Is the Atlantic hurricane season getting longer?

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

Share this Blog
3
+

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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 422 - 372

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13Blog Index

Quoting F4PHANTOM:
Marble Mountain MCAF
Member Since: September 21, 2010 Posts: 1 Comments: 3690
Quoting DontAnnoyMe:


Hey! That's where I am. Which one?
One of the barriers off Camp Legeune.
Member Since: August 29, 2010 Posts: 0 Comments: 5236
Quoting PrivateIdaho:
Sorry to open a wound. But at least I bombed, set on fire, and shot up an island in North Carolina too. :(


Hey! That's where I am. Which one?
Member Since: September 21, 2010 Posts: 1 Comments: 3690
Quoting F4PHANTOM:
Marble Mountain MCAF
Nice! My Father-in-law is a retired Sergeant Major. He did a couple of tours in 'Nam. My Gunny about blew a gasket when he found out I was dating the S. Majors daughter. LOL!
Member Since: August 29, 2010 Posts: 0 Comments: 5236
Quoting JLPR2:


That's nice to hear and the part of the ''it was a big controversy here'', oh you have no idea. XD
I guess bringing back those memories brought out my bitter side, sorry if I was unpleasant.
Sorry to open a wound. But at least I bombed, set on fire, and shot up an island in North Carolina too. :(
Member Since: August 29, 2010 Posts: 0 Comments: 5236
Quoting PrivateIdaho:
In Febuary, when the high temperature had been below freezing for 2 months straight....can I come sleep on your sofa until...oh about June!

We can switch places!! Because I hate heat and love cold!!! LOL
Member Since: Posts: Comments:
Sure he does, he also has some valid points but I still say "Good Man" to VA.
Member Since: Posts: Comments:
Quoting F4PHANTOM:
66-71; SEMPER FI


OMG.. your old... 76-98 hmmm in 66... I was ummmm 7
Member Since: October 1, 2007 Posts: 81 Comments: 26516
Quoting PrivateIdaho:
I've seen the shores of Puerto Rico but never set foot on shore. We practiced bombing a near-by island and got liberty in Saint Thomas.



Well Vieques was a paradise island in the Eastern PR... I had a chance to vacation with famliy 2 years ago and went snorkling to some beaches.... All the reefs are destroyed.. Vieques has a bioluminescent bay, one of the best in the world... Bahia de mosquito.... That one is still in good condition... You get in the Water at night and your body glows in blue..

Bioluminescent Bay

The Bioluminescent Bay (also known as Puerto Mosquito, Mosquito Bay, or "The Bio Bay"), is perhaps the world's largest and brightest. The luminescence is caused by micro-organisms (dinoflagellates) which glow whenever the water is disturbed, leaving a trail of neon blue. A combination of factors create the necessary conditions for bioluminescence: red mangrove trees surround the water (the organisms feed off the dead leaves); a complete lack of modern development around the bay; the water is cool enough and deep enough; and a small channel to the ocean keeps the dinoflagellates in the bay. This small channel is the result of Spanish ships' attempts to choke off the bay from the ocean's waters. The Spanish believed that the bioluminescence they first encountered was the work of the Devil ('El Diablo') and tried to block the ocean's waters from entering the bay by dropping huge boulders in the channel. The Spanish only succeeded in preserving and increasing the luminescence. Kayaking is permitted in the bay and can be arranged through local vendors. Swimming is allowed on limited basis through guided tours.



Vieques is best known internationally as the site of a series of protests against the United States Navy's use of the island as a bombing range and testing ground, which eventually led to the Navy's departure in 2003. Today the former Navy land is a national wildlife refuge, with numerous beaches that still retain the names given by the Navy, including Red Beach, Blue Beach, Green Beach and others. The beaches are commonly listed among the top beaches in the Caribbean for their azure-colored waters and white sands.
Member Since: August 2, 2010 Posts: 21 Comments: 9882
Quoting TORMENTOSO83:

That's ok, he's apologizing and what real makes a true man is that he recognized what he did!!!
In Febuary, when the high temperature had been below freezing for 2 months straight....can I come sleep on your sofa until...oh about June!
Member Since: August 29, 2010 Posts: 0 Comments: 5236
410. JLPR2
Quoting PrivateIdaho:
If I was in charge we would have dropped water balloons and gone to the Virgin Islands a few days earlier. Which explains why I am seldom in charge of things.


That's nice to hear and the part of the ''it was a big controversy here'', oh you have no idea. XD
I guess bringing back those memories brought out my bitter side, sorry if I was unpleasant.
Member Since: Posts: Comments:
Quoting JLPR2:


Oh, you shouldn't have said that in my presence, I really resent you guys doing that there. :\


We evened it up for you... we used to shoot up and bomb theirs off San Diego and Hawaii. and once by mistake.. Port Angeles.

