Brazilian tropical disturbance, and tornado damage surveys

By: Dr. Jeff Masters , 7:23 PM GMT on March 15, 2006

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The season's second South Atlantic tropical/sub-tropical disturbance has formed off of the coast of Brazil today. The disturbance formed from the remains of a cold-core low, which sat over warm waters of 27 degrees C long enough to start acquiring tropical characteristics. We saw this same behavior this past hurricane season with the Greek storms Delta, Epsilon, and Zeta. The disturbance is mostly just a swirl of low clouds, but has seen two bursts of deep convection today. The most recent burst of convection, seen in the satellite photo below, formed in a spiral band well removed from the center. Early this morning, a more impressive burst of deep convection formed near the storm's center, but was quickly ripped away by strong westerly upper-level winds. These strong winds are expected to continue to bring high levels of wind shear over the disturbance over the next few days, and likely keep it from forming into a tropical depression. The system is expected to move slowly southwest, parallel to the Brazilian coast, and get absorbed into a frontal system to the south by Friday. No threat to land is likely, and this storm is mostly just of academic interest.


Figure 1. Tropical/subtropical disturbance off the coast of Brazil. Image credit: NASA Global Hydrology and Climate Center.

So, the academic question to ask is, does this second tropical system of the year off the coast of Brazil show that climate change is affecting the Atlantic? Only one hurricane and two tropical depressions have been observed in the South Atlantic since 1970, when accurate tracking methods became available with the advent of weather satellites. There is usually too much wind shear to allow a tropical cyclone to form, and the South Atlantic lacks an active "Intertropical Convergence Zone" (ITCZ)--that stormy band of weather that stretches along the Equator and acts as a source region for many of the disturbances that grow into Northern Atlantic hurricanes. With Hurricane Catarina of March 2004, another tropical depression in January 2004, a "near miss" tropical cyclone February 24 of this year, and now another tropical or subtropical system trying to form in the South Atlantic today, it is quite possible that climate change might be to blame. It may also be that we are seeing an active period in the South Atlantic that has a long cycle, and last repeated itself before satellites were around. Given the Atlantic Multi-decadal Oscillation (AMO) that affects hurricane activity in the North Atlantic, it is reasonable to think we might see a similar pattern in the South Atlantic.

In either case, I believe is it time that the NHC considered adopting a naming system for the South Atlantic. Had today's system intensified into a tropical storm, it would not have been given a name, since there is no naming system in place for the South Atlantic Ocean. Given the current trends we're seeing, it would be no surprise if we saw more tropical systems here in the next few years.

Tornado damage surveys from the weekend's outbreak
More damage surveys are complete from the weekend's major tornado outbreak, and it now appears that the strongest tornadoes were of F3 intensity on the Fujita scale. There were at least four F3 tornadoes in the outbreak, and these tornadoes had winds in the 158 - 206 mph range (roughly the same winds as found in a Category 5 hurricane). The Springfield, MO NWS office has posted a detailed summary of the the three F3 tornadoes that affected the southwestern portion of Missouri over the weekend, and the Central Illinois NWS office has posted a nice summary of the two F2 tornadoes that slammed Springfield, IL on Sunday, March 12. Included are zoom radar animations of the impressive hook echo, plus many damage photos. Not all the tornado-like damage from the weekend's wild weather was due to tornadoes, though--a storm survey done in along the west side of the Quad City Airport in Moline from Sunday concluded that the damage from a 107 mph wind gust done to homes, trees, and power lines on the west side of the airport was due to a severe thunderstorm downdraft (microburst).

Jeff Masters

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66. hurricanechaser
1:49 AM GMT on March 17, 2006
Hey Inyo,

Thanks for your responses to my posts.:)

"hmm, i dunno if i would say i am a 'big believer; in anthropomorphic warming as the entire cause of global warming.. i think it is part of the cause but i think natural fluxuations are also part of the cause, and i don't pretend to know which factors are the most prevalent."

