Tropical Storm Sally radar
Radar image of Tropical Storm Sally at 2:19 p.m. EDT Saturday, September 12, 2020. (Image credit: Mark Nissenbaum/Florida State University)

Tropical Storm Sally, which formed along the coast of Southwest Florida on Saturday afternoon, is expected to intensify into a hurricane before making landfall between southeast Louisiana and the Florida Panhandle on Tuesday. Sally will be moving very slowly for multiple days up to the time of landfall, increasing chances of dangerous heavy rains in excess of 10 inches along the coast.

At 2 p.m. EDT Saturday, September 12, 2020, Sally was centered near the coast of Southwest Florida, 35 miles south-southeast of Naples. Sally was a minimal tropical storm with 40 mph winds, moving west at 7 mph. The storm was bringing torrential rains and wind gusts of tropical storm force to the Florida Keys. At 12 p.m. EDT, Fowey Rocks in the Florida Keys reported sustained winds of 45 mph, gusting to 47 mph. As of 2 p.m. EDT Saturday, heavy rains of 4 – 8 inches had fallen across much of the Middle and Upper Keys, with over eight inches in Lower Matecumbe Key, the Key West National Weather Service reported. Satellite and radar images showed a steady increase in the organization and intensity of Sally’s heavy thunderstorm activity.

Figure 1
Figure 1. GeoColor visible satellite image of Sally as of 1550Z (11:50 a.m. EDT) Saturday, September 12, 2020. (Image credit: RAMMB/CIRA/Colorado State University)

Forecast for Sally

Sally will move in a general west-northwest motion toward the central Gulf Coast over the next several days. Steering currents will weaken by Sunday and Sally will slow down to a forward speed of about 5 mph, giving it time to gain strength from the very warm waters of the eastern Gulf of Mexico, where sea surface temperatures are around 30°C (86°F). The Gulf waters have largely recovered from the cool wake left by hurricanes Marco and Laura, and Sally should remain just northeast of a cool eddy with low oceanic heat content over the southeast Gulf.

Although wind shear will be moderate over the next several days, at 10-20 knots, Sally will move beneath a broad upper ridge, and the upper winds will support favorable outflow from the storm. The air mass should remain reasonably moist, with a mid-level relative humidity around 60%, so dry air is unlikely to be a major hindrance. By late Monday and into Tuesday, wind shear is expected to tick up a notch, to around 20 knots, which may slow the intensification process.

Figure 2
Figure 2. Sea surface temperatures across the Gulf of Mexico are running about 0.6 degrees Celsius (1°F) above average for this time of year, as depicted in this graphic of anomalies (degrees Celsius) from Saturday, September 12, 2020. (Image credit: tropicaltidbits.com)

How much Sally strengthens will depend in part on how quickly it develops a vertically aligned inner core. A period of rapid intensification cannot be ruled out if the storm organizes quickly enough. The official forecast is for more gradual strengthening, with Sally approaching the central Gulf Coast as a category 1 hurricane. The 06Z Saturday HWRF and HMON intensity models, among the best guidance for intensity, both bring Sally to the coast as a Category 2 storm. The 12Z Saturday HWRF model predicted that Sally would hit southeast Louisiana early Tuesday morning as a high-end category 3 hurricane with 125 mph winds, passing over New Orleans at category 2 strength. The 12Z Saturday HMON model had a category 1 storm with 85 mph winds making landfall near Mobile on Tuesday afternoon. So the uncertainty in landfall intensity is large, with Sally likely to range between a strong tropical storm with 65 mph winds to a high-end category 3 hurricane with 125 mph winds on Tuesday.

The landfall location is also not yet set in stone. There was fairly close agreement between the Friday evening and Saturday morning runs of the GFS, UKMET, and European track models that Sally would approach the coastline between New Orleans and Mobile by Tuesday. However, the center was further south on Saturday afternoon than had been predicted by Saturday morning’s computer models. This implies that the subsequent track may also be further south, bringing the system closer to Louisiana. The European and GFS ensembles from early Saturday morning (06Z) included a number of members with a Louisiana landfall. Because of Sally’s angle of approach, only a slight southward displacement of the track could allow impacts to extend substantially farther west over coastal Louisiana. We can expect track forecasts to shift west as the models incorporate this farther-south location.

