Well Defined Wave off African Coast

[Anthonyl]

I remember last year watching Dean coming off around the same location last year and found it suspect that the ridge seemed to have stregthened simultaneoulsy has the cyclone came accross the Atlantic. Latest modles seemed to indicate a strong summer ridge being in place for next week and beyond.

[Gustywind]

Well,Georges was a cat 3 when it crossed Puerto Rico,after tracking almost all the way from Africa as a hurricane.There are many,many examples.

Absolutely Cycloneye, Georges was Tropical Storm the 16th of September in the morning and Cat 1 Hurricane the 17th, and develops quickly as Cat 2 cane Friday 18th of September 1998 in the morning...with after the story that we all know... !

[Gustywind]

I remember last year watching Dean coming off around the same location last year and found it suspect that the ridge seemed to have stregthened simultaneoulsy has the cyclone came accross the Atlantic. Latest modles seemed to indicate a strong summer ridge being in place for next week and beyond.

Interresting post, for the moment difficult to confirm this ( because it's the beginning of the season i tkink ..), but it seems that this is a trend that we cannot ignore, curiously the ridge seems strong like 2007 at the same period, hope i'm not wrong lol and if you have consulted the models.... busy action down the road with this awesome wave, time will tell, way to early to speculate anything on that, wait and see the next 24h.

[cycloneye]

9:00 PM EDT pic.

[Frank P]

Not sure if this link has been posted or not but it shows a nice sat presentation of the wave.

http://oiswww.eumetsat.org/SDDI/cgi/lis ... 5#controls

[boca]

If it does develop it will likely recurve due to it deepening and likely to hit some weakness out there.

[stevetampa33614]

This wave could be off the ground in the next 24 hours. There really isnt much inhibiting it. No dry air ahead till you get a bit north of the ITCZ. The sooner the better, then it flies north. It could fizzle out tho, who knows. Just the models picking up on it is suspect to me. We see waves like this sometimes, when models pick up on it we need to pay attention.

[boca]

This wave could be off the ground in the next 24 hours. There really isnt much inhibiting it. No dry air ahead till you get a bit north of the ITCZ. The sooner the better, then it flies north. It could fizzle out tho, who knows. Just the models picking up on it is suspect to me. We see waves like this sometimes, when models pick up on it we need to pay attention.

True the models did a great job with Bertha.

[Extremeweatherguy]

The key will be IF there is a weakness. Storms cannot recurve if there is no weakness present to allow them to do so...and that applies to even the strongest and deepest storms too (a.k.a. Hurricanes Dean and Felix). As I said earlier, while the odds generally do favor a recurve, we certainly shouldn't be counting on it as a certainty until after this storm actually exits the coast and forms into a TD or TS. Until that happens, any long range forecast is pretty much a crapshoot.

A few key things I will be looking for over the next 72 hours include...

A) Location at which the system exits the coast. Exiting north of the Cape Verde islands greatly increases the recurve potential, while exiting south of the islands would not.

B) Strength and structure after exiting the coast. A stronger and deeper system has a better chance at finding a weakness (if there is one to find), while a weaker system will generally head more westward.

C) Forecasted Atlantic ridge strength by each new set of model runs. A stronger ridge would favor a more west movement, while a weaker ridge filled with weaknesses would scream recurve. Currently the models show a stronger ridge through the next 7 days, but then try to weaken it in the long term (12z GFS 500mb run: http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml ) Will this weakening of the ridge actually happen? We will just have to wait and see.

All in all, this system definitely looks like it will be a fun one to track. Whether or not it recurves, heads west, becomes a hurricane, or ends up being another week-long invest like 94L, I think we will see plenty of tropical entrainment from it. You really cannot ask for much more than this considering the time of year. I mean seriously, TWO Cape Verde storms in July!? That is just crazy to even think about!

[Blown Away]

Nice post Thanks for posting the model run, I had a difficult time following the low, I guess this low will move off the coast late tomorrow or Monday.

[cycloneye]

The key will be IF there is a weakness. Storms cannot recurve if there is no weakness present to allow them to do so...and that applies to even the strongest and deepest storms too (a.k.a. Hurricanes Dean and Felix). As I said earlier, while the odds generally do favor a recurve, we certainly shouldn't be counting on it as a certainty until after this storm actually exits the coast and forms into a TD or TS. Until that happens, any long range forecast is pretty much a crapshoot.

A few key things I will be looking for over the next 72 hours include...

A) Location at which the system exits the coast. Exiting north of the Cape Verde islands greatly increases the recurve potential, while exiting south of the islands would not.

B) Strength and structure after exiting the coast. A stronger and deeper system has a better chance at finding a weakness (if there is one to find), while a weaker system will generally head more westward.

C) Forecasted Atlantic ridge strength by each new set of model runs. A stronger ridge would favor a more west movement, while a weaker ridge filled with weaknesses would scream recurve. Currently the models show a stronger ridge through the next 7 days, but then try to weaken it in the long term (12z GFS 500mb run: http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml ) Will this weakening of the ridge actually happen? We will just have to wait and see.

All in all, this system definitely looks like it will be a fun one to track. Whether or not it recurves, heads west, becomes a hurricane, or ends up being another week-long invest like 94L, I think we will see plenty of tropical entrainment from it. You really cannot ask for much more than this considering the time of year. I mean seriously, TWO Cape Verde storms in July!? That is just crazy to even think about!

That is a reasonable analysis of all the factors that may occur with this system after it emerges Africa late sunday or early Monday.

[cycloneye]

Pic at 8:00 PM EDT:



Pic at 10.00 PM EDT

[Mecklenburg]

it does look good, even though still inland

[cycloneye]

I think this 00z run of GFS is not right as the low is not that far north.

[americanrebel]

I know I should know this answer, but I can't remember, when this becomes 97L, will we start a new thread in active tropics or move this thread over there?

[RL3AO]

I know I should know this answer, but I can't remember, when this becomes 97L, will we start a new thread in active tropics or move this thread over there?

New thread. And it could be 98L if that Bermuda system gets its act together.

[stevetampa33614]

Bermuda System? Thats just some Sirrus Clouds. There is no expectation for development, is there?

[RL3AO]

Bermuda System? Thats just some Sirrus Clouds. There is no expectation for development, is there?

Probably not, but the NHC is mentioning it.

[KWT]

Well the wave is still looking large and it is still looking very impressive eith huge convective blow up. Should reach the coast fairly soon a lot further south then the GFS expects.

[cycloneye]

It will put its feet in the water on monday.No big changes seen from the past few days since it was over Ethiopia.