Hurricane and Tropical cyclone formation in the GOM is RARE

[Derecho]

I think people are frankly going to be surprised by these numbers, particularly those given to turning every cloud over the GOM into a storm...

Note this is stuff that forms WITHIN THE GOM...not systems that are already TCs and ENTER the GOM.

Overwhelmingly, the vast majority of the destructive GOM storms are systems that entered it from the Carribean or Atlantic.

1900-2000...formation in the GOM:

2 Cat 5s

2 Cat 4s

1 Cat 3

2 Cat 2

21 Cat 1.....28 total hurricanes...


That's one major hurricane every TWENTY FIVE years forming in the GOM; and a hurricane forming in the GOM a little less than every FOUR years.

Total TS: 46

So that's a total of 74 total systems of TS strength or higher forming in the GOM over a 100 year period...less than one a year on average.

I have a feeling most people would have expected 3-4 TSes to form in the GOM yearly on average.

Again, and remember, this is stuff FORMING in the GOM, not stuff entering the GOM already formed from somewhere else.

[Stormcenter]

I'm curious to know how many named systems have formed in the GOM in the last 5 years? It just seems like we've had more develop in the GOM in recent years. Thanks!

[rbaker]

the gom has produced alot of tropical storms, but as the first person said alot of tds or ts that form originate from the caribbean or atlantic. They may form into a 4 or 5 (Camille) when they get into the gulf but they were already something else when they formed. Tds and ts are another story, most of the time when they form in the gom they do not have the time to form into something more, because they hit land.

[ncweatherwizard]

I'm curious to know how many named systems have formed in the GOM in the last 5 years? It just seems like we've had more develop in the GOM in recent years. Thanks!

Well rather well formed or not (most were not), here's a simple list of the storms for which a first advisory was issued when in the GOM since 1999.

99 Maj. Hurr. Bret
00 TS Beryl
00 TS Harvey
01 TS Allison
01 TS Barry
01 TS Gabrielle
02 TS Hanna
02 TS Fay
02 TS Bertha
03 TS Bill
03 Hurr. Erika
03 TS Grace
03 TS Henri
03 TS Larry

That's what I've got in my books, but I should probably go back and confirm all that.

Now for five years that's one major hurricane (which, statistically, could have just been the one in those 25 years, so you can't say one in 5 years of course), 2 hurricanes, or 1 every 2.5 years, and 14 named storms, or 2.8 named storms per year.

So yes, recently, there's been more named "crap" than the usual number of named storms forming in GOM, but quite reasonably, you need to include more years to get the big picture.

[Stormcenter]

[
99 Maj. Hurr. Bret
00 TS Beryl
00 TS Harvey
01 TS Allison
01 TS Barry
01 TS Gabrielle
02 TS Hanna
02 TS Fay
02 TS Bertha
03 TS Bill
03 Hurr. Erika
03 TS Grace
03 TS Henri
03 TS Larry

That's what I've got in my books, but I should probably go back and confirm all that.

Now for five years that's one major hurricane (which, statistically, could have just been the one in those 25 years, so you can't say one in 5 years of course), 2 hurricanes, or 1 every 2.5 years, and 14 named storms, or 2.8 named storms per year.

So yes, recently, there's been more named "crap" than the usual number of named storms forming in GOM, but quite reasonably, you need to include more years to get the big picture.[/quote]

Thanks for the info!

[HurricaneGirl]

Interesting Stuff!

[GalvestonDuck]

One word -- Allison

[Windspeed]

Note this is stuff that forms WITHIN THE GOM...not systems that are already TCs and ENTER the GOM.

Overwhelmingly, the vast majority of the destructive GOM storms are systems that entered it from the Carribean or Atlantic.

1900-2000...formation in the GOM:

2 Cat 5s

2 Cat 4s

1 Cat 3

2 Cat 2

21 Cat 1.....28 total hurricanes...

The explanation for this data is quite logical. Basically, there are two important concepts that should be considered: 1) the GOM's physiography, and 2) the initial development and intensification of LLCs.

