Is the Atlantic hurricane season getting longer?

By: Dr. Jeff Masters , 1:35 PM GMT on November 11, 2010

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It seems like there have been an unusual number of early and late season tropical storms and hurricanes in the Atlantic in recent years. In 2008, we had four named storms in July, and the second most powerful November hurricane on record. Both 2007 and 2005 had rare December storms, and 2003 featured Tropical Storm Anna, the first April tropical storm ever recorded. This year, Hurricane Tomas made 2010 the fourth straight year with a November hurricane, something that has never occurred in the Atlantic since accurate records began in 1851. The latest runs of the GFS and NOGAPS models are suggesting the possibility that we will have Tropical Storm Virginie in the Caribbean between Colombia and Nicaragua a week from now. Is hurricane season getting longer? Dr. Jim Kossin of the University of Wisconsin published a 2008 paper in Geophysical Research Letters, "Is the North Atlantic hurricane season getting longer?" He concluded that yes, there is a "apparent tendency toward more common early- and late-season storms that correlates with warming Sea Surface Temperature but the uncertainty in these relationships is high".


Figure 1. Observed sea surface temperature (SST) trends during the official North Atlantic hurricane season (June-November) for the period 1950-2007. Units are °C per century. The dashed rectangle denotes the tropical storm formation region south of 30° North latitude and east of 75° West longitude. Data are from the NOAA Extended Reconstructed Sea Surface Temperature V3 product [Smith et al., 2008]. Image credit: Kossin, J., 2008, "Is the North Atlantic hurricane season getting longer?", Geophysical Research Letters, Vol. 35, L23705, doi:10.1029/2008GL036012, 2008.

Methods
Dr. Kossin utilized the "best track" database of Atlantic tropical cyclone activity going back to 1851. However, since lack of satellite and aircraft reconnaissance data before 1950 makes the early part of this record suspect, he limited his analysis to the period from 1950 onward. The era of best data--the satellite era beginning in 1980--was also looked at separately, to ensure the highest possible data quality. The area studied was only a portion of the Atlantic--the tropical storm formation region south of 30° North latitude and east of 75° West longitude. This region has shown considerable warming of the Sea Surface Temperatures (SSTs) since 1950, in excess of 1°F (0.6°C) (Figure 1). A statistical method called "quantile regression" was employed. The method looked at how certain thresholds that mark the beginning and end of hurricane season have changed over the years. For example, the date where 5% of all tropical storms form earlier than that date, was called the 0.05 quantile, and the date where 5% of all tropical storms form later than that date, was called the 0.95 quantile. Kossin was able to show that the date of the 0.05 quantile got steadily earlier and the date of the 0.95 quantile steadily got later since 1950. Hurricane season for both the period 1950-present and 1980-present got longer by 5 to 10 days per decade.


Figure 2. Trends in tropical storm formation dates, in the region south of 30° North latitude and east of 75° West longitude, at the 0.05.0.95 quantiles. Trends are based on the periods (left) 1950-2007, and (right) 1980-2007. The dates (month/year) associated with the 0.05, 0.25, 0.50, 0.75, and 0.95 quantiles for each period are shown on the top axis (these threshold dates are based on the full sample for each period). Shading denotes the 90% confidence interval. Image credit: Kossin, J., 2008, "Is the North Atlantic hurricane season getting longer?", Geophysical Research Letters, Vol. 35, L23705, doi:10.1029/2008GL036012, 2008.

Relationship with Sea Surface Temperature
The broadening of the Atlantic hurricane season found was strongly dependent upon Sea Surface Temperatures. Both the onset and end of hurricane season shifted by 20 days per degree C of warming of the SST. With global warming projected to increase tropical Atlantic SSTs 1-2°C by the end of the century, can we then expect a 40-80 day increase in the length of hurricane season? Dr. Kossin doesn't explore this possibility, and doesn't blame the observed increase in the length of the season on human-caused global warming of the oceans. There is reason to believe that future warming of the Atlantic SSTs won't necessarily broaden the area over which tropical storms will form, though. Papers by Henderson-Sellers et al. (1998) and Knutson et al. (2008) theorize that as SSTs warm, the lowest temperature at which tropical storms can form will also increase. The current minimum temperature of 26.5°C (80°F) may increase to 28.5°C for a 2°C warming of Atlantic SSTs. Johnson and Xie (2010) have found observational evidence that the lowest temperature at which tropical storms can form has indeed been increasing at about 0.1°C per decade in the Atlantic, in line with climate model predictions.

