ATL: GRACE - Remnants - Discussion

[ConvergenceZone]

The 5PM NHC Cone center is right down the GA's pipe. It's certainly conceivable that Grace doesn't survive that kind of track.

It's going to be too weak to move along that track in my opinion. It should track south of Cuba...

[hipshot]

Convection seems to have relocated closer to the center. I believe the MLC is attempting to put down a LLC. What implications this has is that the quicker it does so, the more influenced it will be by the ridge and go south IMHO.

Wouldn’t a stronger storm go more north as it can easily feel weaknesses in the ridge?

Sure, if there is a weakness.

Can someone define this "weakness" between ridges and troughs or ridges and ridges etc.?

[captainbarbossa19]

Hopefully this does not turn out like Laura, but here is an interesting tweet I found in Laura's archives here.

 https://twitter.com/MikeFischerWx/status/1296872916987064320

[Blown Away]

could be wrong, but the convection is headed right for P.R. , I am going out on a limb but I think this is going to skirt and may remain just offshore of Hispanola.

Follow the Convection.

That convection ball to the NE of the estimated center is heading WNW towards PR.

[AutoPenalti]

Wouldn’t a stronger storm go more north as it can easily feel weaknesses in the ridge?

Sure, if there is a weakness.

Can someone define this "weakness" between ridges and troughs or ridges and ridges etc.?

The weakness is essentially created when a short wave or trough creates a low level pressure which acts as sort of like a magnet for cyclones to move into, where as ridges, depending on the height of it can act as like a roadblock to keep storms beneath it, now it really depends at what height a ridge is oriented, if the ridge is flowing from the east in the lower levels, then the storm will move west, however if the ridge is south easterly from higher up in the atmosphere then you have competing steering factors, so depending on how strong a storm is will determine the height at which steering will be influenced.

[tolakram]

saved loop

[sunnyday]

So, is this likely another Gulf storm as things look now?

[Woofde]

So, is this likely another Gulf storm as things look now?

If it can survive past Hispaniola and Cuba then it seems likely.

[AtlanticWind]

could be wrong, but the convection is headed right for P.R. , I am going out on a limb but I think this is going to skirt and may remain just offshore of Hispanola.

Follow the Convection.

That convection ball to the NE of the estimated center is heading WNW towards PR.

it looks to me like a solid wnw , this could still get north of the big island.

[Blown Away]

saved loop
https://i.imgur.com/FJt9sYo.gif

Doesn't seem like there is much based on the NHC's 5pm position.

[aspen]

So, is this likely another Gulf storm as things look now?

Who knows. Might get ripped up over the Greater Antilles, because that seems to be the only track any AEW-based system can take this year.

We need recon ASAP to figure out where the center truly is.

[skyline385]

GFS 18Z showing an open wave entering the Gulf, seems like its going to fall to speed as well. The GFS just shows it blazing into the Gulf, never getting the time to organise...

[AtlanticWind]

if this doesnt reform the center to the north under the convection, I think it will struggle big time with the hispanola and cuba.
I said the same thing with Fred ,has to get north of the islands to survive . JMO

[aspen]

Yeah I’m in the “Grace will die horribly and non-gracefully over the GAs” train now. It’ll take something drastic within the next 24 hours to change the fate of this system — and hopefully keep it away from Haiti to not complicate recovery efforts.

[Blown Away]

GFS 18Z showing an open wave entering the Gulf, seems like its going to fall to speed as well. The GFS just shows it blazing into the Gulf, never getting the time to organise...

IMO, Grace will outrun all the convection and the easterlies will continue accelerating her W across the Caribbean likely as a TW...
or
Center reformation to the NE under the current convection ball and move more WNW...

[Category5Kaiju]

Yeah I am still scratching my head here, I honestly have zero idea whether we will get a shredded storm or if Grace manages to dodge Hispaniola's tallest mountains. We'll see though, but imho if storms like the 1900 Galveston storm or Laura happened, then idk.

[Blinhart]

Reading the Disco, basically says we have no idea what is going on with this system. It could relocate its center anywhere, it could go north or south of the GA and be a lot stronger or it could do like Fred and go over the GA and dissipate and then what who knows. So when the official forecasters are saying your guess is as good as ours past 12 hours from now is what is going to happen.

[storminabox]

How on Earth is that the EPac is somehow doing better than the Atlantic? It should be favored right now, but Fred and Grace are both disorganized Shredder food, and somehow the EPac managed to produce a second Cat 4.

It seems like immediately after the MJO progresses through a region, the atmosphere is primed to produce a major. I’m just happy the EPAC managed to produce a gem after the slop we’ve seen. The Atlantic will become favorable eventually, though we may have to wait until after 8/20. Grace so far has been one of those storms that looks great, but is in tough shape underneath the canopy. ETA was similar. It looked like an incredibly powerful Category 5 hurricane, however in reality it was a strong Category 4 - still impressive but not historic.

[hipshot]

Sure, if there is a weakness.

Can someone define this "weakness" between ridges and troughs or ridges and ridges etc.?

The weakness is essentially created when a short wave or trough creates a low level pressure which acts as sort of like a magnet for cyclones to move into, where as ridges, depending on the height of it can act as like a roadblock to keep storms beneath it, now it really depends at what height a ridge is oriented, if the ridge is flowing from the east in the lower levels, then the storm will move west, however if the ridge is south easterly from higher up in the atmosphere then you have competing steering factors, so depending on how strong a storm is will determine the height at which steering will be influenced.

And doesn't it depend also on the orientation of the storm to the ridge or trough as to which way it will steer the storm whether the ridge or
trough is north or south of the storm?

[AutoPenalti]

Can someone define this "weakness" between ridges and troughs or ridges and ridges etc.?

The weakness is essentially created when a short wave or trough creates a low level pressure which acts as sort of like a magnet for cyclones to move into, where as ridges, depending on the height of it can act as like a roadblock to keep storms beneath it, now it really depends at what height a ridge is oriented, if the ridge is flowing from the east in the lower levels, then the storm will move west, however if the ridge is south easterly from higher up in the atmosphere then you have competing steering factors, so depending on how strong a storm is will determine the height at which steering will be influenced.

And doesn't it depend also on the orientation of the storm to the ridge or trough as to which way it will steer the storm whether the ridge or
trough is north or south of the storm?

Yeah that would be the tilt of the trough, kinda like what happened during Sandy.