ATL: ISAIAS - Post-Tropical - Discussion

[ThetaE]

Shear is actually decreasing at the moment over the NW Bahamas and South Florida:

https://i.postimg.cc/gc8Qnvjy/wg8sht.gif

Yeah, here's an animation of deep-layer shear over the past few hours:

If Hispaniola had anything to do with Isaias' currently disorganized state, it seems to be that the anticyclone was severed/abandoned in the Caribbean. But Isaias is moving through a weakening region of shear, and towards lower values to the NW. I think it's clear that shear has weakened Isaias since last night, but I don't know that it will continue to be a long-term problem.

[HurricaneEnzo]

Moisture is not a problem for this storm. It is not far enough behind Hispaniola for that to be much of a problem. Once it gets further West where it is more mountanous and the Island is really blocking the flow maybe. It clearly still has plenty of moisture fcoming in from the South and East of the storm. It's lopsided because of shear.

Still has nice moisture feed going all the way down to SA


http://tropic.ssec.wisc.edu/real-time/m ... anim=html5

[GCANE]

I don't see this going naked yet.
In fact, two rotating hot towers keeping it covered.

Strong jet-type infeed directly from the west and two more east.
One over the water and one clearing Haiti.

As always, a big make or break later will be if convection over Cuba fires up from afternoon popup thunderstorms.
If they occur, it would directly feed moisture into the core and the mid-levels which is where it is needed most.

[eastcoastFL]

Looks like Hispanola may have claimed another one. Isaias is dying a slow death this morning. Shear, of course, is aiding to it, but HIspanola did a job on the center.

It hasn’t claimed anything yet. The center literally just left the Hispaniola coast a few hours ago. Let’s see what happens as it gains latitude and gets away from the mountains.

I disagree. It looks really bad right now. Shear has a lot to do with it but so does the fact that Hispaniola ripped a lot of the storms around it. Like I said, this could be a tropical wave by this time tomorrow. The shear is only getting worse.

I think the odds of it being an open wave are as good as it being cat2 tomorrow

[Jr0d]

Pressure looks like it increase another mb or 2 since the last pass.

Given the burst of convection near the center, it may have reached its weak point for now. It seems like systems like this pulse, now it might start to strengthen some more. If the recon can do another center pass, I would bet that it finds a slightly lower pressure on the next pass than the one that just happened.

[curtadams]

Shear often makes storms vary more. They'll look bad for a while, then better, then bad again, etc. But it normally has to be a fair amount stronger than this to actually kill a storm. In these conditions, don't read too much into moderate changes in appearance, either good or bad.

[DestinHurricane]

It hasn’t claimed anything yet. The center literally just left the Hispaniola coast a few hours ago. Let’s see what happens as it gains latitude and gets away from the mountains.

I disagree. It looks really bad right now. Shear has a lot to do with it but so does the fact that Hispaniola ripped a lot of the storms around it. Like I said, this could be a tropical wave by this time tomorrow. The shear is only getting worse.

I think the odds of it being an open wave are as good as it being cat2 tomorrow

I disagree. I think a cat 2 is much more likely. This is as weak as it's going to get until land IMO.

[Nuno]

I disagree. It looks really bad right now. Shear has a lot to do with it but so does the fact that Hispaniola ripped a lot of the storms around it. Like I said, this could be a tropical wave by this time tomorrow. The shear is only getting worse.

There is absolutely no evidence of that. These posts really need to stop

No evidence of what? Shear? Even the biggest hurricane experts are saying there’s shear. I know you want a cat 5 and all but it’s not happening. It’s on life support right now and is being choked by dry air and shear. That’s just reality. The CMC has been calling for this for days and now the 06 Euro is also starting to fall for it. They see it happening.

I’m just posting reality and what is being said and what I’m seeing. I have a masters degree from the Naval Academy in meteorology. I know these things.

Shear is actually much weaker out in front of the storm as it pulls away from Hispanola. Got a lot of time to watch this as it approaches FL and makes it's turn.

[HurricaneEnzo]

There is absolutely no evidence of that. These posts really need to stop

No evidence of what? Shear? Even the biggest hurricane experts are saying there’s shear. I know you want a cat 5 and all but it’s not happening. It’s on life support right now and is being choked by dry air and shear. That’s just reality. The CMC has been calling for this for days and now the 06 Euro is also starting to fall for it. They see it happening.

I’m just posting reality and what is being said and what I’m seeing. I have a masters degree from the Naval Academy in meteorology. I know these things.

http://tropic.ssec.wisc.edu/real-time/atlantic/winds/wg8shr.GIF

Shear is actually much weaker out in front of the storm as it pulls away from Hispanola. Got a lot of time to watch this as it approaches FL and makes it's turn.

This. All of this. So much for the no shear argument.

[cp79]

It hasn’t claimed anything yet. The center literally just left the Hispaniola coast a few hours ago. Let’s see what happens as it gains latitude and gets away from the mountains.

I disagree. It looks really bad right now. Shear has a lot to do with it but so does the fact that Hispaniola ripped a lot of the storms around it. Like I said, this could be a tropical wave by this time tomorrow. The shear is only getting worse.

