Tropical Wave in East Atlantic - (Is INVEST 94L)

[psyclone]

we are nearing peak day (9-10) which features a 90% historical probability of a named storm somewhere in the Atlantic basin. Something needs to happen soon.

[gatorcane]

I guess this is for the area NHC is giving a 60% chance of development? At any rate, the GFS has shifted more south through 168 hours and looks to develop this:

[gatorcane]

Mods can you update title of thread please?

[abajan]

It's up to 70% now!

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT TUE SEP 6 2016

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

... A tropical wave located near the west coast of Africa is producing
disorganized cloudiness and thunderstorms. A low pressure area
is expected to form in association with the wave several hundred
miles west-southwest of the Cabo Verde Islands in a couple of days.
Environmental conditions are conducive for gradual development, and
a tropical depression could form by the weekend while the system
moves west-northwestward to northwestward toward the central
tropical Atlantic.
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...high...70 percent

[abajan]

The TWO says: "A low pressure area associated with a tropical wave is expected to
form several hundred miles southwest or west-southwest of the Cabo
Verde Islands late this week."
Are we talking about the same area?

Yep. I know the thread's title is about the low at 17N but in my reply to Gustywind I mentioned an area near 12N and that's the one the TWO is about. I probably should've started a separate thread.

Actually, it's the area which has just exited Africa.

[Fishing]

How long do you suppose till we have an invest ?
Fishing

[Blown Away]

N/Central Atlantic & BOC have been fertile grounds for developing systems... It's almost money in the bank for the past @10 years... Everywhere else it's a battle...

[abajan]

How long do you suppose till we have an invest ?
Fishing

Will become 93L very shortly (within a few hours at most).

[jason1912]

70% chance of development now.

[Alyono]

70% is far too high, in my opinion

Through 5 days, this will be in the unfavorable MDR, and most models do not do much with it. may have a chance in the 7-10 day time frame once it escapes the MDR

[jlauderdal]

70% is far too high, in my opinion

Through 5 days, this will be in the unfavorable MDR, and most models do not do much with it. may have a chance in the 7-10 day time frame once it escapes the MDR

MU showing development so that should get at least a 30% reduction right there

[Gustywind]

How long do you suppose till we have an invest ?
Fishing

Will become 93L very shortly (within a few hours at most).

waouw, they put some fuel near the coast of Africa . Could be Invest tonight if things continue to boil like that!

[AJC3]

Just wanted to throw this out here...

As has been mentioned by a few posters here, this thread encompasses two separate features.

As best as I can tell, what started all the confusion was the post on page 1 that included the TWO issued by NHC, which was talking about a different feature, and the thread splintered from there.

I have to apologize to whomever started a separate thread Monday morning about the feature now being discussed in this thread, because I deleted that one Monday afternoon. I had looked at the post in this thread about the TWO, and realized that that post and the new thread were talking about the same feature, and just assumed the new thread was a duplicate. Had I realized at the time that this thread had splintered, I would have simply combined the later posts in this thread with the one or two posts in that new thread.

This also warrants another reminder to all posters to make sure you keep the title of any thread that you start accurate, easy to understand, and up to date!

Make sure you account for changes in location, especially for fast moving tropical waves!! If your thread title mentions a LON or LAT/LON, it is your responsibility to change it to match current conditions - using the latest NHC TWDAT is really helpful in this regard! Don't just assume a mod or admin will come along and do that for you!

In this instance, and it's not my intention to pick on the OP, but the original title of this thread was pretty ambiguous as to the location because it didn't include a longitude. - A low near 17N could be anywhere in the basin from the coast of Africa to western Caribbean Sea!

Thanks, and carry on!
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BTW, if anyone is interested in the evolution of the two waves that this thread encompasses, here are snippets taken from the NHC TWDATs since Friday of last week...

