New African disturbance 96L likely to develop

By: Dr. Jeff Masters , 2:55 PM GMT on September 07, 2009

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A tropical wave (96L) that emerged off the coast of Africa yesterday has organized rather quickly, and will likely become a tropical depression by Tuesday night. Satellite imagery from the European satellite shows a well-organized circulation, but not enough heavy thunderstorm activity near the center of circulation to be considered a tropical depression. The storm is far enough south that the dry air of the Saharan Air Layer is not a major impediment to development. Wind shear is moderate, 10 - 15 knots, and ocean temperatures are 1 - 2°C above the threshold needed for tropical cyclone formation.


Figure 1. Morning satellite image of 96L, off the coast of Africa. The remains of disturbance 95L, which are under 30 - 40 knots of wind shear, can be seen at upper left.

The forecast for 96L
Most of the models develop 96L, and the chances are that this disturbance will become Tropical Storm Fred later this week. The system will initially move west-northwest, but by Thursday, a strong trough of low pressure passing to 96L's north will pull the storm to the northwest, and may be capable of fully recurving the storm to the northeast. However, most of the models foresee that 96L will not move far enough north for this to happen, and that the storm will have to wait for the next trough of low pressure. With the steering pattern for this year continuing to feature plenty of deep troughs of low pressure moving off the U.S. East Coast, the odds of 96L making it all the way across the Atlantic to threaten land areas appear low. Still, much that is unexpected can and does happen in the world of tropical meteorology, and 96L bears watching.

North Carolina low
An area of concentrated thunderstorms has developed off the North Carolina coast in association with the remains of an old cold front. This system is under about 20 - 30 knots of shear, and is not tropical. However, it will bring heavy rain to eastern North Carolina today and Tuesday, as the storm slides north-northeastward along the coast.

I'll have an update Tuesday.

Jeff Masters

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Quoting MiamiHurricanes09:
It should be moved back to orange, convection is lacking too much.




That would be completely stupid if they did that. It needs to fire one good round of thunderstorms then as soon as that happens it would be classified.

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85. IKE
Quoting Bordonaro:

I have come to the conclusion most weather affecanidos come complete with attitudes also!!


They do on here. All I was doing was emphasizing Dr. Masters use of REcurve. Then I was accused of leaving off part of what he was saying.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
Quoting Weather456:
Dakster,

true but this is how I interpret it

recurve - become curved backward or downward

so a curve would be shifting wnw to nw

but then re-curve is to curve that track backwards that is nw to ne



yeah you're right i got it ;)

to recurve is to curve. poetic
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tap...tap...tap...Is this thing on? I tell ya, I get no respect. Just yesterday I looked outside my window to check on the weather...and I got arrested for mooning!
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Quoting extreme236:


Um, where is 30-40kts cause all I see is 20kts down over this blob...there is an anticyclone south of it over Mexico. Not saying its developing or is a threat to, just saying it isn't 30-40kts.



Yellow and Orange is 30-40kts just to the North and 20-30kts in its area to be more accurate........still nothing even close to forming.......its just divergence now.....Maybe in 3-4 days!
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Quoting Weather456:
Dakster,

true but this is how I interpret it

recurve - become curved backward or downward

so a curve would be shifting wnw to nw

but then re-curve is to curve that track backwards that is nw to ne



I never disagreed with you. It doesn't make logical sense, but it is the definition of recurve. (I think I said it is one of the idiosyncrasies of the English Language.)

I can think of another example between curve and recurve, but this is a family blog so I digress.
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Quoting MiamiHurricanes09:
It should be moved back to orange, convection is lacking too much.


No, why would you move it to red? The other agency says its already a TD, just not SAB.
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tr. & intr.v. re·curved, re·curv·ing, re·curves
To curve (something) backward or downward or become curved backward or downward.


So for all intensive purposes..."recurve doesn't neccesarily mean "to curve again". Think of it in term or a "Recurve Bow".....Like a bow and arrow...it refers to the shape.
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move back to orange?

um why?
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Quoting MiamiHurricanes09:
It should be moved back to orange, convection is lacking too much.


??????

It is fine at red.
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Quoting laflastormtracker:
You all bicker like little children about systems that are half way around the world OR haven't even developed yet...

I have come to the conclusion most weather affecanidos come complete with attitudes also!!
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Dakster,

true but this is how I interpret it

recurve - become curved backward or downward

so a curve would be shifting wnw to nw

but then re-curve is to curve that track backwards that is nw to ne

Member Since: July 24, 2005 Posts: 407 Comments: 19076
Quoting Stormchaser2007:


Yes.
It should be moved back to orange, convection is lacking too much.
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Quoting hurristat:
Is that little blob to the northwest of 96L the remnants of 95L?


llc got displaced, thats the thunderstorm activity that remains?
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Quoting PcolaDan:


So if you want to report someone, do you have to port them first?


Hehe... since report is the entire word. You would be Re-Reporting them... Or as presslord would say. Reeeeeeeeeeported.
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Quoting hurristat:
Is that little blob to the northwest of 96L the remnants of 95L?


yep
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Quoting TampaSpin:


100% NO CHANCE yet.....maybe in 3-4 days. There is nothing at any levels on Vorticity and Shear is 30-40kts......Nothing there but divergence.


