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No Zeta: Hurricane Season is over

By: Dr. Jeff Masters, 2:37 PM GMT on December 13, 2005

The strong extratropical low pressure system southwest of the Azores Islands is showing no signs of tropical development today. The amount of deep convection near the low's center has decreased since yesterday, and with wind shear values of 20 knots overhead and steadily increasing, this storm has no chance to develop into Tropical Storm Zeta. The low will get absorbed into an approaching cold front on Wednesday and rapidly dissipate.

Elsewhere in the tropical Atlantic, wind shear levels are very high and expected to remain high for at least the next week, making tropical storm formation very unlikely. Long range models show a weak extratropical low developing near the Canary Islands late in the week, but wind shear is expected to be too strong to allow this low to develop into a tropical storm. I can now confidently predict that the end of the Hurricane Season of 2005 has arrived! Look for my next update on the tropics at the beginning of next year's hurricane season, on June 1. My blog until then will primarily focus on climate change, reviewing the Hurricane Season of 2005, and other topics of interest.

Figure 1. Map of all coastal areas subjected to hurricanes warnings (red) and tropical storm warnings (yellow) during the Hurricane Season of 2005.

Jeff Masters

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

I won't hold my breath, but maybe we can say that the 2005 hurricane season is over. Dr. Masters I am really looking forward to your review of the season because I imagine there is lots of interesting stuff buried in all the data that nobody has had time to look back at. I wonder how many Ph.D. disertations will come out of this year.
many, Thanks Dr. Masters, Will keep on reading
Good morning Dr. Masters,

Great post as usual.:) Thanks again for all you've done this season and continue to do as well.:)

Hey everyone,

I thought I would simply add that above normal sea surface temperatures like those that helped intensify so many storms this season by itself cannot breed tropical cyclone develpment. Although it is an essential ingredient for formation, so are low upper level winds above the system.

For the most part, they need to both be present for any tropical cyclone development to truly take place. Although there will no doubt be an occasional exception to almost every rule, this is about as solid as tropcal meteorology gets at this time.

For example, the 1997 Atlantic hurricane season had all the necessary parameters such as well above normal sea surface temperatures and the current multidecadal cycle in place, yet it was the ONLY below normal hurricane season in the Atlantic during this period (since 1995). I believe it was 2000 if I'm mistaken that was the season of near normal activity. The rest of this period has been above normal while even others have seen very hyperactive seasons, historically speaking.


I will keep this very short. The upper level winds that blow acroos the entire Atlantic Basin from the west to the east in contrast to the tropical waves that form off of the coast of Africa that generally move east to west were very strong and thus precluded too much tropical cyclone formation during this one season. These hostile upper level atmospheric conditions were a direct result of the infamous El Nino phase of the ENSO cycle. During the typical El Nino phase, the warming of the waters just off Peru causes a dramatic change in the upper level atmospheric conditions that have major global impacts as well as creating very strong and hostile upper level winds that serve to decapitate the tops of any thunderstorm development that tries to solidify with a tropical wave during this type of season.

It is interesting and important to note that the following year of 1998 saw an immediate reversal of this trend as that season had well above normal tropical cyclone development as a result of the ENSO phase switching to the La Nina phase which originates as a result of a cooling of the same waters off Peru which has the opposite effect on upper level winds across the entire Atlantic Basin. In these La Nina seasons which could aso be a possibilty for the next hurricane season, it is characterized by below normal upper level wind shear which in association with the above normal sea surface temperatures favor increased tropical cyclone development.

There are a few other important atmospheric factors as well that come into play, but each of them directly affects these two vastly important components of tropical cyclone formation. This season was in what is called a neutral ENSO cycle which basically means a relatively average level of wind shear for the Atlantic Basin more or less throughout the season. Just imagine if the La Nina phase was in place for this remarkable season.

My central point is to highlight why Dr. Masters, myself and others don't expect further tropical cyclone development because the upper level wind shear is increasing and will continue to do so as we get further into a winter type atmospheric pattern. This is why we SHOULDN'T see anymore tropical cyclone development despite sea surface temperatures in some portions of the Atlantic Basin that could realistically support such development otherwise (especially in the short term).

I only mention this to give a little background information since so many seem to wonder whether this hurricane season will actually end before the next one begins. This doesn't mean that we couldn't see another tropical storm Ana development as occured in April of 2003 which became the first ever to do so in April in over 150 years of record keeping. However, such development would be more of an anamoly than something to expect. It is far more likely that there will be no further tropical cyclone development until the beginning of next hurricane season which begins on June 1, 2006.

However, I must put out this disclaimer(LOL)... if it has happened before, it can certainly happen again as Ana serves as a prime example. On the other hand, it is most unlikely at best.

ok... I am off to work.:) I hope everyone has a wonderful day and enjoys the great conversation and fellowship that this great community provides.:)

Your friend,
I am glad that the Hurricane season is finally over. I don't think we need to set anymore records. Thanks a lot for your work, Dr. Masters.

Thanks for all the info! Will keep checking in!
YAY for the hoped-for alleged end of the 2005 hurricane season. May it FINALLY be over, is that TOO MUCH to hope for?
Dr Masters. Thanks for another great update. Sure hope we are done for the year and get a few months off!
I will also keep checking in and out during the winter to see what else you have to say and see what our bloggers are up to!

Merry Christmas and Happy New Year to you all!
.... that is ... unless something unexpected happens ....

Like a storm in january O.o

...so scary ....
wow... excellent posts there Dr. Jeff and hurricanechaser! thanks.

