ATL: SALLY - Post-Tropical - Discussion

[Stormgodess]

Doing rescues in Foley now

 https://twitter.com/KellyAnneTV/status/1306272745479704578

[cycloneye]

BULLETIN
Tropical Storm Sally Intermediate Advisory Number 22A
NWS National Hurricane Center Miami FL AL192020
100 PM CDT Wed Sep 16 2020

...CATASTROPHIC AND LIFE-THREATENING FLOODING OCCURRING OVER
PORTIONS OF THE FLORIDA PANHANDLE AND SOUTHERN ALABAMA...


SUMMARY OF 100 PM CDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...30.9N 87.1W
ABOUT 30 MI...45 KM NNE OF PENSACOLA FLORIDA
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H
PRESENT MOVEMENT...NNE OR 30 DEGREES AT 5 MPH...7 KM/H
MINIMUM CENTRAL PRESSURE...982 MB...29.00 INCHES

[curtadams]

https://twitter.com/MJVentrice/status/1306193872758898688

This has been really amazing all season. People need to stop ignoring this model. It was upgraded this year and has been unbelievably accurate with predicting storm structures and pretty close with tracks.

So true. Mesoscale models have been mostly entertainment until now, but the HWRF has been amazing this year, even with really oddball structures from land interaction with Isaias and Laura. It's not going to be perfect, but clearly it's a major and unique predictive tool now.

[FLpanhandle91]

My storm total for Sally is 21.22 inches of rain in Fort Walton Beach with almost 10 inches falling between midnight and 0600 this morning. Multiple gusts around 55mph with sustained tropical storm force conditions most of the night and morning.

[CrazyC83]

 https://twitter.com/CC_StormWatch/status/1306307921236684802

[Shell Mound]

 https://twitter.com/capitalweather/status/1306305574871740419



 https://twitter.com/classicryan17/status/1306305167982235649



 https://twitter.com/savannahenwfdn/status/1306300776902520837



 https://twitter.com/ErinMorganTV/status/1306301136119500801



 https://twitter.com/maryhope8/status/1306298549265739776

[FLpanhandle91]

So my sensor obviously measures rain as it falls into a cup. Is it possible that my totals are higher than my measured 22 inches since gusts caused rain to miss it?

[us89]

Had another significant rain band move through Atlanta about an hour ago. Looks like most places around here have recorded half an inch of rain already.

Worst of it looks to get here tonight and tomorrow morning. Flash flood watch and wind advisories are in effect - sustained winds here obviously won't quite be to TS force but will probably peak around 30 mph. Thanks to Sally's continued eastward shifts, rain totals in the metro area have come down slightly but it still looks like we'll have widespread totals of at least 4-6 inches when all is said and done.

[Do_For_Love]

So my sensor obviously measures rain as it falls into a cup. Is it possible that my totals are higher than my measured 22 inches since gusts caused rain to miss it?

Makes sense to me, I don't know for sure though. 22 inches though, is everything alright in your house/area? that's as much as my area gets in like 4 months on average.

[StrongWind]

So my sensor obviously measures rain as it falls into a cup. Is it possible that my totals are higher than my measured 22 inches since gusts caused rain to miss it?

No and yes. If wind is pushing some rain drops away from the cup it is also pushing other drops toward the cup. The net effect should be about zero.
However, rain not coming down vertically can have a lower reading. Think of the extreme case of 'horizontal rain.' Only the small portion that hit the inside of the leeward side of the cup would be captured.

[jaxfladude]

How bad will the next few days of sally and her remnants be for those in the path of this system? Is there any good news regrading Sally and the areas in and around landfall? Or is it all pretty much as feared/worse...prayers....

[toad strangler]

WOW

 http://twitter.com/pppapin/status/1306353140351066112

[Steve]

How bad will the next few days of sally and her remnants be for those in the path of this system? Is there any good news regrading Sally and the areas in and around landfall? Or is it all pretty much as feared/worse...prayers....

It's gonna suck. Power's out. Gas lines will be super long once you can get it. Stores will open in a few days, but things will be scarce. Properties will need to be cleaned up and secured. Emergency damage (ala tarping up roofs) will have to be handled sooner than later. There will be lines for everything from relief money to getting the guard to put up a tarp to temporary food or shelter assistance and everything else you can imagine. I had a call about an hour ago from ECUA (Escambia County Utility Authority) which provides water and garbage services in Pensacola. The recorded call said most of the county was going under a precautionary boil water advisory for the foreseeable future.

Then people have to line up insurance adjusters, file claims and all that. It's a pain in the neck. Plus Covid of course doesn't make things any better.