Just a quick post to clarify that I didn't say either you or Dr. Masters thought it was the entire cause but the direct cause...huge difference there.

Just like I believe Natural Climate variability is the direct cause, but most likely not the entire cause, meaning human activity may and probably has had some minimal effect.

These are simply my opinions at this point based on the current data available.:)

I hope you have a great night.:)

Thanks,
Tony


65. zprime
10:00 PM GMT on March 16, 2006
just to put in my $.02 from springfield MO The damage in town was negligible, mostly from hail (softball sized in places). There were serveral surrounding smaller communities that back in may of '04 were essentially completely destroyed by tornadoes, and sadly those same communities were hit again, basically after they finally finished rebuilding. (Personally I think they need to relocate thier towns becase getting completely destroyed twice indicates to me that your in the wrong place).
64. Inyo
8:17 PM GMT on March 16, 2006
We actually had winds over 60 MPH just a few months ago in Pasadena... few trees blew over. Gusts reached over 100 mph on the ridges, and while some trees did fall due to that, its not like it tore up the whole forest. The high elevation pines are very wind resistant.

you and I both know he is a big believer in anthropomorphic global warming as you are unapologetically as well

hmm, i dunno if i would say i am a 'big believer; in anthropomorphic warming as the entire cause of global warming.. i think it is part of the cause but i think natural fluxuations are also part of the cause, and i don't pretend to know which factors are the most prevalent.
Member Since: September 3, 2002 Posts: 42 Comments: 873
63. Geoman
8:05 PM GMT on March 16, 2006
Yeah, Californians are supposed to have earthquake surivival kits--nowadays you just put everything together in a large Rubbermaid trash-can with wheels and keep it in an accessable corner of the garage. The purchasable kits always show up after a big quake hits a city, but after a few years, people forget. I doubt if most Californians are ready for "The Big One" since it has been 12 years since the last truly damaging quake in a metro area (Northridge 1994). As for a hurricane, I agree with Inyo--earthquake resistant construction will survive Cat-1 strength winds with mostly nonstructural damage. (Keep in mind that high winds of this strength are not unknown in Southern California--Santa Ana winds can get up into the 65-80 mph range.) The rain would cause most of the problems--flooding would take out a good portion of the infrastructure, causing unpredictable damage. Such is life in this world.
Member Since: November 8, 2001 Posts: 65 Comments: 8
62. tigerbait
1:08 PM GMT on March 16, 2006
Again, the South Atlantic Ocean temperature is slightly cooler than normal today, as it also was back in 2004 when the hurricane occurred. See the charts on the NOAA/NESDIS site.

So, how do those events tie to global warming? I'm wondering what the mechanism might be.

61. IKE
11:06 AM GMT on March 16, 2006
77 days until hurricane season 2006 officially begins.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
60. hurricanechaser
10:17 AM GMT on March 16, 2006
Hey Inyo,

I am sorry that I somehow totally messed up that last post with all the bold and italics.

Please understand that my comments are in no way reflective on any problems I have with Dr. Masters and his personal opinions about climate change or anyone elses for that matter. In reality, we all have a fundemental right to our own opinions.

My central premise was comparing tropical cyclone development with true tropical cyclone development which tropical disturbances are not and don't legitimately consitute a real anamoly since there has been one identified hurricane and two tropical depressions observed in the past at a time our technology and most likely interest wasn't as focused on that region.

It was not meant to be a debate about the direct cause of global warming, because none of us truly knows that answer as to how much an effect human activities have or will have on global temperature increases, no matter how much we like to think we do. This applies to everyone of us regardless of our own personal opinions on the direct cause of it.

Thanks,
Tony


59. hurricanechaser
10:07 AM GMT on March 16, 2006
Inyo,

I was specifically referring to other posts here that picked up on Dr. Masters comments and the question he posed regarding the development of South Atlantic tropical disturbances and its correlation to climate change. In your comments you missed the central premise of my posts which I will clarify after posting your comments below.