One serious concern with Sally is an extended period of torrential rain along the central Gulf Coast, due to the storm’s expected slow motion of less than 5 mph on Monday through Thursday. Models suggest that a pocket of 10-15 inches of rain is likely near the storm’s center, with even higher localized totals possible. A larger corridor of 5-10 inches can be expected near the coast from southeast Louisiana to the Florida Panhandle. After landfall, the system may linger near the coast for another day or more, adding to the rainfall totals.

The type of west-northwest track predicted for Sally is especially favorable for driving storm surge into the coast of southeast Louisiana. The amount of surge will depend on how quickly Sally strengthens, the exact track it takes, and the eventual size of its wind field. Adding to the mix is the unfortunate timing that the new moon arrives on Thursday, September 17, bringing some the highest tides of the year next week – the king tides.

Figure 3
Figure 3. Rainfall forecast for the five days from 8 a.m. EDT Saturday, September 12, 2020, to September 17. Rainfall amounts in excess of 10″ (yellow colors) are predicted along the Gulf Coast near where Sally makes landfall. (Image credit: NOAA/NWS/WPC)

The 2020 parade of record-early named storms continues

Sally’s arrival on September 12 marks the earliest date that any Atlantic season has produced its eighteenth tropical storm, topping the record held by Stan from October 2, 2005. Only three more names remain on the 2020 Atlantic list: Teddy, Vicky, and Wilfred. Invest 95L in the eastern Atlantic is likely to become Tropical Storm Teddy by Sunday; the record for earliest-forming nineteenth storm in the Atlantic is October 4, 2005 (it was unnamed, as it was classified after the season was over).

With the Atlantic hurricane season just two days past the climatological half-way point, we’ve already had 18 named storms, five hurricanes, and one intense hurricane. Only seven Atlantic hurricane seasons since 1851 have had more named storms during an entire season. According to Colorado State University hurricane scientist Phil Klotzbach, the averages for this point in the season are seven named storms, three hurricanes, and one intense hurricane.

Figure 4
Figure 4. GeoColor visible satellite image of Tropical Storm Paulette (upper left) and much smaller Tropical Depression Rene (lower right) at 1750Z (1:50 p.m. EDT) Saturday, September 12, 2020. (Image credit: RAMMB/CIRA/Colorado State University)

Paulette expected to bring hurricane conditions to Bermuda

Resilient for days amid relentless wind shear, Tropical Storm Paulette is now on its way toward more favorable conditions as it approaches Bermuda. A hurricane warning is in effect for the island, as Paulette is predicted to swing over or very close to the island as a Category 1 or 2 hurricane.

Showers and thunderstorm activity (convection) were limited around Paulette on Saturday, but the storm has a strong, well-defined circulation, with midday Saturday top winds of 70 mph. Paulette will be passing over unusually warm waters of 28-29°C (82-84°F), about 0.5-1.0°C above average for mid-September. Wind shear is expected to drop dramatically to less than 10 knots from Sunday into Monday. Despite being engulfed by dry air (mid-level relative humidity around 40%), Paulette may still preserve a pocket of moist air around its core.

Paulette’s approach to Bermuda from the southeast is unusual: most of the many hurricanes that have threatened the island came from the south or southwest. Moreover, Paulette will be making a sharp recurvature toward the northeast in the vicinity of Bermuda. This adds a wrinkle to the track forecast in terms of the island. The most reliable track models are calling for Paulette to make its northeastward bend very close to Bermuda on Monday morning, as reflected in the NHC forecast. Peak winds in Bermuda will hinge on whether the center passes just east or just west of the island; the latter would put Bermuda in the stronger right-hand side of Paulette’s inner core.

Given its extensive experience with intense hurricanes, Bermuda is well equipped to handle Paulette. Rainfall could total 5″ or more on the island, and significant storm surge is possible depending on the exact track of Paulette’s center.

Rene weakens to a tropical depression

To the southeast of Paulette, Tropical Storm Rene was downgraded to depression status on Saturday morning. Choking on dry air, Rene may become a remnant low or could hang on to depression status as it lingers across the subtropical Atlantic south of Paulette for the next several days.

95L in the central Atlantic likely to become TD 20

Satellite imagery showed that the tropical wave located on Saturday afternoon in the eastern Atlantic, a few hundred miles west-southwest of the Cabo Verde Islands, was near tropical depression status.

This system, designated 95L by NHC, is predicted to initially move westward at 15 to 20 mph. Computer model forecasts increasingly have been suggesting that 95L will turn to the northwest well before reaching the Lesser Antilles Islands, and 95L could well turn out to be a “fish” storm – one that will only be of concern to shipping. In a 2 p.m. EDT Saturday Tropical Weather Outlook, NHC gave 95L two-day and five-day odds of development of 90%.

97L near the Cabo Verde Islands may be a short-lived tropical cyclone

A tropical wave that emerged from the coast of Africa on Friday was near the Cabo Verde Islands on Saturday afternoon. This wave, designated 97L by NHC, will have favorable conditions for development through Sunday, with SSTs near 27.5 Celsius (82°F), moderate wind shear of 5 – 15 knots, and a very moist atmosphere.

However, wind shear is predicted to rise to a high 20 – 30 knots on Monday, then increase to a prohibitively high 50 – 70 knots on Tuesday, likely destroying the system. In a 2 p.m. Saturday EDT Tropical Weather Outlook, NHC gave 97L two-day and five-day odds of development of 40% and 60%, respectively. This system will move slowly west-northwest through Sunday.

The most reliable hurricane models, according to their 2019 performance

A Gulf of Mexico disturbance worth watching

NHC was monitoring an area of interest over the north-central Gulf of Mexico producing a few disorganized showers and thunderstorms on Saturday afternoon. Some slow development is possible while this system moves westward and then southwestward over the northern and western Gulf of Mexico through Tuesday. Dry air over the western Gulf of Mexico is likely to inhibit its development. In a 2 p.m. EDT Saturday Tropical Weather Outlook, NHC gave this system two-day and five-day odds of development of 20% and 30%, respectively.

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Posted on September 12, 2020 (4:16pm EDT).

Topics: Weather Extremes
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Terry
Terry
11 days ago

west pac

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Ivette Ray
Ivette Ray
11 days ago

That place has a name. It’s called Mississippi. For a PhD, you don’t know much about geography.

Bknesal
11 days ago
Reply to  Ivette Ray

comment image

Al Williams
Al Williams
12 days ago

That area between New Orleans and Mobile would be called “Mississippi”.

Terry
Terry
12 days ago
Reply to  Al Williams

ok

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Terry
Terry
12 days ago
Reply to  Terry

.

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Neal
Neal
12 days ago
Reply to  Al Williams

Agreed. This is totally disrespectful and rude.

Jen
Jen
12 days ago

Sally doesnt look like she will have enough time to do too much damage…wind wise.

Terry
Terry
12 days ago
Reply to  Jen

.

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Deano
Deano
12 days ago

For those interested, the Port Bermuda Webcam is an excellent way to watch the storm unfold there. It’s sturdy and usually hangs on.

Shira
Shira
12 days ago

#Sally looks to be bringing her rain game:

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Terry
Terry
12 days ago
Reply to  Shira

re-Sally

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greiner3
greiner3
12 days ago
Reply to  Shira

A few months ago we got 5″ of rain over 2 days.

I can’t imagine what triple that amount would do and feel like.

accu35
accu35
12 days ago

MS is a good bet on LF

accu35
accu35
12 days ago

12z gfs, nam/icon/regem came in east today. If this continues expect a shift to the east today.

