Interesting system over the South Atlantic

[Matt-hurricanewatcher]

Near 4.5 east/6 south there appears to be at the very least a well defined MLC, and possibly a developing LLC. Quickscat shows a tight something at the surface, with 40-45 knot winds. Overall shear levels appear to be droping over it, that is allowing for outflow to spread over most quads. This is very intersting.

[Matt-hurricanewatcher]

http://www.eumetsat.int/Home/Main/Image ... x.htm?l=en

[HURAKAN]

This system?

[Matt-hurricanewatcher]

Yes, lets see if it can form deeper convection over the center and keep it up.

[Cyclone1]

I think it'll be gone within several hours, honestly.

But hey, I've been wrong many many time before.

[Matt-hurricanewatcher]

I been following this for over 8 hours now,. So it most likely will be here still in 3-4 hours. Also the cirus is fanning out around the system=lowering upper level shear. If the convection can form over the core and it can strengthen over the 82 degree water. I say it has a chance.

[Squarethecircle]

Meh. Seems more like a RBoC to me. I don't think it's going anywhere, especially so close to the equator.

[Gustywind]

I been following this for over 8 hours now,. So it most likely will be here still in 3-4 hours. Also the cirus is fanning out around the system=lowering upper level shear. If the convection can form over the core and it can strengthen over the 82 degree water. I say it has a chance.

000
AXNT20 KNHC 241808
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SUN FEB 24 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN
SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC OCEAN TO THE
AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION
IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...
WEATHER OBSERVATIONS...AND RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 7N11W 1N25W 3N40W 1N50W.
SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 100
NM EITHER AXIS FROM 36W-39W.

...DISCUSSION...
GULF OF MEXICO...
THE SOUTHERN EXTENSION OF AN UPPER TROUGH MOVING ACROSS THE
CENTRAL U.S. THROUGH LOUISIANA INTO THE NW GULF. MODERATE TO
STRONG SUBSIDENCE WITH DRY AIR AT THE MID AND UPPER LEVELS
OF THE ATMOSPHERE IS NOTED ACROSS NEARLY ALL THE GULF EXCEPT
FOR THE SE PORTION OF THE AREA. WEAKENING COLD FRONT EXTENDS
FROM TAMPA BAY TO 27N88W. BROKEN/OVERCAST LOW CLOUDS ARE WITHIN
120 NM N OF THE FRONT. A SURFACE TROUGH IS ANALYZED ALON THE
TEXAS COASTAL WATERS FROM GALVESTON TO BROWNSVILLE. THE PRES
PATTERN IS WEAK AND WINDS ARE LIGHT ACROSS THE ENTIRE GULF.

CARIBBEAN...
A BROAD MID/UPPER RIDGE COVERS THE CARIBBEAN WITH AN
ANTICYCLONIC CIRCULATION OVER WESTERN VENEZUELA. AN UPPER LEVEL
WESTERLY WINDS 40-50 KT S OF 16N W OF 79W IS ACCOMPANIED BY THIN
BROKEN CIRRIFORM CLOUDS OTHERWISE STRONG SUBSIDENCE COVERS THE
REMAINDER OF THE CARIBBEAN. AT THE LOW LEVELS THE ATLC
SUBTROPICAL RIDGE IS SUPPORTING BRISK EASTERLY FLOW. LOCALLY
BROKEN LOW CLOUDS WITH EMBEDDED SHOWERS ARE NOTED ACROSS THE
CARIBBEAN SEAS N OF 12N EXCEPT BECOMING LOCALLY OVERCAST N OF
16N W OF 81W.