You said:

"hurricanechaser, i would just like to point out that Dr Masters only said 'climate change' might add to these odd storms, and didnt even mention 'greenhouse warming'. Since we all agree the climate is changing now (as it pretty much always is), and by any standard a fluxuation that lasts 100s of years is a sort of climate change in and of itself, i don't think the statement is invalid even if the cause may not be anthropomorphic."


You left off the most important distinction I made, which is there is nothing "odd" as you put it, about two formations of tropical disturbances, which don't even compare equally with actual tropical cyclones (depressions, storms, and hurricanes) that have actually formed in the past.

Now lets review how he phrased the "climate change" question.

He said:

"it is quite possible that climate change might be to blame."

"It may also be that we are seeing an active period in the South Atlantic that has a long cycle, and last repeated itself before satellites were around."

"Given the Atlantic Multi-decadal Oscillation (AMO) that affects hurricane activity in the North Atlantic, it is reasonable to think we might see a similar pattern in the South Atlantic."em>

Ok, please look at these statements objectively, he is making a distinction between the term "climate change" in the first comment and the Natural climate cycles in the two succeeding ones that he said could "also" be to blame.

Since a Natural climate cycle like the AMO is part of climate change and he is referring to another form of climate change in his comments, what other form of climate change can we presume he is referring to, since you and I both know he is a big believer in anthropomorphic global warming as you are unapologetically as well (which is not something I take issue with for I can respectfully disagree about that, as we all should do on that issue).

Regarding the global warming debate and its correlation with Atlantic Basin activity, there are many proponents of anthropomorphic global warming that say that the increase in our recent activity is due to human induced causes and not the Natural climate variability of the AMO cycles which I support.

Therefore, it seems pretty obvious that one doesn't have to use the term global warming to state the obvious insinuation, when a definite distinction is made between it and natural climate variability.

To be specific, my comments are notto rehash the direct cause of global warming debate, but to suggest everyone legitimately compare the historical record objectively, which hasn't been done by some of the comments that are posted in this blog that preceded my own.

In short, there is nothing unusual about two tropical disturbances being identified in the South Atlantic when in the past we have actually had one hurricane other than the one in 2004 and two real tropical depressions as well.

Consequently, it is safe to say there were most likely many tropical disturbances that formed not in the too distant past that simply went unnoticed because they in itself aren't a big event.

In regards to my view on global warming, please see my two most recent posts in fshheads blog as to "why" I don't feel a need to continue to debate that issue.

Thanks,
Tony


58. Inyo
9:25 AM GMT on March 16, 2006
However over the past few years the Eastern Pacific hurricane season has been less then impressive and this season early indications are that its going to be the same or less overall then last year.

yep, La Nina is bad for the hurricanes. It is very unlikely this year.

ForecasterColby, there is evidence that a full-force hurricane hit San Diego in the 1850s and maybe another one earlier than that. Also a tropical storm hit in the 1930s. Propability alone says a hurricane will hit again in the next 50 to 100 years even if climate does not change at all. However, if the recent upturn in hurricanes is not limited to the North Atlantic/Gulf, it only increases the chances. I still say it will happen, but not during a La Nina year. NY has a much greater chance to get hit this year.

Remember, as this year has shown, hurricanes CAN maintain strength on waters <80 degrees and cover quite a bit of distance before they dissipate if they are moving fast.

Perhaps one day a Cat 1 hurricane will hit southern California. Maybe even a Cat 2 if global warming is stronger than forecast and everything else is just right. But I doubt I will see a major hurricane hit southern California in my lifetime.
major hurricane? very unlikely. However, catergory 1 hurricanes have hit southern California before, and this was long before 'global warming' was even a factor.


Posted By: atmosweather at 4:07 AM GMT on March 16, 2006.
So the same amount of damage as Hurricane Andrew? I think not...


Wind damage would be minor. On the other hand, Florida doesnt have a wall of 7000-10,000 foot mountains behind it to double or even triple the rainfall. 30 inches of rain in a day will mess up any city... and the fact that it would fall on dry soil would probably only make it worse.

