ATL: SALLY - Post-Tropical - Discussion

[ClarCari]

Reminds me a bit of the small inner core Gordon in 2018 developed as it was moving away from Florida. I'm hoping that the same result occurs.

https://twitter.com/pppapin/status/1305045241272164352?s=21

I was looking at the archived thread for 2018's TS Gordon, which had a very similar small core and similar track earlier in Sept with very similar E GOM SSTs near 30C. Like for this storm, there was a pretty good bit of talk about the possibility of RI and most folks expected a H hitting the Gulf coast. The NHC peak strength was projected to be 75 mph offshore before weakening some vs 85 for this one. The peak ended up being 70 mph starting 130 miles from the Gulf coast and lasting til landfall.

Gordon archived thread:
viewtopic.php?f=88&t=119828&start=600


Gordon track:
https://i.imgur.com/eTEXPAQ.png

How does Sally compare to Gordon? Any thoughts?

Pretty similar looking track but sadly the newest forecast not only has it pushing more west towards the Mississippi River delta, but now the forecast peak at the moment is 100MPH!

[GCANE]

Interesting, I haven't seen this before.
It's actually pulling high TPW air from the EPAC.
It's skirting the CA mountains and going across Nicaragua and Panama.
Pickup up moisture also from the W Carib.

[caneman]

Reminds me a bit of the small inner core Gordon in 2018 developed as it was moving away from Florida. I'm hoping that the same result occurs.

https://twitter.com/pppapin/status/1305045241272164352?s=21

I was looking at the archived thread for 2018's TS Gordon, which had a very similar small core and similar track earlier in Sept with very similar E GOM SSTs near 30C. Like for this storm, there was a pretty good bit of talk about the possibility of RI and most folks expected a H hitting the Gulf coast. The NHC peak strength was projected to be 75 mph offshore before weakening some vs 85 for this one. The peak ended up being 70 mph starting 130 miles from the Gulf coast and lasting til landfall.

Gordon archived thread:
viewtopic.php?f=88&t=119828&start=600


Gordon track:
https://i.imgur.com/eTEXPAQ.png

How does Sally compare to Gordon? Any thoughts?

Pretty similar looking track but sadly the newest forecast not only has it pushing more west towards the Mississippi River delta, but now the forecast peak at the moment is 100MPH!

Looks like 90 mph But weakening before landfall to 60 to 80 mph. We will see. Hopefully its minimal.

[sittingduck]

Rained steadily almost all night here in Venice. Breezy with gusts here and there. Sally has a lot of moisture on this side. Sure hope the HRWF is wrong on intensity. Thoughts to those in its final path

[ClarCari]

I was looking at the archived thread for 2018's TS Gordon, which had a very similar small core and similar track earlier in Sept with very similar E GOM SSTs near 30C. Like for this storm, there was a pretty good bit of talk about the possibility of RI and most folks expected a H hitting the Gulf coast. The NHC peak strength was projected to be 75 mph offshore before weakening some vs 85 for this one. The peak ended up being 70 mph starting 130 miles from the Gulf coast and lasting til landfall.

Gordon archived thread:
viewtopic.php?f=88&t=119828&start=600


Gordon track:
https://i.imgur.com/eTEXPAQ.png

How does Sally compare to Gordon? Any thoughts?

Pretty similar looking track but sadly the newest forecast not only has it pushing more west towards the Mississippi River delta, but now the forecast peak at the moment is 100MPH!

Looks like 90 mph But weakening before landfall to 60 to 80 mph. We will see. Hopefully its minimal.

What makes it “look” like 90MPH at landfall. Gotta be specific on these threads. There’s ever growing support for this to be blowing up going into landfall.

[caneman]

Pretty similar looking track but sadly the newest forecast not only has it pushing more west towards the Mississippi River delta, but now the forecast peak at the moment is 100MPH!

Looks like 90 mph But weakening before landfall to 60 to 80 mph. We will see. Hopefully its minimal.

What makes it “look” like 90MPH at landfall. Gotta be specific on these threads. There’s ever growing support for this to be blowing up going into landfall.

Read the 5 o'clock discussion. It shows weakening before landfall

[ClarCari]

Looks like 90 mph But weakening before landfall to 60 to 80 mph. We will see. Hopefully its minimal.

