Monday, September 03, 2007

Where we are

Some discussion about the number and intensity of Atlantic hurricanes has lead Eli to Weather Street, another properly obsessed site which has a very interesting graphic showing the number of hurricanes per season.



Currently 2007 is running a bit above average, but not significantly more than 2006, which was a low year, yet the most striking thing about 2006 was that there were no named storms after October 1. It is also interesting to note that the hurricane season appears to be starting earlier (June) than in the past.

UPDATE: One of the mice asked for the Atlantic hurricane tracks between 1015 and 1037, and o yeah, she also wanted the track of the 1900 Galveston hurricane. Now Eli is REALLY good folk, but unfortunately the 1015 data was recorded on an MFM disc which crashed about 1995, but 1900, a piece of cake

and for the obsessed amongst thee we have the complete record, hurricane and cyclone tracks for all the years since dot.

16 comments:

Anonymous said...

I was looking through the compiled hurricane data, checking how it went in the medieval warm period, and can't seem to find the named storm hurricane listings for 1015-1027 AD. Might you have a copy I could borrow? Also my records are a little shabby on the 1900 Galveston hurricane and the total named storms for that year -- the Galveston hurricane pressure drop seems unrealistically sudden on the copy I have, any idea or a URL where I can find better definitive data? What was that storm's name again?

Man is funny, he thinks he knows all after observing a mere fraction of what he sees. History begins when man is born, nothing of merit came before -- especially when the con is more taxes.

It is true, that a giant meteor collision with Earth will cause globull warming, but what causes the ice ages? Earth's normal climate resting state in a snowball, I like it warm.

BrianR said...

"Earth's normal climate resting state is a snowball"

What gives you that idea?

Anonymous said...

> globull.

John Mashey said...

Well, "normal resting state is a snowball" is fairly imprecise, but it is certainly the case that over the last 2-3M years, it has usually been colder.

Figure 4.2, p 41 or "Plows, Plagues, & Petroleum" has a good chart, or on can see: http://en.wikipedia.org/wiki/Ice_age.

Of course, the issue is that human civilization evolved within a very narrow range of temperature/sea level, and now has large installed infrastructure that depends on that. Going too far in either direction will be painful.

BrianR said...

I'm being purposefully anal (maybe i should be an accountant or auditor), if someone states the normal resting state of the planet is such...I want to know why they think that.

The last 3 million years is 0.0007% of the Earth's history.

If you want to go back to the Cambrian, then the last 3 myr is ~6% of the history since then.

There is no normal resting state. And...99% of all species that ever lived are now extinct.

llewelly said...

There are other important activity metrics not included in the weatherstreet graphic. If you examine the NHC's page on climatology , you will note 2007's first and second hurricanes formed a bit late - August 16 compared to Augsust 14 (2 days late), and September 2 compared to August 30 (3 days late), but 2007's first and second major hurricanes formed early - August 17 compared to September 3 (17 days early) and September 2 compared to September 25 (23 days early). I don't know of similar data for ACE or PDI, but given those metrics are strongly influenced by major hurricanes, I suspect 2007 has been ahead of climatology on ACE and PDI since about August 17 or so (when Dean reached major hurricane strength) .

And since El Nino has its strongest dampening effect on Atlantic hurricane activity in August and October, 2006 having no October or November activity is not a surprise. Conversely, La Nina has its strongest enhancing effect on October activity, and this year conditions in the tropical Pacific are much more like La Nina. An active October should be expected.

llewelly said...


... the Galveston hurricane pressure drop seems unrealistically sudden on the copy I have ...


The HURDAT has only 2 minimum central pressure measurements for the 1900 Galveston hurricane. One during the 1800 UTC 6 September advisory period, when the storm had estimated surface winds of 85 kts, and another during the 0000 UTC 9 September advisory period, of 936 mb when the storm was estimated at 125 kts. (Yeah, 8 advisory periods, or 2 days, between them with no pressure measurements - normal for storms of this time period.) See here and search for '1900' . (It's the first storm on record that year, interestingly.) With the 54-hour gap there is not much of an indication of how fast the intensification was in terms of pressure, but from 974 mb to 936 mb over 54 hours is not a particularly fast drop. The change in wind speed from 100 mph (85 kts) at 1800 UTC 6 September to 145 mph (125 kts) at 1800 UTC 7 September is impressive, but not unheard of. However - since the wind speed numbers are probably based on re-analysis of historical damage reports and written descriptions, and the pressure measurements from less-than-ideal 19th century equipment operated at 19th century standards, and then possibly adjusted during re-analysis, one should take these numbers with a grain of salt. See here for more details on the historical re-analysis project.

Anonymous said...

"Resting state" is a meaningless term for climate.

Resting compared to what?

The issue is not "resting" states. The issue is "adaptation".

Humans can adapt to a changing climate (within reason, of course) while many species can not.

Some people don't care because they don't believe it matters if other species go extinct. That's their opinion and it's their prerogative to hold it.

It might not matter to humans if some animals and plants go extinct -- and then again, it might. At this point, our understanding is too incomplete to know.

EliRabett said...

There is little doubt that humans and many species will survive, there is also little doubt that many individuals will die, have worse lives, and generally not enjoy the experience.

Place your bets that the fickle finger of fate will point away from you and yours.

bigcitylib said...

The next one to watch may be 99l:

http://thegallopingbeaver.blogspot.com/2007/09/here-comes-another-one-maybe.html#links

EliRabett said...

The picture in Listen to the Bunny updates from the NOAA site, so you can see the next one there too. Eli will claim that he did it that way on purpose.

FancyRat said...

"Place your bets that the fickle finger of fate will point away from you and yours"

I bet that those in rich countries such as those Eli and I live in will suffer little - economic loss only - and many more of those in poor countries such as Bangladesh, Indonesia, will suffer much.

I consider many poor people suffering much to be a substantial ethical problem. Some economists consider a 25% drop in my income to be comparable to the deaths of 25 poor people, because the US Dollar economic impact is similar.

stevesadlov said...

Andrea, Chantal and Gabrielle were bogus (mid latitude cut off lows) and should not have been counted. In the Pacific, these types of storms are not counted and never have been. In the past, in NATL, they would not have been counted. But since the "Killer AGW" hysteria really started to kick in, a few years ago, the pressure mounted to count marginal features such as these. This is obvious count padding.

Anonymous said...

Bunny... Your graphic is named STORMS, your text says Hurricanes.

"which has a very interesting graphic showing the number of hurricanes per season."


That's like a 15 year old girl mistake. Fix it.

See your green line... 8..
8 Named storms.. Not hurricanes, we've had three of those.

EliRabett said...

Whatever

Anonymous said...

Eli,

I have to agree with the previous anonymous, this post treats hurricanes and named storms as the same.

Weatherstreet provides an equivalent graph for hurricanes, which is here:

http://www.weatherstreet.com/hurricane/2007/hurricane-climatology.gif

The number of named storms has now exceeded the seasonal average. However, the number of hurricanes is still at half. It is still a long way til Nov 30th. :)