[toad strangler]

How bad will the next few days of sally and her remnants be for those in the path of this system? Is there any good news regrading Sally and the areas in and around landfall? Or is it all pretty much as feared/worse...prayers....

It's gonna suck. Power's out. Gas lines will be super long once you can get it. Stores will open in a few days, but things will be scarce. Properties will need to be cleaned up and secured. Emergency damage (ala tarping up roofs) will have to be handled sooner than later. There will be lines for everything from relief money to getting the guard to put up a tarp to temporary food or shelter assistance and everything else you can imagine. I had a call about an hour ago from ECUA (Escambia County Utility Authority) which provides water and garbage services in Pensacola. The recorded call said most of the county was going under a precautionary boil water advisory for the foreseeable future.

Then people have to line up insurance adjusters, file claims and all that. It's a pain in the neck. Plus Covid of course doesn't make things any better.

It's almost impossible to understand how anybody would wish a storm in knowing all this. But, many weenies do it anyway.

[TallyTracker]

I just saw a report that the Pensacola Bay Bridge has been partially destroyed and could be closed for several months!

https://www.pnj.com/story/news/2020/09/ ... 821373002/

[Hammy]

https://twitter.com/MJVentrice/status/1306193872758898688

This has been really amazing all season. People need to stop ignoring this model. It was upgraded this year and has been unbelievably accurate with predicting storm structures and pretty close with tracks.

So true. Mesoscale models have been mostly entertainment until now, but the HWRF has been amazing this year, even with really oddball structures from land interaction with Isaias and Laura. It's not going to be perfect, but clearly it's a major and unique predictive tool now.

It certainly has my attention after Sally, where I even ignored the NAM trends as the only other model that showed sharp intensification before landfall

[CrazyC83]

The posts in this forum are NOT official forecasts and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or STORM2K. For official information, please refer to products from the NHC and NWS.

Here is my thinking for the BT of Sally (up to this point).

AL172020, SALLY, 25,
20200911, 1200, , TD, 25.0N, 78.0W, 30, 1010,
20200911, 1800, , TD, 25.3N, 78.6W, 30, 1008,
20200912, 0000, , TD, 25.6N, 79.4W, 30, 1007,
20200912, 0600, , TS, 25.6N, 80.2W, 35, 1004,
20200912, 0700, L, TS, 25.6N, 80.3W, 35, 1003,
20200912, 1200, , TS, 25.5N, 80.8W, 35, 1004,
20200912, 1800, , TS, 25.7N, 81.5W, 35, 1004,
20200913, 0000, , TS, 26.1N, 82.4W, 40, 1002,
20200913, 0600, , TS, 26.7N, 83.5W, 50, 999,
20200913, 1200, , TS, 27.3N, 84.6W, 50, 998,
20200913, 1800, , TS, 27.7N, 85.5W, 55, 997,
20200914, 0000, , TS, 27.9N, 86.1W, 55, 996,
20200914, 0600, , TS, 28.1N, 86.6W, 60, 995,
20200914, 1200, , HU, 28.4N, 86.9W, 65, 992,
20200914, 1800, , HU, 28.7N, 87.2W, 75, 986,
20200915, 0000, , HU, 28.8N, 87.5W, 75, 987,
20200915, 0600, , HU, 28.9N, 87.9W, 70, 985,
20200915, 1200, , HU, 29.1N, 88.0W, 70, 983,
20200915, 1800, , HU, 29.3N, 88.1W, 75, 980,
20200916, 0000, , HU, 29.6N, 88.0W, 80, 974,
20200916, 0600, , HU, 29.9N, 87.8W, 90, 968,
20200916, 0945, L, HU, 30.2N, 87.7W, 95, 966,
20200916, 1200, , HU, 30.4N, 87.6W, 80, 972,
20200916, 1800, , TS, 30.9N, 87.1W, 55, 980,
20200917, 0000, , TD, 31.5N, 86.5W, 30, 994,

There are several major changes that I make here.

* I believe that Sally became a tropical storm BEFORE making its first landfall in Florida. That is based on a combination of surface and radar data, with the most convincing result being from the University of Miami station on Key Biscayne. I kept it as a tropical storm all the way through, since the first Recon flight supported such.
* The initial peak I believe was overblown - I think the data to support the operational 85 kt was suspect. I lowered that peak to 75 kt (closer in line with the flight level data) as that was based on one SFMR measurement that quickly corrected itself. After that, until its second rapid intensification, the intensities were also lowered, mostly to 70 kt.
* The peak intensity, at landfall, I estimate to be 95 kt. That is based on a blend of the radar data (peaking at about 118 kt at 5,000 feet = 94 kt), the T5.5 satellite estimate and the 110 kt flight level winds. The SFMR is unreliable in shallow water. The pressure estimate is 966 mb, which is based on a blend of Buoy 42012 (970 mb/52 kt at below standard elevation - supports 964 mb), storm chaser data (lowest 968 mb) and dropsonde data (lowest 967 mb).