ATLANTIC...
AN UPPER ANTICYCLONE CENTERED OVER W VENEZUELA HAS A RIDGE
EXTENDING NE ACROSS HISPANIOLA INTO THE ATLC BEYOND 32N50W. THE
SOUTHERN EXTENSION OF AN UPPER TROUGH IS NOTED OVER THE EXTREME
NW PORTION DISCUSSION AREA ACCOMPANIED BY DRY UPPER AIR NW OF
LINE 32N65W 28N80W. THE ASSOCIATED SURFACE COLD FRONT EXTENDS
FROM 32N66W THEN WEAKENING THE CENTRAL FLORIDA COAST. SCATTERED
SHOWERS AND ISOLATED TSTMS ARE WITHIN 120 NM E OF THE FRONT N OF
28N. MID/UPPER LEVEL TROUGH WITH AXIS FROM 32N30W 17N50W TO THE
WINDWARD ISLANDS. A 90-100 KT SUBTROPICAL JET SE OF THE TROUGH
EXTENDS FROM 12N48W 23N25W TO THE COAST OF AFRICA NEAR 25N15W.
BROKEN CIRRUS CLOUDS ARE WITHIN 400 NM SE OF THE JET WITH
MODERATE TO STRONG SUBSIDENCE WITH 600 NM NW OF JET AXIS W OF
40W. AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS SE OF THE JET.
THE ANTICYCLONE IS CENTERED NEAR 7N21W WITH RIDGE AXIS EXTENDING
E ALONG 7N TO AFRICA AND W TO 3N60W. A 1027 MB SURFACE HIGH PRES
CENTERED NEAR 32N32W...WITH RIDGE TO 27N50W TO THE STRAITS OF
FLORIDA.

$$
DGS
I dont' notice anything about that thing in the lastest TWD...or maybe my eyes are deceiving me? Honestly i'm very doubtfull about this to be something in this part of the season climatogicaly speaking ( just 1 % as usual)..but i don't hope something on this...

[HURAKAN]

Even if it develops, you will most likely not notice anything in the TWD as the TPC doesn't monitor the South Atlantic. By the way, welcome back!

[HURAKAN]

Not much to talk about!

[Cyclone1]

I was right.

[Gustywind]

Even if it develops, you will most likely not notice anything in the TWD as the TPC doesn't monitor the South Atlantic. By the way, welcome back!

Tkanks to you Galaxy ... yeah i'm coming back lool, glad to see that my presence is well welcomed here . ( i hope that as you said). BDon' t worry i knew that NHC TWD as the TPC doesn't monitor the South Atlantic but given some replies i was , but this thing is maybe bringing some "fun or happiness " for my untrained eyes and others lol ( i'm modest so that's great, nice tstorms on sat pic, i appreciate... see you soon everbody before June 1st (i will come back in case of) . Nice regards from Guadeloupe Gustywind

[Gustywind]

Excuse me not Galaxy lool Hurakan!

[boca]

Good to see some of you during the off season.Is there a sat in motion pic of this system?

[HURAKAN]

[RL3AO]

Interesting South Atlantic storm could become subtropical
An extratropical storm centered near 31S 30W, a few hundred miles east of the Brazil-Uruguay border, has begun to acquire subtropical characteristics and could become a subtropical storm this weekend. The storm is not expected to hit land. NASA/MSFC has a clickable satellite image of Southern Hemisphere one can use to zoom in on the storm. An ASCAT pass at 5:29am EST this morning showed winds of 50 mph near the center of the storm. Water temperatures are about 26°C, which is right at the boundary where tropical storm formation can occur. Subtropical and tropical storms are quite rare in the South Atlantic. I'll update this section of the blog through the weekend if the storm develops. There is no naming system in place to name any tropical or subtropical storm that may form in the South Atlantic. It would be up to the World Meteorological Organization (WMO) to institute such a scheme. The last time I checked into this, they had no plans to consider a naming system. Here's nice MODIS image of the storm from 15:30 GMT today.

http://www.wunderground.com/blog/JeffMasters/show.html

[JonathanBelles]

Not much to talk about!