References
Henderson-Sellers, A., et al., 1998, "Tropical Cyclones and Global Climate Change: A Post-IPCC Assessment", Bull. Am. Meteorol. Soc. 79, 19–38.

Johnson, N.C., and S.P. Xie, 2010, "Changes in the sea surface temperature threshold for tropical convection", Nature Geoscience doi:10.1038/ngeo1008

Knutson, T.R., J.J. Sirutis, S.T. Garner, G.A. Vecchi, and I.M. Held, 2008, Simulated reduction in Atlantic hurricane frequency under twenty-first-century warming conditions", Nature Geoscience 1, 359 - 364 (2008), doi:10.1038/ngeo202

Kossin, J., 2008, "Is the North Atlantic hurricane season getting longer?", Geophysical Research Letters, Vol. 35, L23705, doi:10.1029/2008GL036012, 2008.

Jeff Masters

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Pre-Virginie?
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Quoting Orcasystems:



If he comes...its was because he was invited :)


668. PensacolaDoug 1:54 PM GMT on October 08, 2010 Hide this comment.

Quoting Orcasystems:


KOG, PDoug was unhappy with your attempt at snow last year.



Yes I was. So this year I'm putting in my order early for a repeat of Feb 1899!!


SO I take the blame?
Talk about words coming back to haunt ya!!!
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Morning all.

Just a quick look-in before work. Amazing wx.... cool... rain showers woke me up.... sun behind clouds... great stuff. I hope it stays cool today.

Have a great one!
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Quoting aislinnpaps:
Good morning to anyone else up. Lots of rain headed this way hopefully this weekend.
Good morning to you too.
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Good morning to anyone else up. Lots of rain headed this way hopefully this weekend.
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466. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Disturbance Summary
TROPICAL DEPRESSION XX
15:00 PM JST November 12 2010
=============================

At 6:00 AM UTC, Tropical Depression (1006 hPa) located at 13.0N 112.0E has 10 minute sustained winds of 25 knots with gusts of 40 knots. The depression is reported as stationary.
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465. HadesGodWyvern (Mod)
Fiji Meteorological Services
Tropical Disturbance Summary
18:00 PM FST November 12 2010
=========================================

At 6:00 AM UTC, Tropical Disturbance located at 12.5S 175.8E is reported as moving slowly. Position POOR based on Multispectral infrared with animation and peripheral observations. Sea surface temperature is around 29C.

Organization has not improved in the last 24 hours. Convection remains persistent in the southeast sector of the system, but has not increased much elsewhere in the past 24 hours. Cyclonic circulation is from surface to 850 HPA. System lies to the east of a 250 HPA short wave trough in a moderately sheared environment.

Global models has picked up the system and are slowly moving it in the south southeast direction with little intensification.

The potential for this system to develop into a tropical cyclone within the next 24-48 hours is LOW.
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463. JLPR2
Quoting TORMENTOSO83:

u r right!!! but at the same time the tension and uncertainty takes me to feel in a very unpleasant environment!!!


Hmm I repeated a word there, time for bed... xD
But I feel fine when I'm taking classes and when I'm around there, the atmosphere is a little tense but I feel fine, maybe I don't feel it as much as the rest of the people. :P
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Good Night
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Good nite all, thanks for good info...
Member Since: August 2, 2010 Posts: 21 Comments: 9821
Quoting PrivateIdaho:
I'm going to bed. Thanks for the conversation and if I didn't respond to you it's because I've had a few beers and a gin-and-tonic or two so I'm typing slooow.

Thanks to you for had it!!! Gnite!!!
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Quoting PrivateIdaho:
Well, have a good beer and a gin-and-tonic sleep....
Member Since: August 2, 2010 Posts: 21 Comments: 9821
I'm going to bed. Thanks for the conversation and if I didn't respond to you it's because I've had a few beers and a gin-and-tonic or two so I'm typing slooow.
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Quoting JLPR2:


I wouldn't say unpleasant, the word I think the word would be tense or filled with uncertainty. :S

u r right!!! but at the same time the tension and uncertainty takes me to feel in a very unpleasant environment!!!
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Quoting sunlinepr:


Thanks for the info, I was looking for that in order to see the logistics and history related to the Bonus project...
Glad to help.
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453. JLPR2
Quoting TORMENTOSO83:

Totally agreed with you!!!
You can see it reflected on the situation of the University Of Puerto Rico in Rio Piedras!!! I study there and I can tell you that the mood around there is very unpleasant!!


