ATL: INVEST 93L - Discussion

[Aric Dunn]

Needs to maintain longer before they will pull the trigger. Other than that looks completely classifiable. Shear is likely to just blow all the convection away and leave a naked swirl in a couple of hours though. If it defies the shear until late this evening they might feel comfortable enough to make the call.

again.. pulsing convection for the last 24 hours..

the day and life of a sheared TC.. completely classifiable. and from ASCAT and TS>>

No where near organized enough yesterday. This is by far the best it has looked in its existence and should it hold together for a few more hours probably will get classified. Yesterday it was nothing but an elongated looking circ with minimal convection barfing out outflow boundaries everywhere. No way that should have been classified.

Oh but Laura east of islands was a more well defined center and convection? lol wind field was closed ASCAT was a mess of crap. convcetion was in a blob so far removed...

only difference really is laura had a future according to the models. this according to the models wont have a future until maybe later.

anyway... back to reality right ?

[EquusStorm]

Wasn't all that great yesterday, but this morning convection is absolutely organized enough over the last 3 hours or so, subjectively and I think objectively, to be qualified for a TC convective pattern. If the LLC is fully closed off, it meets all the criterion for designation if it can maintain it for a good chunk of the day to meet the persistence qualifier. Surrounding conditions are irrelevant if the cyclone somehow reaches that organization in hostile conditions. The NHC is extremely conservative so dunno if actually gets upgraded officially, but they did classify TD11 in 2018. Might force their hand like TD10 did and have to be backed up in best track if it keeps this up.

[hurricanehunter69]

Could shear actually be lessening a tad? This thing is very close right now.

[MarioProtVI]

With Papin becoming a Hurricane Specialist at NHC today I wonder if his first thing to do will be to raise the chances of 93L to 50/50 at 2pm since he’s more generous

[cycloneye]

No change.

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Tue Oct 13 2020

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

A broad area of low pressure associated with a tropical wave is
located about 400 miles east of the Windward Islands. Although the
low continues to produce an area of showers and thunderstorms, that
activity remains confined to the east of the center due to strong
upper-level winds. In addition, recent satellite data indicate
that the circulation is a little less defined than it was
yesterday. Some slight development of this system is still
possible today while it moves westward to west-northwestward, but
upper-level winds are expected to become even less favorable for
development tonight and Wednesday.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Cangialosi

[HurricaneEnzo]

So much for that. Looks like the circ imploded lol. Too much shear.

https://www.tropicaltidbits.com/sat/sat ... roduct=vis

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 PM EDT Tue Oct 13 2020

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

A broad area of low pressure associated with a tropical wave is
located about 350 miles east of the Windward Islands. Although this
disturbance continues to produce a large area of disorganized
showers and thunderstorms, mainly to the east of the center, strong
upper-level winds are expected to inhibit development for the next
few days. However, the system will move west-northwestward through
the end of the week, and produce locally heavy rainfall and strong
gusty winds across the central and northern Lesser Antilles on
Wednesday, the Virgin Islands and Puerto Rico on Thursday, and
Hispaniola on Friday.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Stewart

[msbee]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 PM EDT Tue Oct 13 2020

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

A broad area of low pressure associated with a tropical wave is
located about 350 miles east of the Windward Islands. Although this
disturbance continues to produce a large area of disorganized
showers and thunderstorms, mainly to the east of the center, strong
upper-level winds are expected to inhibit development for the next
few days. However, the system will move west-northwestward through
the end of the week, and produce locally heavy rainfall and strong
gusty winds across the central and northern Lesser Antilles on
Wednesday, the Virgin Islands and Puerto Rico on Thursday, and
Hispaniola on Friday.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Stewart

https://i.imgur.com/CJqQqXN.png

Guess we are going to get some rain. Luis.

[msbee]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 PM EDT Tue Oct 13 2020

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

A broad area of low pressure associated with a tropical wave is
located about 350 miles east of the Windward Islands. Although this
disturbance continues to produce a large area of disorganized
showers and thunderstorms, mainly to the east of the center, strong
upper-level winds are expected to inhibit development for the next
few days. However, the system will move west-northwestward through
the end of the week, and produce locally heavy rainfall and strong
gusty winds across the central and northern Lesser Antilles on
Wednesday, the Virgin Islands and Puerto Rico on Thursday, and
Hispaniola on Friday.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Stewart

https://i.imgur.com/CJqQqXN.png

Guess we are going to get some rain. Luis.