Member Since: October 1, 2007 Posts: 81 Comments: 26516
Quoting JLPR2:


Oh, you shouldn't have said that in my presence, I really resent you guys doing that there. :\

That's ok, he's apologizing and what real makes a true man is that he recognized what he did!!!
Member Since: Posts: Comments:
Quoting JLPR2:


Oh, you shouldn't have said that in my presence, I really resent you guys doing that there. :\
If I was in charge we would have dropped water balloons and gone to the Virgin Islands a few days earlier. Which explains why I am seldom in charge of things.
Member Since: August 29, 2010 Posts: 0 Comments: 5236
Quoting F4PHANTOM:
66-71; SEMPER FI


Nam? Thank you!
Member Since: September 21, 2010 Posts: 1 Comments: 3690
Complete Update

A mish mash of weather... yours and mine :(







TSPIN BUSTED FORECAST ALIBI
Member Since: October 1, 2007 Posts: 81 Comments: 26516
Quoting PrivateIdaho:
'83-'92


Gulf War? Thank you!
Member Since: September 21, 2010 Posts: 1 Comments: 3690
403. JLPR2
Quoting PrivateIdaho:
I bet Sunline knows more about it than I do. The U.S. Navy used an uninhabited island near PR to practive Navla and Aerial bombardment. The island was also valued for it's wildlife and of course the locals were concerned about the pollution from explosives and metals contamination.


The island isn't uninhabited, that was what bothered me the most and Vieques is actually a municipality of PR not just close by, it's part of PR.
Member Since: Posts: Comments:
Quoting outlookchkr:
I say, good man.
LOL! Neo needs tact and diplomacy lessons. :^)
Member Since: August 29, 2010 Posts: 0 Comments: 5236
Quoting VAbeachhurricanes:


yeah i know, Neo I apologize, Im very thankful for your service to our troops. Im not having a great day I did not mean to insult you. We disagree on a lot, but by no means do I have the right to insult you. Im sorry. heck maybe you even supplied my cousins air support for his extraction.
I say, good man.
Member Since: Posts: Comments:
Quoting KerryInNOLA:
Please explain the bombing of PR. It reminds me of the "Why Ferrara" scene in Catch 22.
I bet Sunline knows more about it than I do. The U.S. Navy used an uninhabited island near PR to practive Navla and Aerial bombardment. The island was also valued for it's wildlife and of course the locals were concerned about the pollution from explosives and metals contamination.
Member Since: August 29, 2010 Posts: 0 Comments: 5236
399. JLPR2
Quoting PrivateIdaho:
Sorry about bombing your island. I learned later that it was a big local controversy.


Oh, you shouldn't have said that in my presence, I really resent you guys doing that there. :\
Member Since: Posts: Comments:
Quoting PrivateIdaho:
Great! I bet you guys are happy about that.

I hope he is... though the last 2 times he's been home, he gets into the idea that he needs to go back to Irak again.... We'll see..
Member Since: August 2, 2010 Posts: 21 Comments: 9882
Quoting F4PHANTOM:
and what years did all of your globe trotting occur, leatherneck?
'83-'92
Member Since: August 29, 2010 Posts: 0 Comments: 5236
Quoting PrivateIdaho:
I've seen the shores of Puerto Rico but never set foot on shore. We practiced bombing a near-by island and got liberty in Saint Thomas.


If that bombing in PR was many years ago, then that was Vieques...
Member Since: August 2, 2010 Posts: 21 Comments: 9882
Sorry about bombing your island. I learned later that it was a big local controversy.
Member Since: August 29, 2010 Posts: 0 Comments: 5236
Quoting sunlinepr:


My sister noticed that he retired around $600 from his account... Seems like he bought already his airplane tickets for Dec.... Seems like he's being offered a MOS in Mainland.... So he's going back home to New Orleans....
Great! I bet you guys are happy about that.
Member Since: August 29, 2010 Posts: 0 Comments: 5236
I've seen the shores of Puerto Rico but never set foot on shore. We practiced bombing a near-by island and got liberty in Saint Thomas.

