Little change to Brazilian tropical disturbance

By: Dr. Jeff Masters , 3:05 PM GMT on March 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).

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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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304: Maybe it is the result of a penchant for data analysis. A certain aptitude, maybe.

But, I, personally, never come in here bashing the NHC.

You, apparently have been having a series of bad days. Maybe you should chew out your refrigerator, or something, instead of bringing it in here. Though, relatively benign, post flagged for lack of civility. Rule of the Road, numero uno.
Member Since: August 16, 2007 Posts: 6 Comments: 12461
309. WAHA
Quoting StormW:


Are you speaking of the South Atlantic feature?
Yes. The center of circulation is exposed but there might be another center of circulation, but I don't have enough imagery to go that much into detail of if there is. I figured since you're a proffesional, you might.
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Quoting CybrTeddy:


If post 2005 terror had a name it would be them. I remember just looking at the radars of Dean as it ramped up coming into the Yucatan.. I must have sent out at least a dozen prayers, and Felix on the other hand was just as terrifying and was only within a few weeks of each other.


Cant forget Felix's little RI episode

REPORTS FROM A NOAA HURRICANE HUNTER AIRCRAFT INDICATE THAT FELIX
HAS INTENSIFIED AND IS NOW A CATEGORY FIVE HURRICANE. THE AIRCRAFT
REPORTED PEAK FLIGHT-LEVEL WINDS OF 152 KT...WITH PEAK SFMR WINDS
OF 142 KT IN THE SOUTHWEST QUADRANT. HIGHER SFMR WINDS WERE FOUND
IN THE NORTHEAST QUADRANT...UP TO 163 KT
...BUT THESE MAY HAVE BEEN
CONTAMINATED BY GROUPEL. A DROPSONDE RELEASED IN THE SOUTHWEST
QUADRANT LANDED IN THE NORTHEAST QUADRANT
...AND THIS DROP YIELDED A
SURFACE ESTIMATE OF 139 KT BASED ON THE LOWEST 150 M LAYER AVERAGE.
BASED ON THESE DATA...THE PEAK SURFACE WINDS ARE ESTIMATED TO BE AT
LEAST 145 KT. AN EYE SONDE MEASURED A SURFACE PRESSURE OF 936 MB
WITH SURFACE WINDS OF 24 KT. BECAUSE OF THE EXTREME TURBULENCE AND
GROUPEL THAT THE AIRCRAFT EXPERIENCED...THE MISSION IS BEING
ABORTED AND THE AIRCRAFT IS RETURNING TO ST. CROIX.

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306. WAHA
Quoting StormW:


When?

Today, and possibly in the future. Where I found it
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Quoting Stormchaser2007:


Yep

Can never forget Felix and Dean


If post 2005 terror had a name it would be them. I remember just looking at the radars of Dean as it ramped up coming into the Yucatan.. I must have sent out at least a dozen prayers, and Felix on the other hand was just as terrifying and was only within a few weeks of each other.
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Interesting little bugger.

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Quoting StormW:


2005 was considered an anomaly, and I was trying to go with years that had a moderate to strong El Nino. 2005 ONI didn't modify that much. Actually, Don't know why I picked 2004. Even throwing out 2004, it averages to 16...if you include 1992...14. Comes within the range I have in mind right now, until we get to May, and I see what else is happening.


Ok I see. Sounds good. 1998 is also a possibility if you don't consider that an anomaly as well lol. That year did slip into a considerable La Nina quite fast but the NAO was analogous to this year. 1998 also has the most similar winter SST profile to this year. I can't find a more perfect analog in that regard, at least since satellite SST-measuring began. The only big difference is the shear strength of the 1998 El Nino, which is obviously unsurpassed by any other year.

March 1998:



March 2010:





I'm out for now later all.
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Quoting atmoaggie:
Water vapor is a better one to see the flow:



Has really increased in organization lately. If this forms I will be really impressed.
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atmo: "Noticed my weeping willow thinks it is spring"

They always come out earlier than other trees. Check out the willows along rivers.
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Quoting CybrTeddy:


Both of those two Category 5's in 2007 made landfall at that intensity.


Yep

Can never forget Felix and Dean
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297. WAHA
Storm, do you see a possible tropical cyclone?
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Quoting Stormchaser2007:


Interesting that all of those years except 1995 (which had 3 Category 4's) had Category 5 hurricanes. 2007 even had two.


Both of those two Category 5's in 2007 made landfall at that intensity.
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Quoting StormW:
Evening all!

I came up with 1995, 1998, 2003, 2004, 2007, and the off one, 1992. These 6 averaged out to 14.3 total named systems. If you take out 1992, the average comes up to 15.8


Interesting that all of those years except 1995 (which had 3 Category 4's) had Category 5 hurricanes. 2007 even had two.
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Quoting StormW:
Evening all!