Rofl...interesting subtitle now

[Ed Mahmoud]

Interesting South Atlantic storm could become subtropical
An extratropical storm centered near 31S 30W, a few hundred miles east of the Brazil-Uruguay border, has begun to acquire subtropical characteristics and could become a subtropical storm this weekend. The storm is not expected to hit land. NASA/MSFC has a clickable satellite image of Southern Hemisphere one can use to zoom in on the storm. An ASCAT pass at 5:29am EST this morning showed winds of 50 mph near the center of the storm. Water temperatures are about 26°C, which is right at the boundary where tropical storm formation can occur. Subtropical and tropical storms are quite rare in the South Atlantic. I'll update this section of the blog through the weekend if the storm develops. There is no naming system in place to name any tropical or subtropical storm that may form in the South Atlantic. It would be up to the World Meteorological Organization (WMO) to institute such a scheme. The last time I checked into this, they had no plans to consider a naming system. Here's nice MODIS image of the storm from 15:30 GMT today.

http://www.wunderground.com/blog/JeffMasters/show.html

Looks like it might be starting to merge with the cold front approaching slowly from the South.

[HURAKAN]

[MetSul Weather Center]

The most interesting system is not this one over the Atlantic Ocean, but another cyclone that NOAA's HPC says it is subtropical and that formed over land and now remains positioned over Uruguay.







HPC:

SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
1239 PM EST FRI FEB 29 2008

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

MODEL COMPARISON (VALID FROM 00Z FEB 29). OVER THE CONTINENT AND
WESTERN ATLANTIC THE MODELS NOW MAINTAIN GOOD CONTINUITY
THROUGH AT LEAST 108 HRS. SIGNIFICANT CHANCES LIMIT TO THE
CENTRAL/EASTERN PACIFIC LATER IN THE CYCLE...AS MODELS MAKE
CORRECTIONS TO THE AMPLITUDE/TIMING OF MID LEVEL PERTURBATIONS.
THE GLOBAL ENSEMBLES REFLECT THIS...AS THEY CONVERGE ON A SIMILAR
SOLUTION OVER THE CONTINENT/ATLANTIC...WITH DIFFERENCES ON THE
SOUTHERN STREAM FLOW OVER THE PACIFIC PROGRESSIVELY ACCRUING
THROUGH DAY 06.

