Atlantic - Sally forms September 12, 2020 (night, locations, traffic, USA)

[Psychoma]

For the afternoon, Sally has leveled off on intensity with pressure/winds holding steady, officially at 90mph winds:
https://twitter.com/tropicaltidbits/...96011109380099

[Psychoma]

Mon 14Sept 5pEDT/4pCDT:
Winds 100mph(155km/h)
Moving WNW 6mph(9km/h)
Pressure 987mb
Center about 105miles(170km) E of mouth of MS River
Center about 145miles(230km) SE of Biloxi, MS

Cat2 hurricane. Warnings have been shifted again a little more Eastward.

Obs: An oil platform on the NW corner of center is reporting 100mph winds, gusting to 117mph (elevated reading though, so ground level will be less).

Surge obs next post.

[Psychoma]

Mon 14Sept 530pEDT/430pCDT surge obs (*My interpretation of graphs only, not official*). Source: https://tidesandcurrents.noaa.gov/in...orm/Sally.html

Note: Many areas are entering Low Tide so some areas surge won't be that noticeable until tide comes back in. Surge is the rise above normal tide levels. (ie: if surge was 3ft, and lets guess normal low and high tide are 3ft apart then 3ftt surge at low tide would just look like normal high tide, but same 3ft surge still present when high tide comes then now you're 3ft higher then normal high tide level which may push water inland). Surge will also help prevent/slow rain water runoff from draining.

From East to West:
FL:
-Apalachicola +2ft
-Panama City +1.8ft
-Panama City Beach +2.1ft
-Pensacola +2.75ft

AL:
-Dauphin Island +2.6ft
-Mobile +1.5ft

MS:
-Pascagoula +2.2ft
-Bay St. Louis +2.6ft

LA:
-Shell Beach +3.5ft Mod Flood Stage
-Lake Pontchartrain - New Canal Station (Lakeshore Park) +1.9ft Min Flood Stage
-Lake Pontchartrain -i10 in SW corner +2ft Min Flood Stage
-Pilottown +2.3ft
-Pilot Station East SW Pass +2.2ft
-Grand Isle +1ft
-Amerada Pass +0.7ft

[Psychoma]

Mon 14Sept 11pEDT/10pCDT:
Winds 100mph(155km/h)
Moving WNW 3mph(6km/h)
Pressure 986mb
Center about 90miles(145km) E of mouth of MS River
Center about 130miles(210km) SE of Biloxi, MS

Holding steady for now. Crawling pace. Another slight eastward shift in forecast cone. Rains right along the FL/AL coast. Small brief, quick moving tornadoes will be possible tonight and next few days in these. Hurricane Warning West of Grand Isle downgraded to TS Warning.

Some potential max surge values have changed, lowered some places. Full list from NHC:
Mouth of the Mississippi River to Dauphin Island including Lake Borgne...6-9 ft
Ocean Springs, MS to Dauphin Island, AL including Mobile Bay...6-9 ft
Dauphin Island, AL to AL/FL Border...4-7 ft
Lake Pontchartrain and Lake Maurepas...3-5 ft
Port Fourchon, LA to Mouth of the Mississippi River...2-4 ft
AL/FL Border to Okaloosa/Walton County Line, FL including Pensacola Bay and Choctawhatchee Bay...2-4 ft
Okaloosa/Walton County Line, FL to Chassahowitzka, FL including Saint Andrew Bay...1-3 ft
Burns Point, LA to Port Fourchon, LA...1-2 ft

[Psychoma]

Tue 15Sept 5aEDT/4aCDT:
Winds 85mph(140km/h)
Moving WNW 2mph(4km/h)
Pressure 983mb
Center about 60miles(100km) ESE of mouth of MS River
Center about 115miles(185km) SSE of Biloxi, MS
Hurricane winds extend up to 45miles(75km) from center, TS winds 125miles(205km).

Sally has failed to take advantage of favorable conditions and thus hasn't intensified further. Storm did not close off South side of eye. Continues to pulse storms on/off instead of more steady. Now crawling, storm is upwelling cooler waters which will be cutting into it's potential as well. Winds have dropped to 85mph, which is now NHC's forecast until landfall.

Watch/Warning:
-Hurricane Warning changed to TS Warning Mouth of Pearl River W to Grand Isle, LA (includes New Orleans, Lake Pontchartrain, Lake Maurepas)
-TS Warning canceled W of Grand Isle, LA
-Storm Surge Warning Port Fourchan and Mouth of MS River canceled.

[Psychoma]

Tue 15Sept 6aEDT/5aCDT surge obs (*My interpretation of graphs only, not official*). Source: https://tidesandcurrents.noaa.gov/in...orm/Sally.html

From East to West:
FL:
-Apalachicola +1.65ft
-Panama City +1.7ft
-Panama City Beach +2.2ft
-Pensacola +2.6ft

AL:
-Dauphin Island +2.5ft
-Mobile +2ft

MS:
-Pascagoula +2.5ft
-Bay St. Louis +3.1ft

LA:
-Shell Beach +4.4ft
-Lake Pontchartrain - New Canal Station (Lakeshore Park) +2.8ft
-Lake Pontchartrain -i10 in SW corner +2.8ft
-Pilottown +3.5ft
-Pilot Station East SW Pass +2.9ft
-Grand Isle +1.6ft
-Amerada Pass +1.2ft

[Psychoma]

And there’s the Tornado Watch. There will be several of these in the end and these will continue to be extended as time goes on.
https://twitter.com/nwstornado/statu...34709751013379

[FrozenI69]

Louisiana has been very unfortunate this year.

[Psychoma]

Tue 15Sept 11aEDT/10aCDT:
Winds 85mph(140km/h)
Moving NW 2mph(4km/h)
Pressure 983mb
Center about 55miles(85km) E of mouth of MS River
Center about 110miles(180km) S of Mobile, AL
Hurricane winds extend up to 45miles(75km) from center, TS winds 125miles(205km).

Track nudged to the East again. More centered about Mobile, AL now. Storm surge values have also been adjusted accordingly: https://twitter.com/nhc_atlantic/sta...85895006932996

Inland rain threat after the Gulf coast looks to be swath of 4-8inches, isolated 12” from AL, across central and North GA, Upstate SC (i85 corridor) and parts of Central and surrounding NC regions late this week. Flooding / flash flood concern. Remember in large scale weather events, authorities will NOT be able to keep up with closing / marking flooded roadways. Over half of all US flood deaths are vehicle related. #TurnAroundDontDrown

Hurricane Warning Pearl River to Bay St. Louis changed to TS Warning.
TS Warning for New Orleans, Lake Pontchartrain, Lake Maurepas canceled (still TS Warning right along E/SE coast of LA tho.)

[Veritas Vincit]

Originally Posted by FrozenI69

Louisiana has been very unfortunate this year.

I wouldn't say that. This storm at some point looked poised to hit NOLA head-on as a stronger hurricane, now it looks to veer eastward and stay a low end hurricane with NOLA dodging the worst again.