ATL: Remnants of INVEST 95L - Discussion

[abajan]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Sat Jun 26 2021

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

1. A tropical wave associated with a broad area of low pressure is
located over the eastern tropical Atlantic Ocean about 400 miles
south-southwest of the Cabo Verde Islands. Although shower and
thunderstorm activity is currently disorganized, some slow
development will be possible over the next several days while the
disturbance moves generally westward at 15 to 20 mph.

* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...30 percent.
...

Forecaster Papin/Stewart

[Stormybajan]

Hmmmm chances have increase from 10-10 to 20-30 in 3 and 5 days maybe theres a twist to this tale with 95L

[Aric Dunn]

Hmmmm chances have increase from 10-10 to 20-30 in 3 and 5 days maybe theres a twist to this tale with 95L

Model hugging can become detrimental to a forecast... models are a tool... you still have to look at the "Live" view of things. Models have not been initializing 95L correctly.. this morning's ASCAT passes may have played a role in the models/nhc chances going up.

[Category5Kaiju]

Hmmmm chances have increase from 10-10 to 20-30 in 3 and 5 days maybe theres a twist to this tale with 95L

Apparently it looks like it is riding just south of 10 N and due west, so unlike some of what the models initially thought 95L did not go as north as expected (which would have ultimately doomed it). Also interesting to see another AOI and the region where 95L would form lengthened, it looks like conditions down the road (like near the islands) could be less hostile

[JRD]

The Invest has been getting more organized in spite of dry air, Saharan dust, SSTs barely higher than 26, and hostile levels of wind shear. There's warmer SSTs and less shear to the west, yet there's a lot of shear over the Caribbean that will surely tear it apart unless it changes by the time 95L reaches the area.

[Category5Kaiju]

The Invest has been getting more organized in spite of dry air, Saharan dust, SSTs barely higher than 26, and hostile levels of wind shear. There's warmer SSTs and less shear to the west, yet there's a lot of shear over the Caribbean that will surely tear it apart unless it changes by the time 95L reaches the area.

 https://twitter.com/Nichola76551479/status/1408840301863596033




Actually shear is predicted to be not very bad in the Caribbean by that time, as according to some of these tweets from Andy Hazelton

[wxman57]

Hmmmm chances have increase from 10-10 to 20-30 in 3 and 5 days maybe theres a twist to this tale with 95L

Development chances are VERY subjective. We analyze the disturbance and the atmosphere ahead of it. We look at model support and past model history with genesis in a region. The NHC's Stewart has a reputation of going higher with probabilities than others there would, given the same information. This disturbance will be battling dry air and wind shear all along its path, particularly when it nears the Caribbean. I think 10% seems about right, but that's my subjective opinion, given the lack of model support for any development beyond a weak low.

[abajan]

Here's Mark Sudduth's take.
(Mark is a fellow S2K member.)

[aspen]

Mark has pointed out that 95L is worth watching to see if it develops once past 50W, when OHC and SSTs become high enough. 95L will cross 50W either late Tuesday or early Wednesday, and might have another day before either entering the Caribbean or striking some of the NE islands. It depends how south the wave is once it reaches that longitude, which itself is determined by the strength of the Bermuda High and if any part of the wave tries to consolidate prior to reaching 50-60W.

By Monday, it should become clearer as to whether or not this has a chance of development once it crosses 50W.

[Sciencerocks]

The Invest has been getting more organized in spite of dry air, Saharan dust, SSTs barely higher than 26, and hostile levels of wind shear. There's warmer SSTs and less shear to the west, yet there's a lot of shear over the Caribbean that will surely tear it apart unless it changes by the time 95L reaches the area.

https://twitter.com/Nichola76551479/status/1408840301863596033

Actually shear is predicted to be not very bad in the Caribbean by that time, as according to some of these tweets from Andy Hazelton

Well, better defined then Claudette's LLC was over the gulf. Looks to be closed with some convection. It would probably have 60 or 70% chances in the gulf and would be borderline ready for PTC advisories.

[Aric Dunn]

VOrticity continues to increase and the circ continues to tighten.. plenty of low to mid level moisture. Shear will be low for the next several days.. and possibly after.

convection is slowly increasing around the center. 1 good solid burst and it would tighten up enough to be a TD.

[Category5Kaiju]

VOrticity continues to increase and the circ continues to tighten.. plenty of low to mid level moisture. Shear will be low for the next several days.. and possibly after.

convection is slowly increasing around the center. 1 good solid burst and it would tighten up enough to be a TD.

https://i.ibb.co/4mTYd6n/LABELS-19700101-000000-94.gif

Oh yeah, it's definitely trying. This is June, but as we have been seeing quite recently, some of these waves (95L in particular) are trying their best to form.

