Little change to Brazilian tropical disturbance

By: Dr. Jeff Masters , 03:05 PM GMT on Μάρτιος 06, 2010

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An area of disturbed weather off the coast of Brazil, near 17S 38W, has changed little over the past day. It has a slight potential to develop into subtropical or tropical depression early next week. Satellite winds estimates from the WindSat instrument show an elongated area of converging winds, but no organized surface circulation. Satellite loops show little organization to the cloud pattern, and only limited heavy thunderstorm activity. Wind shear over the region is about 20 knots, which is rather high, and should keep any development slow. Sea surface temperatures are about 28°C, about 1°C above average, and plenty warm enough to support a tropical storm. The system is small, and this will limit its potential to become a tropical cyclone.


Figure 1. Morning visible satellite image of the Brazilian disturbance.

The ECMWF, UKMET, and NOGAPS models have backed off on their predictions of development a fair amount in recent runs. Phase space diagrams from Florida State University show that this storm has less of a warm core than before, meaning it would probably be classifiable as a subtropical storm if it gets more organized and achieves surface wind speeds of at least 39 mph. The system does not appear to be a threat to bring heavy rains to the Brazilian coast. I give this storm a low (< 30% chance) of developing into a tropical or subtropical depression by Monday. The storm should move to the south or southeast away from the coast. Only six known tropical or subtropical cyclones have formed in the South Atlantic. Tropical cyclones rarely form in the South Atlantic Ocean due to strong upper-level wind shear, cool water temperatures, and the lack of an initial disturbance to get things spinning (no African waves or Intertropical Convergence Zone exist in the proper locations in the South Atlantic to help spawn tropical storms).

Portlight continues relief efforts in Haiti
Portlight and the Liberty Schooner are sponsoring "The Haitian Food Voyage," shipping 10,000 pounds of rice to Haiti. Thanks to your generous donations, the mission is set to sail to Haiti during the second week of April. Please visit the Portlight.org blog to learn more and to donate to this worthy cause.


Figure 2. R.Richard Lumarque, Portlight's on-site coordinator in Haiti, assists a woman who has just received a new walker from Portlight. The woman was injured when a 3-story building collapsed on her during the January earthquake.

Jeff Masters

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Quoting taco2me61:
Atmoaggie I work for Mobile Area Water Sewer System and it was my turn to be on call.... Working for the city has it's ups and downs but I have to take call every 4 weeks (the part I hate)..... It's ok at least I do have a Job where there are so many that don't, if you know what I mean....

Taco :0)

May not be glamorous, but we collectively sure are glad when someone is around to fix a problem in that industry!
Member Since: Αύγουστος 16, 2007 Posts: 6 Comments: 12463
Quoting Skyepony:
Looks like the storm that was expected in Australia was worse than expected..10cm hail. Impressive flooding in the video.

BLOODIED festival-goers, spooked racehorses, smashed windows and torrential rain inside major buildings were some of the surreal scenes unfolding across Melbourne in one of the most intense storms in years.



It was raining heavily down seven floors through two skylights at Media House, home to The Sunday Age, while a similar water feature adorned the ABC headquarters in Southbank, where a reporter delivered a 7pm news broadcast inside, holding an umbrella.

Member Since: Σεπτέμβριος 22, 2005 Posts: 11 Comments: 2032
Atmoaggie I work for Mobile Area Water Sewer System and it was my turn to be on call.... Working for the city has it's ups and downs but I have to take call every 4 weeks (the part I hate)..... It's ok at least I do have a Job where there are so many that don't, if you know what I mean....

Taco :0)
Member Since: Ιούλιος 7, 2005 Posts: 6 Comments: 3261
Quoting taco2me61:
Ok so is that the real reason why the SST's are so different than 3 days ago????

It does make a big difference and explains alot... But I do see that it will not last that long and everything will be warming back up....

Taco:0)

Can't say. Is a possible reason. As StormW and Levi so eloquently pointed out, there simply doesn't seem to be a good atmo/ocean reason for it, so I am just discussing other possibilities.
Member Since: Αύγουστος 16, 2007 Posts: 6 Comments: 12463
Ok so is that the real reason why the SST's are so different than 3 days ago????

