ATL: SALLY - Post-Tropical - Discussion

[Nimbus]

Convection on radar on the east side of the center just offshore naples is starting to really pick up...

Looks like that LLC is the driver,convection will just stack a little better as Sally moves west.

WV loop is a mess almost looks like the trough to the north is retreating and Sally might find herself under the east side of a building high with persisting light shear out of the north?

[NDG]

OCOF125.90/-81.32 @ 7ft.
Name:OCHOPEE RAWS
Provider:RAWS
Valid:12 Sep 4:03 PM EDT
Temp:76 °F24 °C
Dew Point:76 °F24 °C
Relh:100 %
Wind Speed:31 mph27 kts
Wind Dir:SE140°
Gust:44 mph38 kts

NDG, where is that station located?

On Tamiami Trail, close to Everglades City.

[NDG]

0z soundings from Tampa and Tallahassee showing NW shear at h40-h30 letting up some, also getting much moist in that level. We should start seeing convection building near the LLC soon and maintaining it.

[gatorcane]

Flood advisory issued for parts of metro SE Florida with training of feeder bands. Winds gusted to 40+ mph along the coast here earlier, this is the most action we have seen so far here this hurricane season, being on the dirty side of a storm is always so much worse than the west side, as we saw with Isaias when it passed just to our east but was a non-event.

[ConvergenceZone]

Just in case anyone wanted to watch Levi's video released about 20 minutes ago

https://www.youtube.com/watch?v=0M2mOZeiVtA&t=609s

[Shawee]

18z HWRF shifted west with a major hurricane’s NE eye wall passing through or extremely close to NOLA... pucker pressure should rise exponentially for New Orleanians seeing that models run.

As some models shift E, and euro W, and the cone of probability still looking like a ball, the collective puckering from along the entire gulf coast will be off the scale with this one.

[MidnightRain]

18z HWRF shifted west with a major hurricane’s NE eye wall passing through or extremely close to NOLA... pucker pressure should rise exponentially for New Orleanians seeing that models run.

As some models shift E, and euro W, and the cone of probability still looking like a ball, the collective puckering from along the entire gulf coast will be off the scale with this one.

Didn’t see any significant shifts East today, the bullseye is definitely shaping up to be Southeast Louisiana and Mississippi.

[eastcoastFL]

Convection on radar on the east side of the center just offshore naples is starting to really pick up...

Looks like that LLC is the driver,convection will just stack a little better as Sally moves west.

WV loop is a mess almost looks like the trough to the north is retreating and Sally might find herself under the east side of a building high with persisting light shear out of the north?

I guess that would explain why she’s still bottom heavy. Every other storm being so top heavy to the NE this year and this one is heavy to the SW. Meanwhile I’m directly NE of it so I guess I can’t complain.

[Blow_Hard]

18z HWRF shifted west with a major hurricane’s NE eye wall passing through or extremely close to NOLA... pucker pressure should rise exponentially for New Orleanians seeing that models run.

As some models shift E, and euro W, and the cone of probability still looking like a ball, the collective puckering from along the entire gulf coast will be off the scale with this one.

Didn’t see any significant shifts East today, the bullseye is definitely shaping up to be Southeast Louisiana and Mississippi.[/zquote]

I agree with that. Looking like minimal impacts in the Panhandle from FWB eastward IMO. Rain is going to be the biggest thing to worry about but I don't see any real serious problems with that.

[eastcoastFL]

Could anybody tell me if this is a significant surge and flooding potential because of the angle of approach? I would think coming in at this angle from the East that NOLA Mobile and S. Mississippi could face some serious issues with water. I believe Katrina was so bad surgewise because of her similar angle of approach.

I imagine Sally won’t be as strong as Katrina so would surge still be a threat if Sally comes in as a low end CAT 2?

[Frank P]

18z HWRF shifted west with a major hurricane’s NE eye wall passing through or extremely close to NOLA... pucker pressure should rise exponentially for New Orleanians seeing that models run.

As some models shift E, and euro W, and the cone of probability still looking like a ball, the collective puckering from along the entire gulf coast will be off the scale with this one.

The TVCN shifted back to the west a tad now at the LA/MS state line... I don’t expect the next forecast track to change very much.

[CrazyC83]

Whether winds are 50 mph or 150 mph, the rainfall - and storm surge - will likely be significant impacts due to its very slow movement.

[Dean4Storms]

Could anybody tell me if this is a significant surge and flooding potential because of the angle of approach? I would think coming in at this angle from the East that NOLA Mobile and S. Mississippi could face some serious issues with water. I believe Katrina was so bad surgewise because of her similar angle of approach.

I imagine Sally won’t be as strong as Katrina so would surge still be a threat if Sally comes in as a low end CAT 2?

