(Sub)Tropical development likely near the Bahamas: (Invest 90L thread is up)

[TheStormExpert]

The latest 06z GEFS Ensembles have clustered closer to SE Florida just west of Grand Bahama Island in 66hrs, and west nudge compared to this time on the 00z run.

[Aric Dunn]

Next thing you know.... it develops in the SE gulf crosses SE florida and does a loop east of floirda or stalls.

[GCANE]

The LL vort and negative-tilt shortwave opens up a big hole in shear.

[BYG Jacob]

GCANE and Aric are back, you know its hurricane season.

[GCANE]

Next thing you know.... it develops in the SE gulf crosses SE florida and does a loop east of floirda or stalls.

Slight chance could see some F1 tornadoes and water spouts.

[SFLcane]

Though.... EPS is way NE.

[cycloneye]

Special Tropical Weather Outlook
NWS National Hurricane Center Miami FL
845 AM EDT Wed May 13 2020

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

Special Tropical Weather Outlook issued to discuss the potential
for subtropical development this weekend northeast of the
Bahamas.

1. A broad area of low pressure is expected to develop late this
week or early this weekend near or within a couple of hundred miles
north of the Bahamas. Environmental conditions appear conducive for
gradual development of this system, and a subtropical depression or
storm is likely to form this weekend while it moves northeastward
over the western Atlantic. The next Special Tropical Weather Outlook
on this system will be issued by 9 PM EDT Wednesday, or earlier, if
necessary.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...high...70 percent.

$$
Forecaster Latto

[northjaxpro]

This morning's 06Z Operational GFS run actually has the potential cyclone (1006 mb) forming right at the Southeast Florida coast, in the vicinity of Palm Beach and Martin Counties, by 06Z Saturday.morning. This is a considerable shift west ftom previous runs. I will be very closerly watchng to see if the other guidsnce models are picking.up on this as time progresses.
Well, if this trend continues, those of you down in South Florida who suffered ftom last weekend's gigantic bust, just maybe, just maybe , get impacts from the season's first named storm.

Future runs over the next couple of days will go a long way in helping to clue us in on what woll.happen this weekend.

[Hypercane_Kyle]

The whole 06Z GFS run was kind of wacky, to be honest. Nearly landfalls SFL, makes a run for hurricane status on the way out.

[SFLcane]

06z euro now develops this very near SFL trending towards the GFS.

[boca]

06z euro now develops this very near SFL trending towards the GFS.

How do you get access to the 06z euro?

[SFLcane]

06z euro now develops this very near SFL trending towards the GFS.

How do you get access to the 06z euro?

This is a paid subscription.

[Shell Mound]

Given that this system will be sheared, even a technical landfall on South Florida will produce little rainfall vs. areas offshore and in the Bahamas. In order for South Florida to see significant rainfall, the system would need to head west-northwest across the FL peninsula and enter the eastern Gulf of Mexico. The steering currents clearly do not favour anything remotely akin to this scenario. At most, the system would briefly make landfall on the east coast of the state and then quickly head off to the northeast. If you live in South FL (or anywhere in FL, for that matter), do not expect much, if anything, from this system.

[northjaxpro]

06z euro now develops this very near SFL trending towards the GFS.

Yeah, no sooner than I posted about the GFS 06Z run, I did see the 06Z EURO run showing show similar to what the 06Z GFS has well.
So, the next few run cycles will be interesting as if they continue to show this cyclone developing near the Southeast Florida coast, then we really have a potential big weekend in store farther down the peninsula.

[Shell Mound]

06z euro now develops this very near SFL trending towards the GFS.

Yeah, no sooner than I posted about the GFS 06Z run, I did see the 06Z EURO run showing show similar to what the 06Z GFS has well.
So, the next few run cycles will be interesting as if they continue to show this cyclone developing near the Southeast Florida coast, then we really have a potential big weekend in store farther down the peninsula.

Uh, no—at least not so far (at the moment). The system would only flirt with the peninsula for a very brief period before heading off to the northeast:

Given that this system will be sheared, even a technical landfall on South Florida will produce little rainfall vs. areas offshore and in the Bahamas. In order for South Florida to see significant rainfall, the system would need to head west-northwest across the FL peninsula and enter the eastern Gulf of Mexico. The steering currents clearly do not favour anything remotely akin to this scenario. At most, the system would briefly make landfall on the east coast of the state and then quickly head off to the northeast. If you live in South FL (or anywhere in FL, for that matter), do not expect much, if anything, from this system.

Respectfully, this is how I see the situation at this time.

[SFLcane]

Given that this system will be sheared, even a technical landfall on South Florida will produce little rainfall vs. areas offshore and in the Bahamas.

No.. given the low pressure hasn’t even developed. The counter clock wise rotation while it’s disorganized could swing rain bands into the mainland. There could also be a tornado threat.

[Shell Mound]

Given that this system will be sheared, even a technical landfall on South Florida will produce little rainfall vs. areas offshore and in the Bahamas.

No.. given the low pressure hasn’t even developed. The counter clock wise rotation while it’s disorganized could swing rain bands into the mainland. There could also be a tornado threat.

I was referring to the prospects of significant rainfall. Southwesterly shear will largely confine convection (and tornadoes) to the northern and eastern semicircles.

The system would need to develop over or cross into the Gulf of Mexico for South Florida (and/or the peninsula) to observe significant impacts from soon-to-be Arthur.

[Aric Dunn]

Given that this system will be sheared, even a technical landfall on South Florida will produce little rainfall vs. areas offshore and in the Bahamas.

No.. given the low pressure hasn’t even developed. The counter clock wise rotation while it’s disorganized could swing rain bands into the mainland. There could also be a tornado threat.

I like this whole "given" thing going on so ill join in


Given the energy appears to be coming from the NW carrib and enters in the Se gulf and florida straight which means it could develop there as well.. .... then the vorticity elongates NE where the models consolidate it..

it is also quite possible GIVEN as you said nothing has developed or in this case even there yet for the models to track.. I would not focus any solution.. and focus more on the synoptics..



which tell us there will be a massive and expansive ridge over the central and eastern US extending out over the atlantic in 4 days time with a short wave possibly swinging through..

without that short wave ( which also does not exist yet) .. there is zero way for this to go out to sea.. hence the earlier runs of the GFS and Euro showing it turn back west towards florida.

in two days there will be something for the models to actually focus on.. then we can all start talking track..

[northjaxpro]

Given that this system will be sheared, even a technical landfall on South Florida will produce little rainfall vs. areas offshore and in the Bahamas. In order for South Florida to see significant rainfall, the system would need to head west-northwest across the FL peninsula and enter the eastern Gulf of Mexico. The steering currents clearly do not favour anything remotely akin to this scenario. At most, the system would briefly make landfall on the east coast of the state and then quickly head off to the northeast. If you live in South FL (or anywhere in FL, for that matter), do not expect much, if anything, from this system.

Yeah, good analysis. Should the cyclone moves northeast, Florida will be on the subsident side of the cyclone as it moves away. As a matter of fact I am expectiing very hot and dry weather here in North Florida, especially on Sunday. Highs will potentially be in the mid 90s in some locales late in the weekend.

Lots still on the table though. Still have to watch closely.

[NDG]

Even with the Euro's further east with development on its 0z run it still dumps some much needed rains in SE FL this weekend as the disturbance lifts to the NE.
Obviously a more shift to the west brings heavier rains to the rest of SE FL.