Tropical Wave Over the Bahamas/Cuba (Is Invest 91L)

[NDG]

This might be one those TWs that come across the GOM and not develop a closed circulation until is pretty much on the coast, as we have often seen. Lets see if it takes advantage of some of the warmest SSTs of the Atlantic Basin.

[TheStormExpert]

No one mentioned that the NHC highlighted this with a 20% within 5 days at the 8am TWO.

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Sun Jul 19 2020

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

A tropical wave located over Hispaniola and the adjacent waters of
the southwestern Atlantic is expected to move west-northwestward
over the next several days and enter the southeastern Gulf of
Mexico by late Tuesday, and then move across the central Gulf on
Wednesday and reach the northwestern Gulf on Thursday. This
disturbance is currently producing disorganized shower activity,
but environmental conditions are expected to become at least
marginally conducive for development by Wednesday or Thursday.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Beven

[cycloneye]

No one mentioned that the NHC highlighted this with a 20% within 5 days at the 8am TWO.

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Sun Jul 19 2020

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

A tropical wave located over Hispaniola and the adjacent waters of
the southwestern Atlantic is expected to move west-northwestward
over the next several days and enter the southeastern Gulf of
Mexico by late Tuesday, and then move across the central Gulf on
Wednesday and reach the northwestern Gulf on Thursday. This
disturbance is currently producing disorganized shower activity,
but environmental conditions are expected to become at least
marginally conducive for development by Wednesday or Thursday.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Beven

https://i.ibb.co/59xys7V/two-atl-2d1.png

https://i.ibb.co/230G1Lb/two-atl-5d0.png

I posted the 8 AM TWO but anyway you posted the graphics that I did not so we are good.

[Aric Dunn]

I figured that was going to happen. with the upper tough to its west convection would build well north from the SW divergent flow. .

if it continues it will have a better chance.

morning visible showing the wave axis is still north of where the models have it.


I think models will begin to latch onto it if this convection continues over the next 12 to 24 hours.

[boca]

It looks like the convection is building with this wave as it moves WNW.

https://www.star.nesdis.noaa.gov/GOES/s ... &length=24

[Aric Dunn]

12z NAM is liking this a lot more..

[NDG]

Fairly pronounced TW axis.

[Aric Dunn]

Fairly pronounced TW axis.

https://i.imgur.com/8MFTPWN.gif

Yeppers. and if that convection keeps firing through the day the axis will begin to sharpen and since it is mostly north of the islands it should have a better shot than the models are indicating.

[Aric Dunn]

ICON is back to a solid devlopment and about 24 hours earlier over the central gulf.

[wxman22]

Yep this wave is starting to look interesting..

[stormlover2013]

We shall see maybe weak trop storm could get out of it

[toad strangler]

ICON is back to a solid devlopment and about 24 hours earlier over the central gulf.

Weak sauce and it's the ICON .... but definitely something to watch. None of the models show more than a wave moving through the GOM. So far, and of course stranger things have happened.

[Aric Dunn]

ICON is back to a solid devlopment and about 24 hours earlier over the central gulf.

Weak sauce and it's the ICON .... but definitely something to watch. None of the models show more than a wave moving through the GOM. So far, and of course stranger things have happened.

https://i.ibb.co/XJVRpp0/icon-mslp-wind-watl-39.png

Well it does not help that the models have the wave axis and bulk vorticity way to far south when it has clearly been north of the islands.

I bet we see the models begin to show it more.

[aspen]

If this thing would to put itself together earlier, like around the Florida Straits, then I would be concerned about the possibility of a 60-70 kt system. However, for now it looks like development might occur midway through the Gulf. We’ll have to wait and see what the wave does as it nears the Bahamas; will it get too low and weaken, or will it encounter a favorable enough environment to start developing into a TD?

[stormlover2013]

Glad it’s not late August

[Do_For_Love]

Since this now has a 20% probability of development, how come it hasn't been given a number and called an "invest"?

[KatDaddy]

We could use rainfall in the Houston-Galveston areas but nothing more. Definitely something to watch especially once it enters the GOM.

[SconnieCane]

Yep this wave is starting to look interesting..

https://i.ibb.co/vcJn0TW/icon-mslp-pcpn-frzn-scus-39.png

Uh oh, that's the classic "put some city in southeast Texas underwater" landfall zone.

[NDG]

This is why I don't go by the shear forecast by the GFS, it exaggerates it by at least 5-10 knots if not more. It shows shear near 45 knots just north of Hispaniola when actually is analyzed near 30 knots.
Same thing it shows in the eastern Caribbean, shear near 35 knots when actually it was analyzed near 25 knots.

[NDG]

Since this now has a 20% probability of development, how come it hasn't been given a number and called an "invest"?

If trends go for development I am sure later today or tomorrow it will be declared an Invest.