[ScottNAtlanta]

If there is one thing that I have learned over the years, it's that you have to keep an eye on these systems that seem to persist in the most unfriendly conditions. When they find a favorable area they usually will develop. Now, I'm not sure this will find a favorable area...but something to be aware of.

[abajan]

VOrticity continues to increase and the circ continues to tighten.. plenty of low to mid level moisture. Shear will be low for the next several days.. and possibly after.

convection is slowly increasing around the center. 1 good solid burst and it would tighten up enough to be a TD.

https://i.ibb.co/4mTYd6n/LABELS-19700101-000000-94.gif

That's one heck of a vorticity signature!

[Category5Kaiju]

If there is one thing that I have learned over the years, it's that you have to keep an eye on these systems that seem to persist in the most unfriendly conditions. When they find a favorable area they usually will develop. Now, I'm not sure this will find a favorable area...but something to be aware of.

Laura and Dorian are two perfect, historic examples of this. I specifically remember people thinking that Laura was screwed as a TS near the Antilles due to all that SAL, but once it reached the Gulf, kaboom. Then you have Dorian, which was also struggling due to the dry air, but once it found that sweet spot above Puerto Rico and next to the Bahamas, it went haywire. Even Andrew back in 1992 was an example of how a struggling system, when escaping the hostile conditions and entering more favorable conditions, can do a 180.

[ScottNAtlanta]

If there is one thing that I have learned over the years, it's that you have to keep an eye on these systems that seem to persist in the most unfriendly conditions. When they find a favorable area they usually will develop. Now, I'm not sure this will find a favorable area...but something to be aware of.

Laura and Dorian are two perfect, historic examples of this. I specifically remember people thinking that Laura was screwed as a TS near the Antilles due to all that SAL, but once it reached the Gulf, kaboom. Then you have Dorian, which was also struggling due to the dry air, but once it found that sweet spot above Puerto Rico and next to the Bahamas, it went haywire. Even Andrew back in 1992 was an example of how a struggling system, when escaping the hostile conditions and entering more favorable conditions, can do a 180.

There are lots of examples...Jeanne 2004 meandered all over the place as a TS then it found a favorable area and RI started. Katrina was actually TD10 that had degenerated into a wave and then found a good area and strengthened (the NHC listed it as 2 systems but it was the same wave)

[abajan]

If there is one thing that I have learned over the years, it's that you have to keep an eye on these systems that seem to persist in the most unfriendly conditions. When they find a favorable area they usually will develop. Now, I'm not sure this will find a favorable area...but something to be aware of.

Laura and Dorian are two perfect, historic examples of this. I specifically remember people thinking that Laura was screwed as a TS near the Antilles due to all that SAL, but once it reached the Gulf, kaboom. Then you have Dorian, which was also struggling due to the dry air, but once it found that sweet spot above Puerto Rico and next to the Bahamas, it went haywire. Even Andrew back in 1992 was an example of how a struggling system, when escaping the hostile conditions and entering more favorable conditions, can do a 180.

Dorian was indeed the perfect example. Even though it passed directly over Barbados, it was poorly organized. I can hardly recall what happened. For the great majority of Barbadians it was basically a non-event (despite what the international news media had stated). Yes, there were some downed utility poles and such, but nothing major. We could hardly believe that what later devastated The Bahamas was the same system!

[Stormybajan]

If there is one thing that I have learned over the years, it's that you have to keep an eye on these systems that seem to persist in the most unfriendly conditions. When they find a favorable area they usually will develop. Now, I'm not sure this will find a favorable area...but something to be aware of.

Laura and Dorian are two perfect, historic examples of this. I specifically remember people thinking that Laura was screwed as a TS near the Antilles due to all that SAL, but once it reached the Gulf, kaboom. Then you have Dorian, which was also struggling due to the dry air, but once it found that sweet spot above Puerto Rico and next to the Bahamas, it went haywire. Even Andrew back in 1992 was an example of how a struggling system, when escaping the hostile conditions and entering more favorable conditions, can do a 180.

Dorian was indeed the perfect example. Even though it passed directly over Barbados, it was poorly organized. I can hardly recall what happened. For the great majority of Barbadians it was basically a non-event (despite what the international news media had stated). Yes, there were some downed utility poles and such, but nothing major. We could hardly believe that what later devastated The Bahamas was the same system!

Its funny because what I mainly remember from Dorian was a rough rain shower or 2 and how beautiful the evening was with this strange Orange tint the sky it had in the evening. In regards of 95L I will say I am impressed in the way its fought off the marginal waters so far and has atleast tried to build a structure and based on the uptick in vorticity from the model runs today we will looking at 95L for quite a while yet

[ElectricStorm]

Yeah this is definitely going to need to be watched down the road.

[JRD]

L95 has become a little less organized and more elongated. It's directly below a zone of high shear which will limit organization until it abates. Also, shear in the Caribbean and SW Atlantic is starting to weaken.