It does make a big difference and explains alot... But I do see that it will not last that long and everything will be warming back up....

Taco:0)
Member Since: Ιούλιος 7, 2005 Posts: 6 Comments: 3261
Quoting taco2me61:
Doing Good Atmo as long as they don't call me back in....
LOL How about you....

Taco :0)

I am pre-sore. Already hurting in my back, arms, shoulders, and fingers from 3 hours of machete work today...prolly will not want to move tomorrow.

After our freezes, though, now is a great time to clear out brush and reclaim a little of the yard from the forest...well, the undergrowth, anyway.

Call you back...to work? What do you do?
Member Since: Αύγουστος 16, 2007 Posts: 6 Comments: 12463
Quoting Grothar:
Average time between comments on the blog tonight 17.5 minutes. Now if atmoaggie were on he would say "Actually, Grothar that would be 17.6 minutes. Only kidding Atmo! You keep us all on our toes.

Anyone figure out why the sudden cooling of the SST's in the Atlantic? If would be a good question for Dr. Master's for new blog entry.

Alright, Gro...

Thinking further on that...the values didn't change *that* much...and there does seem to be a little smoothing in the SST anomaly plots. It is possible that an erroneously cold, cloud-contaminated pixel(s) got into the data.

There is no such thing as a perfect cloud mask algorithm. Aggressive ones remove a lot of valid data. The more amicable ones *do* allow a slightly cloud-contaminated (thereby erroneously cool) pixel in now and again. Not saying I can verify that this is the case, but is certainly possible.

Our satellite data is reasonably good, but is does have a few certain caveats to watch out for...
Member Since: Αύγουστος 16, 2007 Posts: 6 Comments: 12463
Doing Good Atmo as long as they don't call me back in....
LOL How about you....

Taco :0)
Member Since: Ιούλιος 7, 2005 Posts: 6 Comments: 3261
Quoting taco2me61:
wow not much going on in here tonight.....

So I will say this....

MARCO

POLO

How are you, taco?
Member Since: Αύγουστος 16, 2007 Posts: 6 Comments: 12463
wow not much going on in here tonight.....

So I will say this....

MARCO
Member Since: Ιούλιος 7, 2005 Posts: 6 Comments: 3261
Edited -- Could the Ocean currents have played role with the unusually cold weather in parts of the Northern Hemisphere on the SST's? I believe I read about some changes in the North Atlantic currents a while ago. Just a thought. We don't know very much about the dynamics/impacts of deep water currents on many things. :)
Member Since: Ιούνιος 12, 2005 Posts: 6 Comments: 8186
Quoting Levi32:


I'm not sure. The usual influencing factors that have been making the SSTs warm (weak trade winds, warm temps in the tropics) have not changed over the last week, so I'm at a loss for explanations. Atmo may be right that it's just variability with the satellite's ability to measure through clouds. I seriously doubt the cooling trend will continue.


I would post the image, but the link has more information, such as the standard deviation used to determine the anomaly. The use the average over a 20 year period. Very interesting link of SST' up to last week.

Link
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98. JRRP
Member Since: Αύγουστος 16, 2007 Posts: 0 Comments: 5995
Quoting Grothar:
Average time between comments on the blog tonight 17.5 minutes. Now if atmoaggie were on he would say "Actually, Grothar that would be 17.6 minutes. Only kidding Atmo! You keep us all on our toes.

Anyone figure out why the sudden cooling of the SST's in the Atlantic? If would be a good question for Dr. Master's for new blog entry.


I'm not sure. The usual influencing factors that have been making the SSTs warm (weak trade winds, warm temps in the tropics) have not changed over the last week, so I'm at a loss for explanations. Atmo may be right that it's just variability with the satellite's ability to measure through clouds. I seriously doubt the cooling trend will continue.
Member Since: Νοέμβριος 24, 2005 Posts: 635 Comments: 26661
Quoting Ossqss:


LoL, anyone remember the HAL 9000 :)



I am sure Dave does.
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Average time between comments on the blog tonight 17.5 minutes. Now if atmoaggie were on he would say "Actually, Grothar that would be 17.6 minutes. Only kidding Atmo! You keep us all on our toes.