Just got kicking some numbers around...and going just by some years that transitioned from El Nino to Neutral, no other factors...I picked 6 years. I threw in 1992 for kind of an offset, but wnet with years since we picked up in activity since 1995. I tried to come as close to what we might expect as departure temps from El Nino (with only spending a short time on them), and I came up with 1995, 1998, 2003, 2004, 2007, and the off one, 1992. These 6 averaged out to 14.3 total named systems. If you take out 1992, the average comes up to 15.8

Cold and Warm Episodes by Season


Evening Storm!

Those are good picks. I don't have 2003 or 2004 in my package due to upswinging in the ONI during those hurricane seasons.

One question though...if you're gonna put 2003 and 2004 in there why not 2005 as well? 2005 was more similar with the ONI than either of those years.
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report
Buy a pothole in Germany!
:)
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289: Well, no surprises cropping up there! Well monitored, that is.
;-)
Member Since: August 16, 2007 Posts: 6 Comments: 12461
:)
Member Since: July 15, 2006 Posts: 173 Comments: 54268
Quoting atmoaggie:

I am going to have to remember these for when we have systems approaching the lessers...that don't have a floater on yet, anyway.
i will have an array of these images up on my tropical blog as season approaches as a matter of fact already starting to write a code for the blog page hang on i will post a brief sample image
Member Since: July 15, 2006 Posts: 173 Comments: 54268
Member Since: July 15, 2006 Posts: 173 Comments: 54268
Quoting KEEPEROFTHEGATE:
thanks atmo just came back

I am going to have to remember these for when we have systems approaching the lessers...that don't have a floater on yet, anyway.
Member Since: August 16, 2007 Posts: 6 Comments: 12461
S Atlantic cyclone is looking good
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Quoting atmoaggie:

If you go here, you'll find most any sat image you want for the eastern hemisphere: http://oiswww.eumetsat.org/IPPS/html/MTP/IMAGERY/IR115/BW/EUROPE/index.htm
thanks atmo just came back
Member Since: July 15, 2006 Posts: 173 Comments: 54268
Water vapor is a better one to see the flow:

Member Since: August 16, 2007 Posts: 6 Comments: 12461
And this gives a little more southern coverage and for the South Atlantic: http://oiswww.eumetsat.org/IPPS/html/MSG/IMAGERY/IR039/BW/index.htm

Such as:
Member Since: August 16, 2007 Posts: 6 Comments: 12461
Quoting MississippiBoy:
keeper where do you get those sat. images you are showing.

If you go here, you'll find most any sat image you want for the eastern hemisphere: http://oiswww.eumetsat.org/IPPS/html/MTP/IMAGERY/IR115/BW/EUROPE/index.htm
Member Since: August 16, 2007 Posts: 6 Comments: 12461
so guys what up with S ATL Invest 80SL
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keeper where do you get those sat. images you are showing.
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The med storm really bombed out over warm waters

Both systems
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It's fantastic here in Ohio! It is sunny and warm for a change and it looks like it is going to stay that way for a while (except for the days that it's going to be rainy!)
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The last 3 hours have started to look a lot better on the IR, and have revealed where the low's center is. It seems to have found a pocket of 10-knot shear, but strong westerlies are just to the south. We know for nearly a fact that a subtropical low is going to develop, but it's a question of what the structure will be, and exactly how warm-core the system is. This isn't a fully-tropical system and I doubt we'll get the NHC to pay attention to this, but I still find it interesting. I dismissed the possibility of a true tropical storm or hurricane 2 days ago though because this low missed that opportunity and is now too far south interacting with the upper low.

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274. WAHA
Quoting KEEPEROFTHEGATE:
267. WAHA 8:52 PM GMT on March 07, 2010
South atlantic storm strengthening
Action: Quote | Ignore User



THANK you.
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273. WAHA
South atlantic tropical cyclone? Every time this happens there's no posts for a while then someone goes offtopic from what i'm saying. besides this is the comments section, not a chat section. The topic was on South atlantic tropical cyclones.
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267. WAHA 8:52 PM GMT on March 07, 2010
South atlantic storm strengthening
Action: Quote | Ignore User


Member Since: July 15, 2006 Posts: 173 Comments: 54268
Quoting CycloneUK:
Deary me this med storm is big.
Look at the top



HERE IS SOME REAL TIME IMAGES OF SYSTEM



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poor IE6






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269. xcool
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Quoting scottsvb:



I hope your not refering to West Central Florida on that 27.1 lowest readings were around 37 deg, most locations went down to the upper 30s to low
40s


scottsvb,I was saying it got that cold heres another site 5 miles from me.check out Dade City just as cold.
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267. WAHA
South atlantic storm strengthening
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Deary me this med storm is big.
Look at the top