Places the Corps sent me:
Paris Island SC
Cherry Point NC
Millington TN
Norfolk VA
Virginia Beach VA
Jacksonville NC
Honduras (coast)
P. R. (coast)
Norway (coast)
Copenhagen Denmark
Portsmouth England
Rota Spain
Malaga Spain
Palma de Mallorca Spain
Toulon France
Trieste Italy
Morocco (coast)
Belle Chase LA
Jacksonville FL
Pensacola FL
Camp Pendleton CA
Al Jubail Saudi Arabia
Member Since: August 29, 2010 Posts: 0 Comments: 5236
Quoting TORMENTOSO83:

LOL those are the only words that you need if you wanna have fun hanging out in PR!!!
Yes in my travels I found that any attempt at learning the local language is seen as a sign of respect. I could order a beer and find the bathroom in 5 languages in my younger days.
Member Since: August 29, 2010 Posts: 0 Comments: 5236
Quoting PrivateIdaho:
Gracias! I hope your nephew is well and had a great veterans day. (and you as too!)


My sister noticed that he retired around $600 from his account... Seems like he bought already his airplane tickets for Dec.... Seems like he's being offered a MOS in Mainland.... So he's going back home to New Orleans....
Member Since: August 2, 2010 Posts: 21 Comments: 9882
Quoting KerryInNOLA:
Good Evening PrivateIdaho! I hope you had a nice Veterans Day.
Not bad Kerry, my boss (who I have been working for for 10 years) actually remembered to thank me for my service (for the first time in 10 years)....wow, I hope I don't sound bitter....lol!
Member Since: August 29, 2010 Posts: 0 Comments: 5236
Quoting sunlinepr:


Excellent!!

Gracias! I hope your nephew is well and had a great veterans day. (and you as too!)
Member Since: August 29, 2010 Posts: 0 Comments: 5236
Quoting PrivateIdaho:
I mostly just speak beer in spanish.."dos cervesa por favor" followed by "donde esta' el bano?" But I'm going to take a guess and say " the rain is from the stationary cold front". :)

LOL those are the only words that you need if you wanna have fun hanging out in PR!!!
Member Since: Posts: Comments:
Quoting sunlinepr:

Un frente de frio estacionario...

Gracias!!!
Member Since: Posts: Comments:
Quoting PSLFLCaneVet:



It's been an emotional day. I will leave the blog with this, as it is nearly midnight.

Thank you to our past, present and future defenders!


Army - "This We'll Defend"

Navy - "Non sibi sed patriae"

Air Force - "Aim High"

Marines - "Semper Fidelis"

Coast Guard - "Semper Paratus"
Member Since: Posts: Comments:
Quoting PrivateIdaho:
I mostly just speak beer in spanish.."dos cervesa por favor" followed by "donde esta' el bano?" But I'm going to take a guess and say " the rain is from the stationary cold front". :)


Excellent!!

Member Since: August 2, 2010 Posts: 21 Comments: 9882
Quoting sunlinepr:

Un frente de frio estacionario...
I mostly just speak beer in spanish.."dos cervesa por favor" followed by "donde esta' el bano?" But I'm going to take a guess and say " the rain is from the stationary cold front". :)
Member Since: August 29, 2010 Posts: 0 Comments: 5236
Member Since: August 2, 2010 Posts: 21 Comments: 9882
00z NOGAPS

Member Since: October 28, 2006 Posts: 57 Comments: 30825
Quoting TORMENTOSO83:
In Puerto Rico the pouring rainfall hasn't stop since yesterday early morning, severals streets are flooded and there's severals mudslides, BTW, I was almost dragged by a huge corrent!!! I'm a survival!! :)
What is causing all this mess?

Un frente de frio estacionario...
Member Since: August 2, 2010 Posts: 21 Comments: 9882



It's been an emotional day. I will leave the blog with this, as it is nearly midnight.

Thank you to our past, present and future defenders!


Member Since: Posts: Comments:

AMZ089-120930-
SYNOPSIS FOR CARIBBEAN SEA AND TROPICAL N ATLC FROM 07N TO 22N
BETWEEN 55W AND 65W
1030 PM EST THU NOV 11 2010

.SYNOPSIS...STATIONARY FRONT FROM 22N59W TO 18N64W. MODERATE TO
FRESH TRADE WINDS EXPECTED OVER MOST OF THE CARIBBEAN THROUGH FRI
NIGHT...HIGHEST IN WINDWARD AND MONA PASSAGES. BROAD AREA OF LOW
PRES EXPECTED TO DEVELOP OVER THE SW CARIBBEAN THIS WEEKEND.


....as per model in post 366
Member Since: Posts: Comments:
In Puerto Rico the pouring rainfall hasn't stop since yesterday early morning, severals streets are flooded and there's severals mudslides, BTW, I was almost dragged by a huge corrent!!! I'm a survival!! :)
What is causing all this mess?
Member Since: Posts: Comments:
11/15/2010 NAM 84 hrs

Member Since: August 2, 2010 Posts: 21 Comments: 9882

Viewing: 422 - 372

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13Blog Index

Top of Page

About

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

Local Weather

Overcast
30 °F
Overcast

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron