ATL: SALLY - Post-Tropical - Discussion

[TheStormExpert]

This can’t be accurate!?

[RL3AO]

Looks a little better than a couple of hours ago. Finally seeing some signs of more anti cyclonic outflow in the NE and SW quads.

[ClarCari]

Pressure is still steadily dropping.
One thing to note that as (and if) it starts clearing away more and more shear the rate of intensification no matter how small grows exponentially. A 10mph increase over the last 12 hours could turn into a 15-25mph increase over the next 12 hrs.

[stormhunter7]

The feeder band passing NW Florida (PCB) is showing the mid level and upper clouds are now starting to move to the east and not south. The shear is changing.... Think Sally will respond to this soon.

[tropicwatch]

Sally might be slowing down, has not moved much the past three hours.

[toad strangler]

Now don't get me wrong. I still think we're looking at a 65 or 70 kt landfall and of course the rain will be the big story as we've talked about now for a few days. I just think the high end chance of a major/near major hurricane has gotten much lower today.

Oh wow, all I was reading yesterday was talk of RI and exploding once it splashed off of Florida. What are your thoughts on this not getting to Cat 1?

I don't believe it was supposed to strengthen, if any, until early tomorrow morning, per NHC. NHC is saying a CAT 1, so prepare for a CAT 2. My thoughts on whether it will get to CAT 1 is, it might. It has a lot of work to do to get itself together. I can only watch and learn from all on the Board. It amazes me how much has to "line up" for a hurricane to spin up or form. It's a wonder it ever happens! Every year, I learn something new, and I am thankful for everyone. I am pulling for shear and dry air to be victorious, I pray that for every storm!

This place was full of bullish posts post FL in regards to intensification. That was my context. This place is full of a bunch of storm weenies so they see the silver lining in everything. I talked about trusting the models a bit more with this system but that didn't sit well with them

Regardless, you are correct, there is MUCH to learn here Hopefully Sally behaves herself.

[MississippiWx]

This can’t be accurate!?

https://i.ibb.co/XYMFxGZ/wg8sht.gif

It's correct.

The GFS shows this as well. Shear has dropped below 10kts and is forecast to drop below 5kts tonight into tomorrow. This is why the ceiling is still high for Sally. However, sometimes it's not so simple as shear dropping. The MLC is quite robust as is the LLC. They are at odds and competing with one another. I think this is the main issue currently and stacking may not occur until the low-level center slows down enough for the MLC to catch up with it. When this happens is anyone's guess, but most models don't show it happening until tomorrow. I'd expect more of the same the rest of today.

[us89]

Pressure is still steadily dropping.
One thing to note that as (and if) it starts clearing away more and more shear the rate of intensification no matter how small grows exponentially. A 10mph increase over the last 12 hours could turn into a 15-25mph increase over the next 12 hrs.

Every millibar of pressure drop at this point is going to be crucial in just how strong this can get in the long run. We're in a slow, gradual intensification phase now, but I'd imagine if Sally isn't fully vertically stacked by the end of today the typical nighttime convective maximum will do the trick - which will probably help Sally build up an organized inner core that can resist the light to moderate shear we're seeing now. Right now we're setting the baseline from which any later, faster intensification begins.

[Nimbus]

NHC was thinking Monday before Sally becomes organized and forecast depends on the stall scenario.
Has the slowdown in forward speed started?

[GCANE]

Those towers were zipping across really nice and then just hit a brick wall.
Can't figure what the hell happened.
Everything looks good.
Strange.

[RL3AO]

Here's a look at the improved outflow north of the center compared to two hours ago.

[Deshaunrob17]

I can't wait for Sally to be over because some persons act like the Gulf of Mexico has super powers that cause every storm to blow up into a MH.
Plenty credit to the National Hurricane Center for predicting shear from the beginning

[Nimbus]

Here's a look at the improved outflow north of the center compared to two hours ago.

https://i.imgur.com/GYP4aAJ.png

https://i.imgur.com/YDeyS1N.png

All I'm getting in the loop is the 2005 UTC?
Looked to me like the LLC is still moving yet we have some posters saying it hasn't moved for three hours.
The red blob wrapped and stayed but the LLC is still moving.

[LarryWx]

This is neither exploding nor falling apart but rather something in between. It is closer to being between holding its own and strengthening slowly.

[ClarCari]

All I’m hoping for is that the state governors and officials are letting everyone know this things will bring major flooding regardless of strength.

But if I have to bite the bullet, I will still say there is a chance for this to become Cat.3. Do I expect an intensifying Cat.4? Nope that sailed over night.
As is the way the world works, things can blow up in our faces easily because our brains cannot process exponential growth, another reason viruses spread so fast without us understanding wtf happened. About 48 hours left over water...it has the time to strengthen the extra 55mph. Hopefully its a small wind radius regardless.

[eastcoastFL]

Now don't get me wrong. I still think we're looking at a 65 or 70 kt landfall and of course the rain will be the big story as we've talked about now for a few days. I just think the high end chance of a major/near major hurricane has gotten much lower today.

That’s good. We know the rain is going to be a major issue regardless of how much wind there is so at least there will be less surge to worry about. I’m liking that the hwrf is seeing less organized storm 2 runs in a row now

[eastcoastFL]

This is neither exploding nor falling apart but rather something in between. It is closer to being between holding its own and strengthening slowly.

It’s pretty much on par with the nhc forecast of gradual strengthening which they expect to level off sometime later tomorrow

[stormhunter7]

NOAA49 dropsondes data showed at 500mb over the center is where the shear/drier air was at. This appears to be warming up now and relaxing... aircraft is on a north to south pass over CoC it looks like now. We will see how it's changing

[us89]

This is neither exploding nor falling apart but rather something in between. It is closer to being between holding its own and strengthening slowly.

It’s pretty much on par with the nhc forecast of gradual strengthening which they expect to level off sometime later tomorrow

NHC expects strengthening to continue up into landfall:

Sally is forecast to move beneath a narrow upper-level ridge axis
through Monday and the expected decrease in shear should allow the
storm to strengthen. Since Sally is forecast to decelerate on its
approach to the northern Gulf coast, the system still has at least
another 36 h to take advantage of the expected conducive
environmental conditions. As a result, the NHC intensity forecast
continues to call for Sally to become a hurricane on Monday, with
additional strengthening likely until landfall. The intensity
guidance has trended slightly lower this cycle, with the HMON model
now at the upper end of the guidance envelope. The reduction in the
statistical guidance is likely due to the fact that Sally has not
strengthened today and there is a persistence component to the
forecast from those models. The latest NHC intensity forecast is
similar to the previous advisory and lies a little above the latest
HFIP corrected consensus aid.

[Dave C]

Almost seems like rotation further back to the east in the convection, is that mid-level or possible relocation of llc.