ATL: GONZALO - Remnants - Discussion

[HurricaneEnzo]

Convection has warmed but CDO has expanded. Lets see if some deeper convection fires off shortly and this thing really gets going.

[gatorcane]

Yes the shear is strong and I would be shocked if all the globals are wrong and Gonzalo survives. This shear has been well advertised by the long-range GFS going back to models runs last week so should be of no surprise

The same GFS shows the shear to get out of the way, haven't you looked that?
Is the dry air that it could have a problem with not the shear, as mentioned by the experts at the NHC.

Edit: By the way, the GFS shear forecast has been horrible past its 5 day range forecast, if it would had been right it would had been ripping Gonzalo apart starting tomorrow way before getting the Windward Islands.

https://i.imgur.com/it5eiSy.gif

Yes mid-level dry air is a problem too. The model as of 06Z has quite a bit of shear hitting the small cyclone as it approaches the islands and that with the dry air is likely what disrupts the core not allowing it to reorganize once in the Caribbean. The shear does look to relax some but it is too late according to the GFS and the globals. We will likely end up with a naked swirl or a trough with minimal convection heading west in the Caribbean if the globals are right. I know this is not the models thread but to make my point:

[gfsperpendicular]

The NHC discussion has weakening starting in 48 hours, so we should be able to see how favorable the environment is pretty soon.

[drezee]

Convection has warmed but CDO has expanded. Lets see if some deeper convection fires off shortly and this thing really gets going.

The gravity wave on the east side makes me think the new convection will come from the East Eyewall

[Shell Mound]

 https://twitter.com/splillo/status/1285959128683171843



 https://twitter.com/pppapin/status/1285962371366825987



 https://twitter.com/RyanMaue/status/1285963484124057600



 https://twitter.com/mfdwx/status/1285944500674756608

[ScottNAtlanta]

https://twitter.com/splillo/status/1285959128683171843

I believe Emily 2005 had a track further south

[tiger_deF]

Convection has warmed up slightly overall but I would say the overall structure of the CDO is much improved from yesterday, and it looks to be firing off another round of hot towers. This one's a fighter and has already overperformed, I think Gonzalo may surprise us again

[HurricaneEnzo]

Convection has warmed but CDO has expanded. Lets see if some deeper convection fires off shortly and this thing really gets going.

The gravity wave on the east side makes me think the new convection will come from the East Eyewall

Good call some small hot towers shooting up on Eastern side of circ right now.

[HurricaneFrances04]

Ivan became a hurricane at 9.5 43.4, just to the south of Gonzalo. Of course, it was also September then.

[BYG Jacob]

Looking increasingly likely Gonzalo will be our first hurricane

[NDG]

The same GFS shows the shear to get out of the way, haven't you looked that?
Is the dry air that it could have a problem with not the shear, as mentioned by the experts at the NHC.

Edit: By the way, the GFS shear forecast has been horrible past its 5 day range forecast, if it would had been right it would had been ripping Gonzalo apart starting tomorrow way before getting the Windward Islands.

https://i.imgur.com/it5eiSy.gif

Yes mid-level dry air is a problem too. The model as of 06Z has quite a bit of shear hitting the small cyclone as it approaches the islands and that with the dry air is likely what disrupts the core not allowing it to reorganize once in the Caribbean. The shear does look to relax some but it is too late according to the GFS and the globals. We will likely end up with a naked swirl or a trough with minimal convection heading west in the Caribbean if the globals are right. I know this is not the models thread but to make my point:

https://i.postimg.cc/k5xR14zM/gfs-shear-watl-16.png

First of all like I have mentioned the GFS shear image exaggerates the shear on its graphic, it shows 30-45 knots shear across the Caribbean this morning when the UW-CIMMS group analyzed shear 20-30 knots at the most.
Secondly I rather use the sounding forecast for the area.
The same GFS 120 hr shear (which is way better than its 5-15 day range) forecasts that 25-30 knot shear will get out of the way by the time it gets to the windward Islands and drop to only near 10 knots as it gets to the Windward Islands.
Nothing but easterly winds in the upper levels above it, maybe some light mid level southerly shear over it.
Edit: Another thing thing to keep in mind besides the dry air is the usual diverging low level flow that happens in the central Caribbean between Hispaniola and S.A. this time of the year, that could also be problematic for a small system like Gonzalo.

[al78]

https://twitter.com/mfdwx/status/1285944500674756608

It is a valid point about the pre-satellite era. How many of the weak short lived subtropical systems this year would have been named prior to 1960?

[BYG Jacob]

https://twitter.com/mfdwx/status/1285944500674756608

It is a valid point about the pre-satellite era. How many of the weak short lived subtropical systems this year would have been named prior to 1960?

None of the storms this year were subtropical.

[Aric Dunn]

Hey look at that closed eye wall building up quickly..

hurricane very shortly

[BYG Jacob]

Hey look at that closed eye wall building up quickly..

hurricane very shortly

https://i.ibb.co/hdf00gH/LABELS-19700101-000000-1.gif

Holy hot tower batman!

[Shell Mound]

Looking increasingly likely Gonzalo will be our first hurricane

Given organisational trends, I think it could certainly attain low-end Cat-2 status within the next day and a half before the trade surge and the retrogressive TUTT begin to exact their toll on the system. The low latitude and compact size certainly afford some short-term insulation from the SAL to the north. The fact that a sprawling tropical wave is closely trailing the system also results in southeasterly flow on its eastern flank, which effectively places Gonzalo in a plume of relatively higher, ITCZ-related PWATs. Effectively, the trailing wave “steals” some of the mid-level dry air that would otherwise be absorbed by Gonzalo. In the end, shear, not dry air, is likely going to be the main factor that kills Gonzalo as it nears the Caribbean.

[shiny-pebble]

Looks like the eye is closing off

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[Aric Dunn]

Coming to a theater near you... Hurricane Gonazalo.. lol

[Aric Dunn]

Hmmm.. possibly another special advisory..

[Aric Dunn]

So far the HWRF has nailed it.. yesterday 12z run said 24 hours would be a hurricane..