[toad strangler]

Thankfully Sally had nearly no backside what-so-ever. A halfacane just like Irma was at US landfall. THat was the silver lining for the areas hit hardest.

[SconnieCane]

Thankfully Sally had nearly no backside what-so-ever. A halfacane just like Irma was at US landfall. THat was the silver lining for the areas hit hardest.

It's very odd how with some of these storms, on the visible and infrared the CDO looks solid yet radar shows there is essentially no convection on what should be the back half of the eyewall.

[cheezyWXguy]

The posts in this forum are NOT official forecasts and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or STORM2K. For official information, please refer to products from the NHC and NWS.

Here is my thinking for the BT of Sally (up to this point).

AL172020, SALLY, 25,
20200911, 1200, , TD, 25.0N, 78.0W, 30, 1010,
20200911, 1800, , TD, 25.3N, 78.6W, 30, 1008,
20200912, 0000, , TD, 25.6N, 79.4W, 30, 1007,
20200912, 0600, , TS, 25.6N, 80.2W, 35, 1004,
20200912, 0700, L, TS, 25.6N, 80.3W, 35, 1003,
20200912, 1200, , TS, 25.5N, 80.8W, 35, 1004,
20200912, 1800, , TS, 25.7N, 81.5W, 35, 1004,
20200913, 0000, , TS, 26.1N, 82.4W, 40, 1002,
20200913, 0600, , TS, 26.7N, 83.5W, 50, 999,
20200913, 1200, , TS, 27.3N, 84.6W, 50, 998,
20200913, 1800, , TS, 27.7N, 85.5W, 55, 997,
20200914, 0000, , TS, 27.9N, 86.1W, 55, 996,
20200914, 0600, , TS, 28.1N, 86.6W, 60, 995,
20200914, 1200, , HU, 28.4N, 86.9W, 65, 992,
20200914, 1800, , HU, 28.7N, 87.2W, 75, 986,
20200915, 0000, , HU, 28.8N, 87.5W, 75, 987,
20200915, 0600, , HU, 28.9N, 87.9W, 70, 985,
20200915, 1200, , HU, 29.1N, 88.0W, 70, 983,
20200915, 1800, , HU, 29.3N, 88.1W, 75, 980,
20200916, 0000, , HU, 29.6N, 88.0W, 80, 974,
20200916, 0600, , HU, 29.9N, 87.8W, 90, 968,
20200916, 0945, L, HU, 30.2N, 87.7W, 95, 966,
20200916, 1200, , HU, 30.4N, 87.6W, 80, 972,
20200916, 1800, , TS, 30.9N, 87.1W, 55, 980,
20200917, 0000, , TD, 31.5N, 86.5W, 30, 994,

There are several major changes that I make here.

* I believe that Sally became a tropical storm BEFORE making its first landfall in Florida. That is based on a combination of surface and radar data, with the most convincing result being from the University of Miami station on Key Biscayne. I kept it as a tropical storm all the way through, since the first Recon flight supported such.
* The initial peak I believe was overblown - I think the data to support the operational 85 kt was suspect. I lowered that peak to 75 kt (closer in line with the flight level data) as that was based on one SFMR measurement that quickly corrected itself. After that, until its second rapid intensification, the intensities were also lowered, mostly to 70 kt.
* The peak intensity, at landfall, I estimate to be 95 kt. That is based on a blend of the radar data (peaking at about 118 kt at 5,000 feet = 94 kt), the T5.5 satellite estimate and the 110 kt flight level winds. The SFMR is unreliable in shallow water. The pressure estimate is 966 mb, which is based on a blend of Buoy 42012 (970 mb/52 kt at below standard elevation - supports 964 mb), storm chaser data (lowest 968 mb) and dropsonde data (lowest 967 mb).

Largely splitting hairs, but I differ on the 95kt peak. At two separate instances, I saw multiple bins of 122kt (140mph). Given your 80% reduction, that would bump it to 98kt. Additionally, with the flight level wind of 110kt, wouldn’t that justify 99kt?

https://imgur.com/a/Dbc00C2