Why no hurricanes for Puerto Rico this year?

By: Dr. Jeff Masters , 3:06 PM GMT on December 12, 2005

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A brief update on the tropics today:

A strong extratropical low pressure system (993 mb) is just south of the Azores Islands today, in the far eastern Atlantic. This storm is generating winds of 40-45 mph, and has the potential to make the transition to a tropical storm later in the week as it moves slowly westward. Water temperatures beneath it are 21-22C and wind shear is a low 5-10 knots. However, strong wind shear associated with an appraoching trough is expected to impact the storm on Wednesday, which may not leave it enough time to make the transition to Tropical Storm Zeta.

Why no hurricanes for Puerto Rico this year?

I've plotted an image (Figure 1) showing every stretch of Atlantic coast placed under a hurricane or tropical storm warning during the Hurricane Season of 2005. The phenomenal number of landfalling storms in 2005 led to warnings being hoisted for the entire Atlantic coast from Plymouth Massachusetts southwards to Costa Rica. A small section of Guatemala and Honduras escaped warnings, but nonetheless received damage from heavy rains from at least one tropical storm. Most of the Caribbean islands also suffered blows from at least one hurricane, with the notable exception of the area around Puerto Rico--the northeastern Caribbean
--where no storms occurred. Why did this region escape the wrath of the Hurricane Season of 2005?


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

One obvious possibility is that wind shear levels in the northeast Caribbean happened to be higher than average. This is the theory advanced by Dr. Bill Gray of Colorado State University in his summary of the 2005 hurricane season. However, when one plots the average wind shear over the various portions of the Atlantic for 2005 (Figure 2), only the western Caribbean shows near average levels of wind shear. The ocean areas on either side of Puerto Rico--the eastern Caribbean and the tropical Atlantic--both show below-average levels of wind shear.


Figure 2. Historical average wind shear levels (black lines) and observed wind shear for the 2005 hurricane season (blue lines). The Gulf of Mexico, eastern Caribbean, and tropical Atlantic all had wind shear levels well below average for much of the 2005 hurricane season.

Another possibility is that large amounts of African dust inhibited tropical storm formation in the northeast Caribbean. This is likely a significant factor, since many large clouds of African dust tended to push across the Atlantic and into the northeast Caribbean between late July and early September of 2005, the prime part of hurricane season for this region. I can recall in particular that the dry air associated with Tropical Depression Ten helped kill this storm as it approached the northeast Caribbean in mid-August. Unfortunately, the dry air diluted enough by the time it reached the Bahamas that Hurricane Katrina was able to form from the remnants of Tropical Depression Ten.


Figure 2. Visible satellite image of one of the many clouds of African dust that crossed the Atlantic during the Summer of 2005.

Jeff Masters

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194. TampaSteve
6:22 PM GMT on December 15, 2005
SemperScopusPrimus wrote:

"The denser a gas, the lower the (perceived) temperature."

Actually, temperature, including perceived temperature, of a gas is relative to the level of molecular motion in that gas, not its density. While it's true that as you cool a gas, it becomes more dense, the density is not what makes it feel cooler. You have cause and effect reversed.
193. TampaSteve
6:16 PM GMT on December 15, 2005
BTW, Colby...thanks for posting...you saved me quite a bit of typing. Folks, this is a WEATHER blog...there are plenty of other forums on which to discuss politics. HINT.
192. TampaSteve
6:14 PM GMT on December 15, 2005
Fshhead wrote:

"personally I think the oil acts like a lubricant for all the shifting plates in the world.... hmmmm seems like they just had some bad ones over in the East!"

Either you are joking or you are ignorant of basic geology. Oil is contained entirely within the plates of the crust, far from the interface between the crust and the liquid mantle, on which the plates ride.
191. Trouper415
1:40 AM GMT on December 14, 2005
Someone who is advocating that our c02 emmisions over the last couple centuries have 'delayed an ice age, please answer this.

If Ice Ages are indeed caused by the Earth tilting on its axis so the northern latitudes tern darker and thus colder. Then how is our stopping of c02 emmissions going to keep us from having all these wacky and zany weather patterns occuring, followed by an ice age? For if we dont cause ice ages in the first place? whats it going to do to stop as much c02 emmision as possible? As the earth cooled back down, since we are 'in an ice age already,' wouldnt that send us into one faster? Seems like that wouldnt solve the problem. Fact of the matter is, humans cannot cause an ice age because they dont occur based on c02 emmisions, they occur because of the cyclical tilt in the earths axis every 40000 years or so.

