ATL: LAURA - Post-Tropical - Discussion

[CyclonicFury]

ASCAT from last night and this morning, as well as the recon mission tonight have all struggled to locate a well-defined center. I'm a bit surprised NHC did not decide to use the Potential TC system until more conclusive evidence of a LLC was found.

Has recon found a closed circulation yet? I can’t tell.

So far there has been no westerlies and barely any pressure fall. It's going to be interesting to see if a more defined LLC forms, because the ECMWF has been insistent on recent runs it won't even happen.

[Hammy]

We all need to chill. The most likely scenario right now is a cat 1 landfalling in south FL, just as NHC has it. Don't bet against the NHC. Chill with the model wars until its north of the antellies.

They outright said in their discussions that they're splitting the difference between the models that strengthen, and the ones that dissipate--and that their confidence is low.

So my post didn't seem to go through. What is your confidence level on your forecast for an open wave that never develops?

It went through but when I replied it said this post does not exist.

I'm thinking weaker side of the guidance at the moment, and it has already degenerated to an open wave (but I doubt NHC will downgrade it as long as there are watches up.) While I'm not confident enough to say that it will definitely be an open wave by the time it gets to the Islands, I am confident enough to say that solution is more likely than seeing a stronger hurricane.

My expectation of intensification prior to today were based on the GFS/Euro being the outliers (things have changed and the models have all instead trended in their direction) and maintaining organized convection/closed circulation through today and tomorrow until it reached more favorable conditions, something that has failed to happen.

What are your thoughts on the outcome?

[rigbyrigz]

Yah that’s scary. As much as I don’t want anything here in Florida I’d rather us get something weak that fizzles out than see something get into the gulf unscathed. Bad scenario.[/quote]
Thanks... feeling kinda squeezed up here between 13 and 14 in Big Bend (waiting to see what (delayed) Levi says about the outcome; I wonder how both going northerly at same time affect each other's path and intensity.)

The real downside of course is "it" could haul off and smack both our areas with a wallop. These guys and girls are so shameless like that. Sigh.

[AutoPenalti]

Impressive blow up this evening...

https://cdn1.bbcode0.com/uploads/2020/8/21/1ce288e17758b9030b09701cf8481040-full.png

DMAX most likely going to do some work on it.

[Ivanhater]

HWRF corrected itself even without radar It’s was 974mb last run now it’s 1000mb.

What are you talking about? It gets down to the 950s in the gulf. 970's before the keys.

Great point.

We need to be careful when we make overall observations on a system. Just because it doesn't blow up in your area doesn't mean it will not later. This system is forecast to move in the Gulf, not just South Florida.

[eastcoastFL]

[Nimbus]

Yah that’s scary. As much as I don’t want anything here in Florida I’d rather us get something weak that fizzles out than see something get into the gulf unscathed. Bad scenario.

Thanks... feeling kinda squeezed up here between 13 and 14 in Big Bend (waiting to see what (delayed) Levi says about the outcome; I wonder how both going northerly at same time affect each other's path and intensity.)

The real downside of course is "it" could haul off and smack both our areas with a wallop. These guys and girls are so shameless like that. Sigh.[/quote]

If nothing else that trough in the gulf is going to strip and pump many inches of rain up into the northeastern corner of the gulf. That will soften up the tree root soil for any kind of wind event later.

[eastcoastFL]

They outright said in their discussions that they're splitting the difference between the models that strengthen, and the ones that dissipate--and that their confidence is low.

So my post didn't seem to go through. What is your confidence level on your forecast for an open wave that never develops?

It went through but when I replied it said this post does not exist.

I'm thinking weaker side of the guidance at the moment, and it has already degenerated to an open wave (but I doubt NHC will downgrade it as long as there are watches up.) While I'm not confident enough to say that it will definitely be an open wave by the time it gets to the Islands, I am confident enough to say that solution is more likely than seeing a stronger hurricane.

My expectation of intensification prior to today were based on the GFS/Euro being the outliers (things have changed and the models have all instead trended in their direction) and maintaining organized convection/closed circulation through today and tomorrow until it reached more favorable conditions, something that has failed to happen.

What are your thoughts on the outcome?

Tomorrow hasn’t quite happened yet... might be jumping the gun. I hope you are correct

[EquusStorm]

Definitely got some work to do if it wants to be named. Much further south and it's going to be some pretty substantial flash flooding risk across the Greater Antilles.

[Blown Away]

Impressive blow up this evening...

https://cdn1.bbcode0.com/uploads/2020/8/21/1ce288e17758b9030b09701cf8481040-full.png

That blob at the top @19N/59W for sure is that LLC we were tracking on visible earlier and mentioned by the NHC, but I think the NHC might think the larger convection area farther SE may be a reformation?

[eastcoastFL]

ASCAT from last night and this morning, as well as the recon mission tonight have all struggled to locate a well-defined center. I'm a bit surprised NHC did not decide to use the Potential TC system until more conclusive evidence of a LLC was found.

Has recon found a closed circulation yet? I can’t tell.

So far there has been no westerlies and barely any pressure fall. It's going to be interesting to see if a more defined LLC forms, because the ECMWF has been insistent on recent runs it won't even happen.

How can I tell when looking at the recon data which direction the winds are that they are sampling?

[Blown Away]

Impressive blow up this evening...

https://cdn1.bbcode0.com/uploads/2020/8/21/1ce288e17758b9030b09701cf8481040-full.png

That blob at the top @19N/59W for sure is that LLC we were tracking on visible earlier and mentioned by the NHC, but I think the NHC might think the larger convection area farther SE may be a reformation?

https://www.tropicaltidbits.com/sat/sat ... product=ir

[eastcoastFL]

Impressive blow up this evening...

https://cdn1.bbcode0.com/uploads/2020/8/21/1ce288e17758b9030b09701cf8481040-full.png

That blob at the top @19N/59W for sure is that LLC we were tracking on visible earlier and mentioned by the NHC, but I think the NHC might think the larger convection area farther SE may be a reformation?

I’m not sure but it looks like 19n is where recon had the highest FL winds so far

[Hurricaneman]

Impressive blow up this evening...

https://cdn1.bbcode0.com/uploads/2020/8/21/1ce288e17758b9030b09701cf8481040-full.png

That blob at the top @19N/59W for sure is that LLC we were tracking on visible earlier and mentioned by the NHC, but I think the NHC might think the larger convection area farther SE may be a reformation?

We may have been following an eddy earlier that a broader low spit out, seems to be relocating in the convection

[ozonepete]

They outright said in their discussions that they're splitting the difference between the models that strengthen, and the ones that dissipate--and that their confidence is low.

So my post didn't seem to go through. What is your confidence level on your forecast for an open wave that never develops?

It went through but when I replied it said this post does not exist.

I'm thinking weaker side of the guidance at the moment, and it has already degenerated to an open wave (but I doubt NHC will downgrade it as long as there are watches up.) While I'm not confident enough to say that it will definitely be an open wave by the time it gets to the Islands, I am confident enough to say that solution is more likely than seeing a stronger hurricane.

My expectation of intensification prior to today were based on the GFS/Euro being the outliers (things have changed and the models have all instead trended in their direction) and maintaining organized convection/closed circulation through today and tomorrow until it reached more favorable conditions, something that has failed to happen.

What are your thoughts on the outcome?

Hi Hammy,
1. You should say "I think it has already degenerated to an open wave" since a lot of people, including pros, don't think it has. And you know RECON is not done yet. And you know that multiple centers rotating around each other is very common in a developing TC like this, so no one should be calling a definite center or lack of one right now. Looks aren't everything!

2. My expectations haven't changed from what the NHC has discussed. It is over very warm water and moving into a pretty low shear environment. The one negative to me is some fairly substantial mid-level dry air which has to be worked in and out of the system first. Thus the NHC forecast of gradual strengthening makes good sense.

3. A better track forecast is still hard to nail down considering the intensity fluctuations, but a track towards south Florida looks likely for now.

[Blown Away]

I wonder if recon will check out @19N/58W... They are farther SE in the big convection area, but does not appear to be a circulation down there?

[SFLcane]

Biggest blow up it’s probably ever had.

[AutoPenalti]

Am I crazy or is the blow up a lot further south now?

[SFLcane]

 https://twitter.com/andyhazelton/status/1296617818897690624

[TheStormExpert]

Impressive blow up this evening...

https://cdn1.bbcode0.com/uploads/2020/8/21/1ce288e17758b9030b09701cf8481040-full.png

Still looks like Scrambled Eggs!