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265. WAHA
I am on tropics talk, I came in and everybody's gone
btw what about south atlantic storm?
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Quoting Ossqss:
231- this is a little bit newer and not $31. I have read some time ago of cascade reactions. Mostly chemical in nature. :)

Plants Can Recognize, Communicate With Relatives, Studies Find


Plants Communicate to Warn Against Danger

Then of course plants have twitter now - LoL


Hmmm, next thing, of course, is that a pet bird can send a tweet that it needs food, water, or a fresh layer of newsprint...
(Doh! Is that a bad techno-pun?)
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Quoting CycloneUK:




Wow, looks like that ship was left "high and dry"! Do you know where that picture was taken?
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UKMET office still forecasting development in the South Atlantic:




015

WTNT80 EGRR 071800


MET OFFICE TROPICAL CYCLONE GUIDANCE FOR NORTH-EAST PACIFIC

AND ATLANTIC

GLOBAL MODEL DATA TIME 12UTC 07.03.2010

NEW TROPICAL STORM FORECAST TO DEVELOP AFTER 12 HOURS
FORECAST POSITION AT T+ 12 : 24.2S 39.7W

VERIFYING TIME POSITION STRENGTH TENDENCY
-------------- -------- -------- --------
00UTC 08.03.2010 24.2S 39.7W WEAK
12UTC 08.03.2010 27.3S 42.5W WEAK INTENSIFYING SLIGHTLY
00UTC 09.03.2010 29.4S 45.2W WEAK WEAKENING SLIGHTLY
12UTC 09.03.2010 30.1S 47.6W WEAK INTENSIFYING SLIGHTLY
00UTC 10.03.2010 30.1S 47.7W MODERATE LITTLE CHANGE
12UTC 10.03.2010 30.6S 47.7W WEAK LITTLE CHANGE
00UTC 11.03.2010 31.4S 47.0W WEAK WEAKENING SLIGHTLY
12UTC 11.03.2010 32.1S 45.4W WEAK WEAKENING SLIGHTLY
00UTC 12.03.2010 33.5S 42.6W WEAK WEAKENING SLIGHTLY
12UTC 12.03.2010 35.4S 38.2W WEAK LITTLE CHANGE
00UTC 13.03.2010 BELOW TROPICAL STORM STRENGTH


THIS INFORMATION IS PROVIDED AS GUIDANCE FOR TROPICAL CYCLONE
RSMCS. IT REQUIRES INTERPRETATION BY TROPICAL CYCLONE SPECIALISTS
AND SHOULD NOT BE CONSIDERED AS A FINAL PRODUCT


MET OFFICE, EXETER, UK

TOO 071704


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VALID 081200Z - 091200Z



...NO SVR TSTM AREAS FORECAST...



...SYNOPSIS...



AN ALREADY POWERFUL MID AND UPPER-LEVEL LOW INITIALLY CENTERED OVER

THE SRN ROCKIES WILL INTENSIFY FURTHER WHILE TRANSLATING NEWD INTO

THE CNTRL PLAINS BY TUESDAY MORNING. THIS SYSTEM WILL BE

ACCOMPANIED BY A 70-80 KT MIDLEVEL JET STREAK AND A CORRIDOR OF

12-HR HEIGHT FALLS OF 100-150 M WHICH WILL OVERSPREAD THE SRN PLAINS

THROUGH THE PERIOD.



AT THE SURFACE...AN ELONGATED LOW PRESSURE AREA INITIALLY OVER THE

CNTRL AND SRN HIGH PLAINS WILL CONSOLIDATE INTO A DEEPENING CYCLONE

OVER THE TX/OK PNHDLS MONDAY PRIOR TO OCCLUDING AND SLOWLY FILLING

OVER THE SAME GENERAL AREA DURING THE LATTER HALF OF THE FORECAST

PERIOD. PACIFIC FRONT ASSOCIATED WITH THIS SYSTEM WILL PUSH

EWD/NEWD THROUGH WRN INTO CNTRL PARTS OF OK AND TX...WHILE A WARM

FRONT LIFTS MORE SLOWLY NWD THROUGH CNTRL AND ERN PARTS OF TX.



LATEST MODEL GUIDANCE SUGGESTS THAT THE GREATEST POTENTIAL FOR A FEW

SEVERE STORMS WILL BE CONFINED TO A COUPLE OF AREAS: ONE NEAR THE

OCCLUDING SURFACE CYCLONE OVER THE SRN HIGH PLAINS...AND THE OTHER

NEARER TO THE SYSTEM WARM SECTOR OVER PARTS OF CNTRL/SRN TX.



...OK/TX PNHDLS...SWRN KS...WRN OK...