I dont come here to say we shouldnt conserve our natural resouces. Pollution in many parts of the world are horrid and our ecological systems are a wreck. I will continue to educate the importance of using alternitive types of energy, beucause we gotta make a transition sometime. My geology teacher, who I respect very much, estimates that we will be out of oil by 2065. You guys heard any other guesses?

BB73
Member Since: September 22, 2005 Posts: 5 Comments: 639
190. Trouper415
1:27 AM GMT on December 14, 2005
HENSCOLASC, notice how i said super volcano. The average volcano, while we are talking about them, release c02 that warms the earth. probably .001 of all volcanic eruptions 'cool' the earth.
Member Since: September 22, 2005 Posts: 5 Comments: 639
189. HENSCOLASC
4:33 PM GMT on December 13, 2005
Trouper - your comment on volcanoes was interesting. There have been documented cases where a severe volcanic eruption has altered the earth's climate. If I remember correctly, sometime in the 1800's a massive volcano erupted that sent volcanic ash high into the atmosphere so that it was able to circle the earth. Weather observations were able to determine that for 1 to 2 years, the earth's climate was significantly cooler. If you do a google search on "the year without a summer", that should provide you with more information. In short, while man can make a very small impact on the earth's climate. It's mother nature herself that can drastically change the climate any time she wants, and there's nothing that man can do about it.
Member Since: August 27, 2005 Posts: 12 Comments: 146
188. Trouper415
3:22 PM GMT on December 13, 2005
You guys gotta realize we as humans are not able to have a catastrophic impact on this earth unless it was detonating lots and lots of hydrogen bombs or something idiotic like that. I believe we may be warming the planet just a little, causing a slight rise in temperatures around the globe. However, this global warming is not going to have catastrophic impacts if we dont do anything about it. The real 'catastrophic' event as you call it will happen when the northern latitudes become much darker as the earth turns fully on its axis. Until then we're fine, although pollution is going to be bad in the future hehe.
Member Since: September 22, 2005 Posts: 5 Comments: 639
187. Trouper415
3:18 PM GMT on December 13, 2005
Colby great points
Member Since: September 22, 2005 Posts: 5 Comments: 639
186. Trouper415
3:14 PM GMT on December 13, 2005
"volcanoes cool by releasing all the ash into the atmosphere which forms shade, which cools"
I believe this is not true. That would be similar to saying something like the higher in elevation you go the hotter it gets becuase you are getitng closer to the sun. Maybe only a super volvano would have this ash colling effect, however a normal volcano continuously producing c02 would have a larger warming effect on the earth not cooling.
Member Since: September 22, 2005 Posts: 5 Comments: 639
185. AySz88
1:47 PM GMT on December 13, 2005
On the contrary, I'm pretty sure the scientific consensus (in the "lack of substantial doubt in the majority of scientists" sense) is that much of global warming is human-induced. http://en.wikipedia.org/wiki/Scientific_opinion_on_climate_change
Member Since: August 25, 2005 Posts: 0 Comments: 8
184. seflagamma
1:41 PM GMT on December 13, 2005
Good morning,

Haven't posted in a while here but do keep up a little. See we had a mostly one man show last night on "global warming"... Interesting the scientist have been telling us for 10 year (1995) we are once again in a very active stage like the the turn of the century, the 1920's and the 50-60's...that this active hurricane season is just the natural cycle of things.
We had really active seasons in the past that lasted for decades. We don't even know for sure if some of them were even worse than this year because we lacked the science we have today.
Just my opinion.

This morning in SE Florida, Broward County, we have beautiful Sunny skies but a little too cool for most of us.
Had to turn heater on this morning to knock the chill out of the house! But remember, we consider the temps in the 50s as very cold!
Got to go for now, will check back later.
Have a good day.
Gamma
Member Since: August 29, 2005 Posts: 303 Comments: 40968
183. lobcarl
1:12 PM GMT on December 13, 2005
Where is this global warming. Snowing hard here and 18 degrees. Got to go and throw off 50 lobster traps onto my wharf. The fun never ends.
182. ForecasterColby
12:23 PM GMT on December 13, 2005
Okay, one more thing:

"Overwhelming majority of scientists agree..."

