh ... found the source of the WMO quote here.

Note, this is from 1997.

Here's the whole thing in context:

There is little evidence to support any significant long-term trends in the frequency or intensity of tropical storms, or of hurricanes in the North Atlantic during the past several decades. Although the hurricane frequency was high during 1995 and 1996, an anomalously low number of hurricanes occurred during the 1960s through the 1980s, including those hitting the United States during that period (Figure 8.2). Reliable data from the North Atlantic since the 1940s indicate that the peak strength of the strongest hurricanes has not changed, and the mean maximum intensity of all hurricanes has decreased. There is also some evidence for a decrease in the frequency of cyclones in the Indian Ocean during the past two decades relative to earlier records and an increase in the frequency of typhoons in the western Pacific. Wide variations in the total number of tropical storms including hurricanes, typhoons, and cyclones occurring per decade have been observed, with no apparent long-term trends in most ocean basins. There is little consensus about how global warming will affect the intensity and frequency of these storms in the future.

(original quoted portion in italics)

So again, this omits the recent active decade, and interestingly the author thought it worthwhile to obscure the fact that the quoted sentence referred to the North Atlantic only.

Also, contrary to the implication, the overall gist of this passage is to indicate no particular trend, as evidenced by the highlighted portion indicationg an increase in the western Pacific counterbalancing the decrease (through 1997) in the Atlantic.

Interesting. Here is a cheer for thoughtful analysis:

http://www.cheerleader.com/graf/CheerleaderMasthead.jpg

[Stephanie]

If only the author waited a few more years....

[x-y-no]

Dude, read it again. More and more tropical cyclones have "weakened" before landfall in the last 10 years. This has been the trend elsewhere too since about 1996. Those are the hard facts, even last year.

Bye

Dude, read it again yourself.

I think you're reading way more than is really there into the phrase "a growing list".

Shear is nothing new. Cooler shelf water is nothing new. Hence the conditions for storms weakening prior to landfall in that area are nothing new.

[Patrick99]

I don't know that Alberto is indicative of anything. Seems a pretty pedestrian June storm to me. I think a lot of June storms fight shear, because there tends to be more of it.