Two African waves worth mentioning

By: Dr. Jeff Masters , 3:51 PM GMT on July 18, 2009

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There are two African tropical waves worth mentioning today, though neither looks particularly threatening. A tropical wave near 12N 45W, about 1200 miles east of the Lesser Antilles Islands (97 L), is moving west at 15 - 20 mph. This wave is now surrounded by an area of very dry air from the Sahara Desert. The dry air has disrupted most of the wave's heavy thunderstorm activity, and will continue to make it difficult for this system to develop over the next 2 - 3 days. Wind shear is a modest 10 knots over the disturbance, and should remain in the moderate 10 - 15 knot range over the next 2 - 3 days. Thereafter, shear is expected to rise to 20 - 30 knots. This morning's QuikSCAT pass showed no evidence of a surface circulation, and only a modest wind shift associated with 97L. The National Hurricane Center is giving this system a low (less than 30% chance) of developing into a tropical depression in the next 48 hours.

A second tropical wave now approaching the northern Lesser Antilles Islands is under 30 knots of wind shear, and has little prospect of development due to the high shear. However, the wave will bring heavy rain to the islands over the next two days.

None of the computer models are forecasting tropical storm development over the next seven days, and I don't expect either of the two African waves mentioned today to develop over at least the next three days.


Figure 1. Current satellite image of African wave 97L, 1200 miles east of the Lesser Antilles Islands.

I'll have an update Sunday afternoon.
Jeff Masters

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CMC T = 60 Southern Florida

mm5fsu-merge T = 24 GOM

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New shear tendency map...

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.
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It's forward speed may be it's worst enemy right now...
Member Since: August 17, 2005 Posts: 26 Comments: 15633
1445. Drakoen
It has crossed the 28C isotherm...did so a few hours ago...
Member Since: October 28, 2006 Posts: 57 Comments: 29883
Quoting homelesswanderer:


Lol. Yes I enjoyed it! Stood at the door and watched it barrel through. It was wild! Just wish I had my new camera figured out. :(
Lol. I'm just never ready.


There's always a next time.. had the good old Canon Rebel out getting a few shots... The rain along with wind and lightning was welcomed with open arms here
Member Since: August 30, 2007 Posts: 0 Comments: 1837
1443. Patrap
There was a Storm called Gustav that did a Boatload of Misery is S La. as well.

But Like ya said,not much press,but it did manage to Draw a lotta blog posts.

Member Since: July 3, 2005 Posts: 420 Comments: 127512
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I'm not going to make any judgments on ex-97 until I see something on it in the afternoon. It has less dry air to contend with now, and the area is fairly conducive for now. It may regain invest status tomorrow, but as for anything beyond that, I can't say. Chances are probably low.
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Quoting Drakoen:



Don't put too much pressure on him lol. They don't like to hold their convection that long.


Well Im not really talking about convection. Im talking about if it can get some of its organization back between now and then. IE 850mb vorticity and structure. It would just be an added bonus if it could hold its convection till then...though I doubt it.
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Quoting CybrTeddy:


Your right, 2 Category 5 landfalls in 2007,
the 3rd most destructive Hurricane to hit the US in 2008, your absolutely right, not been too many since Katrina. Oh wait..

Just cause the media doesn't bother to cover them doesn't mean they haven't existed. I personally think well, media coverage was absolutely poor for Ike. The day after landfall, people didn't even know of Ike. Thats because well.. things went right for Texas. Gustav recived way more coverage..


thanks for saying that...soooo true
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Quoting SomeRandomTexan:


did you enjoy your rain this evening? I know i went and stood in it like a fool


Lol. Yes I enjoyed it! Stood at the door and watched it barrel through. It was wild! Just wish I had my new camera figured out. :(
Lol. I'm just never ready.
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Quoting WeatherStudent:
I'm I being ignored on here this morning?


no y?
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EX97L is relatively small in comparison to the Antilles blob earlier today.

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1435. Drakoen
Quoting Stormchaser2007:
I want to see EX97L tomorrow at 2pm before saying anything.

Things will change between now and then.



Don't put too much pressure on him lol. They don't like to hold their convection that long.
Member Since: October 28, 2006 Posts: 57 Comments: 29883
Quoting WeatherStudent:
I'm I being ignored on here this morning?


Hi WeatherStudent
Member Since: July 1, 2008 Posts: 13 Comments: 7340
Member Since: May 16, 2009 Posts: 1 Comments: 1231
If the navy is continuing to update on 97L. I'm not gonna call it X97L. I'll call it 94L(NAVY) :)
Member Since: July 1, 2008 Posts: 13 Comments: 7340
I want to see EX97L tomorrow at 2pm before saying anything.

Things will change between now and then.
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1429. Drakoen
Quoting Funkadelic:


Lol so where EX97L is right now, what time is it in that part of the carribean? like isnt it 3:25am?