Anyone figure out why the sudden cooling of the SST's in the Atlantic? If would be a good question for Dr. Master's for new blog entry.
Member Since: Posts: Comments:
Quoting Grothar:


Yes, Like watching a rerun of an old Star Trek. "Oh, computer.........! Afraid to make a decision until the computer said it was OK.


LoL, anyone remember the HAL 9000 :)



HAL9000
Member Since: Ιούνιος 12, 2005 Posts: 6 Comments: 8186
93. WAHA
Quoting Grothar:


Yes, Like watching a rerun of an old Star Trek. "Oh, computer.........! Afraid to make a decision until the computer said it was OK.
yeah i don't want the same with this one.
Quoting Levi32:


Thanks that is an interesting article. Yeah I remember all the NHC's troubles with that storm. I laughed when I found out their hurricane models wouldn't run. I remember thinking why don't they just forecast the dang thing themselves? That's what they're there for...they don't HAVE to have a computer do it for them right? And then they had doubts the system was even tropical....LOL.

Oh well...


Yes, Like watching a rerun of an old Star Trek. "Oh, computer.........! Afraid to make a decision until the computer said it was OK.
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91. Skyepony (Mod)
Looks like the storm that was expected in Australia was worse than expected..10cm hail. Impressive flooding in the video.

BLOODIED festival-goers, spooked racehorses, smashed windows and torrential rain inside major buildings were some of the surreal scenes unfolding across Melbourne in one of the most intense storms in years.

Member Since: Αύγουστος 10, 2005 Posts: 178 Comments: 38313
Quoting Grothar:


Here is a link you might find interestin:

Link


Thanks that is an interesting article. Yeah I remember all the NHC's troubles with that storm. I laughed when I found out their hurricane models wouldn't run. I remember thinking why don't they just forecast the dang thing themselves? That's what they're there for...they don't HAVE to have a computer do it for them right? And then they had doubts the system was even tropical....LOL.

Oh well...
Member Since: Νοέμβριος 24, 2005 Posts: 635 Comments: 26661
Quoting Levi32:


I don't know, did you find an official list? There wasn't one back when Catarina formed, which is why it got named Catarina.


Here is a link you might find interestin:

Link
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88. WAHA
Quoting Levi32:


I don't know, did you find an official list? There wasn't one back when Catarina formed, which is why it got named Catarina.

I came up with my own. I wish to send it to the comitee (or whatever it's called).
Quoting WAHA:
Okay, thanks, Levi! Do you think Abrew is the name, if so?


I don't know, did you find an official list? There wasn't one back when Catarina formed, which is why it got named Catarina.
Member Since: Νοέμβριος 24, 2005 Posts: 635 Comments: 26661
86. WAHA
Okay, thanks, Levi! Do you think Abrew is the name, if so?
Also, the CMC, which was previously developing this into a hurricane, has become confuzzled since yesterday morning and no longer has a clear picture of the lows at hand. The low that it does develop ends up being fully tropical for a short time on the model, but that doesn't make sense because by that time the model has the system over 24C waters and already being picked up by the westerlies.

Member Since: Νοέμβριος 24, 2005 Posts: 635 Comments: 26661
Quoting WAHA:
I meant just north of the system that you were talking about. That is what I'm talking about.


You mean south...lol. I was talking about the northern system east of Caravelas, which I have been tracking for 3 days now. You must be looking at the system southeast of Sao Paulo just off the coast, which does have a lot of apparent spin. That spin is not a surface circulation but a mid-upper shortwave that has moved NE from over Uruguay today. The models can't decide which area to use for cyclogenesis. The latest 12z GFS has compromized by developing the low to the north, east of Caravelas, and moving it SW under the shortwave SE of Sao Paulo. This would technically be a subtropical low at that point, which is shown by the phase diagram below, but something tells me they wouldn't name it if this situation came to pass.

