ATL: SALLY - Post-Tropical - Discussion

[LowerAlabamaTider]

Does Baton Rouge have much to be concerned about? It seems clear we will stay to the west but almost all model pics in that thread are a snapshot of landfall. I know in the past it was landfalling and then hooking sharp to the NE. Is this still the case or is it coming in further west?

Unknown at this time. Could be a little further west, or could be further east. Only time will tell.

[GCANE]

Another high rain-rate tower firing.
Warm core is starting to gel.

[cheezyWXguy]

New burst looks to be going up directly over the center in the last minute or two

[SouthDadeFish]

Be careful saying things like "shear is no longer an issue". The TC is still being sheared. The TC is still very asymmetric. However, recent trends show an uptick in precipitation near the TC center. We saw a similar process for a stretch about ~6 h ago, but that reach toward symmetry failed. We will have to see if convection can successfully migrate toward the upshear regions, or if this is just another temporary blip. On radar, I can see what seems to be some mid-level precip cells still getting ripped off to the SSW, indicating the presence of persistent mid-level shear. I am skeptical we will see any rapid uptick in organization as long as this is occurring. Even if the storm intensifies, shear will still affect the system.

Today is a very important day for the future intensity of Sally. If the storm becomes aligned and more symmetric by tonight, like the 00Z HWRF showed, the potential for a stronger hurricane exists. If not, Sally will likely have a much more limited amount of time to significantly intensify before landfall.

[GCANE]

Deeper convection in the Evil Twin Blob to the SE.
Could indicate increasing entrainment of TPW air from the south.
If the next pass shows a couple mb drop, she's probably about to enter a RI phase.

[MississippiWx]

Be careful saying things like "shear is no longer an issue". The TC is still being sheared. The TC is still very asymmetric. However, recent trends show an uptick in precipitation near the TC center. We saw a similar process for a stretch about ~6 h ago, but that reach toward symmetry failed. We will have to see if convection can successfully migrate toward the upshear regions, or if this is just another temporary blip. On radar, I can see what seems to be some mid-level precip cells still getting ripped off to the SSW, indicating the presence of persistent mid-level shear. I am skeptical we will see any rapid uptick in organization as long as this is occurring. Even if the storm intensifies, shear will still affect the system.

Today is a very important day for the future intensity of Sally. If the storm becomes aligned and more symmetric by tonight, like the 00Z HWRF showed, the potential for a stronger hurricane exists. If not, Sally will likely have a much more limited amount of time to significantly intensify before landfall.

Agreed. Only thing I noticed is that the convection a few hours ago never was able to radiate outflow to the north or west. This morning, however, there is expanding outflow in all directions and the convective burst is trying to reach over the center.

[tolakram]

It was said a few pages ago but needs repeating. If you're near the path you need to be worried about the potential amount of rain this slow moving system might put down. Regardless of landfall strength I'm afraid rainfall amounts might be the biggest story here.

[RL3AO]

To me it still looks like a storm that is slowly becoming more organized. We're seeing signs that the shear is starting to become less of an issue and we're starting to see some outflow near/west of the center. But today seems like more of the day for Sally to set the stage for future intensification. Can the ML and LLC line up? Can it become a more symmetrical storm? If Sally can do that, then it opens up tomorrow to be the big intensification day.

[Nimbus]

6Z HWRF still has this meandering WNW into NOLA the last 12 hours or so.
Just not much deepening this run from about 995's at 27 hours till landfall which is odd.

[bella_may]

Mobile NWS is calling for 10-15 inches even for a few places well inland

[LowerAlabamaTider]

Mobile NWS is calling for 10-15 inches even for a few places well inland

That’s insane! And awful for all those South of I-10.

[Shawee]

Be careful saying things like "shear is no longer an issue". The TC is still being sheared. The TC is still very asymmetric. However, recent trends show an uptick in precipitation near the TC center. We saw a similar process for a stretch about ~6 h ago, but that reach toward symmetry failed. We will have to see if convection can successfully migrate toward the upshear regions, or if this is just another temporary blip. On radar, I can see what seems to be some mid-level precip cells still getting ripped off to the SSW, indicating the presence of persistent mid-level shear. I am skeptical we will see any rapid uptick in organization as long as this is occurring. Even if the storm intensifies, shear will still affect the system.

Today is a very important day for the future intensity of Sally. If the storm becomes aligned and more symmetric by tonight, like the 00Z HWRF showed, the potential for a stronger hurricane exists. If not, Sally will likely have a much more limited amount of time to significantly intensify before landfall.

Agreed. Only thing I noticed is that the convection a few hours ago never was able to radiate outflow to the north or west. This morning, however, there is expanding outflow in all directions and the convective burst is trying to reach over the center.

She still seems to be sort of boxed in, http://rammb.cira.colostate.edu/ramsdis ... display=24 similarly to Marco (not predicting a Marco solution, but that would be nice), both from the E and SW. I also like the drier air in the central gulf (wish there was more), and air mass moving from the NW into La. Hopefully some of these factors will hinder her development somewhat, but only time will tell. The time margins are getting razor thin now, and we are planning for NHC projections regardless of my nonprofessional WX prognostications. Good luck everyone!

[slamdaddy]

Yep. In the 10-15 inch location area here at the house. Have not had any rain here this month so that may help a lil bit, not much, but a little.

[tolakram]

https://whirlwind.aos.wisc.edu/~wxp/goes16/grb/meso_vis_sqrt/meso1_60.html

The center is not moving much but the CDO is expanding west and north. I agree that it looks to be doing a good job organizing.

[GCANE]

A couple overshooting tops in the CDO.

[GCANE]

Another warm-core signature from the last tower.

[gfsperpendicular]

Another warm-core signature from the last tower.

Hi gcane, can you explain what you mean by a warm-core signature?

[ronjon]

Yep. In the 10-15 inch location area here at the house. Have not had any rain here this month so that may help a lil bit, not much, but a little.

10-15 inches not out of the realm of possibilities. Key West Airport has recorded 9.71 inches so far from Sally....and its still raining.

[us89]

Winds are up to 60 mph on the new advisory:

Tropical Storm Sally Advisory Number 8
NWS National Hurricane Center Miami FL AL192020
1100 AM EDT Sun Sep 13 2020

...SALLY EXPECTED TO STRENGTHEN TONIGHT AND MONDAY...
...LIFE-THREATENING STORM SURGE, HURRICANE-FORCE WINDS AND HEAVY
RAINFALL EXPECTED ALONG PORTIONS OF THE NORTHERN GULF COAST
STARTING ON MONDAY...


SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...27.5N 84.9W
ABOUT 135 MI...220 KM W OF ST. PETERSBURG FLORIDA
ABOUT 280 MI...450 KM ESE OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...998 MB...29.48 INCHES

[Nimbus]

Another warm-core signature from the last tower.

Hi gcane, can you explain what you mean by a warm-core signature?

There is an eye button in the center of the convection.
Not stacked yet maybe a few more hours, later tonight might even get a clean eye.