Though the GOM contains some of the warmest SSTs in the Atlantic basin from mid-summer to early fall, there simply is not that much oceanic realistate compared to the rest of the Atlantic Basin. Its total area is approximately 1,812,990 sq km in area. It covers 1,770 km at its widest margins north and south, likewise 1,287 km from east to west. This compared to the rest of the tropical regions of the Atlantic Basin that consists of over 21,610,880 sq km of open ocean. Also, the location of the GOM with respect to North American Continent heavily influences the upper air environment over the Gulf. And essentially, continentality can be as much as an inhibitor to tropical cyclone development as an inducer with respect to the Jet Stream, dry air, short/long wave troughs--all contributing to either sheer, suppression, or both.

The statistical data posted by Derecho also shows that most of the major hurricanes that occur in the GOM were already well-developed LLCs (i.e. depressions, tropical storms, or hurricanes) before their presence there. Simply put, LLCs take time to develop from any disturbance, albeit convective plumes or tropical waves; and when you only have so much realistate to begin with, LLCs that form within the GOM are going to have less time to develop before interacting with land. Unfortunately, I don't have the time to research how much the warmer SSTs of the GOM work to counter physiographic inhibitors of development, but I suspect that it would not be too great. If I find some time in the future, I may try to do this myself or look to see if someone else already has obtained such data.

Considering what we know about the initial development of LLCs, if they get their act together relatively quickly and have the right atmospheric environments, they have the potential to intensify extremely fast in the Gulf because it is so warm. Again, it is the innitial developmental characteristics of those LLCs that are so vital. Sometimes they just take longer to form depending on the responsible disturbances. Obviously, if we already have a well defined LLC with convection that moves into the GOM, then initial development has already occurred; and therefore, as the statistics show above, hurricane and major hurricane formation is much more probable.

[HURAKAN]

It doesn't surprise me at all, the Gulf of Mexico although it's a hot spot for hurricane activity, very hot water and full of moisture, but the size doesn't help, storms would need t move very slowly or move from east to west or vice-versa to reach their full strength. Remember that most of the tropical system that affect the Gulf Coast don't form in the Gulf of Mexico but the Caribbean Sea or the Atlantic Ocean.

[corpusbreeze]

1983 Cat 3 Hurricane Alicia.

[HURAKAN]

1983 Cat 3 Hurricane Alicia.

Alicia developed extremely quickly, which makes me believe the environment surrounding the system must have been very favorable for development, not all systems have such a good luck as Alicia had.

[corpusbreeze]

I know, I went through that storm living in Baytown. Nobody was prepared because first it was not suppose to hit us, and second it was suppose to be a small cat1 storm. Surprise! It was a very long night listening to our roof being ripped off.

[HurricaneBill]

Hurricane Anita 1977

[bahamaswx]

Roof ripped off in only a cat3?

[The Dark Knight]

Hmmmmmmmm..........

[Windspeed]

Hurricane Anita 1977

Anita is certainly one of the two catagory five hurricanes to completely form within GOM:

"The origins of Anita have been traced to a tropical wave that moved off the African coast on 16 August 1977 ... the system spread across the Bahamas on 25 and 26 August and over Florida and western Cuba on the 27th ... on 28 August the system shifted into the eastern Gulf of Mexico ... a tropical depression formed in the east central Gulf of Mexico on 29 August" -Monthly Weather Review, NOAA/NHC

Does anybody know when the other Cat 5 occurred?

I remember that Opal nearly reached Cat 5 status during it's eyewall contraction on October 4th, but the central pressure came up just as fast as it bottomed out. So even though the pressure fell as low as 916mb, it rebounded too quickly before the sustained winds had time to match it.

[corpusbreeze]

At the time my family and I lived on a second story apartment, and yes our roof was being ripped off. We found out the next day the unit roof next to ours collapsed. Lucky for our neighbors they were in Florida on vacation. I was 16 and was hired by the complex for 2 weeks to remove wet carpet through out the complex. Alicia was a nasty storm.

[Derek Ortt]

Of note though is the increased activity since 1993. Since then, we've had the following storms form in the GOM: Arlene, Beryl, Dean, Gabrielle, Josephine, Danny, Charley, Frances, Hermine, Harvey, Beryl, Allison, Barry, Gabrielle, Bertha, Fay, Hanna, Grace, Henri for a total of 19 in the last 10 years. Of these, only 1997 Danny and 2001 Gabrielle became a hurricane, and it didnt become a cane unitl it left the GOM. It should be noted that I didnt include Bret and Bill as they formed over the Yucatan and techincally in the GOM