The other possibility is the northern trough just fizzles and the mid-level circulation associated with the cut-off shortwave near Sao Paulo works its way to the surface. However this would make the low even more cold-core than the former possibility, and hence even less chance of it being named. The system would get picked up quite fast by the westerlies and convert to fully extratropical.

At any rate, a subtropical system is still possible in either of the two areas, but I doubt we'll be able to get a name out of the NHC. Heck they didn't even want to give Catarina credit for being tropical.

Member Since: Νοέμβριος 24, 2005 Posts: 635 Comments: 26661
Member Since: Ιούλιος 15, 2006 Posts: 174 Comments: 54616
82. WAHA
Quoting Levi32:


Yeah well it looked a ton better two days ago. It had a well-defined tight, closed circulation and everything. Now it's just a broad trough with spread-out and disorganized convection. I suspect the 20 knots of westerly shear was just too much for the poor thing. It's running out of time now. Of course there's still a chance, but I'm starting to lean towards less so.
I meant just north of the system that you were talking about. That is what I'm talking about.
Quoting WAHA:
You better look at this; the south atlantic disturbance he was talking about looks like it's circulating! If this does become a storm, keep in mind that I have a complete name of lists for the south atlantic, starting with Abrew.


Yeah well it looked a ton better two days ago. It had a well-defined tight, closed circulation and everything. Now it's just a broad trough with spread-out and disorganized convection. I suspect the 20 knots of westerly shear was just too much for the poor thing. It's running out of time now. Of course there's still a chance, but I'm starting to lean towards less so.
Member Since: Νοέμβριος 24, 2005 Posts: 635 Comments: 26661
Quoting stormpetrol:
It's been unseasonably cool here in the Caymans, so I suspect the water temperatures are slightly below average.Nevertheless I suspect the upcoming hurricane season in 3 months will be an active one full of surprises, just my opinion of course.


It is cooler than normal there. You're right the edge of the cold winter to the north, but warm waters and seasonable temperatures are just to the south.

Member Since: Νοέμβριος 24, 2005 Posts: 635 Comments: 26661
It's been unseasonably cool here in the Caymans, so I suspect the water temperatures are slightly below average.Nevertheless I suspect the upcoming hurricane season in 3 months will be an active one full of surprises, just my opinion of course.
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78. WAHA
You better look at this; the south atlantic disturbance he was talking about looks like it's circulating! If this does become a storm, keep in mind that I have a complete name of lists for the south atlantic, starting with Abrew.
Quoting all4hurricanes:
where can one gets imagery of the south Atlantic disturbance?


Here

Or Here

Or Here
Member Since: Νοέμβριος 24, 2005 Posts: 635 Comments: 26661
:|
Member Since: Ιούλιος 15, 2006 Posts: 174 Comments: 54616
where can one gets imagery of the south Atlantic disturbance?
Member Since: Μάρτιος 29, 2008 Posts: 0 Comments: 2373
Quoting weatherbro:
Sanford Conditions=Sunny

Temp=61F

Humidity=16%

Dewpoint=15F

Winds light NW at 5-10MPH

I just went out for a walk and couldn't believe how gorgeous it was outside!


we got to a high of 51 today here clear sunny skies tomorrow and mon same a tad warmer highs mid 50's or slighly higher
Member Since: Ιούλιος 15, 2006 Posts: 174 Comments: 54616
Sanford Conditions=Sunny

Temp=61F

Humidity=16%

Dewpoint=15F

Winds light NW at 5-10MPH

I just went out for a walk and couldn't believe how gorgeous it was outside!
Member Since: Posts: Comments:
Current Conditions

Homer, Alaska (Airport)
Updated: 18 min 2 sec ago

18 °F
Snow Blowing Snow
Windchill: -1 °F
Humidity: 86%
Dew Point: 14 °F
Wind: 26 mph from the SW

Wind Gust: 31 mph
Pressure: 29.37 in (Steady)
Visibility: 0.5 miles
Elevation: 82 ft
Member Since: Νοέμβριος 24, 2005 Posts: 635 Comments: 26661
Quoting altesticstorm10:
How long is the NAO expected to be positive? A week or so, or enough to actually last into hurricane season before it becomes negative again?


