South Atlantic tropical depression dissipates

By: Dr. Jeff Masters , 1:39 AM GMT on February 25, 2006

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Satellite images and wind measurements from the Quikscat satellite show that a rare tropical depression in the South Atlantic probably formed for a few hours today, but the storm has since been sheared apart by strong upper-level winds, and is not a threat to re-develop. Although the storm was tropical, had a closed circulation, and winds of up to 35 mph (according to the Quikscat satellite), it only had those characteristics for about three hours today. The National Hurricane Center usually does not designate a system as a tropical depression unless it can hold together for at least six hours. The system formed near 29S 36W, about 600 miles southeast of Rio de Janeiro, Brazil, over waters of about 27 degrees C--well above the 26 C threshold needed for tropical storm formation.


Figure 1.Visible image from 1613 GMT February 24, 2006, taken by the polar-orbiting AQUA satellite, showing a possible tropical depression that formed in the South Atlantic.

Are South Atlantic tropical cyclones a sign of climate change?
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 disturances that grow into Northern Atlantic hurricanes. With Hurricane Catarina of March 2004, another tropical depression in January 2004, and now yet another "near miss" tropical cyclone in the South Atlantic, I believe is it time that the NHC considered adopting a naming system. Had today's system intensified into a tropical storm, it would not have been given a name, since there is no naming system for the South Atlantic Ocean. It's quite possible that the recent activity in the South Atlantic is due to climate change causing wind shear levels to drop over the South Atlantic. The alternative explanation is that we are seeing an active period 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, it's time we had a system in place to start naming these storms to avoid confusion.

My next blog will be on Monday, a discussion of the proposed NWS staff reductions via an early retirement plan. Will we lose our best forecasters at the NHC and other NWS forecast offices?

Jeff Masters

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157. Inyo
1:22 AM GMT on February 28, 2006
Stormchaser, i'm sure the government HAS done experiments on hurricanes.. i just doubt they were successful
Member Since: September 3, 2002 Posts: 42 Comments: 873
156. lightning10
4:19 PM GMT on February 27, 2006
Hi friends.

Just wanted to point out that the NAM computer modle has weakend the storm that is expected to move in durning the next few hours. This is what the other web site I go to (not 1/2 as good as wunderground) has been saying for the past few days.

I am not an expert or anything and I see that there is still a ton of subtropical moisture out there looks like even more then yesterday. However it looks from the satellite that some of that rain is coming up a little more north.

In my personal opinion I would not be suprised (even thow I want the most rain possable) if we saw rain fall totals of more on the average of 1-3 inches for coast and valley and 3-5 inches for the foothills.
Member Since: November 24, 2005 Posts: 41 Comments: 630
155. globalize
4:17 PM GMT on February 27, 2006
Stormchaser- you are right. There are drying agents with very impressive properties which, if introduced at the right moment, in considerable quantity, would perhaps trigger the collapse of the eye wall and weaken a storm.
It would seem that if a country can spend thousands of millions every single day to carry war abroad, it might come up with new ideas for combatting these monster storms. What would a dozen transport planes delivering
drying agent over a storm cost? About 10% of the cost of a single Abrams tank.
Member Since: August 30, 2005 Posts: 0 Comments: 1150
150. Inyo
8:34 AM GMT on February 27, 2006
great idea arnold, suspend environmental laws even though environmental damage is what caused the stupid problem in the first place! not too bright...
Member Since: September 3, 2002 Posts: 42 Comments: 873
148. louastu
6:34 AM GMT on February 27, 2006
I can't imagine why the government would try to weaken storms just prior to landfall based on the fact that most storms when they start to weaken tend to spread out. This means that while it may save some areas from major damage it would create greater damage in places where it would have otherwise been fairly mild. This would more than likely cause the total bill to be much higher than it would have been, and also stretch relief efforts over a larger area.
146. Skyepony (Mod)
5:31 AM GMT on February 27, 2006
Just got a 57.2 mph gust. A new record for my garden this year.