I think the odds of it being an open wave are as good as it being cat2 tomorrow

We’ll see. Just saying there’s a chance of it becoming a wave. I think it’ll be a weak TS that goes into So. Fl with a naked swirl and then quickly be downgraded to just a low as it drifts north. That’s just my opinion and it looks liked the CMC and latest Euro from 06z are leaning that way too.

Just posting what I’m seeing and hearing from the experts...it’s in trouble.

[eastcoastFL]

I disagree. It looks really bad right now. Shear has a lot to do with it but so does the fact that Hispaniola ripped a lot of the storms around it. Like I said, this could be a tropical wave by this time tomorrow. The shear is only getting worse.

There is absolutely no evidence of that. These posts really need to stop

No evidence of what? Shear? Even the biggest hurricane experts are saying there’s shear. I know you want a cat 5 and all but it’s not happening. It’s on life support right now and is being choked by dry air and shear. That’s just reality. The CMC has been calling for this for days and now the 06 Euro is also starting to fall for it. They see it happening.

I’m just posting reality and what is being said and what I’m seeing. I have a masters degree from the Naval Academy in meteorology. I know these things.

It’s in an area of 25 to 35 knots of shear heading towards an area with 5-10 so it’s moving towards a more favorable area unless shear moves west more. I’d take it easy with killing a storm right now a few hours of weakening isn’t the end. It still has quite a way to go. Take it easy

[aspen]

It hasn’t claimed anything yet. The center literally just left the Hispaniola coast a few hours ago. Let’s see what happens as it gains latitude and gets away from the mountains.

I disagree. It looks really bad right now. Shear has a lot to do with it but so does the fact that Hispaniola ripped a lot of the storms around it. Like I said, this could be a tropical wave by this time tomorrow. The shear is only getting worse.

I think the odds of it being an open wave are as good as it being cat2 tomorrow

It’s going to take a lot more than 15-25 kt of shear to turn a ~990 mbar system into an open wave. And as ThetaE posted, shear is starting to lessen a bit, so Isaias opening up into a wave anytime soon is unlikely. It would have to run into 30-40+ kt of shear to be opened up.

[TheStormExpert]

There’s about 25-30kts. of Southwesterly shear on top of Isaias this morning. The anticyclone it had on top is now south of Haiti. Let’s see what the NHC says in a hour but winds have decreased to 65kts. and that may be too generous.

[DestinHurricane]

I disagree. It looks really bad right now. Shear has a lot to do with it but so does the fact that Hispaniola ripped a lot of the storms around it. Like I said, this could be a tropical wave by this time tomorrow. The shear is only getting worse.

There is absolutely no evidence of that. These posts really need to stop

No evidence of what? Shear? Even the biggest hurricane experts are saying there’s shear. I know you want a cat 5 and all but it’s not happening. It’s on life support right now and is being choked by dry air and shear. That’s just reality. The CMC has been calling for this for days and now the 06 Euro is also starting to fall for it. They see it happening.

I’m just posting reality and what is being said and what I’m seeing. I have a masters degree from the Naval Academy in meteorology. I know these things.

As others with a lot of experience have pointed out, the shear is expected to get better. Also it takes a lot more shear than this to kill a storm. 2 models are not enough, especially one of them being the CMC.

Second of all, no one here wants a cat 5. If it were out in the open Atlantic like Lorenzo last year then maybe but not in this area. Abaco island is still ravaged and I don't think anyone here wishes more death and destruction on that island. Please do not make rude remarks like this towards members here.

[eastcoastFL]

Looks like convection is firing off to the west now also. Possibly in an area of less shear

[HurricaneEnzo]

There is absolutely no evidence of that. These posts really need to stop

No evidence of what? Shear? Even the biggest hurricane experts are saying there’s shear. I know you want a cat 5 and all but it’s not happening. It’s on life support right now and is being choked by dry air and shear. That’s just reality. The CMC has been calling for this for days and now the 06 Euro is also starting to fall for it. They see it happening.

I’m just posting reality and what is being said and what I’m seeing. I have a masters degree from the Naval Academy in meteorology. I know these things.

As others with a lot of experience have pointed out, the shear is expected to get better. Also it takes a lot more shear than this to kill a storm. 2 models are not enough, especially one of them being the CMC.

Second of all, no one here wants a cat 5. If it were out in the open Atlantic like Lorenzo last year then maybe but not in this area. Abaco island is still ravaged and I don't think anyone here wishes more death and destruction on that island. Please do not make rude remarks like this towards members here.

I think he meant no evidence the storm would die as the one poster indicated. Some people are saying shear isn't the current problem though which it clearly is.

[GCANE]

Inflowing dramatically increasing into those two rotating hot towers.
And they're getting bigger.
Hot towers have a habit of pushing shear out of the way.

[TheStormExpert]

If shear wasn’t enough there’s also a thin layer of SAL out ahead of it over South Florida and the NW Bahamas along with plenty of mid-level dry air ahead.

[wxman57]

It looks like shear is going to increase over the next 24 hrs. Shear decreases once it turns north to NNE on Sunday.

[Jr0d]

I’m just posting reality and what is being said and what I’m seeing. I have a masters degree from the Naval Academy in meteorology. I know these things.

Given how poorly the Navy weather model consistently performs, those credentials will not get you much respect on here.

Currently there is a convection burst near the center, it appears Isaias weakening trend is over for at least an hour or two.