CONSISTENT WITH PREVIOUS FORECASTS A MID LEVEL TROUGH IS
INITIALIZED OVER RIO DE LA PLATA BASIN-MESOPOTAMIA VALLEY-
SOUTHERN BRASIL. THIS SYSTEM WILL REMAIN THE ONE OF CONCERN
DURING THE ENTIRE CYCLE...AS IT IS TO PERSIST DURING THE NEXT
FIVE DAYS...TO ONLY EXPERIENCE MINOR MODULATIONS AS THE CYCLE
EVOLVES. A CLOSED LOW OVER URUGUAY/RIO DE LA PLATA WILL ANCHOR
THIS TROUGH. AT LOW LEVELS THE MID LEVEL PERTURBATION SUPPORTS A
CLOSED LOW OVER URUGUAY...WHERE IT IS TO GENERALLY REMAIN THROUGH
DAY FIVE. THIS LOW WILL DEVELOP WARM CORE CHARACTERISTICS BELOW
600 HPA...WHILE THE MID/UPPER PERTURBATION WILL RETAIN ITS COLD
CORE CHARACTERISTICS. IT WILL ALSO SUPPORT A TROUGH ACROSS
BUENOS AIRES PROVINCE-URUGUAY TO SOUTHERN BRASIL/MESOPOTAMIA
VALLEY. THIS SYSTEM WILL SUSTAIN STRONG BOUNDARY LAYER WINDS
ACROSS SOUTHERN BRASIL-URUGUAY-BUENOS AIRES PROVINCE-CENTRAL
ARGENTINA...WITH WINDS OF 20-35KT (SOUTHERLY COMPONENT OVER
CENTRAL/NORTHERN ARGENTINA AND NORTHEASTERLY COMPONENT ALONG THE
COAST OF BRASIL/URUGUAY). WE EXPECT THE POTENTIAL/RISK OF
ORGANIZED CONVECTION OVER URUGUAY-PORTIONS OF BUENOS AIRES
PROVINCE AND RIO GRANDE DO SUL IN SOUTHERN BRASIL TO REMAIN HIGH
DURING MOST OF THE CYCLE...WHILE OVER PARA-SANTA CATARINA BRASIL-
MESOPOTAMIA VALLEY AND SOUTHEAST PARAGUAY THE BEST PROBABILITY
FOR HEAVY RAINFALL IS DURING THE NEXT 36 HRS. OVER URUGUAY-BUENOS
AIRES PROVINCE WE NOW PROJECT DAILY MAXIMA OF 25-50MM. LOCALLY
HIGHER AMOUNTS ARE QUITE POSSIBLE...WITH MODELS DIVERGING
ON BEST LOCATION. THE GFS AND THE ETA FROM ARGENTINA BOTH
CONVERGE ACROSS THE BUENOS AIRES PROVINCE...WHILE THE ECMWF
FAVORS URUGUAY FOR BEST LOCATION. CONSIDERING THE POSITION
OF THE SURFACE LOW...AND MOIST INFLOW ACROSS RIO DE LA PLATA...WE
EXPECT A HIGHER RISK ACROSS BUENOS AIRES PROVINCE/SOUTHERN
URUGUAY. OVER SOUTHERN BRASIL/MESOPOTAMIA INITIALLY EXPECT MAXIMA
OF 25-50MM/DAY...TO DECREASE TO 15-35MM/DAY AFTER 36-48 HRS.
PERSISTENT RAINFALLS OVER THIS REGION WILL RESULT IN HIGH RISK OF
FLOODING OVER URUGUAY-BUENOS AIRES PROVINCE. ON THE LEE OF THE
ANDES...OVER NORTHWEST ARGENTINA...SCATTERED CONVECTION IS TO
BUILD IN A DIURNAL PATTERN WILL MAXIMA OF 15-25MM.

OVER THE EASTERN PACIFIC...AT 500 HPA...A BROAD TROUGH DOMINATES
THE FLOW PATTERN. THIS SYSTEM IS TO PUSH EAST ACROSS 70W/75W BY
24 HRS...AND THROUGH 48 HRS IT WILL MOVE ALONG 60W...MEANWHILE
SHEARING A SHORT WAVE VORTEX OVER SOUTHERN CHILE/PATAGONIA. THE
LATTER WILL THEN MERGE WITH/REINFORCE THE NORTHERN STREAM SHORT
WAVE TROUGH OVER CENTRAL SOUTH AMERICA...AND PROVIDE FOR THE
AFOREMENTIONED CONVECTION. BY 72 HRS THE TROUGH WILL PUSH FARTHER
EAST...AND IT WILL MOVE ACROSS 40W/50W...MEANWHILE DAMPENING TO
SOUTH OF 45S. AFTERWARDS...THE MODELS CONSISTENTLY FORECAST THIS
TROUGH TO AMPLIFY NORTH ALONG 30W/40W TO 35S AS A RIDGE BUILDS
SOUTH ALONG 50W/60W. AT LOW LEVELS THE MODELS INITIALIZE A BROAD
TROUGH OVER THE EASTERN PACIFIC...WITH POLAR FRONTS PUSHING EAST
ACROSS SOUTHERN CHILE INTO PATAGONIA IN ARGENTINA. THE TROUGH
WILL MOVE ACROSS THE DRAKE PASSAGE TO THE SOUTH ATLANTIC THROUGH
60-72 HRS...TO THEN AMPLIFY AS IT MOVES ACROSS 30W/40W BY 96 HRS.
THE ASSOCIATED FRONT WILL UNDULATE NORTH INTO LA PAMPA/SOUTHERN
BUENOS AIRES-CENTRAL CHILE BY 48-60 HRS...WITH A WAVE/LOW TO FORM
OFF THE COAST. OVER SOUTHERN CHILE IT WILL FAVOR SCATTERED
RAINFALL...WITH DAILY MAXIMA NOT TO EXCEED 10-15MM. OVER LA
PAMPA/BUENOS AIRES PROVINCE...THERE IS A GOOD CHANCE THIS FRONT
IS GOING TO INTERACT WITH THE AFOREMENTIONED SUBTROPICAL CYCLONE
TO FAVOR A SURGE IN ACTIVITY BY PROVIDING A SOURCE OF MECHANICAL
FORCING. IS THIS IS THE CASE...EXPECT HIGHER RAINFALL AMOUNTS
THAN WHAT WE ARE FORECASTING.