Also, LA by nature is not really possible to evacuate...

hurricanechaser, i would just like to point out that Dr Masters only said 'climate change' might add to these odd storms, and didnt even mention 'greenhouse warming'. Since we all agree the climate is changing now (as it pretty much always is), and by any standard a fluxuation that lasts 100s of years is a sort of climate change in and of itself, i don't think the statement is invalid even if the cause may not be anthropomorphic.
Member Since: September 3, 2002 Posts: 42 Comments: 873
57. hurricanechaser
8:32 AM GMT on March 16, 2006
Hey everyone,

I noticed a typo in my previous post, it was a hurricane in the South Atlantic during the 2004 season not 2003.

To further substantiate my previous point in the aforementioned post below.

Dr. Masters stated the following:

"So, the academic question to ask is, does this second tropical system of the year off the coast of Brazil show that climate change is affecting the Atlantic?"

"Only one hurricane and two tropical depressions have been observed in the South Atlantic since 1970, when accurate tracking methods became available with the advent of weather satellites."

To reiterate, there still has not been one tropical cyclone to develop since the one hurricane in 2004, despite the two tropical disturbances noted in Dr. Masters comments.

Once again, a tropical disturbance is not a tropical cyclone.

So, the answer to the question is a respectful "no" in regards to whether the two identified tropical disturbances this year give evidence of climate change based on the current data.

However, if we see real tropical cyclones develop on a consistent basis, then and only then, can one legitimately suggest it to be a result of climate change. Furthermore, if that indeed did occur, the direct cause would still be unknown as to whether it was related to Natural climate cycles or human activities that some would like to think regardless.

I hope everyone has a great weekend.:)

Thanks,
Tony


56. hurricanechaser
8:14 AM GMT on March 16, 2006
Hey everyone,

It is important to recognize that one has to compare apples with apples and not apples and oranges to substantiate a claim.

Specifically, two tropical disturbances identified recently in the South Atlantic doesnot constitute a tropical cyclone which still has not formed this year, despite the two tropical disturbances identified in the South Atlantic that some want to use to support as possiible evidence of global warming.

Think about this objectively, we compare increases in Atlantic hurricane activity based solely upon the actual development of a tropical storm or subtropical one, and not tropical depressions and certainly not the number of tropical disturbances that originate.

So can those who wish to blame every new big snow storm, tornado outbreak, hurricane landfall, UFO in their own backyard, etc. on global warming, please keep things in their proper perspective.

One must realize that we most likely know far less about the immense complexities of our Atmosphere, than we do currently understand, despite how much we in the scientific field or anyone else for that matter, likes to think we do.

My posts in here will be very far and in between but some of these unfounded claims needed to be clarified and kept in their proper perspective. Naturally, I don't expect to change anyones mind who wants to try and support a global warming argument with the aforementioned for they are entitled to their own personal opinions as well.

That being said, the unusual development of a real tropical cyclone in 2003 (hurricane)in the South Atlantic can be accunted for just as easily by what we do not know about that region (i.e. Natural climate cycles like the AMO Dr. Masters mentioned) amongst the prospect others went unnoticed without satewllite detection capability.

Moreover, one unusual event does not legitimately consitute climate change by its very definition.

