South Atlantic TC?

[Ed Mahmoud]

JB just mentioned someone in South America has mentioned that a TC may soon form in the South Atlantic.

I don't see anything on this TWC satellite (quick ask.com search), but anyone who actually knows weather wants to chime in, I'm all ears.

[HURAKAN]

I don't see anything that indicates that a TC is forming.

[Squarethecircle]

I see a few lows and some half-decent convection, but nothing you would expect to form even in the North Atlantic, prime season.

[Cyclone1]

This areas got my undevided attention, now.

Honestly, I don't think these storms are as rare as we think they are. I've found suspicious systems in the S Atl, specifically March 2002. I'll post it if anyone's interested.

JB hHit the nail on the head with Olga, so I'll keep an eye on it.

[Ed Mahmoud]

I'm interested...

[Squarethecircle]

If I may so ask, why mention this now?

[Cyclone1]

ftp://eclipse.ncdc.noaa.gov/pub/isccp/b1/.D2790P/images/2002/080/Img-2002-03-21-12-MET-7-IR.jpg

Possible storm from 2002. That's the best looking one I've found so far.

[Ed Mahmoud]

:uarrow: If I may so ask, why mention this now?

JB mentioned that someone in S. America clued him off to look for a possible TC in the South Atlantic.

[HURAKAN]

ftp://eclipse.ncdc.noaa.gov/pub/isccp/b1/.D2790P/images/2002/080/Img-2002-03-21-12-MET-7-IR.jpg

Possible storm from 2002. That's the best looking one I've found so far.

In the Southern Hemisphere, where???

[Coredesat]

ftp://eclipse.ncdc.noaa.gov/pub/isccp/b1/.D2790P/images/2002/080/Img-2002-03-21-12-MET-7-IR.jpg

Possible storm from 2002. That's the best looking one I've found so far.

I see nothing here that looks like a tropical storm. The convection present south of the equator off the African coast is almost totally gone in the 18Z image.

[Cyclone1]

Yeah, I did notice later it was very short lived.

I'm sure there are some out there that are within the age of satellites, just gotta find them. And who has the time for that? I came across that one scrictly by accident.

The other ones I've found are more extratropical than anything.

I'd like to see a storm off the coast of Chile, but that's about as likely as a hurricane in Oklahoma...

erm...

That's about as likely as a ... ... it's unlikely, okay?

[Coredesat]

Well, I have heard the same thing and the models do form a weak warm-core low in this area. The HPC has hinted that it could be a subtropical system, but I see no reason why it would be anything more than a weak, transient low.

[brunota2003]

Well, there is always these two:
http://www.aoml.noaa.gov/hrd/tcfaq/G6.html

[MetSul Weather Center]

From the South America NOAA's HPC discussion yesterday:

A MID/UPPER LEVEL TROUGH (COLD CORE) WILL INDUCE A SURFACE WAVE ALONG THE TAIL END OF THE FRONT AND OFF THE COAST OF SAO PAULO BY MID CYCLE. THIS LOW DEEPENS THROUGH 96-108 HRS. FORECAST GUIDANCE SHOWS WARM CORE CHARACTERISTICS WITH THE LOW LEVEL CYCLONE...WHILE THE UPPER PERTURBATION RETAINS ITS COLD CORE CHARACTERISTICS THROUGH 120 HRS. THUS THIS SYSTEM WILL RETAIN SUBTROPICAL CYCLONE CHARACTERISTICS.

This Tuesday, HPC backed off to a cold core system.

It is worth taking a look at some FSU diagrams from the forecast models:

http://moe.met.fsu.edu/cyclonephase/cmc ... 12/72.html

http://moe.met.fsu.edu/cyclonephase/gfs ... 18/77.html

http://moe.met.fsu.edu/cyclonephase/ukm ... 18/51.html

These are global models. The solutions of the regional models are much more interesting.

Alexandre

[Ptarmigan]

Yeah, I did notice later it was very short lived.

I'm sure there are some out there that are within the age of satellites, just gotta find them. And who has the time for that? I came across that one scrictly by accident.

The other ones I've found are more extratropical than anything.

I'd like to see a storm off the coast of Chile, but that's about as likely as a hurricane in Oklahoma...

erm...

That's about as likely as a ... ... it's unlikely, okay?

Don't expect that to happen. The water is cold and also it has to contend with windsheer from extratropical systems.

[Meso]

Sadly it will never happen.Unless all this global warming stuff takes and the SST's rise by like 7 degrees.Us here in South Africa get about the same weather as Chile,as we're at about the same latitude,but when SST's reach about 23`C max in summer.There aren't even thundershowers that come from low latitude South Atlantic systems (well maybe once in a while there will be a few flashes and bangs)..Boring latitude this I tell you...

[HURAKAN]

Take out Antarctica and then, we will have cyclones in the SA.

[Coredesat]

Sadly it will never happen.Unless all this global warming stuff takes and the SST's rise by like 7 degrees.Us here in South Africa get about the same weather as Chile,as we're at about the same latitude,but when SST's reach about 23`C max in summer.There aren't even thundershowers that come from low latitude South Atlantic systems (well maybe once in a while there will be a few flashes and bangs)..Boring latitude this I tell you...

Well, SSTs aren't everything, there are other factors involved such as wind shear and upper-level temperatures. Anomalously cold upper-level temperatures can support cyclogenesis even if SSTs are as low as 20C, as was the case with Vince, Epsilon, and Zeta in 2005; as well as that Mediterranean system last year that caused a lot of headaches on this forum (though for other reasons entirely).

This may have been the case with what South Africa's weather service analyzed as an extratropical cut-off low in March 2007; I still believe this low may have been a subtropical cyclone, though RSMC La Réunion decided not to warn on it (though they were monitoring it - it probably did not become sufficiently detached from the frontal system to warrant advisories).

[MetSul Weather Center]

Do not forget the Catarina hurricane, the only recorded hurricane in the South Atlantic.

[Meso]

Yeah Cordesat,true...That system you posted caused lots of damage to Durban (I think it was that one),that caused heavy swells.And it's not hard to believe since tropical cyclones in that area of S.A aren't that far-fetched and tropical cyclones often get rather close to that area.Indian Ocean gets nice and warm too