ATL: GONZALO - Remnants - Discussion

[Hurricane Mike]

My take on Gonzalo and 91L
https://www.youtube.com/watch?v=FUbIsynNciI

[tiger_deF]

Next few hours are really make or break it with Gonzalo. It has Dmax approaching, a slightly larger CDO, and some great SST content and shear profiling coming up. The only major concern, and what I think has been limiting it's intensity so far us the amount of dry air nearby even with it's moisture pocket. Either it fires those crucial hot towers or it doesn't.

[storminabox]

Despite the waning convection, Gonzalo has a pretty classic coma shape appearance to it. It definitely does not look like a struggling tropical cyclone. Dmax should be interesting.

[gfsperpendicular]

Is it possible that Gonzalo's loss of banding is due to the dry air surrounding it? You often hear that dry air is not a problem without shear, and that could explain why the core remains seemingly intact.

[EquusStorm]

Dry air seems closer on the NW side now. If it can stay out of that, good to go, but wouldn't take too much of it to enter the circulation to become meddlesome to its structure

[drezee]

I wouldn't get too frustrated - the NHC has time and will make needed adjustments. Perhaps it'll be based on what you mentioned, but they've been burned too many times when it comes to upgrading solely on satellite measurements. Nothing like surface or aircraft observations. Outside of an undeniable eye, they might wait for recon to verify it's strength.

Also, the ongoing split between models as they continue to state is a low-confidence forecast and probably why they are hesitant.

Frank

With no recon and the ability to disregard ASCAT, why not increase intensity skill scores. Nobody is getting hurt. By the time it matters, recon will have flown in. Only people that care are weather nuts like us...

[storminabox]

Dry air seems closer on the NW side now. If it can stay out of that, good to go, but wouldn't take too much of it to enter the circulation to become meddlesome to its structure

I noticed that too. It almost seems to be moving NW.

[Aric Dunn]

alright.. lets see what happens now..

big towers going off in the SW quad and NE quad.. plenty of upper level vorticty to clear out the eye above the mid levels.

[Monsoonjr99]

Seems some westerly shear might be entraining dry air.

 https://twitter.com/pppapin/status/1286042383583531011

[USTropics]

Is it possible that Gonzalo's loss of banding is due to the dry air surrounding it? You often hear that dry air is not a problem without shear, and that could explain why the core remains seemingly intact.

That is likely one of the main culprits. If you take a step back, and look at the larger picture, you can see the expansion of Gonzalo, coupled with a slight north heading, has left it precariously close to the dry boundary layer of the recent SAL plume that is now directly north of the system:


There is an additional second leading mass of stable air in front of Gonzalo as well. This is causing 2 issues currently; some dry air entrainment is now occurring from the west/southwest due to this leading air mass:


In addition, said feeder band's moisture has been stretched out and elongated between these two dry air masses:


This isn't unusual to see systems go through phases essentially. There will be steady strengthening, system increases in size/circulation deepens, and a larger surrounding environment is needed to persist. These tropical systems have processes that can help negate this and give it proper time to recover (in a low shear environment of course).

[Aric Dunn]

Is it possible that Gonzalo's loss of banding is due to the dry air surrounding it? You often hear that dry air is not a problem without shear, and that could explain why the core remains seemingly intact.

That is likely one of the main culprits. If you take a step back, and look at the larger picture, you can see the expansion of Gonzalo, coupled with a slight north heading, has left it precariously close to the dry boundary layer of the recent SAL plume that is now directly north of the system:
https://i.imgur.com/2OfOd8g.jpg

There is an additional second leading mass of stable air in front of Gonzalo as well. This is causing 2 issues currently; some dry air entrainment is now occurring from the west/southwest due to this leading air mass:
https://i.imgur.com/CmeydiK.png

In addition, said feeder band's moisture has been stretched out and elongated between these two dry air masses:
https://i.imgur.com/WrSssEb.png

This isn't unusual to see systems go through phases essentially. There will be steady strengthening, system increases in size/circulation deepens, and a larger surrounding environment is needed to persist. These tropical systems have processes that can help negate this and give it proper time to recover (in a low shear environment of course).

It is still just south of 10 N .. DUE west..

also note the most important thing in your images.. the majority of the sal has already past it with a surge of deep moisture coming behind it. just like the HWRF>.

[Weatherwatcher2018]

What impacts can we expect in Barbados

[USTropics]

Is it possible that Gonzalo's loss of banding is due to the dry air surrounding it? You often hear that dry air is not a problem without shear, and that could explain why the core remains seemingly intact.

That is likely one of the main culprits. If you take a step back, and look at the larger picture, you can see the expansion of Gonzalo, coupled with a slight north heading, has left it precariously close to the dry boundary layer of the recent SAL plume that is now directly north of the system:
https://i.imgur.com/2OfOd8g.jpg

There is an additional second leading mass of stable air in front of Gonzalo as well. This is causing 2 issues currently; some dry air entrainment is now occurring from the west/southwest due to this leading air mass:
https://i.imgur.com/CmeydiK.png

In addition, said feeder band's moisture has been stretched out and elongated between these two dry air masses:
https://i.imgur.com/WrSssEb.png

This isn't unusual to see systems go through phases essentially. There will be steady strengthening, system increases in size/circulation deepens, and a larger surrounding environment is needed to persist. These tropical systems have processes that can help negate this and give it proper time to recover (in a low shear environment of course).

It is still just south of 10 N .. DUE west..

also note the most important thing in your images.. the majority of the sal has already past it with a surge of deep moisture coming behind it. just like the HWRF>.

I was mainly referring to the feeder band that was "sacrificed" so to speak to the northerly SAL plume. The southerly ingestion of SAL is what has put a cap on intensity imo, although the storm has handled it fine so far (it even intensified this morning despite this). Stripping away some of the available moisture from the north, capping the outflow, and that southerly dry air entrainment is creating this cyclical phases of strengthening, tapering off, strengthening, etc. instead of out right RI.

[supercane4867]

New hot tower popping up.

[BYG Jacob]

What storm are people looking at that's sucking in dry air? It ain't this one.

[HurricaneFrances04]

What impacts can we expect in Barbados

Hurricane center says it is too soon to tell what direct impacts it'll have. Still have a couple of days to watch it, but of course make sure your normal early preparations are in place. Current forecast gives it a 48 hour window for strengthening, but it is a question of how much stronger it is able to get.

https://www.nhc.noaa.gov/refresh/graphi ... s#contents

[Hurricane Mike]

I'm getting the impression right now that Gonzalo isn't evacuating air and ventilation quite enough. He needs to do some venting.

[Weatherwatcher2018]

I'm getting the impression right now that Gonzalo isn't evacuating air and ventilation quite enough. He needs to do some venting.

What you mean by this

[cycloneye]

 https://twitter.com/pppapin/status/1286082525975150592

[EquusStorm]

Maybe a little resurgence in the NW corner where dry air was getting kinda close with some convection trying to develop there. Sure would love to see it bomb out while it isn't bothering anyone, we'll see tonight