Here's the Peak Surge Forecast for the currently forecast of a Cat. 1 so with a Cat. 2 you would add a couple feet I'm sure.......

https://www.nhc.noaa.gov/refresh/graphics_at4+shtml/215703.shtml?peakSurge#contents

[Frank P]

Could anybody tell me if this is a significant surge and flooding potential because of the angle of approach? I would think coming in at this angle from the East that NOLA Mobile and S. Mississippi could face some serious issues with water. I believe Katrina was so bad surgewise because of her similar angle of approach.

I imagine Sally won’t be as strong as Katrina so would surge still be a threat if Sally comes in as a low end CAT 2?

Sally’s Surge is forecasted to be 6-9 feet.. This is no where near Katrina’s surge, and the angle does make a big difference, as does the size of the wind field, and forward motion.. Elena in 85 had winds near 120 mph at my house on the beach in Biloxi, surge was about 8-9 feet... it came in at a very steep angle, probably around 40 degrees best guess.. Sally looks overall like about 45-50 degrees angle in approach so that will help reduce the surge. This applies for the Biloxi area only. That angle of approach is not good for SELA however!

[MississippiWx]

0z soundings from Tampa and Tallahassee showing NW shear at h40-h30 letting up some, also getting much moist in that level. We should start seeing convection building near the LLC soon and maintaining it.

https://i.imgur.com/dV79Ge9.gif

Agreed. It’s already happening on radar.

[eastcoastFL]

Could anybody tell me if this is a significant surge and flooding potential because of the angle of approach? I would think coming in at this angle from the East that NOLA Mobile and S. Mississippi could face some serious issues with water. I believe Katrina was so bad surgewise because of her similar angle of approach.

I imagine Sally won’t be as strong as Katrina so would surge still be a threat if Sally comes in as a low end CAT 2?

Here's the Peak Surge Forecast for the currently forecast of a Cat. 1 so with a Cat. 2 you would add a couple feet I'm sure.......

https://www.nhc.noaa.gov/refresh/graphics_at4+shtml/215703.shtml?peakSurge#contents

Thanks. That could get pretty rough if it does intensify more than forecast and you’re looking at 10ft plus of surge in these extremely surge prone areas.

[Jr0d]

Key West is flooded! Going through a heavy squall right now that is bringing some wind(finally!) and very heavy rain with lightening.

I tried to get some pictures of the flooding but it is too dark. I will try to get out tomorrow and snap a few. While this is not uncommon to have this kind of flooding, a few more hours of heavy rain can really start to cause significant problems and damage.

We are lucky there is no surge here. Even a foot of surge would be a major problem given the current flooding.

[ThetaE]

A few (small-ish) hot towers have started popping up just offshore of Sanibel. This is well co-located with some stronger radar returns, and the best sign I've seen yet of deeper convection beginning to work its way upshear.

[eastcoastFL]

Could anybody tell me if this is a significant surge and flooding potential because of the angle of approach? I would think coming in at this angle from the East that NOLA Mobile and S. Mississippi could face some serious issues with water. I believe Katrina was so bad surgewise because of her similar angle of approach.

I imagine Sally won’t be as strong as Katrina so would surge still be a threat if Sally comes in as a low end CAT 2?

Sally’s Surge is forecasted to be 6-9 feet.. This is no where near Katrina’s surge, and the angle does make a big difference, as does the size of the wind field, and forward motion.. Elena in 85 had winds near 120 mph at my house on the beach in Biloxi, surge was about 8-9 feet... it came in at a very steep angle, probably around 40 degrees best guess.. Sally looks overall like about 45-50 degrees angle in approach so that will help reduce the surge. This applies for the Biloxi area only. That angle of approach is not good for SELA however!

Thanks for the detailed info! Let’s hope sally runs into some inhibiting factors as she makes her approach and doesn’t intensify or expand. That’s a good point I didn’t consider the wind field. Now I recall that when Katrina weakened her wind field blew up. I wouldn’t be surprised if Sally was stronger than forecasted that seems to be pretty normal for early advisories on storms entering the gulf. So that 6-9 feet of surge could easily turn to 9-12 ft and neither scenario is good especially in our current climate. Are you still on the gulf coast?

[Shawee]

18z HWRF shifted west with a major hurricane’s NE eye wall passing through or extremely close to NOLA... pucker pressure should rise exponentially for New Orleanians seeing that models run.

As some models shift E, and euro W, and the cone of probability still looking like a ball, the collective puckering from along the entire gulf coast will be off the scale with this one.

Didn’t see any significant shifts East today, the bullseye is definitely shaping up to be Southeast Louisiana and Mississippi.

Apologies for the over generalization; just saying there seems to be more disagreement for something less 3 days from landfall than usual, and New Orleans isn’t alone in the puckering! I agree with you (and the NHC) on the general projected landfall. 50 miles makes an massive difference in surge impact, particularly west of the MS river.