Btw, thanks for answering my questions lol This stuff can get confusing (time zones)


It is 2:28am where ex 97L is. He is two hours ahead of Eastern Standard Time.
Member Since: October 28, 2006 Posts: 57 Comments: 29883
I think ex97L has a decent chance to become the first named storm of the season.
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1427. Drakoen
Quoting reedzone:
ok, sorry.. sheesh, not DMAX.. Though I see these things blow up convection around 10 p.m. thru morning. Seen it with lots of past invests.


That's because the difference in temperature between the ocean and land is becoming greater. It is the greatest before sunrise at diurnal maximum.
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Quoting SomeRandomTexan:
I think he meant as it approaches D-max...


Its close to 5 hours away.
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Drak, is ex-97 plowing through that dry air, looks like?
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ok, sorry.. sheesh, not DMAX.. Though I see these things blow up convection around 10 p.m. thru morning. Seen it with lots of past invests.
Member Since: July 1, 2008 Posts: 13 Comments: 7340
1422. Drakoen
Quoting SomeRandomTexan:
I think he meant as it approaches D-max...


He's been saying it's in Dmax for the umpteenth time now
Member Since: October 28, 2006 Posts: 57 Comments: 29883
I think he meant as it approaches D-max...
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1420. Drakoen
Quoting Stormchaser2007:


Good to see your back Drak.


Good to be back...
Member Since: October 28, 2006 Posts: 57 Comments: 29883
1419. Drakoen
Quoting Patrap:
We gotta get a Dmin and Dmax Tutorial,and a easy to access one.


People will still ask. Dmin, Dmax monomania
Member Since: October 28, 2006 Posts: 57 Comments: 29883
Quoting Drakoen:


For the umpteenth time...


Good to see your back Drak.
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1417. Patrap
We gotta get a Dmin and Dmax Tutorial,and a easy to access one at that.
Member Since: July 3, 2005 Posts: 420 Comments: 127512
1416. Drakoen
Quoting Stormchaser2007:


This isnt DMAX...DMAX is before sunrise.


For the umpteenth time...
Member Since: October 28, 2006 Posts: 57 Comments: 29883
Quoting reedzone:
Well I am impressed, 97L is holding it's own and DMAX is helping it go through. If organization continues, they should re-tag it by the a.m.


This isnt DMAX...DMAX is before sunrise.

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Quoting homelesswanderer:


Oh ok. Thank you very much too. :)


did you enjoy your rain this evening? I know i went and stood in it like a fool
Member Since: August 30, 2007 Posts: 0 Comments: 1837
1413. Drakoen
A little more recent:
Member Since: October 28, 2006 Posts: 57 Comments: 29883
Quoting glenclear:
You should be blogging about the record cool wave. But I know you can't. Their will not be to many huricanes this year. By the way their has not been to many since Katrina.


Your right, 2 Category 5 landfalls in 2007,
the 3rd most destructive Hurricane to hit the US in 2008, your absolutely right, not been too many since Katrina. Oh wait..

Just cause the media doesn't bother to cover them doesn't mean they haven't existed. I personally think well, media coverage was absolutely poor for Ike. The day after landfall, people didn't even know of Ike. Thats because well.. things went right for Texas. Gustav recived way more coverage..
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1411. Patrap
That's it Pat...muchas Thankas!

..Anytime,LOL
Member Since: July 3, 2005 Posts: 420 Comments: 127512
That's it Pat...muchas Thankas!
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Quoting beell:
Drak is too quick-yes Homeless, the axis or "centerline" of the ridge.

The other is the 1014mb line of constant pressure.


Oh ok. Thank you very much too. :)
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Quoting Stoopid1:
Long time no see. Another quite night in the tropics, I see. Well, I won't write a story of my last 3 months, but I have a blog on it if you'd like to see. I'm in the Navy now, so my time to track the tropics will be limited, but I still hope to get on and do so when I can. As for 97, I haven't seen much on it, but it doesn't seem like a player to me. I still need to get some info, though.


Let me say.. THANK YOU.. for serving our country
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Stoopid!!!! The immortal creator of the Stoopid Circle!!!! Thanks for your service...
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1404. Drakoen
Member Since: October 28, 2006 Posts: 57 Comments: 29883
1403. Patrap
Heres one that forms here and rides up towards "Middle" Carolina..


Member Since: July 3, 2005 Posts: 420 Comments: 127512
You should be blogging about the record cool wave. But I know you can't. Their will not be to many huricanes this year. By the way their has not been to many since Katrina.
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1400. JLPR
Quoting TampaSpin:


Thank you for being observant...its not tearing it apart yet....just enough to cause some uplift.....but, in 6-12hrs...its poof as i have been stating...why do you all think NHC took the invest away......


no prob xD normally this small systems need perfect conditions to develop as opposed to large systems so if that ULL moves a little bit more to the south to cause some decent shear 97L might be done for
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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.