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 PM EDT Tue Oct 13 2020

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

A broad area of low pressure associated with a tropical wave is
located about 350 miles east of the Windward Islands. Although this
disturbance continues to produce a large area of disorganized
showers and thunderstorms, mainly to the east of the center, strong
upper-level winds are expected to inhibit development for the next
few days. However, the system will move west-northwestward through
the end of the week, and produce locally heavy rainfall and strong
gusty winds across the central and northern Lesser Antilles on
Wednesday, the Virgin Islands and Puerto Rico on Thursday, and
Hispaniola on Friday.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Stewart

https://i.imgur.com/CJqQqXN.png

Guess we are going to get some rain. Luis.

Yes,that is right but nothing more strong thanks to the TUTT trough.

[GCANE]

Tomorrow may be a good opportunity to develop.
Wave axis looks to be nearly vertical then and will be away from the influence of the TUTT.
Going to be in a very high CAPE environment then.
May slip south of Hispaniola.

[aspen]

Tomorrow may be a good opportunity to develop.
Wave axis looks to be nearly vertical then and will be away from the influence of the TUTT.
Going to be in a very high CAPE environment then.
May slip south of Hispaniola.

If it does get south of the islands, it could end up interacting or merging with the gyre expected to form the WCar system. This solution is present in today’s 00z CMC run.

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Wed Oct 14 2020

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

1. A broad area of low pressure located a few hundred miles east of
the Lesser Antilles continues to produce a large area of
disorganized showers and thunderstorms, mainly to the east of its
center. Strong upper-level winds are expected to inhibit
significant development while the system moves west-northwestward
over the next couple of days. Regardless of development, the
system could produce locally heavy rainfall across portions of the
central and northern Lesser Antilles today, the Virgin Islands and
Puerto Rico on Thursday, and Hispaniola on Friday.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...10 percent.

Forecaster Beven

[wxman57]

Development chances are beyond the next 5 days. They really start going up at day 7 (next Wednesday). Way too much shear until it reaches the SW Caribbean.

[drezee]

Development chances are beyond the next 5 days. They really start going up at day 7 (next Wednesday). Way too much shear until it reaches the SW Caribbean.

But even without 93L, pattern will produce something.

[cycloneye]

 https://twitter.com/NWSSanJuan/status/1316436539375747073

[cycloneye]

A broad area of low pressure near the Lesser Antilles continues to
produce a large area of disorganized showers and thunderstorms,
mainly to the east of its center. Strong upper-level winds are
expected to inhibit significant development while the system moves
west-northwestward over the next couple of days. Regardless of
development, the system could produce locally heavy rainfall and
gusty winds across portions of the Lesser Antilles tonight and
Thursday morning, the Virgin Islands, Puerto Rico, and the eastern
Caribbean Sea late Thursday into Friday, and Hispaniola Friday
night into Saturday.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...10 percent.

[underthwx]

If this does develop, will it go north of the GAs and perhaps try to become something more significant there, or will it continue due west and become the Caribbean TC we’ve been following in the models thread? How much does the solution of that Caribbean TC depend on 93L remaining as an open wave?

I have been wondering the same thing

[toad strangler]

If this does develop, will it go north of the GAs and perhaps try to become something more significant there, or will it continue due west and become the Caribbean TC we’ve been following in the models thread? How much does the solution of that Caribbean TC depend on 93L remaining as an open wave?

I have been wondering the same thing

THe two sure as hell look disconnected on the 5 day

[USTropics]

Here is how I evaluate the operational 00z GFS analysis and what is likely to occur. A cold front extends all the way down from the NE US towards Cuba in the WATL (blue). Ahead of this frontal boundary, we can already start to see some broad mid-level vorticity forming (pink L) in what is likely to be some sort of subtropical system that attempts to form and heads towards the SE CONUS later next week (pink arrow). In addition, we have an elongated tropical wave axis that extends all the way into SA just now entering the Caribbean (red). We are likely to see some type of fracturing, (black) with the northern axis ejecting towards GA and the south axis providing a catalyst for lowering pressures in the SE Caribbean. This is where the monsoonal trough (green) is currently situated as well. I've provided a loop to 240 hours to show how this plays out. I would again advise against taking operational runs verbatim past 5 days (ensembles provide a better understanding of these possible evolutions). These are more the player to watch though.