Thanks,
Tony


55. Skyepony (Mod)
6:28 AM GMT on March 16, 2006
Yeah I know, not real Accurate ~ that was implied with the word GFS. Judging by size & wind speed (some 45 & 50kt vectors on Quikscat a few hours ago) ~ Figured they were near & they were close.
Member Since: August 10, 2005 Posts: 175 Comments: 38212
54. atmosweather
5:40 AM GMT on March 16, 2006
I do see your point, louastu. Besides, San Diego is the 5th biggest city in the U.S.
Member Since: September 24, 2005 Posts: 33 Comments: 9265
53. louastu
4:49 AM GMT on March 16, 2006
I am not sure if they have emergency kits for earthquakes. I never really considered that they might have something like that, as I don't live anywhere near California. I suppose if they do, then they very well could have the supplies they would need. I am not sure that the buildings, even though they are capable of withstanding an earthquake would be able to stand up to a hurricane, which would exert a different type of force on the structure than they are designed for, and last a lot longer. I could be completely wrong, and I hope I never have to find out.
49. Skyepony (Mod)
4:35 AM GMT on March 16, 2006
I'd hope people in California kept some extra batteries food & water around. Is that a part of quake prepareness?
Member Since: August 10, 2005 Posts: 175 Comments: 38212
48. Skyepony (Mod)
4:31 AM GMT on March 16, 2006
Hadn't had much time to look at it, from the GFS it looks to have gotten down to the 970's range, now 980's (flirting with being warm core), forecasted to weaken & move back to symetric cold core.

I never kept or lost my satalite links for watchin storms in that area. Anybody got one?
Member Since: August 10, 2005 Posts: 175 Comments: 38212
47. louastu
4:31 AM GMT on March 16, 2006
I suppose that is true. My point is that a hurricane hitting San Diego would cause far more destruction than a hurricane of the same size and strength hitting Miami. The reason for this is that San Diego is far less prepared for hurricanes. They would probably have a death toll about 2-3 times higher than Miami would, due to structures failing, and panic, which could lead to deadly car accidents, and even heart attacks. After the storm there would be even more deaths do to people not having the supplies they need (partially due to them not knowing what they needed to stock up on), emergency forces being cut off, and possibly slow government response.
44. atmosweather
4:11 AM GMT on March 16, 2006
Not in Miami; they got 135-140 mph sustained winds. Which is weak Category 4 strength.
Member Since: September 24, 2005 Posts: 33 Comments: 9265
43. louastu
4:10 AM GMT on March 16, 2006
Andrew was a cat-5. They upgraded it in 2002.
42. louastu
4:09 AM GMT on March 16, 2006
I read what you said wrong. Still, a borderline tropical storm/hurricane would be like a strong cat-2 in Miami.
41. atmosweather
4:07 AM GMT on March 16, 2006
So the same amount of damage as Hurricane Andrew? I think not...
Member Since: September 24, 2005 Posts: 33 Comments: 9265
40. louastu
4:06 AM GMT on March 16, 2006
It is a good thing that Hurricane Linda decided to stay out at sea. If it had hit as a strong cat-1 or weak cat-2, it would have been like Miami getting hit by a relatively weak cat-4.
39. Skyepony (Mod)
3:58 AM GMT on March 16, 2006
I've been watching this come along from the models. Anybody got a satalite link? Colby?

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST WED MAR 15 2006

LARGE MID-LATITUDE CYCLONE N
OF THE AZORES HAS DISPLACED THE SUBTROPICAL HIGH FARTHER S AND W
THAN TYPICAL AND THE HIGH WILL SLOWLY MIGRATE EASTWARD WITH TIME
AS THE LOW NEAR THE AZORES MOVES OUT.

$$
BLAKE

Quickscat looks interesting.
Member Since: August 10, 2005 Posts: 175 Comments: 38212
35. ForecasterColby
3:47 AM GMT on March 16, 2006
5-8 degrees is a LOT of difference. Basically, LA does not get hit by hurricanes - NYC gets more.
34. lightning10
1:11 AM GMT on March 16, 2006
Inyo

I remember durning the last El Nino it was September 1997 I remember on the news they where saying that if the water temp was around 5-8 degrees warmer then LA would have had a real storng chance of something tropical happening.