I laughed at that. I know quite a few, and though some will agree that we are PARTLY responsible, they also agree that this is mostly a natural cycle.

"oceans turning to acid"

......Okay, this is BEYOND ridiculous. Find me a scientific explanation for this and I'll rip it to shreds.
181. ForecasterColby
12:21 PM GMT on December 13, 2005
Fshhead...

If you'd like to get in line with "the rest of the world", let's set up a dictatorship where you're executed for disagreeing with current administration.

All the climatological evidence shows an unusually quiet period for the past 10-11 thousand years. We've had very little temperature variance since the last Ice Age, and now we're going back to the normal. Bad as this year's hurricanes were, they could've been twice as bad (which is about as bad as it's possible to get) and they STILL wouldn't be a significant threat to the human race. COMBINED, every storm this year killed 4-5 thousand people. The tsunami (please explain how global warming caused this one) killed, what, 200,000+? The quake in Pakistan? Heck, given your likely liberal political views, the war in Iraq has killed many more if you count insurgents.

Remember, this planet has it's own systems to moderate temperature. The hurricanes this year cooled the waters significantly, converting heat energy to motion.The arctic ice IS a heat-sink, and it's taking a MASSIVE amount of heat to melt that ice, again moderating our climate. Fossil fuels aren't going away anytime soon. If you want to live in a country under Kyoto, I'll see you in China.

This is all I will say on the matter. Stop spamming the blog with articles which all say the same thing, unless you would like me to spam just as many denying human causes as part of global warming.
180. Fshhead
11:38 AM GMT on December 13, 2005
oh!!! dont forget gang.... please stop by my blog & post comments on the global warming issue. Wether u agree with me or not!!!!!! Like I said maybe u can change my mind......but doubtful!!!!
Member Since: November 19, 2005 Posts: 9 Comments: 9960
179. Fshhead
11:35 AM GMT on December 13, 2005
later semper think im gonna hit it too very late here. lookin forward to talkin to ya more!!!!!!!!
Member Since: November 19, 2005 Posts: 9 Comments: 9960
178. Fshhead
11:34 AM GMT on December 13, 2005
The award winning environmental writer Geoffrey Lean wrote: “Future historians, looking back from a much hotter and less hospitable world . . . will puzzle over how a whole generation could have sleepwalked into disaster -- destroying the climate that has allowed human civilization to flourish over the past 11,000 years.”

The overwhelming majority of scientists and international climate monitoring bodies now agree that climate change is taking place, that humans are responsible, and that time is running out. In fact, we could reach “the point of no return” in a decade, reported Lean
Member Since: November 19, 2005 Posts: 9 Comments: 9960
177. Fshhead
11:32 AM GMT on December 13, 2005
This headline appeared in the London Independent in early February of 2005, following a conference at the Hadley Centre in Exeter, England, where 200 of the world’s leading scientists issued the most urgent warning to date: that dangerous climate change is taking place today, and not the day after tomorrow.

Floods, storms, and droughts. Melting polar ice, shrinking glaciers, oceans turning to acid. Scientists from the fields of glaciology, biology, meteorology, oceanography, and ecology reported seeing a dramatic rise over the last 50 years of all the indicators of climate change: increase in average world temperatures, extreme weather events, in the levels of CO2 and other greenhouse gases, and in the level of the oceans.

The award winning environmental writer Geoffrey Lean wrote: “Future historians, looking back from a much hotter and less hospitable world . . . will puzzle over how a whole generation could have sleepwalked into disaster -- destroying the climate that has allowed human civilization to flourish over the past 11,000 years.”

