ATL: EARL - Post-Tropical - Discussion

[cycloneye]

1. East of the Leeward Islands:
Showers and thunderstorms associated with a broad area of low
pressure located several hundred miles east of the Leeward Islands
have gradually increased in organization over the past day or so.
Although environmental conditions remain only marginally conducive,
only slight additional development of the system over the next few
days would lead to the formation of a tropical depression. The
disturbance is forecast to move slowly west-northwestward, toward
the adjacent waters of the northern Leeward Islands. Additional
information on this system can be found in High Seas Forecasts
issued by the National Weather Service.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...high...80 percent.

[skyline385]

Looks like convection is starting to poof again

Wouldn't it be funny if this thing opened up into a wave and never became a cyclone.

If it did that, a lot of people here would be done with this season lol

[IsabelaWeather]

I'm not seeing any significant risk to the islands of the NE Caribbean. Should pass well to the north Fri-Sat. Nothing to keep it on a westerly track into the islands.

Yes, as you said, the NW movement is now apparent.

[SconnieCane]

Looks like convection is starting to poof again

Wouldn't it be funny if this thing opened up into a wave and never became a cyclone.

Well technically it is and always has been an open wave...hence why it hasn't already been classified as a TC, but I see your point. It would be ironic, and a pretty big model fail especially from those Euro runs which had it as a MH near the Bahamas, and IMO definitive confirmation that this season is irredeemably borked and preseason forecasts of AA to hyper activity were way out to lunch.

[Nimbus]

It is picking up convection again as it heads for D max, and recon found a mid level center yesterday.

Doesn't look ready to dissipate yet we can hope for a digging TUTT.

There are two TUTT's to the north of 91L the first moved out and the second would have to miss for the 00Z Euro to verify for a storm track near north shore of PR.

https://www.tropicaltidbits.com/sat/sat ... uct=wv_mid

[aspen]

Looks okay this morning. The circulation looks a little more centered to the north, and recon shows a closed circulation isn’t far off from developing. We could get a TD sometime today.

[BobHarlem]

If this persists it may have a chance to form into something later today, still not a lot going for it though, I'm starting to think the models that keep it weak are going to be the right ones.

[NDG]

If this persists it may have a chance to form into something later today, still not a lot going for it though, I'm starting to think the models that keep it weak are going to be the right ones.

https://i.imgur.com/sES1FnV.gif

Clearly it is being squeezed by two large areas of bone dry air, with the Euro showing the dry air winning.

[cycloneye]

East of the Leeward Islands:
Showers and thunderstorms associated with a broad area of low
pressure located several hundred miles east of the Leeward Islands
have changed little this morning. Although environmental conditions
remain only marginally conducive, any additional development of the
system over the next few days would lead to the formation of a
tropical depression. The disturbance is forecast to move slowly
west-northwestward, toward the adjacent waters of the northern
Leeward Islands. Additional information on this system can be found
in High Seas Forecasts issued by the National Weather Service.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...high...80 percent.

[wxman57]

Recon just finished its investigation. Not a hint of an LLC yet. It may not do much for another 2-3 days, and it may never develop into a TS. Some increased showers and thunderstorms for the islands of the NE Caribbean as it passes to the north, about the same as for any tropical wave. I think I'll take a vacation day tomorrow and enjoy a 4-day weekend. I've never done that on Labor Day weekend before. We'll have only 4 active storms - Hinnamnor in the WPAC, a new storm heading out to sea in the EPAC, Danielle west of the Azores, and a track on 91L to issue. Regular shifts can handle that load without my help. No conference calls to handle, either. New forecast numbers are 14/6/3, and they may still be too high.

[skyline385]

Still struggling, the Euro solution might just verify at this rate

 https://twitter.com/andyhazelton/status/1565336552057647107





Sent from my iPhone using Tapatalk

[USTropics]

Here is the evolution of the near-surface vorticity of 91L over the past 5 days. After lifting from the convectively active ITCZ, the system has struggled to fight against a very dry background state and enhanced upper-level flow from the ULL in the CATL:


While the vorticity has become weak and elongated at the surface, the real culprit has been the upper to mid levels. Here is a high-def loop of the upper-level water vapor flow currently and we can see convection is still being stripped away:


In addition, mid-level dry air is now being entrained from the SW, further eroding the convective layer away:




That's quite the background state to overcome, and the struggle for the next few days will be if 91L can continue to produce convection. If a signature still exists when it reaches north of the Caribbean later this weekend, conditions look more favorable.

[NDG]

Still struggling, the Euro solution might just verify at this rate

https://twitter.com/andyhazelton/status/1565336552057647107?s=21&t=RDZ1caQqJdMhOqgtSZlDLg


Sent from my iPhone using Tapatalk

Clearly evident on visible satellite loop that 91L is a big mess with multiple weak vorticities. The HWRF needs to be thrown out the window, just 24 hrs ago it was showing it becoming a TS this morning.

[Sciencerocks]

[ElectricStorm]

Models have been very consistent for a while now showing that this won't really get going until it gets north of the islands (except HWRF which is clearly wrong) and it seems like we are still on track for that. I'm thinking this will become a TD around Sunday and then a TS shortly after that. Until then I think we will continue to see convection wax and wane.

[ElectricStorm]

Down to 50/70

[cycloneye]

 https://twitter.com/OSUWXGUY/status/1565393092852813825

[MGC]

Down to 50/70

This might be generous. Looks like 91L fell apart overnight......MGC

[aspen]

Hey, look, some popping convection. Not much but it’s something lol

[Kingarabian]

Best case scenario here is this follows the NCEP solution, where it gets act together quicker and thus recurving early.