Wyatt Washburn
Wyatt Washburn
12 days ago

NHC going down ten mph in forecast intensity is big news to me. I would think they have some high confidence T.S Sally won’t make major status. Yet rapid intensification should catch no one surprised anymore, especially not in this location. This is just my opinion, but if I was in New Orleans I’d evacuate my family and pets now. If R.I does happen, it may be too late too if you wait. The hard west turn and the climb northwest into New Orleans will make T.S Sally a much different looking storm tomorrow. New Orleans looking to take the front right quadrant for now. Out for the afternoon, fires just reported up 2000% this year compared to last from TWC, just insane. This season is fully out of control in just about every way possible. Stay safe out there! comment image

Shira
Shira
12 days ago
Reply to  Wyatt Washburn

The predicted rainfall is going to the major factor if those numbers pan out

Terry
Terry
12 days ago

Climate change is real

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ChanceShowerLA
ChanceShowerLA
12 days ago

7-day rainfall outlook….

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ChanceShowerLA
ChanceShowerLA
12 days ago

I’ve been dealing with a COVID-19 patient at home, as well as still working and running family operations….everyone be safe….

GFS (via WeatherTap) is showing an off-the-charts amount of precipitable water on Tues morning in SE LA…..that could be a major problem for the pumps in the city of New Orleans…..

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Wyatt Washburn
Wyatt Washburn
12 days ago
Reply to  ChanceShowerLA

May they get well soon, and may you all make it safe through this.

Wyatt Washburn
Wyatt Washburn
12 days ago

NHC #1 Jeff Masters and Team #2 TWC and Rick Knabb #3 Wunderblogs now YCC #4, but seriously go to the Discus if you’re looking for the traffic of the the old Blog for now. That’s my top four when it comes to go to for accurate information. I did not include individuals like Levi, and about 100 other experts from the old days who are now successful and ridiculously brilliant. They can be found at the NHC these days and many still at Wunderblogs now YCC. I hope you all are getting prepared in Louisiana, Alabama, and Mississipi who need to. I hope you all have a nice day with your loved ones.

MattMo
MattMo
12 days ago
Reply to  Wyatt Washburn

Link?….the Discus blog I’m seeing shows no new posts, latest one is 2 months old

greiner3
greiner3
12 days ago
Reply to  MattMo

https://disqus.com/home/discussion/wund/weather_underground_2993/newest/

I bookmarked the site for just such emergencies, with apologies to Daffy Duck.

Jen
Jen
12 days ago
Reply to  Wyatt Washburn

I’ve been looking for Jeff master’s on discus. I can’t find him this year. But found his blog post here

Dirk
Dirk
12 days ago
Reply to  Jen

Dr. Jeff Masters moved here to YCC

Terry
Terry
12 days ago

2 ppl I trust!

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Wyatt Washburn
Wyatt Washburn
12 days ago
Reply to  Terry

Two of the best, and nicest too. WXManWannabe would call himself an armchair Met. He’s got that humility, but we all know better than that.

Wyatt Washburn
Wyatt Washburn
12 days ago

While I am one of the few opining here regularly, I will put this out here for any who find their way here, the old home over on the discus backup is running at full speed. Full of many sincere experts who have helped guide people through major hurricanes for almost two decades. The link is on pretty much on every blog post somewhere in the comments. I encourage others to check it out if you’re looking for a lot of information, humor, and concise information. Haven’t been over today, but it’s a fun read with a lot of brilliant people.

Last edited 12 days ago by Wyatt Washburn
Kraull
Kraull
12 days ago

Florida isnt the only state in this situation you selfish twat

Deano
Deano
12 days ago
Reply to  Kraull

Fl makes it easier to understand how a lemon could get into DC. The home of oranges sure knows how to cultivate lemons.