A follow up to the Sacramento, Ca ~levee situation:

Gov. Arnold Schwarzenegger declared a state of emergency for fragile Sacramento River and Delta levees, freeing up at least $75 million and suspending state environmental and contracting laws to speed repair at two dozen eroded sites.
Member Since: August 10, 2005 Posts: 160 Comments: 37148
145. Skyepony (Mod)
5:16 AM GMT on February 27, 2006
Yeah inyo~ I hadn't seen the govt stop any canes either & the gloating is a good point~ they could have claimed that great weaking on Katrina before landfall & everyone would be ralling around this bill & though FEMA would still have look like a failer the president would have come out smelling like a rose. The tunnels could raise approval points for sure.
Member Since: August 10, 2005 Posts: 160 Comments: 37148
144. Inyo
4:53 AM GMT on February 27, 2006
i don't buy any of the theories about the US stopping hurricanes. Come on, if we had that kind of power, the government would be gloating about it like mad. Besides, i don't even buy seeding weakening the storm.. if it increases condensation, the condensation will create heat, which if anything would STRENGTHEN the storm. Until we get the tunnels up and running, we can't do anything to them, unless we can make them stronger via CO2 emissions. I suppose we could start a nuclear war with someone, and after we all died, the nuclear winter would decrease the severity of hurricanes.
Member Since: September 3, 2002 Posts: 42 Comments: 873
142. ForecasterColby
4:12 AM GMT on February 27, 2006


Eye now evident on IR.
141. ForecasterColby
2:02 AM GMT on February 27, 2006


Stronger and stronger and stronger!
140. ForecasterColby
1:29 AM GMT on February 27, 2006
That's been there for a while, it's just now showing up on IR. Beautiful storm, and I don't see anything to stop it. Take a look at the shear map. I have a thread on my site for her, I'm posting imagery and intensity as I get them.
138. ForecasterColby
1:20 AM GMT on February 27, 2006
Carina just keeps on stregnthening! 95kt, 949mb!

137. Skyepony (Mod)
12:32 AM GMT on February 27, 2006
Granted this has nothing to do with seeding hurricanes, but cloud seeding none the less~ Texas Department of Liciensing & Regulation.

The Weather Modification program administers grants to political subdivisions who sponsor rain-enhancement activities. Currently, cloud-seeding projects are conducted in some 37 million acres of the state (or about one-fifth of the state’s land area). The State grants help pay for these seeding operations, reimbursing water conservation districts, county commissions, and other political subdivisions for up to half of the costs to conduct them. This grant program, initiated with the Texas Department of Agriculture in 2001, was transferred to the TDLR in August 2003.

There are other states doing similiar things Texas doesn't only do cloud seeding but other weather modification operations.

MichaelSTL~ I left you an answer concerning all this lastnight on my blog. Check it out.
Member Since: August 10, 2005 Posts: 160 Comments: 37148
135. ForecasterColby
12:12 AM GMT on February 27, 2006
A hurricane puts out the energy of the world's combined nuclear arsenal every hour or so. Have fun trying to blow it up.
134. MarcKeys
11:52 PM GMT on February 26, 2006
Looks as though we are in for a tough decade of tropical weather. It never seems to stop.Link
131. ForecasterColby
9:52 PM GMT on February 26, 2006
TC Carina continues to just explode in the Indian, with official winds of 90kt (roughly 97kt when adjusted to U.S. 1-minute averages) and a T5.5/101kt sat estimate:

