South Atlantic Development?

[cycloneye]

Hmmm... I don't see the invest on NRL's webpage.

Anyway, on the letter assignment, it's really a coin-flip. The local models require the L suffix, as Derek mention. As PK quoted me on saying, USN also uses the L-suffix. This was used on the other two invests in the SoAtl in the past few years as well as Catarina. UKMO typically uses the T-suffix. Several world agencies also follow suit with the T-suffix.

My person thoughts is a T-suffix should be used officially. Remember back to Catarina, it was numbered 01L, as was Alex. A T-suffix would eliminate possible errors. (Note: USN/NRL had to renumber Catarina at a later time to 50L to avoid overwriting data when Alex developed.)

It is not there as you said but for a couple of hours it was at NRL as 77L but with pic only of the South Atlantic Area not with the header that says 90L Invest.Well they must haved been doing excercises there.

[Matt-hurricanewatcher]

This looks like a tropical cyclone to me. Nice cirualtion with a area of convection that formed over the center. Who says cyclone can't form over the south Atlatnic.
As it moves north it will be entering warmer waters. If that convection can close off we could be looking at the second hurricane to form down there.
With 2.5 t number theres no quastion about it.

[Matt-hurricanewatcher]

Another thing is all the south Atlatnic cyclones are small?

[Rainband]

there is zero connection regarding activity in the south vs the north. Its a different basin and there are no connections due to no cross equatorial monsoo flow

guess it was a coincidence

[cycloneye]

03/0000 UTC 0.0N 0.0W ST / -- Unknown


http://www.ssd.noaa.gov/PS/TROP/positions.html

Well it was interesting to see for a few hours.SSD dvorak update tonight shows nothing.But nerverless it was interesting to see it while it lasted.

[Matt-hurricanewatcher]

Its still there. In very well defined ciruatlion. With convection trying to wrap the low. As for that t number that is a typo. Or mess up. Because I have never ever seen them do that.

[senorpepr]

Here's what the metsat folks at AFWA have to say...

TPNT KGWC 032230 RTD COR
A. SUBTROPICAL DEPRESSION IN THE SOUTH ATLANTIC
B. 03/2031Z (37)
C. 32.8S/3
D. 23.0W/5
E. FOUR/MET7
F. ST2.5/2.5/INIT OBS -03/2031Z-
G. IR/EIR

17A/ PBO XPSD LLCC/ANMTN. FINAL-T IS BASED ON A PT OF
E2.5 USING THE HEBERT/POTEAT ST METHOD. COR FOR LINE C.
COR SENT...03/2242Z.

AODT: N/A SINCE SYS IS NON-TROPICAL.

LAURENTI

[senorpepr]

Looking at a metsat loop over the past few days, it look like the system is actually weakening. The bulk of the associated moisture has pulled away from the center altogether.

[senorpepr]

Looking at model guidance... it appears to be a dud. As I mentioned, the bulk of the moisture is being pulled eastward from the low. The low is forecast to fill and drift northward as the subtropical ridge strengthens (and quite powerfully) behind it. It looks like the system may affect central Brazil as a weak trough in a few days.

[Matt-hurricanewatcher]

Is that the way it works down there. Darn it!!! Looks like we got are tropical storm but it looks to be getting distoryed.

[senorpepr]

Remember that this is late in the season, especially for a part of the world where cyclones have a hard time forming in the first place. Imagine a hurricane trying to form in the NoAtl in the beginning of November. Then lower the odds with the hostile SoAtl environment. It would have been a long-shot.

[Matt-hurricanewatcher]

It made a 2.5 t number number. In for about 6 or so hours had a convection over the center. What do they mean about not quite? It must take alot to get your interest it just can't be a subtropical storm can't it?
That data you posted Serp Said subtropical depression?


When did it ever change that it has to be around for days before it is a tropical cyclone. I can be around hours or days or weeks. Time doe's not matter to a developed system. But is it or is it not matters.

[cycloneye]

It made a 2.5 t number number. In for about 6 or so hours had a convection over the center. What do they mean about not quite?

That data you posted Serp Said subtropical depression?

Well it not made it to a subtropical nor tropical entity but it tried a little bit however it's like november there and sst's are not warm and shear is a bit strong.

[senorpepr]

Don't focus so much on the term "subtropical depression." It was just to note that it was subtropical in nature with "depression" meaning a low.

