Strong wave emerging Africa (Is Invest 93L)

[cycloneye]

The predict team made a new analysis of this pouch.

Pouch 13L new analysis

[blp]

Hurricane Ike developed at 17.2N 37.0 W and made it all the way to Texas. We can guess all we want on the future track of this potential system but until we actually have a storm we wont know at what lat and long this develops.

I was looking at development between 17W & 24W longitude, but I understand your point. It looks to me like it may come off below 15N. Below 15N opens up a new ballgame. One thing I have noticed is that a lot of the ones that do make it across at some point had a dip to the SW which would obviously allow them to get further west.

[KWT]

168hrs GFS and is far more northerly than in previous runs, very close to the ECM:

http://raleighwx.americanwx.com/models/ ... cal168.gif

Might be a threat to Bermuda though.

I suspect the GFS develops this too far north but I think the general motion won't be far off, with 280-285 likely.

[Hurricaneman]

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products

This will probably come off Africa at 11 N in 36 hrs, The gfs IMO has this coming off about 7 to 8 degrees too far north

[cycloneye]

It doesn't matter at which latitude this emerges as by the looks of things it will be a classic CV longtracker that will be great to track in open waters,unless at some point it affects a landmass down the road.

[ConvergenceZone]

It doesn't matter at which latitude this emerges as by the looks of things it will be a classic CV longtracker that will be great to track in open waters,unless at some point it affects a landmass down the road.

I agree and whether or not it recurves all depends as if there's a high in place or not, and
nobody can say at this point if it won't be there or if it will be there.

[SFLcane]

[OuterBanker]

Will the 20/60 rule hold true this year? (above 20 n at 60 w fish, below look out).

Also, for us in NC we have the Cycloneye effect.

Just about every storm that hits NC goes through Cycloneye (PR) first.

No offense Cycloneye

[AEWspotter]

While GFS may have this system emerging too far north, I don't think it will emerge as far south at 11N. My money would be on emerging at 14N and passing very close to the CV Islands before taking on a more westward trajectory.

[KWT]

Totally agree, 13-14N looks about right and indeed that's pretty much where currently the best rotation of the system and the strongest convectyion has been located today.

Motion at first maybe more to the WNW as an upper trough digs down way to the north near the Azores but once thats over it'll be westward for a time.

[jimvb]

The posts in this forum, and in particular my posts, are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products. Nevertheless...

It seems to me that Invest 92L may help determine the future of this Mali storm, also known as Pouch 13. I notice that in the 2012 Aug 8 00Z GFS run, that Invest 92L fizzled out, and Pouch 13 went across the Atlantic and threatened the eastern seaboard. But in the Euro model at the same time (and at 12Z), Invest 92L hangs in there, at least as a small tropical wave or disturbance of some sort. When Pouch 13 approaches it, the two storms do whenever two storms come close together. They rotate around each other counterclockwise. That is why 92L slows down or even retrogrades (to use a term from astronomy) and why in the Euro 00Z, Pouch 13 is kicked to the NE and so takes a trajectory that would have it miss the coast. Indeed, in the 12Z GFS run, 92L does hang together to some extent, and Pouch 13 turns to the NE and misses the coast by a wide margin. At least this is my idea of what is going on.

[Hybridstorm_November2001]

The posts in this forum, and in particular my posts, are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products. Nevertheless...

It seems to me that Invest 92L may help determine the future of this Mali storm, also known as Pouch 13. I notice that in the 2012 Aug 8 00Z GFS run, that Invest 92L fizzled out, and Pouch 13 went across the Atlantic and threatened the eastern seaboard. But in the Euro model at the same time (and at 12Z), Invest 92L hangs in there, at least as a small tropical wave or disturbance of some sort. When Pouch 13 approaches it, the two storms do whenever two storms come close together. They rotate around each other counterclockwise. That is why 92L slows down or even retrogrades (to use a term from astronomy) and why in the Euro 00Z, Pouch 13 is kicked to the NE and so takes a trajectory that would have it miss the coast. Indeed, in the 12Z GFS run, 92L does hang together to some extent, and Pouch 13 turns to the NE and misses the coast by a wide margin. At least this is my idea of what is going on.

Oh you mean like this -

http://en.wikipedia.org/wiki/Fujiwhara_effect

[jimvb]

Yes.

[cycloneye]

Saved image at 21:30 UTC or 5:30 PM EDT.

[cycloneye]

I have a general question about NHC/West Africa waves. Has NHC mentioned a system in Tropical Weather Outlooks that are still inside West Africa in past years?

[KWT]

GFS far weaker on its 18z run, doesn't really develop it all that much. Partly down to the fact that it starts weaker as well from the looks of things.

[Gustywind]

I have a general question about NHC/West Africa waves. Has NHC mentioned a system in Tropical Weather Outlooks that are still inside West Africa in past years?

Excellent post, very interresting question!!! I will be glad to have an answer from the others posters

[Zanthe]

I have a general question about NHC/West Africa waves. Has NHC mentioned a system in Tropical Weather Outlooks that are still inside West Africa in past years?

I think so. Like I mentioned before, check out TS Christine from 1973. Officially declared a TD over Guinea.

[Florida1118]

I have a general question about NHC/West Africa waves. Has NHC mentioned a system in Tropical Weather Outlooks that are still inside West Africa in past years?

I think so. Like I mentioned before, check out TS Christine from 1973. Officially declared a TD over Guinea.

The genesis of Julia was not well anticipated. The disturbance that became Julia was
introduced into the Tropical Weather Outlook (TWO) with a medium (30%) chance of formation
only 18 h before the system became a tropical cyclone. This prediction was raised to a high
(70%) chance 6 h before genesis occurred. The lateness in mentioning the disturbance that
spawned Julia may have been due to the typical operational practice of not introducing an
African wave disturbance into the TWO until it reaches the Atlantic Ocean.

They do not, as stated from Hurricane Julia's Tropical Cyclone Report in 2010. They probably wait just to see if it poofs or not.

[KBBOCA]

I thought I'd try to find some weather obs from Senegal to track this storm.

There's a town with an airport, Kedougou, right in the storm's path, but unfortunately the station seems to be down since 16h GMT (5 hours ago)

Here's a list of Senegal's airports:
http://en.wikipedia.org/wiki/List_of_ai ... in_Senegal

And here's a map of Senegal's airports.
http://www.mapsofworld.com/internationa ... negal.html

if I find any interesting obs I will post them.