However over the past few years the Eastern Pacific hurricane season has been less then impressive and this season early indications are that its going to be the same or less overall then last year.
Member Since: November 24, 2005 Posts: 41 Comments: 630
33. Inyo
12:26 AM GMT on March 16, 2006
I'll bet a tropical system impacts southern California by the next moderate or strong el nino, and a full strength hurricane hits that area in the next 50 years
Member Since: September 3, 2002 Posts: 42 Comments: 873
32. atmosweather
12:09 AM GMT on March 16, 2006
Hey AceDeuce :)

That map is showing the precipitation that is forecast to fall at a particular time. If you look at the top, the date and time are listed, along with how many hours out this forecast is for. It reads 060331/0600v372: the 06 indicates 2006, 0331 is March 31st, 0600 is 6AM GMT (1AM EST, 10PM PST), v372 means the forecast is for 372 hours away (that is 15 days and 12 hours away). The scale depicts the amount of precipitation forecast at that time. For example, that strong system over Florida shows a lot of blue, indicating 1-2 inches of precipitation. The numbers are not really significant except the ones in black do show the sea level pressure at a particular point on the map.

Hope that helps :)

Rihc
Member Since: September 24, 2005 Posts: 33 Comments: 9265
30. AceDeuce
12:03 AM GMT on March 16, 2006
Would someone be kind enough to explain how to interpret the GFS map that KatrinaRitaWilmaZeta posted? I can't even figure out what the scale on the left means.

Thanks.
29. KatrinaRitaWilmaZeta
11:54 PM GMT on March 15, 2006
ok atmosweather i am back on my blog
28. atmosweather
11:48 PM GMT on March 15, 2006
Member Since: September 24, 2005 Posts: 33 Comments: 9265
27. lightning10
11:33 PM GMT on March 15, 2006
Look at weatherunderground back in 1997
Member Since: November 24, 2005 Posts: 41 Comments: 630
26. louastu
11:18 PM GMT on March 15, 2006
It was named Catarina. I believe it was named for the place it made landfall, rather than a person.
25. 147257
11:16 PM GMT on March 15, 2006
ow sorry was catharine when i read the article a year ago it hadnt a name =/
Member Since: August 2, 2005 Posts: 7 Comments: 68
24. 147257
11:14 PM GMT on March 15, 2006
last year there was also a hurricane hitting land in brazillie at least the satelite pictures said it was a hurricane why i dont read anything about this ?
Member Since: August 2, 2005 Posts: 7 Comments: 68
23. atmosweather
11:13 PM GMT on March 15, 2006
GFS still showing a mess along the east coast on March 30-31. Look at that system crossing Florida!!! Something that bears watching.
Member Since: September 24, 2005 Posts: 33 Comments: 9265
22. ForecasterColby
11:07 PM GMT on March 15, 2006
Bah, you're right. I should just shut up today...duh-huh.
19. globalize
10:03 PM GMT on March 15, 2006
No arguments, are your photo of the S. Atlantic system and the Master's Wunderblog photo the same systems? Yours looks to be off Uruguay.
Member Since: August 30, 2005 Posts: 0 Comments: 1150
18. ForecasterColby
9:57 PM GMT on March 15, 2006
"The NHC might 'consider' a naming system for south Atlantic storms, but it won't 'create' a naming system for south Atlantic storms. The NHC is a bureaucracy of the government, and governnment policy is to deny or pay begrudging lip service to the fact of global warming. For the present, the increase in tropical activity is 'cyclical'. Haven't you heard we are in a ten year cycle? Naming storms which historically hardly ever occurred would be admitting there is a problem. There is no problem people!!"

Actually, the official naming of S Atl systems would be controlled by the WMO. And don't get me started on global warming/government policy, I'd prefer not to argue.
17. ForecasterColby
9:56 PM GMT on March 15, 2006


Here's a scaled-down image of the S Atl system.
16. globalize
9:52 PM GMT on March 15, 2006
Yes, where is the media coverage of these storms? I read an obscure internet article quoting the mayor of Springfield, Mo. in which he said there is hardly an undamaged structure in the whole city. There are 150,000 people in that one city. Was I looking at the wrong Springfield?
Member Since: August 30, 2005 Posts: 0 Comments: 1150

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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.