Um, where is 30-40kts cause all I see is 20kts down over this blob...there is an anticyclone south of it over Mexico. Not saying its developing or is a threat to, just saying it isn't 30-40kts.
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During the month of october in a normal season southeast florida would have to watch those stalled fronts in the gulf/caribbean but el nino's enfluence has pretty much shut down most of the caribbean this season.Great news if you asked me as the really took a beating last season with several major hurricane impacts on the cuban island.
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Quoting Weather456:


the same time I was accuse of wanting it to go over the islands becuz of I wanted rain. I did wanted the rain, but that was not the basis of my forecast (a saw high building in) - the rain was just an added benefit.


Same as i did which is when IKE started his RECURVE or CURVE idea as usual.
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96L dos not look has good has it was this time sunday we sould give it more time be for they make it a TD
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Is that little blob to the northwest of 96L the remnants of 95L?
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Quoting Dakster:
WEather456 - I think the arguement is how can something "recurve" if it hasn't curved at least one time yet.

Kind of like, refinishing furniture - you gotta "restart" - which makes sense since it was already done once.


So if you want to report someone, do you have to port them first?
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You all bicker like little children about systems that are half way around the world OR haven't even developed yet...
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Quoting AllStar17:


It appears 96L is gradually organizing, but is lacking some strong convection....as soon as it gets that, I would expect a Tropical Depression to be classified.


If you look at 15E over in the EPAC I'd say 96L is pretty close convectively to being a TD. If SAB was more inline with the TAFB we wouldve already had it.
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Quoting AllStar17:


It appears 96L is gradually organizing, but is lacking some strong convection....as soon as it gets that, I would expect a Tropical Depression to be classified.


It should begin to develop some stronger convection later today or early tonight. I Tropical depression is likely by tomorrow.
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Quoting laflastormtracker:


I'm with ya things sure are persisting down there...


100% NO CHANCE yet.....maybe in 3-4 days. There is nothing at any levels on Vorticity and Shear is 30-40kts......Nothing there but divergence.
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Quoting Weather456:


the same time I was accuse of wanting it to go over the islands becuz of I wanted rain. I did wanted the rain, but that was not the basis of my forecast (a saw high building in) - the rain was just an added benefit.


yup I remember that, and you were right lol
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Quoting Stormchaser2007:
10:30am Tropical Update.



It appears 96L is gradually organizing, but is lacking some strong convection....as soon as it gets that, I would expect a Tropical Depression to be classified.
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Quoting MiamiHurricanes09:
is that a current image of 96L?


Yes.
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Quoting TampaSpin:


IKE i believe you called for Erika to move well out to sea, well before Puerto Rico and the Islands......to the best of my memeory


the same time I was accuse of wanting it to go over the islands becuz of I wanted rain. I did wanted the rain, but that was not the basis of my forecast (a saw high building in) - the rain was just an added benefit.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Quoting Stormchaser2007:
10:30am Tropical Update.

is that a current image of 96L?
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AOI

AOI

AOI

AOI


Updated with some of the graphics on the 850MB Relative Vorticity Overlay
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WEather456 - I think the arguement is how can something "recurve" if it hasn't curved at least one time yet.

Kind of like, refinishing furniture - you gotta "restart" - which makes sense since it was already done once.
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.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Quoting IKE:


I wasn't even emphasizing whether it went back west or not. Just emphasizing Dr. Masters using recurving.

96L has a 1 in 100 chance of affecting the USA and that may be generous.


Did you know that 83.7% of all statistics are made up on the spot?
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10:30am Tropical Update.

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48. IKE
Quoting TampaSpin:


IKE i believe you called for Erika to move well out to sea, well before Puerto Rico and the Islands......to the best of my memeory


I believe you called for it to possibly pull an Andrew and be a threat to the NC/SC area.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
Quoting btwntx08:
like i mention earlier i wouldn't be surpised if the boc aoi goes yellow at 2 pm imo


I'm with ya things sure are persisting down there...
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Thanks, Doc!
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Quoting Dakster:


Just think, if it rained for ANOTHER 15 hours, it would be like FAY was for us. That storm seemed like it lasted a week.


funny thing was they gave free afternoons thursday in preparations for erika, but it was sunny and never came. friday everyone back to work. I think friday 7PM it started to rain, and didn't let up till like, sunday in the AM
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Quoting serialteg:
Re-curving is curving after a curve, I guess

"Oh Well"
RECURVING MEANS TO MOVE W, THAN WNW, THAN NW, THEN N, THEN NE. Goodness gracious.
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Quoting IKE:


Probably the remnants of Erika.....


IKE i believe you called for Erika to Curve or Recurve well out to sea, well before Puerto Rico and the Islands......to the best of my memeory
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The best way to look at TC motion is:

a turn is a shift in the same direction (w to nw)

a re-curve is a shift in opposite direction (nw to ne)
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Quoting serialteg:


sorry, but 97L has been the strongest storm of the seasn for me in pr... brought heavy heavy winds and rains to south PR, for erika it rained for 15+ hours straight...


Just think, if it rained for ANOTHER 15 hours, it would be like FAY was for us. That storm seemed like it lasted a week.
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Quoting TexasHurricane:
unless it develops an LLC that area is absolutely nothing to worry about right now.
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Is the NAM really any good for picking up tropical cyclogenesis? Oh wait, it shows a low moving over the Florida Panhandle, what a coincidence.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Re-curving is curving after a curve, I guess

"Oh Well"
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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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