CLUSTERS OF MAINLY ELEVATED TSTMS ARE EXPECTED TO SPREAD NEWD

THROUGH REGION EARLY IN THE DAY IN ASSOCIATION WITH THE LEADING EDGE

OF STRONGER HEIGHT FALLS ATTENDANT TO UPPER SYSTEM. FORECAST

SOUNDINGS SUGGEST THAT ELEVATED CONVECTIVE INSTABILITY WILL REMAIN

MARGINAL WHICH SHOULD LIMIT THE POTENTIAL FOR AN ORGANIZED SEVERE

HAIL THREAT.



BY AFTERNOON...A SERIES OF LOW-TOPPED STORMS ARE LIKELY TO DEVELOP

FROM VICINITY OF OCCLUDING SURFACE LOW SEWD ALONG PACIFIC/OCCLUDED

FRONT WITHIN A THERMODYNAMIC ENVIRONMENT CHARACTERIZED BY MARGINAL

BOUNDARY LAYER MOISTURE /DEWPOINTS IN THE 40S TO LOW 50S/ BUT STEEP

LAPSE RATES. DEEP-LAYER VERTICAL SHEAR WILL BE DECREASING WITH TIME

OWING TO APPROACH OF MIDLEVEL LOW...BUT LOW-LEVEL WIND PROFILE WILL

EXHIBIT MODEST VEERING E OF SURFACE FRONT. THE PRIMARY HAZARD

ASSOCIATED WITH THESE DIURNAL STORMS WILL BE HAIL /SOME THAT MAY

APPROACH SEVERE CRITERIA/...THOUGH A BRIEF TORNADO IS ALSO POSSIBLE

NEAR SURFACE LOW WHERE AMBIENT VERTICAL VORTICITY IS MAXIMIZED.



...CNTRL OK INTO CNTRL/SRN TX...



HERE TOO...CLUSTERS OF ELEVATED TSTMS WILL BE POSSIBLE EARLY IN THE

DAY IN CONJUNCTION WITH STRENGTHENING WAA ALONG 40-50 KT LLJ AXIS.

THE MAJORITY OF THIS ACTIVITY WILL LIKELY BE LOCATED TO THE N OF

SURFACE WARM FRONT WITHIN A MARGINALLY UNSTABLE ENVIRONMENT. WITH

TIME...REGENERATIVE STORM DEVELOPMENT IS EXPECTED TO BUILD

PROGRESSIVELY SWD/SWWD...EVENTUALLY BECOMING ROOTED IN

MOISTENING/DESTABILIZING WARM SECTOR OVER PARTS OF CNTRL/SRN TX.

FARTHER N ALONG PACIFIC/OCCLUDED FRONT... ISOLATED...SURFACE-BASED

STORMS WILL BE POSSIBLE FROM CNTRL OK INTO N-CNTRL TX MONDAY

AFTERNOON INTO MONDAY NIGHT.



THE HIGHEST BOUNDARY LAYER MOISTURE CONTENT /I.E. DEWPOINTS IN THE

60S/ WILL REMAIN CONFINED TO ALONG AND S OF WARM FRONT OVER

CNTRL/SRN TX. HOWEVER...LAPSE RATES WILL BE WEAKER THAN LOCATIONS

TO THE N/NW...LIMITING MLCAPE TO GENERALLY LESS THAN 1000 J/KG.

MIDLEVEL WIND FIELD WILL STRENGTHEN THROUGH THE DAY TO THE S/SE OF

PARENT CIRCULATION /I.E. GENERALLY S OF THE RED RIVER/...RESULTING

IN INCREASINGLY LONG HODOGRAPHS. HOWEVER...STRONGER LOW-LEVEL SHEAR

ASSOCIATED WITH LLJ AXIS WILL REMAIN LARGELY DISPLACED TO THE NE/E

OF PRIMARY INSTABILITY AXIS THROUGH THE FORECAST PERIOD. THE NET

RESULT IS RATHER LONG...STRAIGHT HODOGRAPHS...SUPPORTIVE OF

ORGANIZED/ROTATING STORMS CAPABLE OF MAINLY HAIL AND DAMAGING

WINDS.



THE MARGINAL INSTABILITY REMAINS THE PRIMARY FACTOR LIMITING A MORE

ROBUST SEVERE WEATHER THREAT. THEREFORE...LOW SEVERE WEATHER

PROBABILITIES WILL BE MAINTAINED IN THIS FORECAST. AN UPGRADE TO

SLIGHT RISK MAY BECOME NECESSARY IN SUBSEQUENT DAY ONE OUTLOOKS ONCE

FINER-SCALE DETAILS IN THE MOISTURE/INSTABILITY FIELD BECOME MORE

CLEAR.



..MEAD.. 03/07/2010
Member Since: July 15, 2006 Posts: 173 Comments: 54268
Quoting cchsweatherman:


All I gotta say is hot damn. Definitely not a good day for a Mediterranean cruise. lol


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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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