S ATL: ARANI (01Q) - Subtropical Storm

[HURAKAN]

Latest loop

[HURAKAN]

the LLC is easy to find

[cycloneye]

GFDL drops that cat 2 scenario it had in the first runs,but develops a maximun 68kt system.


http://moe.met.fsu.edu/cgi-bin/gfdltc2. ... =Animation

[Chacor]

Continues to deepen, 00z warning:
DEPRESSAO SUBTROPICAL 1000 EM 23S039W.

[HURAKAN]

Latest infrared

[vegastar]

It looks fully tropical now:





I think hurricane Catarina never had cloud tops so cold as this system.

[DanieleItalyRm]

I think hurricane Catarina never had cloud tops so cold as this system.

I have often noticed that the cloud tops more 'cold are present in the beginning of the tropical systems development..

[Chacor]

WARNING NR 091/2011
NEAR GALE/SEVERE GALE WARNING
ISSUED AT 1530 GMT - MON - 14/MAR/2011
AREA DELTA E OF 040W. WIND NE/NW BACK NW/SW FORCE 7/9 WITH GUSTS.
VALID UNTIL 160000 GMT.
THIS WARNING REPLACES THE WARNING NR 081/2011.

[HURAKAN]

Impressive system, looks fully tropical

[cycloneye]

First dvorak T numbers for Q.

15/1145 UTC 24.2S 37.9W T1.0/1.0 90Q -- South Atlantic

[cycloneye]

From HPC:

SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
906 AM EDT TUE MAR 15 2011

GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/

SPECIAL STATEMENT. AT 1245 UTC THIS MORNING...NOAA/NESDIS-SAB
INITIALIZED A TROPICAL DISTURBANCE WITH CLOSED CIRCULATION OFF
THE COAST OF BRASIL NEAR 24.25S 37.9W. MAXIMUM SUSTAINED WINDS
ARE ESTIMATED AT 25KT. MODEL GUIDANCE CONTINUES TO SHOW
POSSIBILITY OF THIS SYSTEM BECOMING BETTER ORGANIZED/
STRENGTHENING OVER THE NEXT 24 HRS AS IT MEANDERS OVER WARM
WATERS. AS NECESSARY...THE NAVY HYDROGRAPHIC CENTER-BRAZILIAN
NAVY (SMM)...IN COORDINATION WITH THE NATIONAL INSTITUTE OF
METEOROLOGY (INMET)...WILL ISSUE THE OFFICIAL WEATHER ADVISORIES
FOR THIS SYSTEM.

[HURAKAN]

latest microwave

[CrazyC83]

Agreed, looks like a TD or weak TS. I wonder if they will name it if it becomes a TS?

[Hurricane Jed]

I'm beginning to think subtropical and tropical cyclones are more common in the South Atlantic than previously thought. Not all the time but every now and then they form. Kinda like the Central Pacific.

[KWT]

I think the same goes for the Med as well, I think both areas are capable of supporting tropical systems in the right conditions.

[CrazyC83]

The one area that doesn't seem to have any record of tropical activity is the Southeastern Pacific...I wonder why there?

[Hurricane Jed]

I saw something on the weather channel about that. The Peru current helps thwart development in that region because its a cold water current. There is also a Benguela current off the coast of southwest Africa that is also cold. Along the coast of Brazil there is a Brazil Current which is similar to the Gulf Stream in that it is warm but also significantly weaker than its North Atlantic counterpart.

[P.K.]

Officially named by Brazil.

WARNING NR 096/2011
SPECIAL WARNING
ISSUED AT 1500 GMT - TUE - 15/MAR/2011
SUBTROPICAL STORM ARANI WITH 998HPA AT 24S037W ASSOCIATED CICLONIC WIND FORCE 8/9 AFFETING 180MN AROUND CENTER MOVING TO E/SE WITH 10/15 KT.
VALID TILL161500 GMT

[HURAKAN]

I saw something on the weather channel about that. The Peru current helps thwart development in that region because its a cold water current. There is also a Benguela current off the coast of southwest Africa that is also cold. Along the coast of Brazil there is a Brazil Current which is similar to the Gulf Stream in that it is warm but also significantly weaker than its North Atlantic counterpart.

This graphic gives a good explanation

[HURAKAN]

Looking good