Tropical Wave SW of Cabo Verde Islands: (Is Invest 96L)

[cycloneye]

A broad area of shower and thunderstorm activity is associated with
a tropical wave located several hundred miles southwest of the Cabo
Verde Islands. Little to no development of the wave is expected for
the next few days while it moves westward across the eastern and
central tropical Atlantic Ocean at about 15 mph. Environmental
conditions are forecast to become more conducive for development
over the weekend and a tropical depression could form by early next
week several hundred miles east of the Lesser Antilles.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...60 percent.

[abajan]

A broad area of shower and thunderstorm activity is associated with
a tropical wave located several hundred miles southwest of the Cabo
Verde Islands. Little to no development of the wave is expected for
the next few days while it moves westward across the eastern and
central tropical Atlantic Ocean at about 15 mph. Environmental
conditions are forecast to become more conducive for development
over the weekend and a tropical depression could form by early next
week several hundred miles east of the Lesser Antilles.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...60 percent.

Thanks. I'm trying to locate the image but can't find it anywhere online as yet.

[artist]

A broad area of shower and thunderstorm activity is associated with
a tropical wave located several hundred miles southwest of the Cabo
Verde Islands. Little to no development of the wave is expected for
the next few days while it moves westward across the eastern and
central tropical Atlantic Ocean at about 15 mph. Environmental
conditions are forecast to become more conducive for development
over the weekend and a tropical depression could form by early next
week several hundred miles east of the Lesser Antilles.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...60 percent.

Thanks. I'm trying to locate the image but can't find it anywhere online as yet.

Updated image

[LarryWx]

At what longitude do the trade winds start to not have an effect on the westward movement? When does the Bermuda High have to pick the system up and keep it moving west? Still relatively new to the science behind meteorology but to me it seems like the ridging in the Atlantic isn't strong enough to keep the system moving westward after it becomes uninfluenced by the trades. Or is it the trough on the EC that is causing the ridge to move out of the way and letting it recurve? Like I said, still new so if anyone can help me understand what we are looking for i'd greatly appreciate it!

Hi,
1. You need to substitute "westerlies" for "trade winds".
2. I think it is more like the E US trough weakens or keeps weak the western extent of the Atlantic high thus allowing a recurve on the models. But the key words are "on the models". It is still too far out to know if they're right. They may very well be correct as recurves from TCs that have genesis well out in the MDR are significantly more common than non-recurves, even in early August. BUT, we have to watch for the POSSSIBILTY that the model consensus has the E US trough too far east/south since there's a bias. The SE Ridge has often been underdone on model consensus for at least a year.

[jfk08c]

At what longitude do the trade winds start to not have an effect on the westward movement? When does the Bermuda High have to pick the system up and keep it moving west? Still relatively new to the science behind meteorology but to me it seems like the ridging in the Atlantic isn't strong enough to keep the system moving westward after it becomes uninfluenced by the trades. Or is it the trough on the EC that is causing the ridge to move out of the way and letting it recurve? Like I said, still new so if anyone can help me understand what we are looking for i'd greatly appreciate it!

Hi,
1. You need to substitute "westerlies" for "trade winds".
2. I think it is more like the E US trough weakens or keeps weak the western extent of the Atlantic high thus allowing a recurve on the models. But they key words are "on the models". It is still too far out to know if they're right. they may very well be correct and a recurves from TCs that have genesis well out in the MDR are significantly more common than non-recurves, even in early August. BUT, we have to watch for the POSSSIBILTY that the model consensus has the E US trough too far east/south since there's a bias. The SE Ridge has often been underdone on mode consensus for at least a year.

Thanks for the explanation. I know the system is still way too far out to know exactly where its headed, just wasn't sure the exact interaction between the trough and the Atlantic high and what would keep the storm moving west after it exited the area of influence of the "westerlies" lol. Thanks again, great information!

[LarryWx]

At what longitude do the trade winds start to not have an effect on the westward movement? When does the Bermuda High have to pick the system up and keep it moving west? Still relatively new to the science behind meteorology but to me it seems like the ridging in the Atlantic isn't strong enough to keep the system moving westward after it becomes uninfluenced by the trades. Or is it the trough on the EC that is causing the ridge to move out of the way and letting it recurve? Like I said, still new so if anyone can help me understand what we are looking for i'd greatly appreciate it!

Hi,
1. You need to substitute "westerlies" for "trade winds".
2. I think it is more like the E US trough weakens or keeps weak the western extent of the Atlantic high thus allowing a recurve on the models. But they key words are "on the models". It is still too far out to know if they're right. they may very well be correct and a recurves from TCs that have genesis well out in the MDR are significantly more common than non-recurves, even in early August. BUT, we have to watch for the POSSSIBILTY that the model consensus has the E US trough too far east/south since there's a bias. The SE Ridge has often been underdone on mode consensus for at least a year.

Thanks for the explanation. I know the system is still way too far out to know exactly where its headed, just wasn't sure the exact interaction between the trough and the Atlantic high and what would keep the storm moving west after it exited the area of influence of the "westerlies" lol. Thanks again, great information!

Ooops, I misread your first post. You were right and me wrong to say substitute westerlies for trade winds. Oy

[NDG]

I think this still needs a good 48-72 hrs if not closer to 96 hrs to consolidate. IMO.

[jfk08c]

Ooops, I misread your first post. You were right and me wrong to say substitute westerlies for trade winds. Oy

No worries, solid information regardless!

[ava_ati]

Watching the 12z Euro, my eyes are on this upper level feature in the Gulf both models have it, and it appears to have some influence on the GFS on eroding away the ridge once it "hooks-up" with the trough coming across the US

[shiny-pebble]

Odd, the image still shows 50% but the writeup is at 60%.

The image you posted is from the 8 A.M. outlook

Sent from my LG-H700 using Tapatalk

[artist]

Odd, the image still shows 50% but the writeup is at 60%.

The image you posted is from the 8 A.M. outlook

Sent from my LG-H700 using Tapatalk

Oops, didn’t notice that. Guess they posted the outlook before the image. Thanks.

[abajan]

Odd, the image still shows 50% but the writeup is at 60%.

It took a while to get updated. But it's correct now. Too many S2Kers were bombarding their servers.

[Aric Dunn]

I think this still needs a good 48-72 hrs if not closer to 96 hrs to consolidate. IMO.

https://i.imgur.com/Qv851DP.gif

Well it would not take much to consolidate once convection can build. Everything else is there

[AutoPenalti]

FWIW, NAO tilting to positive by the middle of August.

[NDG]

12z Euro and GFS are pretty close to each other on its forecasted track through day 7.
12z Euro does not really consolidates its vorticity until at least Sunday night if not Monday morning.

[GCANE]

850mb vort appears to be consolidating and taking a dip to the SW.

[TheStormExpert]

FWIW, NAO tilting to positive by the middle of August.

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif

If anything every time the ensembles show the NAO going positive it does but not as much as originally forecasted.

[Aric Dunn]

12z Euro and GFS are pretty close to each other on its forecasted track through day 7.
12z Euro does not really consolidates its vorticity until at least Sunday night if not Monday morning.

8am tomorrow...

[TheStormExpert]

Now the Euro kills this in 9 days east of the Bahamas, what good consistency!

[Aric Dunn]

850mb vort appears to be consolidating and taking a dip to the SW.

Yeah even with the minimal convection it has had. The surface circ has been able to slowly consolidate. Wont take much convection to really tighten up.