Wyatt Washburn
Wyatt Washburn
12 days ago

Shear and Shear Tendency maps don’t add up for me. Shear map shows a solid 15kts of shear. Tendency suggests shear is almost zero, or soon to have such effect. If so, the center will blow up a CDO over it today, and convection will fill in on the west a whole lot more. The hard west turn coming will give Tropical Storm Sally a much different look later today into tomorrow. http://tropic.ssec.wisc.edu/real-time/atlantic/winds/wg8sht.GIF

Wyatt Washburn
Wyatt Washburn
12 days ago

Right at the level New Orleans could handle if Sally doesn’t get stronger than expected. Storm surge predictions to up to eleven feet is already disturbing. Rapid Intensification happens and that number will get closer to 15ft if not higher. Hurricane Katrina brought a 24-28 ft. storm surge for about 20 miles of the coast, 90 miles of coastline from Louisiana to Alabama took a Category 3 storm surge. comment image

Terry
Terry
12 days ago
Reply to  Wyatt Washburn

An abrupt climate change occurs when the climate system is forced to transition to a new climate state at a rate that is determined by the climate system energy-balance, and which is more rapid than the rate of change of the external forcing

greiner3
greiner3
12 days ago
Reply to  Terry

The problem going forward is there will come a time when there will be abrupt and changing energy-balances.

This will bring about total chaos re weather and climate.

Dirk
Dirk
12 days ago

Thanks Dr. Jeff , i hope people wil keep save.

Wyatt Washburn
Wyatt Washburn
12 days ago

Shear has fallen off the map pretty much for T.S Sally. Still shows 15kts, but shear tendency shows shear is having much less effect now. Divergence has gone bonkers overnight, and convergence has rebloomed in earnest too. MId and Low Levels still not aligned enough to really give Sally the core needed to rapidly intensify; but, Sally’s well on her way to getting more organized today. Flee from the water, shelter from the wind, do not take risks with you or your loved ones lives. This divergence signal is off the charts with T.S Sally this morning. Super dangerous when people have such little time to prepare.comment image http://tropic.ssec.wisc.edu/real-time/atlantic/winds/wg8dvg.GIF

Wyatt Washburn
Wyatt Washburn
12 days ago
Reply to  Wyatt Washburn

Please remove the trolls who endlessly target and downvote me and others here who are genuinely trying to add to this place. Sends confusion, and numerous are here only to cause disruption and chaos. Saying disingenous things about a very dangerous situation is just sad and wrong.

Last edited 12 days ago by Wyatt Washburn
Saint
Saint
12 days ago
Reply to  Wyatt Washburn

What’s annoying about that?

greiner3
greiner3
12 days ago
Reply to  Wyatt Washburn

Over at Weather Underground’s Disqus posts, they are saying the local news stations are mostly ignoring Sally.

Personal accounts posted are saying people at Lowe’s are buying garden supplies.

Terry
Terry
12 days ago

Thx Lurkindanger!

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Terry
Terry
12 days ago
Reply to  Terry

..

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Terry
Terry
12 days ago
Reply to  Terry

.-

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Michael
Michael
12 days ago

I’m thinking Sally has the potential to cause some real issues.

TERRY
TERRY
12 days ago

I’m already concerned. Jeff Masters or ANYONE ELSE — my mother just received a storm surge warning n her cell phone in Slidell. She lives about 10 miles from Lake Pontchartrain. Her house is on an elevated piece of land (her backyard is about 5 feet below her house foundation). and had 3-4 feet of water in her house for Katrina (which means her neighborhood had about 8 feet). My sister lived about a mile away and her property was a little lower. She had 8 feet water and 1 foot sludge.

I am concerned about the possibility of rapid intensification, which happened with Hurricane Laura and Katrina. I always heard it said that Katrina’s surge was exceptionally strong because the storm was so wide and it had no time to subside from the time the storm was Cat 5 and dropped to Cat 3 at landfall. In essence it was the storm surge of a Cat 5 storm with the wind speed of a Cat 3.

Can anyone speak to these concerns I have?