What makes it “look” like 90MPH at landfall. Gotta be specific on these threads. There’s ever growing support for this to be blowing up going into landfall.

Edit: They mention in the 2nd paragraph how tricky strengthening rate will be close to landfall, so they unfortunately have no confidence at all in weakening close to landfall. Their intensity guidance was either a mistake or a combination of some models intensity guidance which is all subject to change over time.

Read the 5 o'clock discussion.

I read it and nothing in their worded discussion mentions weakening like that upon landfall. Only their intensity guidance suggests that, but until the NHC explicitly states that rather than stating “intensity is uncertain” every other sentence (which is the wise thing for them to do!), we have every reason to believe this thing won’t weaken like that upon landfall.

[Shell Mound]

What makes it “look” like 90MPH at landfall. Gotta be specific on these threads. There’s ever growing support for this to be blowing up going into landfall.

Read the 5 o'clock discussion.

I read it and nothing in their worded discussion mentions weakening like that upon landfall. Only their intensity guidance suggests that, but until the NHC explicitly states that rather than stating “intensity is uncertain” every other sentence (which is the wise thing for them to do!), we have every reason to believe this thing won’t weaken like that upon landfall.

The last position prior to landfall (15/0600Z) indicates a rapidly intensifying 85-knot system. The next position after that is inland. Additionally:

While northwesterly shear has been affecting Sally, the global
models suggest that the shear will decrease later today as it moves
under a narrow ridge. Models all respond to these changing
conditions by showing intensification, but they disagree on the rate
of change. It is an extremely tricky forecast because of how this
might happen close to landfall, but guidance is generally 5-10 kt
higher than the last cycle so the intensity forecast has been raised
by those amounts up through landfall. It is worth noting that rapid
intensification is a possibility if the system develops a more solid
inner core on Monday, and stronger solutions like the HWRF model
can't be dismissed. ...

INIT 13/0900Z 27.0N 84.0W 45 KT 50 MPH
12H 13/1800Z 27.7N 85.4W 50 KT 60 MPH
24H 14/0600Z 28.3N 87.2W 60 KT 70 MPH
36H 14/1800Z 28.7N 88.7W 70 KT 80 MPH
48H 15/0600Z 29.2N 89.7W 85 KT 100 MPH
60H 15/1800Z 30.1N 90.0W 70 KT 80 MPH (inland – ed.)
72H 16/0600Z 31.0N 90.0W 50 KT 60 MPH (inland – ed.)
96H 17/0600Z 32.8N 88.6W 30 KT 35 MPH...INLAND
120H 18/0600Z 34.5N 84.5W 20 KT 25 MPH...INLAND[/b]

[caneman]

What makes it “look” like 90MPH at landfall. Gotta be specific on these threads. There’s ever growing support for this to be blowing up going into landfall.

Read the 5 o'clock discussion.

I read it and nothing in their worded discussion mentions weakening like that upon landfall. Only their intensity guidance suggests that, but until the NHC explicitly states that rather than stating “intensity is uncertain” every other sentence (which is the wise thing for them to do!), we have every reason to believe this thing won’t weaken like that upon landfall.

Who is we. You are blowing it up to 100 mph. I'm stating what the intensity forecase shows at landfall. That could be wrong and that could be right. However, you posted it would be 100 mph with no mention of a possible forecast weakening. Calm down and be prepared for a worst case scenario.

[ClarCari]

Read the 5 o'clock discussion.

I read it and nothing in their worded discussion mentions weakening like that upon landfall. Only their intensity guidance suggests that, but until the NHC explicitly states that rather than stating “intensity is uncertain” every other sentence (which is the wise thing for them to do!), we have every reason to believe this thing won’t weaken like that upon landfall.

Who is we. You are blowing it up to 100 mph. I'm stating what the intensity forecase shows at landfall. That could be wrong and that could be right. However, you posted it would be 100 mph with no mention of a possible forecast weakening. Calm down and be prepared for a worst case scenario.

If their discussion can’t explicitly say it will weaken upon landfall it then you can’t either. I mean this in an informative way. I just don’t want to see people sell a dangerous storm short when it’s becoming more and more clear that sadly it won’t be the case.

Edit: Also consider possible NHC typos by forgetting to add Inland next to the 60 and 72 hr guidance. They’ve had quite a few today from everything going on.

[caneman]

Read the 5 o'clock discussion.