130. lightning10
9:14 PM GMT on February 26, 2006
This Weather Modification bill sounds like nothing more then to make government smaller :( I hope it doesnt pass as well.
Member Since: November 24, 2005 Posts: 41 Comments: 630
129. Fshhead
8:39 PM GMT on February 26, 2006
Stormchaser,
Kinda hard to explain here. The NHC is 5-10 miles north of me. They really did not get the super high winds, they were out of the solid eyewall. Where I live was about the cutoff point. We got ahhhhh maybe what you saying about vortex. I cant remember what they called it. That Fujimora guy did the surveys & said we had incredible downbursts where I live. I also live right around the corner from Country Walk. The development that was shown all the tome in the media.
Homestead Air force base is very near the power plant so I guess the rumor of 200 mph wind was accurate.
The major problem I saw with wind speeds is MOST of the measurind devices failed.As a matter of fact the NHC was in different location for Andrew, it was in a taller building & had the big rader ball on top of it. LOL,needless to say it was airborne!!!!!
Telling you guys again Andrew was one mean storm.
Member Since: November 19, 2005 Posts: 9 Comments: 9960
128. Inyo
7:27 PM GMT on February 26, 2006
haha blow up the eyewall? with what? laser beams?
Member Since: September 3, 2002 Posts: 42 Comments: 873
125. fredwx
3:41 PM GMT on February 26, 2006
All that will be left at NOAA will be the researchers and computer scientists.
Member Since: June 8, 2005 Posts: 221 Comments: 261
124. jeffB
3:36 PM GMT on February 26, 2006
It is sounding like we heading for a 100% machine based NWS? Automated observations being analyzed by computers that generate fully computerized forecasts that are delived via the internet and read on various PC and wireless devices!

And don't make politically incorrect statments about global climate change. :-)
Member Since: July 8, 2005 Posts: 0 Comments: 42
123. fredwx
3:12 PM GMT on February 26, 2006
Dr Masters:


It is sounding like we heading for a 100% machine based NWS? Automated observations being analyzed by computers that generate fully computerized forecasts that are delived via the internet and read on various PC and wireless devices!
Member Since: June 8, 2005 Posts: 221 Comments: 261
122. buckeyefan1
1:31 PM GMT on February 26, 2006
Unfortunately..This is nothing but my "gut" speeking, but I believe this year the East Coast might need to watch out this year for landfalling Huricanes. The Bermuda high will be sitting in the correct position to bring the more active ITCZ just right to the east coast. I rely on the upcomming patterns of the set Bermuda high, with the higher SST's than in prevoius years. I'm not sure who posted the fact that if Hugo was slower it wouldn't have caused as much wind damage. Not true, this was our only saving grace was the fact that it was a fast mover, and the fact that as soon as he went past Charleston, he was over the National Park reserve that is just timber,that is the reduction of the cost of this hurricane. Hugo was so similar to Andrew, that if Hugo hit through a very populated area for the extended track, would have caused a larger area of devistation to personal property. The cost would have been close to Andrew. What was missing was the Bermuda high last year. It steered everything either out to sea,brushing the coast, or right through the Carib./S.Florida, and into the Gulf. This year will be just as active but more concentrated on the east coast instead of the Gulf. Don't get me wrong...the gulf will get something I'm sure but not to the extent of last year. Just my 2 cents.
121. 147257
12:32 PM GMT on February 26, 2006
this isnt the first time 2 years ago a hurricane hit brazilie although the brazilian govnerment denied it was a hurricane but there were made some pictures with a satelite and those pictures said it was a weak cat 1 hurricane
Member Since: August 2, 2005 Posts: 7 Comments: 68
120. stansimms72
8:43 AM GMT on February 26, 2006
i don't think katrina was a cat 3. i think it was a cat 4. however, as this has been said on here before, if it were a cat 3, i can understand why it still had the high storm surge. it weakened from a cat 5 to a cat 3 or 4 just a few hours before landfall. sure, the winds might have died down but, the ocean waters i doubt would have had the time to die down to a cat 3 or 4. same, or the exact opposite i guess you can say, as with charley. it strenghtened to a cat 4 right before landfall but, it didn't have the so-called cat 4 storm surge because the water didn't have time to get to that point. it seems logical.
119. Fshhead
8:24 AM GMT on February 26, 2006
stormchaser77 at 6:24 AM GMT on February 26, 2006.
Taco2me61..... Something really interesting about Andrew
Taco was That The "Eye" actually passed right over The NHC
while it was a CAT5.
Actually stormchaser, the eye did NOT pass over the NHC.
I live like 5 mins. from the NHC. We never got the eye.
We got the northern eyewall, not the eye itself. The eye passed about 20 miles to the south of the NHC. One of my blogs shows where Andrew came in & the wind speeds also.
At my house we had 140 mph. winds BEFORE the measuring devices failed!! Tell you right now he was one mean mean storm. I heard a rumor after that at the Nuclear plant in Homestead they measured a gust at around 200 mph. Not sure how accurate this is though!! He was a definite cat 5 though.
Member Since: November 19, 2005 Posts: 9 Comments: 9960
114. taco2me61
7:04 AM GMT on February 26, 2006
DenverMark,