O Smith
O Smith
12 days ago
Reply to  TERRY

it’s easier and un-erringly accurate to evacuate ahead of any storm you or your family feel threatened by. If conditions prove to be less destructive than forecast, no harm done. You are saving resources and assisting the responders in the event of destruction if you are not there during recovery.
Its never a simple decision but commit to a plan of action at least 24 hours prior to landfall and fpllow that plan. Sit down and talk to your family now to make a plan you all can live with. This is no game.
Do not believe every un-named “expert” here or any where else, and no, I am NOT referring to regular contributors or blog authors.

O Smith
O Smith
12 days ago
Reply to  TERRY

You should go

Wyatt Washburn
Wyatt Washburn
12 days ago
Reply to  TERRY

Time to get em’ out till Sally’s out of town.

Art
Art
12 days ago
Reply to  TERRY

well the only mention i saw from NWS is the possibility of a Cat 2 strength at landfall..and im assuming that,,is their best guess right now…best thing for Mom is to listen to her Local NWS and warnings and do what they say,,but..good luck to her and hope she stays safe ok…

Deano
Deano
12 days ago
Reply to  TERRY

Over preparation is always the way to go. Over warning. Listen to the professionals along with a dose of your own common sense. Ignore the neophytes and wish casters. Do that and you’ll be fine.

Deano
Deano
12 days ago
Reply to  TERRY

When someone invents a way to troll proof blogs, they will be billionaires.

Michael
Michael
12 days ago

So happy to see there is a comment section now!

Terry
Terry
12 days ago

Thanks FIUStormChaser.

Information that is needed during times like this.

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Terry
Terry
12 days ago
Reply to  Terry

getting a bit worried ..

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Leilaf
Leilaf
12 days ago

Thanks for the updates everyone. I am in NO and very nervous about this storm. After Laura, I made up my mind I am selling everything and leaving this awesome city. I cannot go through another Katrina at my age. It took me 7 years to rebuild everything. I hope Sally dies or goes where few people live.

greiner3
greiner3
12 days ago
Reply to  Leilaf

If not Sally, it’ll be a retired named storm in the not too distant future.

Just saying.

Terry
Terry
12 days ago

hmm

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Terry
Terry
12 days ago
Reply to  Terry

more smoke on the way for Tdot n rain 🙁

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Art
Art
12 days ago

comment image

Art
Art
12 days ago

NWS Tall. is warning the panhandle area’s to expect 5-10 inches of rain and strong winds heed your warnings and stay safe everyone

Amature Met
12 days ago

My weather station says I had over 4 inches of rain last night, emptied it at 5 am and it has another 2 inches in it now. Kinda crazy for a storm moving away. Elkton Fl. wows

Art
Art
12 days ago
Reply to  Amature Met

gee stay safe there ok

Amature Met
12 days ago

One way or another, sooner or latter I think that part of the coast where (Hurricane) Sally is headed will slowly be abandoned by residential buildings.

I am sure the oil ports will stay open as long as possible.

Katrina was just a warning. Going to get another warning Monday-Wednesday.

We need to change the federal flood program. You should not be required to rebuild on the same lot. Most people rebuild in a flood prone area because they have to.

Amature Met
12 days ago
Reply to  Amature Met

Not looking so good for NO.

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Terry
Terry
12 days ago
Reply to  Amature Met

oh gosh!

Art
Art
12 days ago

so now NWS is thinking TS Sally might make landfall as a Cat #2 Hurricane.hopefully the word gets out there..so people can evacuate early and stay safe huh

Terry
Terry
12 days ago
Reply to  Art

thinking a higher Cat

Terry
Terry
12 days ago
Reply to  Terry

13th

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Art
Art
12 days ago
Reply to  Terry

it still has alot of time to do that

Amature Met
12 days ago
Reply to  Art

It looks like sally may have 24-36 hours of RI and that aint good.

Terry
Terry
12 days ago
Reply to  Amature Met

UR RIGHT!