I wouldn't say unpleasant, the word I think the word would be tense or filled with uncertainty. :S
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Quoting PrivateIdaho:
Link


Thanks for the info, I was looking for that in order to see the logistics and history related to the Bonus project...
Member Since: August 2, 2010 Posts: 21 Comments: 9821
Don't know if you've been to Vieques, but in the northwestern coast, there is what is called the mosquito pier.... That was a US army road that was begun during the final days of WWII, and the purpose was to link Vieques with the main island... The war ended and the project was abandoned... Thats why Now you hear our politicians talking about a project for building a bridge to link Vieques and PR....
Member Since: August 2, 2010 Posts: 21 Comments: 9821
Link

Experimental Breeder Reactor I (EBR-I) is a decommissioned research reactor and U.S. National Historic Landmark located in the desert about 18 miles (29 km) southeast of Arco, Idaho. At 1:50 pm on December 20, 1951 it became the world's first electricity-generating nuclear power plant when it produced sufficient electricity to illuminate four 200-watt light bulbs.[3][4] It subsequently generated sufficient electricity to power its building, and continued to be used for experimental purposes until it was decommissioned in 1964.
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Quoting PrivateIdaho:
I could tell you...but then I'd have to keel you!
LOL...the In Situ Reactor....
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Quoting KerryInNOLA:
Wow, there's some cool stuff going on at INL. Which one are you involved in?
I could tell you...but then I'd have to keel you!
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Quoting sunlinepr:


I prefer to keep neutral on those matters, but you know that you're dealing with politicians and like in every corner in the world, money buys anything.... and As we all know locally, the political situation of PR also affects....

Totally agreed with you!!!
You can see it reflected on the situation of the University Of Puerto Rico in Rio Piedras!!! I study there and I can tell you that the mood around there is very unpleasant!!
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Quoting PrivateIdaho:
We have a nuclear museum here and the first operational nuclear powerplant in the world.


This Bonus project were one of the first US experiments to make water boil using Uranium rods.... it was constructed in 1960.... There was another Bonus plant built in the US, and they were experimental....
Member Since: August 2, 2010 Posts: 21 Comments: 9821
Quoting TORMENTOSO83:

I heard about those studies, but the problem with those studies is that it showed the cancer incidence, but it couldn't related the cancer with the bombs!!! It's that true?
It's very difficult to determine causes in areas of increased cancer occurance...that said most explosive residues, lead, uranium and other metals used in bombs and explosives are know carcinogens so it there is a pathway for exposure, it is a logical conclusion that the cancer rates are caused by these pollutants.
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Quoting PrivateIdaho:
I like the change of season but get tired of the cold a little quicker that I tire of the heat. I would love to visit your Island someday and cause some explosions that people enjoy.

HAHAHA LOL,
of course, anytime!!!
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Quoting TORMENTOSO83:

I heard about those studies, but the problem with those studies is that it showed the cancer incidence, but it couldn't related the cancer with the bombs!!! It's that true?


I prefer to keep neutral on those matters, but you know that you're dealing with politicians and like in every corner in the world, money buys anything.... and As we all know locally, the political situation of PR also affects....
Member Since: August 2, 2010 Posts: 21 Comments: 9821
Quoting sunlinepr:
Do you know that PR was used by the US to perform experiments, including exp. with the population.....
Just one example from many documented...
Many Americans don't know that before you had your first operating Nuclear plant the US built an experimental plant in the Rincon Area.... called Bonus

The Boiling Nuclear Superheater (BONUS) Reactor Facility, is a decommissioned nuclear plant in Rinc%uFFFDn, Puerto Rico. It was listed on the U.S. National Register of Historic Places in 2007.[1]



BONUS was a prototype to investigate economic and technical feasibility of the integral boiling superheating concept.

Construction started in 1960 and had its first controlled nuclear chain reaction in April 13, 1964. In September 1965 was archived 50MW thermic (full power) and highest steam temperature (900%uFFFDF/482%uFFFDC). The reactor ended operations in June 1968 because of high cost modifications and technical problems. The reactor was decommissioned by Puerto Rico Water Resources Authority between 1969 and 1970.

The fuel and control rods were returned to the United States for disposal. The remainder of the radioactive material was either decontaminated on site or placed into the core which was then entombed in concrete. Additional cleanup and shielding was completed in the 1990s and 2000s. A museum is planned for the main floor of the facility.
We have a nuclear museum here and the first operational nuclear powerplant in the world.
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Quoting TORMENTOSO83:

I think that situation is a bitter memory for those who got bombed and for those that had to bombed because it was their job not because they wanted it!!!