I read it and nothing in their worded discussion mentions weakening like that upon landfall. Only their intensity guidance suggests that, but until the NHC explicitly states that rather than stating “intensity is uncertain” every other sentence (which is the wise thing for them to do!), we have every reason to believe this thing won’t weaken like that upon landfall.

The last position prior to landfall (15/0600Z) indicates a rapidly intensifying 85-knot system. The next position after that is inland. Additionally:

While northwesterly shear has been affecting Sally, the global
models suggest that the shear will decrease later today as it moves
under a narrow ridge. Models all respond to these changing
conditions by showing intensification, but they disagree on the rate
of change. It is an extremely tricky forecast because of how this
might happen close to landfall, but guidance is generally 5-10 kt
higher than the last cycle so the intensity forecast has been raised
by those amounts up through landfall. It is worth noting that rapid
intensification is a possibility if the system develops a more solid
inner core on Monday, and stronger solutions like the HWRF model
can't be dismissed. ...

INIT 13/0900Z 27.0N 84.0W 45 KT 50 MPH
12H 13/1800Z 27.7N 85.4W 50 KT 60 MPH
24H 14/0600Z 28.3N 87.2W 60 KT 70 MPH
36H 14/1800Z 28.7N 88.7W 70 KT 80 MPH
48H 15/0600Z 29.2N 89.7W 85 KT 100 MPH
60H 15/1800Z 30.1N 90.0W 70 KT 80 MPH (inland – ed.)
72H 16/0600Z 31.0N 90.0W 50 KT 60 MPH (inland – ed.)
96H 17/0600Z 32.8N 88.6W 30 KT 35 MPH...INLAND
120H 18/0600Z 34.5N 84.5W 20 KT 25 MPH...INLAND[/b]

It does not. This is from the 5 update. Prior to landfall
60H 15/1800Z 30.1N 90.0W 70 KT 80 MPH
72H 16/0600Z 31.0N 90.0W 50 KT 60 MPH
Thereafter it says inland.

I dont know how strong it will end up being but its best to remain calm.

[caneman]

I read it and nothing in their worded discussion mentions weakening like that upon landfall. Only their intensity guidance suggests that, but until the NHC explicitly states that rather than stating “intensity is uncertain” every other sentence (which is the wise thing for them to do!), we have every reason to believe this thing won’t weaken like that upon landfall.

Who is we. You are blowing it up to 100 mph. I'm stating what the intensity forecase shows at landfall. That could be wrong and that could be right. However, you posted it would be 100 mph with no mention of a possible forecast weakening. Calm down and be prepared for a worst case scenario.

If their discussion can’t explicitly say it will weaken upon landfall it then you can’t either. I mean this in an informative way. I just don’t want to see people sell a dangerous storm short when it’s becoming more and more clear that sadly it won’t be the case.

And I don't want to see if overhyped without all facts laid out. You make no mention of a possible weakening an only mention the always aggressive HWRF. As always prepare for worst, hope for best and remain calm. I say this in an informative way. Now lets get back to the storm.

[USTropics]

There is an error with the forecast discussion, it doesn't explicit state those are inland but these two plots:

Code: Select all

 60H  15/1800Z 30.1N  90.0W   70 KT  80 MPH
 72H  16/0600Z 31.0N  90.0W   50 KT  60 MPH

Are clearly inland:


This has happened a few times this year now (likely an automated issue with the forecast package), and it was manually updated later in the advisory.

[ClarCari]

Who is we. You are blowing it up to 100 mph. I'm stating what the intensity forecase shows at landfall. That could be wrong and that could be right. However, you posted it would be 100 mph with no mention of a possible forecast weakening. Calm down and be prepared for a worst case scenario.

If their discussion can’t explicitly say it will weaken upon landfall it then you can’t either. I mean this in an informative way. I just don’t want to see people sell a dangerous storm short when it’s becoming more and more clear that sadly it won’t be the case.

And I don't want to see if overhyped without all facts laid out. You make no mention of a possible weakening an only mention the always aggressive HWRF. As always prepare for worst, hope for best and remain calm. I say this in an informative way.

I....never mentioned the HWRF. I don’t even look at models. I’m simply stating now it was a typo in the NHC guidance, they may have forgotten to put inland next to the 60 and 72 hr. They’ve had a long day

[3090]

Read the 5 o'clock discussion.