The winds associated with the system were baroclinic (not tropical). The convect hasn't been over the center for a few days. This actually would have been something to focus on a few days ago.

[Matt-hurricanewatcher]

What is your supporting data saying that it did not get down to the surface or had a warmer central core then the outside cycloneye? Thats the big quastion.

[cycloneye]

What is your supporting data saying that it did not get down to the surface or had a warmer central core then the outside cycloneye? Thats the big quastion.

Well Mike answered that question and I wont repeat what he said as I agree.

[senorpepr]

First of all, water temperatures are around 68°F (20°C).

Secondly, this system appears to be a frontal system that moved off of Brazil a few days ago. Over the open waters it matured and became occluded. Today, it looks as if the parent low detached itself from the existing occluded system as a secondary low formed near the triple-point. The remnant low, what we're monitoring, maintained structure long enough to possibly go subtropical, but since the bulk of the moisture left, the low didn't develop.

Check out this link. I came up with a Meteosat-7 loop starting from 29/18Z through 04/00Z. That should help tell the story.

http://meteosat.e-technik.uni-ulm.de/cgi-bin/meteosat-movie?imgtype=color-small&startdate=20050502&starttime=0030&stopdate=20050504&stoptime=2400&interval=30&D.x=46&D.y=158

[HURAKAN]

GREAT CIRCULATION, BUT LITTLE FLESH TO PROTECT THE BONE. THE THUNDERSTOM ACTIVITY IS VERY LITTLE AT BEST, THIS IS NOT GOOD FOR TROPICAL TRANSITION IF THAT HAS BEEN A POSSIBILITY WHICH I THOUGHT.

[senorpepr]

Here's a bulletin I grabbed from the South African Wx Service. They point out the 1000mb low in question and also remark about the attached cold front. As I mentioned in my previous post, this system was a baroclinc system that has matured. The original low has seperated and was being monitored for possible subtropical development, but it didn't survive the seperation...

========= weather bulletin for the high seas for Metarea VII. West of 20e. Issued by the South African weather service on the 03rd of may 2005 at 17:00 UTC.

Note: wx observations. ====================== Could all vessels experiencing unexpected, severe wx/sea state please make every Effort to report this to saws via cape town radio.

Forecast valid from 032200 to 041000 UTC. Wind in knots, wave heights in metres. No sea state given if waves less than 3m.

Note the wind speeds quoted here are the expected average speeds. Individual gusts may exceed these values by a factor of up to 1.5. Wave heights are significant wave heights which may be accompanied by individual waves 1.5 to 2.0 times higher.

Gale warning(s): ================ nil.


Synoptic situation at 031200 utc: ================================= high 1026 hpa 31s00e high 1024 hpa 37s37e low 1000 hpa 33s23w low 950 hpa 64s20w low 958 hpa 67s31e low 984 hpa 55s54e low 990 hpa 43s67e

1. Cold front: 17s26w 25s18w 30s16w 35s18w 40s19w 45s13w 50s07w 2. Cold front: 37s10e 45s22e 50s27e 55s31e 60s34e


Area forecast: ==============

Ascension (06s/15s, 00e/20w) wind : se to E 15 to 20 but NE 10 to 15 in the South-West. Vis : good but moderate in showers in the north-west.

Angola (06s/15s, 00e/west coast) wind : S to SW 05 to 10 in the east, otherwise se 10 to 15 but 15 to 20 in the south. Vis : good. Sea state: 2 to 2.5m but 1.5m in the east, SSW swell.

St Helena (15s/30s, 00e/20w) wind : se to E 15 to 20 in the north, otherwise N to NW 15 to 25 reaching 30 in the South-West but NE 10 to 20 in the east. Vis : good but poor in rain in the west. Sea state: 3m in the South-West, with SSW swell.

Trades (15s/30s, 00e/west coast) wind : S to se 10 to 20. Vis : good.

Tristan (30s/40s, 00e/20w) wind : W to SW 10 to 15 in the South-West, otherwise NW 15 to 25. Vis : poor in rain. Sea state: 3m, with SSW swell.

Cape west (30s/40s, 00e/20e) wind : NW 15 to 25 in the west, otherwise SW 15 to 25 but se 15 to 20 in the north. Vis : poor in showers in the east and west. Sea state: 3m in the east, with S to se swell.

[Matt-hurricanewatcher]

This thing now is removed of that front. Plus new pop up thunderstorms/convection is popping close to the center. Don't write it off yet. Looking better to me.