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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AussieStorm - Thanks for the very detailed analysis. So an El Niño is not a good thing for rainfall for you, if it developes.

You need a La Niña to get back to normal.

Out of curiosity, why have records only been kept since 1950 in Australia? I thought Australia has been inhabited for a lot longer than the past 60 years.
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Quoting NWWNCAVL:
Totaly off subjuect and I apologize in advance if i offend anyone.

My daughter is having surgery tomorrow at Brenners Childrens Hospital and i am reaching out for Prayers to anyone willing...The more the better...8:00 a.m....TIA...

No hard feelings if a Ban is in order...

She will be in mine and my families prayers.
Wish her a heartfelt good luck and god bless
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96L - DT numbers

SAB - 1.0
TAFB - 2.5
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Off topic but figured so many folks in here with such a wide array of jobs. If there is anyone who is in the construction biz, can you please email me? Just a question.

Heat has finally broken here in S. Cal and it feels AWESOME to not be sweating.
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Quoting NWWNCAVL:
Totaly off subjuect and I apologize in advance if i offend anyone.

My daughter is having surgery tomorrow at Brenners Childrens Hospital and i am reaching out for Prayers to anyone willing...The more the better...8:00 a.m....TIA...

No hard feelings if a Ban is in order...

I'll pray and best of luck to here.
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12z GFS @ 126hrs, GOM heating up??

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Quoting NWWNCAVL:
Totaly off subjuect and I apologize in advance if i offend anyone.

My daughter is having surgery tomorrow at Brenners Childrens Hospital and i am reaching out for Prayers to anyone willing...The more the better...8:00 a.m....TIA...

No hard feelings if a Ban is in order...

I'll pray
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Totaly off subjuect and I apologize in advance if i offend anyone.

My daughter is having surgery tomorrow at Brenners Childrens Hospital and i am reaching out for Prayers to anyone willing...The more the better...8:00 a.m....TIA...

No hard feelings if a Ban is in order...
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Quoting Dakster:
Aussie - Does your rainfall increase or decrease during an El Nino event?

In other words, is this going to get worse or better for you in the coming months?

Mixed El Niño indicators, but Pacific continues to warm

Temperatures have risen across the equatorial Pacific during the past fortnight, in response to generally weakened Trade Winds. However, the warming has been strongest in the west of the basin which has resulted in anomalous warmth across the entire breadth of the Pacific. The typical El Niño pattern sees warmth concentrated in the central or eastern Pacific with cooler than normal temperatures in the western Pacific.

Furthermore, the coupling between the ocean and atmosphere which amplifies and maintains El Niño events has so far failed to eventuate. The neutral SOI (−5) and sub-surface cooling are evidence of this.

Leading climate models continue to predict further development of the El Niño (i.e. warming of the Pacific), although not as emphatically as a month or two back. Therefore, the odds remain strongly in favour of 2009 being recognised as an El Niño year.

El Niño events are usually (but not always) associated with below normal rainfall in the second half of the year across large parts of southern and inland eastern Australia. In keeping with this, rainfall has been below average across much of eastern Australia during July and August, with particularly dry conditions through Queensland and parts of NSW.

Conditions have recently been very warm for the time of year across Australia, with the national mean August temperature being the highest since records began in 1950. For more information about the exceptional winter heat over large parts of Australia see the Special Climate Statement issued on the 26th of August.

The most recent values of the Indian Ocean Dipole (IOD), as measured by the Dipole Mode Index (DMI), are near zero. The Bureau's POAMA model suggests the DMI should remain neutral over the coming months.
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Quoting Drakoen:
Reading of 1006mb just south of the circulation:

Convection beginning to fire once more, indicative that 96L is strengthening.
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Quoting AussieStorm:

For the 8-month period from January to August 2009, serious to severe rainfall deficiencies remain evident over the south coast of NSW and over central and eastern Victoria. A few very isolated areas of serious to severe deficiencies also remain evident across central Australia and in parts of southwest WA, including an area of the Great Southern district centered on Lake Grace. Several stations near Melbourne and in Gippsland have recorded lowest on record rainfall for the period. Low August rainfall across all of these regions has resulted in a slight worsening of the short-term deficits compared with those that existed for the 7-month period ending July 2009.
Read more here


Thanks for the information and I sincerely hope the drought conditions improve in your nation! Here in the US, S Central Texas and most of California are in severe drought conditions. But the El Nino will bring them rain over the coming months, hopefully enough to end the drought!
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Victoria - if that low in the BOC flares up you have a chance to get some rain.
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Any wishcasters for S.Texas?Sure could use the rain..
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Aussie - Does your rainfall increase or decrease during an El Nino event?

In other words, is this going to get worse or better for you in the coming months?
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Reading of 1006mb just south of the circulation:

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North Carolina Low and 96L
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Quoting Bordonaro:

Have the drought conditions in Australia improved?

For the 8-month period from January to August 2009, serious to severe rainfall deficiencies remain evident over the south coast of NSW and over central and eastern Victoria. A few very isolated areas of serious to severe deficiencies also remain evident across central Australia and in parts of southwest WA, including an area of the Great Southern district centered on Lake Grace. Several stations near Melbourne and in Gippsland have recorded lowest on record rainfall for the period. Low August rainfall across all of these regions has resulted in a slight worsening of the short-term deficits compared with those that existed for the 7-month period ending July 2009.
Read more here

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Quoting Dakster:


Sorry I wasn't specific, it seems to apply when UM, Gators, or FSU play each other.