And hey, the looooog season is over!!!! ding-dong, the wicked season of 2005 is dead! Break out the champagne and everyone heave a big sigh of relief and celebrate the fact that we're alive to enjoy another Christmas season with family and friends..
The SST anomalies have been on a downward trend for the past 3 months or so, and are slowing down. Perhaps more madness next year? Stay tuned.
lets prepare for next year
let's celebrate the end of this nasty year as well..
Great read there hurricanechaser. This year I would beleave we are in a weak La Nina. With the way the fall has been here in Southern California. There has been a pesky high pressure over the Great Basin that has keeped the Santa Ana Winds over the area with a dry warm flow. In return the jet stream has been far to the north up near Washington and Oregon they have been slammed with several winter like storms early in the season.
Let's not give up on Zeta until Dec. 31st. As crazy as things have been this year, I wouldn't rule anything out just yet. We might even see the first-ever named storm forming in January.
any one home?
Well, I like to cry wolf. Their seems to be a couple of pesky lows in the middle of the Atlantic. They seem to be getting ready to marry, and cause trouble.....
melli there is
well.... at least I got a response to all the stuff on warming last nite!!!lol. I have to apoligize to everyone about all the "spamming" that I put in but, there was only 2 people on the site at the time. I realize that some of the stuff I found was rather far-fetched but, also there was alot of fact in there too. I have to say that from what I hear most scientists agree on this issue. There is proof of ice melting, wild weather, etc... Now as far as my "liberal" views being questioned.....I must say that I love this country, that debate is what it was founded on & I am tired of being called unpatriotic & such because my views are different from the "mainstream". Like I said I wanted to have a good discussion on this subject without the anger & such! I appreciate the views from the "other" side & like I said maybe u can change my mind lol.Pleasse stop by my blog & feel free to post both sides of the coin

GOD BLESS THE U.S.A.!!!!!!!!!!!!!!
oh where oh where did ever one go oh where oh where did ever go may be hurricane comes and they went all out to sea oh where oh where are they at lol this kinding on that part there but way where is ever today and tonight
there is a cat 5 hurricane comeing to fl it has winds of 175 and it going to make land fall in fl in a few days has a cat 5 hurricane mb is down to 880mb and winds went up to 185mph lol lol lol lol

and some one is going to kill me for this oops did i say a cat 5 hurricane is comeing to fl hmmm no one his on her tonight lol lol i am safe no you is going to kill me for say that lol lol lol
Hey Zeta, can I ask u a question??? why u always wishing for bad storms?? Just curious.....
Fshhead about time some one come on the blog i new that would work

i do not no i this like hurricane i can not help it

and there is NO cat 5 hurricane comeing to fl
Fshhead and i am not wishing for bad storms for bad storm to hit but we can not tell them what to do now can we
True... but being someone who has been through a cat. 5 storm, I can tell u that is the most scared I've been in my life!!!!lol
lol & yea I know no storms coming cause nowadays I keep close close eye out for storms lol
Fshhead you where in a storm that was a cat 5 hurricane that not good
Gotta say, smaller ones are actually kinda kewl cause they break the heat & cause some excitement. Also to feel the winds. But as far as major storms go..... no thanxlol
Yea went through Andrew..... very scary, u would not believe the winds WOW!!!!!!!
well Fshhead i think we sould get some ZZZZZZZ there is no one on her tonight but you and me
Yea, go to my blog & I got some graphs & stuff that show wind speeds & where it came ashore
Fshhead what where the winds 165 or 175 and how do when a hurricane is going to make land fall
wind speeds in my area before the measuring devices failed were gusts to 140 mph. & u definitely know when the storm is makin landfall.... u hear the winds pick up
wow 140mph wow this like the K storm was it raining too well i got to go get soem zzzzzzzz now but i be back and you got your frist post in your blog
good night Fshhead got to go to bad now so good night
TAKE IT EASY & thanx for the post:)
good night Fshhead and are you going to bad too
Naaaaa I am a nightowl, I work nite so I sleep during the day
Funny I got this off this website!!!!! only "spam" I will post.........

Unfortunately, it appears that we have not learned our lesson from the past 30 years' experience with the ozone-CFC debate. Once again, we find a theory that has wide support in the scientific community being attacked by a handful of skeptics, publishing outside of the peer-reviewed scientific literature, their voices greatly amplified by the public relations machines of powerful corporations and politicians sympathetic to them. And once again, some environmentalists have responded by presenting a distorted or imbalanced version of the facts, often colored by excessive emphasis on the low-probability scenarios of doom, that the popular press is only too eager to repeat, since prophesies of disaster sell. A balanced and truthful treatment of the Global Warming debate that focuses on presenting an unbiased version of our current scientific understanding is difficult to find.
In a 1984 interview in The New Yorker, Rowland concluded, "Nothing will be done about this problem until there is further evidence that a significant loss of ozone has occurred. Unfortunately, this means that if there is a disaster in the making in the stratosphere we are probably not going to avoid it." These prophetic words were proved true the very next year with the discovery of the Antarctic ozone hole. Luckily, it appears that serious damage to the planet was averted with the swift implementation of the Montreal Protocol. Let's hope that it won't take another near-disaster to motivate us to take meaningful action to address the threat of Global Warming
Hmmm & what was that comment about the Kyoto treaty??? lol
K sorry 1 more.... I got this off of this site.......

Skeptics have routinely called global warming "a hoax", and attacked the credibility of scientists promoting the idea. Are the skeptics right? To shed light on the issue, it is helpful to review how the same skeptics treated the ozone hole issue. Read the Weather Underground special feature, The Skeptics vs. The Ozone Hole.

Gotta say I am really, really interested to hear what Dr. Masters has to say in upcoming blogs about this issue........
Remember, it's all Bush's fault...lol...