I would hope not either, Because I just don't think we could have another one here. I had enough damage from Katrina that I know my insurance would close up shop and leave town...

Well anyway I am off to bed I will be downtown for the next 3 days for Mardi Gras so I won't be posting much ...

Yall have a great night see you in 3 days...:0)

Taco
Member Since: July 7, 2005 Posts: 6 Comments: 3237
113. DenverMark
6:53 AM GMT on February 26, 2006
The three hurricanes officially rated Cat 5 at landfall in the U.S. are Labor Day 1935 in the Florida Keys, Camille and Andrew.

Yes,Katrina is such a political mess that it may be many years before she is reevaluated. I feel the winds had to be at least Cat 4 on the Mississippi Gulf Coast. Although the devastation was most due to the enormous storm surge.

I'm just a rank amateur, but my gut feeling is that '06 may be just as wild as '05 was. I sure don't wish a Cat 5 landfall on anyone, though.
Member Since: February 11, 2006 Posts: 125 Comments: 6988
112. stansimms72
6:51 AM GMT on February 26, 2006
"Hey Stan,
DenverMark did and you are right It was Andrew in 92 but the reason why I was asking was,that same year we had a big wind storm on the west coast and during Hurricane Season we had 19 named storms. Now Andrew hit in 92 but the waters were not that warm like they are now and do you think this will be the year of the Cat 5???"

i saw the answer after i had posted. about the year of the cat 5? good question. i really don't know. i thought katrina was gonna be the one but, she weakened very quickly prior to landfall. and, i do believe had charley in 04 had another hour or two over water, considering it's rapid strengthening prior to landfall, it very well could have been a cat 5 at landfall. i would say no because they are rare around here. although i would probably say the same thing for 07 and beyond for the exact same reasoning.
111. taco2me61
6:45 AM GMT on February 26, 2006
Yes I meant to put 95 on my post, that same year on the west coast they had a Big Wind Storm, lots of damage... This year they are having the same type of storm on the West Coast and this year we are to have around 15-19 Named Storms... So I was asking do you think this will be the Year of the Cat 5???

Sorry for the mess up>>>

Taco
Member Since: July 7, 2005 Posts: 6 Comments: 3237
109. taco2me61
6:21 AM GMT on February 26, 2006
Hey Stan,
DenverMark did and you are right It was Andrew in 92 but the reason why I was asking was,that same year we had a big wind storm on the west coast and during Hurricane Season we had 19 named storms. Now Andrew hit in 92 but the waters were not that warm like they are now and do you think this will be the year of the Cat 5???
Member Since: July 7, 2005 Posts: 6 Comments: 3237
108. stansimms72
6:07 AM GMT on February 26, 2006
at least i think it's only three. anyone?
107. stansimms72
6:03 AM GMT on February 26, 2006
taco wrote::

"I have a question??? When was the last cat 5 to hit the US (Gulf Coast or the East Coast)???"

don't know if this has been answered yet. it was andrew in 92. only three (since recordkeeeping began) storms have made landfall in the U.S. as cat 5 storms. the one before andrew was camille in 69. or was there one in between the two?

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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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