NORTH OVER THE CONTINENT...AT 200 HPA...WE EXPECT THE
SUBTROPICAL RIDGE TO TRAVERSE THE CONTINENT FROM WEST-TO-EAST
ALONG 18S. THE RIDGE WILL ENVELOP CONTINENTAL AREA NORTH OF
25S....AND IT WILL ANCHOR ON A HIGH THAT IS TO INITIALLY CENTER
OVER CENTRAL/EASTERN BOLIVIA. BUT...THROUGH 24-48 HRS...IT WILL
SPLIT IN TWO CENTERS...WITH ONE OVER BOLIVIA/SOUTHERN PERU AND
THE OTHER OVER BRASIL NEAR 15S 50W. THE LATTER WILL BECOME THE
DOMINANT FEATURE BY THE END OF THE CYCLE. ACROSS NORTHERN
CHILE/NORTHWEST ARGENTINA THIS RIDGE WILL SUSTAIN A BRISK
WESTERLY FLOW...WHILE ACROSS BRASIL INTO PERU NORTH OF 10S IT
WILL FAVOR A DIVERGENT EASTERLY FLOW. AT LOW LEVELS AN ELONGATED
FRONT EXTENDS ACROSS THE SOUTH ATLANTIC TO BAHIA BRASIL...WHERE
IT MERGES INTO THE SACZ. THE FRONT WILL DRIFT SOUTH TO ESPIRITO
SANTO/MINAS GERAIS EARLY THIS CYCLE. THE SACZ...MEANWHILE...WILL
PERSIST ACROSS MINAS GERAIS-MATO GROSSO BRASIL TO NORTHERN
BOLIVIA/SOUTHERN PERU. OVER BRASIL INTO BOLIVIA...ALONG THE
CONVERGENCE ZONE...EXPECT RAINFALL AMOUNTS OF 20-35MM/DAY...WITH
LOCALLY HIGHER AMOUNTS OVER THE MOUNTAINS IN MINAS GERAIS WHERE
WE EXPECT MAXIMA OF 25-50MM/DAY THROUGH 36-48 HRS. ACROSS MATO
GROSSO/NORTHERN BOLIVIA CONVECTION IS TO GRADUALLY INTENSIFY
THROUGH 48-60 HRS...TO REMAIN FAIRLY ACTIVE THROUGH 84 HRS...WITH
DAILY MAXIMA OF 30-60MM. OVER NORTHERN PERU INTO ECUADOR WE NOW
EXPECT MAXIMA OF 20-40MM/DAY...WITH A SLIGHT DECREASE IN ACTIVITY
OVER PERU BY MID CYCLE. OVER NORTHERN PARA-RORAIMA DAILY MAXIMA
WILL REMAIN AROUND 15-35MM/DAY ALONG THE NET...WITH SIMILAR
AMOUNTS ON THE NORTHERN COAST OF BRASIL. MOST INTENSE IS EXPECTED
OVER AMAPA-ILHA DE MARAJO...WHERE THE ATLANTIC ITCZ MAKES
LANDFALL...WITH MAXIMA OF 20-40MM/DAY ON DAY 01...30-60MM/DAY ON
DAYS 02-03...AND 20-35MM/DAY THEREAFTER.

ARMANINI...SMN (ARGENTINA)
CARVAJAL...DAC (ECUADOR)
DAVISON...HPC (USA)