I read it and nothing in their worded discussion mentions weakening like that upon landfall. Only their intensity guidance suggests that, but until the NHC explicitly states that rather than stating “intensity is uncertain” every other sentence (which is the wise thing for them to do!), we have every reason to believe this thing won’t weaken like that upon landfall.

Who is we. You are blowing it up to 100 mph. I'm stating what the intensity forecase shows at landfall. That could be wrong and that could be right. However, you posted it would be 100 mph with no mention of a possible forecast weakening. Calm down and be prepared for a worst case scenario.

Just so you understand, the 80 mph wind forecast, right after the 100 mph wind forecast happens to be right over New Orleans. The 100 mph wind forecast is just prior to landfall.

[USTropics]

If their discussion can’t explicitly say it will weaken upon landfall it then you can’t either. I mean this in an informative way. I just don’t want to see people sell a dangerous storm short when it’s becoming more and more clear that sadly it won’t be the case.

And I don't want to see if overhyped without all facts laid out. You make no mention of a possible weakening an only mention the always aggressive HWRF. As always prepare for worst, hope for best and remain calm. I say this in an informative way.

I....never mentioned the HWRF. I don’t even look at models. I’m simply stating now it was a typo in the NHC guidance, they may have forgotten to put inland next to the 60 and 72 hr. They’ve had a long day

Correct, and it was just manually updated;

Code: Select all

INIT  13/0900Z 27.0N  84.0W   45 KT  50 MPH
 12H  13/1800Z 27.7N  85.4W   50 KT  60 MPH
 24H  14/0600Z 28.3N  87.2W   60 KT  70 MPH
 36H  14/1800Z 28.7N  88.7W   70 KT  80 MPH
 48H  15/0600Z 29.2N  89.7W   85 KT 100 MPH
 60H  15/1800Z 30.1N  90.0W   70 KT  80 MPH...INLAND
 72H  16/0600Z 31.0N  90.0W   50 KT  60 MPH...INLAND
 96H  17/0600Z 32.8N  88.6W   30 KT  35 MPH...INLAND
120H  18/0600Z 34.5N  84.5W   20 KT  25 MPH...INLAND

[caneman]

If their discussion can’t explicitly say it will weaken upon landfall it then you can’t either. I mean this in an informative way. I just don’t want to see people sell a dangerous storm short when it’s becoming more and more clear that sadly it won’t be the case.

And I don't want to see if overhyped without all facts laid out. You make no mention of a possible weakening an only mention the always aggressive HWRF. As always prepare for worst, hope for best and remain calm. I say this in an informative way.

I....never mentioned the HWRF. I don’t even look at models. I’m simply stating now it was a typo in the NHC guidance, they may have forgotten to put inland next to the 60 and 72 hr. They’ve had a long day

That could be but they do state it needs to develop an inner core for that type of strengthening. The higher end seems to heavily rely on HWRF. we will see what happens. Its moving faster now so hopefully its onshore soon and doesn't stall.

[GCANE]

Vortical hot tower continuing to fire.
3500 CAPE in the core.

[3090]

There is an error with the forecast discussion, it doesn't explicit state those are inland but these two plots:

Code: Select all

 60H  15/1800Z 30.1N  90.0W   70 KT  80 MPH
 72H  16/0600Z 31.0N  90.0W   50 KT  60 MPH

Are clearly inland:
https://i.imgur.com/QDjXakW.png

This has happened a few times this year now (likely an automated issue with the forecast package), and it was manually updated later in the advisory.

The 30.1N-90W coordinate is New Orleans, not the coast, or over open water.

[caneman]

I read it and nothing in their worded discussion mentions weakening like that upon landfall. Only their intensity guidance suggests that, but until the NHC explicitly states that rather than stating “intensity is uncertain” every other sentence (which is the wise thing for them to do!), we have every reason to believe this thing won’t weaken like that upon landfall.

Who is we. You are blowing it up to 100 mph. I'm stating what the intensity forecase shows at landfall. That could be wrong and that could be right. However, you posted it would be 100 mph with no mention of a possible forecast weakening. Calm down and be prepared for a worst case scenario.

Just so you understand, the 80 mph wind forecast, right after the 100 mph wind forecast happens to be right over New Orleans. The 100 mph wind forecast is just prior to landfall.

I understand that. NHC failed to mention that it was inland. They have since corrected it.