The overwhelming majority of scientists and international climate monitoring bodies now agree that climate change is taking place, that humans are responsible, and that time is running out. In fact, we could reach “the point of no return” in a decade, reported Lean.
Member Since: November 19, 2005 Posts: 9 Comments: 9960
176. SemperScopusPrimus
11:32 AM GMT on December 13, 2005
Well, I think I'm going to call it a night. Had a long day yesterday, and I need some sleep. Good talking with you, and perhaps I will 'blog' with you later.
Good night.
175. Fshhead
11:30 AM GMT on December 13, 2005
yea semper alot of ancient civilizations believed this. Funny we are supposed to be so advanced but we forget all that stuff
Member Since: November 19, 2005 Posts: 9 Comments: 9960
174. SemperScopusPrimus
11:30 AM GMT on December 13, 2005
They believed in the harmony between man and their environment, much like the native americans of north and south america did, and still do today.
173. SemperScopusPrimus
11:27 AM GMT on December 13, 2005
Ancient European civilizations did also. They worship Gaeus and Gaea (I think I speeled them right). Gaea was what we now call 'Mother Earth.'
172. Fshhead
11:27 AM GMT on December 13, 2005
Semper, gotta say ur friend deserves a pat on the back for that. We gotta start somewhere!!
Member Since: November 19, 2005 Posts: 9 Comments: 9960
171. Fshhead
11:25 AM GMT on December 13, 2005
I wish alot of what they believed would rub off on us
Member Since: November 19, 2005 Posts: 9 Comments: 9960
170. SemperScopusPrimus
11:25 AM GMT on December 13, 2005
We all seem (in the US anyway) to depend on that delivery truck at the grocery store to arrive on time. My friend doesn't depend on a car to get to work anymore. He told me that when the gas prices hit $2 a gallon, he was going to start riding a bike, and he did. That's at least a start.
169. Fshhead
11:23 AM GMT on December 13, 2005
American indians were very in tune with the Earth, they had the right idea for sure
Member Since: November 19, 2005 Posts: 9 Comments: 9960
168. Fshhead
11:22 AM GMT on December 13, 2005
one thing the ancient civilizations were very intelligent about.... The fact of we have to live in HARMONY with the planet not trash it & deplete all the resources!!!!!!!!!!!!!!
Member Since: November 19, 2005 Posts: 9 Comments: 9960
167. SemperScopusPrimus
11:22 AM GMT on December 13, 2005
There's always the mountains. . .fresh water, food, and the materials needed for a shelter. We just have to learn to be self-sufficient again. We have kinda forgot how to fend for ourselves in the last couple thousand years.
166. Fshhead
11:19 AM GMT on December 13, 2005
thats what I'm saying semper, I have knowledge of engines also..... I keep tellin people that fact all the time... I get blank stares in return... like no way thats gonna happen.... well I guess we gonna find out cause we are ravenous for oil & our thirst just gettin worse!!!!!!!!!!!!!!!!
Member Since: November 19, 2005 Posts: 9 Comments: 9960
165. globalize
11:19 AM GMT on December 13, 2005
Semper- true. And catastrophic failure is really what is needed for the good of the whole. But I'm worried because I don't have a fortified cave with losts of provisions to hide in with my family!
Member Since: August 30, 2005 Posts: 0 Comments: 1150
164. SemperScopusPrimus
11:16 AM GMT on December 13, 2005
Well, what happens to an engine when it runs out of oil??? It seizes up. But that's not all folks. When the engine seizes up, the other parts of the engine (piston rods, crank, etc) still want to keep moving, as well as the parts that still have some oil. So what happens, you might ask? Catastrophic failure. A piston rod snaps and shoots out the side of the engine because of a sudden release of energy. Now, if the plates are lubricated with the oil we pump out, what happens when the lubrication is gone? 10.2
163. globalize
11:15 AM GMT on December 13, 2005
The movement in this country is world corporate globalization of everything from banks to hamburger joints. Nearly every soul, from the truck driver to the office worker serves that movement. Now what does that have to do with environmental conscientousness?
Member Since: August 30, 2005 Posts: 0 Comments: 1150
162. Fshhead
11:14 AM GMT on December 13, 2005
grrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
Member Since: November 19, 2005 Posts: 9 Comments: 9960
161. Fshhead
11:14 AM GMT on December 13, 2005
& these people have huge families & they are settin them up for disaester. I dont have kids & I seem more concerned than they are!! all for a buck!!!!!!!!!!!!!!!!!!!!!!
Member Since: November 19, 2005 Posts: 9 Comments: 9960
160. Fshhead