So, the situation is finally over in Vieques, PR, so PrivateIdaho why you come over for June 23rd for "Noche de San Juan" and bring with you some bombs, we can use it as fireworks on that night!!! LOL

OMG! I was kidding!!! :p
I like the change of season but get tired of the cold a little quicker that I tire of the heat. I would love to visit your Island someday and cause some explosions that people enjoy.
Member Since: Posts: Comments:
Do you know that PR was used by the US to perform experiments, including exp. with the population.....
Just one example from many documented...
Many Americans don't know that before you had your first operating Nuclear plant the US built an experimental plant in the Rincon Area.... called Bonus

The Boiling Nuclear Superheater (BONUS) Reactor Facility, is a decommissioned nuclear plant in Rinc%uFFFDn, Puerto Rico. It was listed on the U.S. National Register of Historic Places in 2007.[1]



BONUS was a prototype to investigate economic and technical feasibility of the integral boiling superheating concept.

Construction started in 1960 and had its first controlled nuclear chain reaction in April 13, 1964. In September 1965 was archived 50MW thermic (full power) and highest steam temperature (900%uFFFDF/482%uFFFDC). The reactor ended operations in June 1968 because of high cost modifications and technical problems. The reactor was decommissioned by Puerto Rico Water Resources Authority between 1969 and 1970.

The fuel and control rods were returned to the United States for disposal. The remainder of the radioactive material was either decontaminated on site or placed into the core which was then entombed in concrete. Additional cleanup and shielding was completed in the 1990s and 2000s. A museum is planned for the main floor of the facility.
Member Since: August 2, 2010 Posts: 21 Comments: 9821
435. JLPR2
No tropical systems or disturbances means I'm bored... :\

Still 18 days left of the season...
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I'm one of these guys....Link
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Quoting KerryInNOLA:
VAbeachhurricanes apologized and Neapolitan refused to accept it or acknowledge it in any way. It just reflects poorly.


Not defending him, but maybe Nea had logged out by then. He's usually not on after 11 or so.
Member Since: September 21, 2010 Posts: 1 Comments: 3690
Quoting sunlinepr:
Quoting PrivateIdaho: I've seen the shores of Puerto Rico but never set foot on shore.

I just told you about the reefs... The island is contaminated with heavy metals including residual uranium from the bombings.... There are studies due to a high cancer incidence on the island... There are active bombs in many areas... And there is sitll a lot of controversy about how it's going to be cleaned by the Army...
The DOD now spents millions of dollars cleaning up former firing and bombing ranges. I have done research and actually have a couple of patents on ways to reduce the pollution hazards asociated with the sites.
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Quoting sunlinepr:
Quoting PrivateIdaho: I've seen the shores of Puerto Rico but never set foot on shore.

I just told you about the reefs... The island is contaminated with heavy metals including residual uranium from the bombings.... There are studies due to a high cancer incidence on the island... There are active bombs in many areas... And there is sitll a lot of controversy about how it's going to be cleaned by the Navy...

I heard about those studies, but the problem with those studies is that it showed the cancer incidence, but it couldn't related the cancer with the bombs!!! It's that true?
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Quoting PrivateIdaho:
One of the barriers off Camp Legeune.


Interesting, looks like the MC has ownership of those islands.
Member Since: September 21, 2010 Posts: 1 Comments: 3690
Must be Dare.
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Quoting PrivateIdaho:
Sorry to open a wound. But at least I bombed, set on fire, and shot up an island in North Carolina too. :(

I think that situation is a bitter memory for those who got bombed and for those that had to bombed because it was their job not because they wanted it!!!

So, the situation is finally over in Vieques, PR, so PrivateIdaho why you come over for June 23rd for "Noche de San Juan" and bring with you some bombs, we can use it as fireworks on that night!!! LOL

OMG! I was kidding!!! :p
Member Since: Posts: Comments:
Quoting PrivateIdaho: I've seen the shores of Puerto Rico but never set foot on shore.

I just told you about the reefs... The island is contaminated with heavy metals including residual uranium from the bombings.... There are studies due to a high cancer incidence on the island... There are active bombs in many areas... And there is sitll a lot of controversy about how it's going to be cleaned by the Navy...
Member Since: August 2, 2010 Posts: 21 Comments: 9821
Quoting F4PHANTOM:
Marble Mountain MCAF
Member Since: September 21, 2010 Posts: 1 Comments: 3690

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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