It appears the NAO will climb toward neutral(00's positive or negative) while the AO continues to make a leap. The models put that at a positive 1.5-3.0!

But by Saint Patrick's Day, both the AO and NAO look to plummet once more while the PNA goes positive.
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.
Member Since: Νοέμβριος 24, 2005 Posts: 635 Comments: 26661
Grothar! (Funny old codger)
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277

NWUS22 KWNS 062106

STAHRY



SPC TORNADO AND SEVERE THUNDERSTORM REPORTS

UNOFFICIAL - FOR OFFICIAL REPORTS, SEE PUBLICATION 'STORM DATA'

FOR 06CST SAT MAR 6 2010 THRU 15CST SAT MAR 6 2010



EVENT LOCATION REMARKS (CST)TIME



********** NO SEVERE REPORTS RECEIVED BY SPC **********
Member Since: Ιούλιος 15, 2006 Posts: 174 Comments: 54616
929

ACUS01 KWNS 061948

SWODY1

SPC AC 061946



DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0146 PM CST SAT MAR 06 2010



VALID 062000Z - 071200Z



...NO SVR TSTM AREAS FORECAST...



CURRENT FORECAST APPEARS ON TRACK WITH ONLY SMALL CHANGES MADE TO

THE GENERAL THUNDERSTORM LINES.



..MEAD.. 03/06/2010



.PREV DISCUSSION... /ISSUED 1024 AM CST SAT MAR 06 2010/



COLD UPPER LOW WHICH HAS BEEN DROPPING SWD OFF THE CA COAST WILL

TURN EWD TO JUST W OF LAX/SAN BY 12Z SUN. SLY FLOW ACROSS THE SWRN

STATES WILL GRADUALLY INCREASE BOTH MOISTURE AND

INSTABILITY...PARTICULARLY TONIGHT...SUFFICIENT TO SUPPORT AT LEAST

ISOLATED THUNDERSTORM DEVELOPMENT. WITH THE UPPER LOW STILL WELL TO

THE W...CONVECTIVE ACTIVITY SHOULD BE WIDELY SCATTERED THRU THE

PERIOD AND WELL BELOW ANY SEVERE LEVELS.



STEEP LAPSE RATES WILL MOVE ONSHORE SRN CA OVERNIGHT BUT ANY

INSTABILITY WILL BE PRIMARILY CONFINED TO COASTAL AREAS WWD TO THE

UPPER LOW CENTER. GIVEN WEAK UPWARD MOTION AND SHEAR...THUNDERSTORMS

THAT DO OCCUR SHOULD BE LIMITED TO COASTAL REGION.



COLD CORE UPPER LOW NWRN NEB WILL GRADUALLY WEAKEN ON TOP OF

SCENTRAL U.S. RIDGE AS IT MOVES EWD TO IA OVERNIGHT. SUFFICIENT

HEATING WILL OCCUR THIS AFTERNOON EWD ACROSS NEB FOR A FEW LOW

TOPPED THUNDERSTORMS DEVELOPING IN A MARGINALLY UNSTABLE AIR

MASS...SPREADING EWD INTO IA AND NRN MO THIS EVENING
Member Since: Ιούλιος 15, 2006 Posts: 174 Comments: 54616
Thanks for the update Dr. Masters,

good afternoon all
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Valid 00z Saturday
Could be related to the SST's.

850mb Temp Anomaly
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156 hours
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Good afternoon to everyone. Things are quiet weatherwise for the lower 48, except for the blizzard in Alaska.

I am here in Dallas-Ft. Worth, TX, where the temperatures have finally returned to normal. Right now we're about 71F, Pt Sunny, and breezy! Beats the temps in the 20's, 30's and 40's we had the majority of Feb 2010.
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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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