11:12 AM GMT on December 13, 2005
See.... thats the part that burns my butt, all of this because of greed & money!!!!!!!!!!!
Member Since: November 19, 2005 Posts: 9 Comments: 9960
159. SemperScopusPrimus
11:11 AM GMT on December 13, 2005
They just don't want to (the oil tycoons, that is). It would hurt Profits.
158. Fshhead
11:10 AM GMT on December 13, 2005
personally I think the oil acts like a lubricant for all the shifting plates in the world.... hmmmm seems like they just had some bad ones over in the East!
Member Since: November 19, 2005 Posts: 9 Comments: 9960
157. Fshhead
11:08 AM GMT on December 13, 2005
YES!!!!!!!!!!!!!! u cannot tell me if this country put it's mind to it that they could not come up with better advances on the solar front
Member Since: November 19, 2005 Posts: 9 Comments: 9960
156. SemperScopusPrimus
11:07 AM GMT on December 13, 2005
I think the oil pressure downthere is partially reponsible for holding parts of up here up. If we remove it, we may fall down.
155. Fshhead
11:06 AM GMT on December 13, 2005
gonna jump on my box again......
I cannot believe that this country thinks that going to alternative energy is gonna cripple this economy. It would only strenghten it when we become the forfront on all this technology & in turn sell it to the rest of the world. We could also possibly start changing the way the world views the U.S. these days. You know kinda embracing kyoto treaty instead of shunnin it.considering we are the worlds worst polluters!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Member Since: November 19, 2005 Posts: 9 Comments: 9960
154. SemperScopusPrimus
11:04 AM GMT on December 13, 2005
The technology for solar cells is still in its infancy. They are, what, 12% efficient??? The new carbon nanotubes do offer some hope. They recently found that if you putwires or something at the bottom of these tubes, they will collect electromagnetic (radio) waves. Well, visible light, infrared & UV, are all electromagnetic waves. Why can't they use those for solar cells???
153. Fshhead
11:01 AM GMT on December 13, 2005
claap clap clap agreed semper & by the way we will run out of oil... noone thinkin of the consequences on the planet when that happens.... pretty sure it serves some purpose down there!!!!!!!!!!!!!!!
Member Since: November 19, 2005 Posts: 9 Comments: 9960
152. globalize
11:00 AM GMT on December 13, 2005
Our understanding of temperature is relative to friction of heat. The movement of atoms defines heat, but the lack of heat is also defined as heat. Example, move around some freon atoms. The 'higher' science of slowing the movement of atoms is really less important than the world relative to 98.6 degrees of Fahrenheit temperature.
Member Since: August 30, 2005 Posts: 0 Comments: 1150
151. SemperScopusPrimus
11:00 AM GMT on December 13, 2005
When we humans do something, we do it all the way, or not at all!
150. Fshhead
10:59 AM GMT on December 13, 2005
personally I think we should be capitalizing on the solar energ, since there seems to be such an abundance of it these daysLOL (ozone depletion!)
Member Since: November 19, 2005 Posts: 9 Comments: 9960
149. SemperScopusPrimus
10:58 AM GMT on December 13, 2005
Well, when we run out of oil, we can resort to wood burning, steam powered engines again. Not only will we deplete the oil reserves and cause global warming, but we will also destroy the one thing that might get us out of this mess; the forests.
148. Fshhead
10:57 AM GMT on December 13, 2005
yea ethanol made from corn & husk matter. Seems to me if we were growing our fuel & at the same time putting more plants on the planet we would be better off!!!!!!!!!!
Member Since: November 19, 2005 Posts: 9 Comments: 9960
147. Fshhead
10:56 AM GMT on December 13, 2005
lol you know when I was a little kid..... we were supposed to be in flying cars & all that stuff... Man, we still using coal & oil to run our transportation. We are a long long way from flying cars LOL
Member Since: November 19, 2005 Posts: 9 Comments: 9960
146. SemperScopusPrimus
10:55 AM GMT on December 13, 2005
Fshhead.. . I beleive it is made from corn and husks, but I'm not sure at 3 am :)
145. Fshhead
10:54 AM GMT on December 13, 2005
Hmmmm seems to me that isn't ethanol made out of plant waste????? Would at least be the 1st steppin stone!
Member Since: November 19, 2005 Posts: 9 Comments: 9960
144. SemperScopusPrimus
10:53 AM GMT on December 13, 2005
While we're at it, why don't we get rid of anything that uses COAL. Aren't we just a little beyond that, technilogically???

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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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