Anyways, back to the weather. Are we placing bets on when Fred will be declared?


haha gotcha ;) um, fred, tomorrow evening?
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Quoting tornadodude:


well I guess us at Purdue must be pretty cocky then ;)

good afternoon all


Sorry I wasn't specific, it seems to apply when UM, Gators, or FSU play each other.

Anyways, back to the weather. Are we placing bets on when Fred will be declared?
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Quoting MiamiHurricanes09:
You have the typing skills of a 4 year old.


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Tropical update for anyone who missed it before.

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Quoting Acemmett90:

Wow comming fro a buy saying we had noughing to worry abour
i suggest you read so of Keepers orca and Stomw post next time if dont want to make a fool of your self
You have the typing skills of a 4 year old.
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Quoting Dakster:
I hope that FSU is as cocky and overconfident as you are. The cockiest team loses the most.


well I guess us at Purdue must be pretty cocky then ;)

good afternoon all
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The spin in the S. GOM is that a new storm building?
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happy end of summer
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Quoting AussieStorm:

3.6mm(1.4in) at my place
Sydney City had 5.4mm(2.1in)
Sydney Airport had 6.2mm(2.4in)

Have the drought conditions in Australia improved?
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Quoting serialteg:


check out post 148 borondaro i quoted his explanation :)

Thanks :0) !
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Quoting 786:
Thanks, right no BAMS is showing a loop back to Africa around where it came from.lol


talk about back to your roots
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Quoting BurnedAfterPosting:


Oh right you mean that team in N Florida that is too chicken to schedule any tough opponents outside their conference lol

It was pathetic this week, Alabama played Virginia Tech, Georgia goes to OK State and even LSU travels all the way to Washington

Yet the precious Gators have Charleston Southern? lol

Is this a weather blog or a sports blog?????
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156. 786
Thanks, right no BAMS is showing a loop back to Africa around where it came from.lol
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I hope that FSU is as cocky and overconfident as you are. The cockiest team loses the most.
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Quoting Bordonaro:

I am new to some of these charts, could you briefly explain how its read! Thanks :0)


check out post 148 borondaro i quoted his explanation :)
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Quoting hurricane23:
Having said that the 40 day 200-hPa velocity potential forecast says we might see some favorable conditions in few weeks as we had into the month of my birthday. I have my doupts though the way things have been down there so far this season. you can get those 15-40 day outlooks here.

I am new to some of these charts, could you briefly explain how its read! Thanks :0)
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Quoting justmehouston:
That looked like a bad Thunderstorm Aussie ...how much rain did you get?

3.6mm(1.4in) at my place
Sydney City had 5.4mm(2.1in)
Sydney Airport had 6.2mm(2.4in)
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Quoting hurricane23:


Sorry about that...Basically i find these particular maps/model rather interesting as the highlight potential areas of sinking/rising air.Areas shaded in green indicate the possibility of rising air which is what your looking for if you like tc's and the brownish indicates sinking air which is not what you want when looking for positive indicators for tc development.

As of now the 40-day Chi predicts we might see some favorable conditions around that time.


all right than you and storm W for answering my questions :D someday i'll be able to answer you guys some lol
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Quoting PensacolaDoug:




Now that was a good one!


that was hilarious wasnt it? LOL
Quoting 786:


LOL Thanks! but seriously almost all of the ensemble models are showing this - this is after it is to recurve so ..are they seeing a weaker system? are they seeing the high move back in? how reliable are they? and if reliable then this is not necessarily a fish storm..


About a reliable as they were with Erika, which is to say - not much...

I like Dr. Masters comment about anything can happen. It is not developed enough for the models to get a good handle on the system. (In My Humble Opinion) Maybe they will get better as development occurs. However, when models trend a certain way, I do think it is something to watch out for. If you look at the BAM model suite, that should give you an idea of what the storm should do depending on how deep the storm is. BAMS (Shallow - TS and below), BAMM (Medium) Minor Canes, BAMD, Major Canes. (I forget the cat breakdown).
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Quoting mikatnight:


I'd rather dicker than bicker...

lol!
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Quoting Dakster:


Sure. We can talk about how the canes are going to blow through Tallahassee tonight.




Now that was a good one!
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Quoting Acemmett90:

Drak i know he's canes fan but he also a troll


Ur gonna get it :)
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Quoting Dakster:


Sure. We can talk about how the canes are going to blow through Tallahassee tonight.


Just so long as they don't make the very bad mistake of going through Gainseville first ;)
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138. 786
Quoting BurnedAfterPosting:


Bill Gates stationed in the Azores lol


LOL Thanks! but seriously almost all of the ensemble models are showing this - this is after it is to recurve so ..are they seeing a weaker system? are they seeing the high move back in? how reliable are they? and if reliable then this is not necessarily a fish storm..
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Quoting MiamiHurricanes09:
Are we going to get back to the tropics?


Sure. We can talk about how the canes are going to blow through Tallahassee tonight.
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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.