144 AM EDT FRI SEP 2 2016 - A tropical wave has been introduced to this analysis with axis extending from 21N20W to a 1012 mb surface low near 16N21W to 09N20W.
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637 AM EDT FRI SEP 2 2016 - A tropical wave is moving across the eastern Atlantic with axis extending from 21N22W to a 1011 mb surface low near 16N23W to 10N23W.
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205 PM EDT FRI SEP 2 2016 - An Atlantic Ocean tropical wave is along 22W/23W from 21N southward, moving westward 10 to 15 knots.
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805 PM EDT FRI SEP 2 2016 - A tropical wave is over the eastern Atlantic with an axis along 24W/25W, through a 1010 mb low near 16N25W.
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137 AM EDT SAT SEP 3 2016 - A tropical wave is over the eastern Atlantic with an axis extending from 21N26W to a 1011 mb low near 17N27W to 09N27W, moving west at 10-15 kt.
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635 AM EDT SAT SEP 3 2016 - A tropical wave is over the eastern Atlantic with an axis extending from 22N28W to a 1010 mb low near 18N28W to 10N28W, moving west at 10-15 kt.
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205 PM EDT SAT SEP 3 2016 - An Atlantic Ocean tropical wave is along 28W/29W from 22N southward, moving westward 10 to 15 knots. A 1012 mb low pressure center is along the tropical wave near 17N.
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805 PM EDT SAT SEP 3 2016 - A tropical wave over the eastern Atlc has an axis extending from 22N30W to a 1012 mb low near 17N30W to 08N30W. The wave is moving W at 10-15 kt.
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205 AM EDT SUN SEP 4 2016 - A tropical wave over the eastern Atlc extending from 07N to 22N with axis near 31W, moving west at 10 kt within the last 24 hours. A 1012 mb center of low pressure is associated with the wave and is located near 18N31W, which is expected to dissipate within the next 24 hours.
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819 AM EDT SUN SEP 4 2016 - A tropical wave is over the eastern Atlc extending from 10N to 21N with axis near 32W, moving west at 10 kt within the last 24 hours. A 1011 mb center of low pressure is associated with the wave and is located near 18N32W, which is expected to move NW to 20N36W within the next 24 hours.
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205 PM EDT SUN SEP 4 2016 - An Atlantic Ocean tropical wave is along 33W/34W from 21N southward, moving westward 10 to 15 knots. A 1012 mb low pressure center is along the tropical wave near 19N.
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805 PM EDT SUN SEP 4 2016 - An Atlantic Ocean tropical wave extends from 09N33W through low pres 1012 mb centered at 20N35W to 21N35W. The wave is moving westward at 10 to 15 knots.
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203 AM EDT MON SEP 5 2016 - A tropical wave is over the central Atlc extending from 08N to 21N with axis near 35W, moving west at 10 kt within the last 24 hours. A 1013 mb low is associated with the wave and is located near 20N36W, which is expected to move NW to 23N39W within the next 24 hours.
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825 AM EDT MON SEP 5 2016 - A tropical wave is over the central Atlc extending from 10N to 20N with axis near 38W, moving west at 10-15 kt within the last 24 hours.
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205 PM EDT MON SEP 5 2016 - An Atlantic Ocean tropical wave is along 35W/36W from 20N southward, moving westward 10 to 15 knots. The wave has been re-positioned, with respect to the analysis of 05/0600 UTC, in order to agree with the satellite imagery. A 1016 mb low pressure center is near 23N37W. The low pressure center has moved away from the 35W/36W tropical wave.

An Atlantic Ocean 1012 mb low pressure center is near 13N45W. (A new thread was started on this feature at viewtopic.php?f=31&t=118284)
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805 PM EDT MON SEP 5 2016 - A tropical wave is over the central Atlc was relocated earlier and currently extends from 10N to 20N with axis along 37W/38W, moving west at 10-15 kt.
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200 AM EDT TUE SEP 6 2016 - A tropical wave is over the central Atlc extending from 10N to 20N with axis near 37W, moving W at 5-10 kt within the last 24 hours.
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631 AM EDT TUE SEP 6 2016 - A tropical wave is over the central Atlc extending from 07N to 20N with axis near 38W, moving W at 5-10 kt within the last 24 hours.

A tropical wave came off the West African coast earlier this morning. The wave extends from 06N to 18N with axis near 17W, expected to move west at 10 kt within the next 24 hours. (This is the feature the last several TWOs have been talking about and what the thread is about now).
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205 PM EDT TUE SEP 6 2016 - Tropical wave in the central Atlantic extends along 39W/40W from 7N-20N moving west near 10 kt over the past 24 hours.

Tropical wave off the coast of Africa extends along 19W from 6N-17N moving west near 15 to 20 kt over the past 12 hours. (The "new" feature, again)

[Kazmit]

Held at 20%/70% as of 8pm.

1. A tropical wave located over the far eastern Atlantic Ocean just
west of the coast of Africa is producing disorganized showers and a
few thunderstorms. A low pressure area is expected to form in
association with the wave several hundred miles west-southwest
of the Cabo Verde Islands in a couple of days. Environmental
conditions are expected to be conducive for gradual development,
and a tropical depression could form by the weekend while the
system moves west-northwestward to northwestward toward the
central tropical Atlantic.
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...high...70 percent

[abajan]

[Nimbus]

Still looks kind of dry out there considering this is the peak of the season.
I remember years these waves would just explode and the convection would expand flat against the stratosphere almost as soon as they left the coast of Africa.

[SoupBone]

Is this the one that might be 93L?

[abajan]

Is this the one that might be 93L?

Yes. I'm surprised it's not yet.

[blp]

I for one am not buying what the models are selling. First it needs to develop and I think the MDR is too hostile for any rapid development like the Euro and UKmet are showing. I think it will stay weak and move further west than progged. I say let's see what we have if anything by the weekend.

[USTropics]

This is P30L:



http://www.met.nps.edu/~mtmontgo/storms2016/P30L.html

SYNOPSIS 2016090600

P30L (NHC: 10% 2-day / 60% 5-day)
11N, 8W
700 hPa

ECMWF: No pouch in analysis. Tiny OW max depicted in the center of a larger circulation at 12 hours. Gradually, steadily intensifies and grows while tracking to the WNW. OW is 1.5x10-9 s-2 at 12 hours and peaks at 16x10-9 s-2 at 108 hours. 120-h position is over 19N.

GFS: Tracking more westward, not gaining as much latitude as ECMWF. 120-h position is about 17N. Weaker than ECMWF, with OW peaking at less than 3x10-9 s-2 at 108 hours.

UKMET:

HWRF-GEN:


ECMWF -8.0 2.8 track 120h
GFS -9.2 2.0 track 120h
UKMET
HWGEN