2023 Atlantic Hurricane season

[cptcatz]

3 hours ago, GaWx said:

 Although I'm not saying they can't end up with a dangerous situation then, I'd say that the worry regarding the 12Z GFS would be the case for folks not realizing that the exact 10 day position on the GFS or really on any operational for that matter is of very limited forecasting value since they jump around a lot that far out from run to run. Regarding GFS runs over the last 5 days, only the 0Z 8/16 run has anything similar. 

Quite a few of the GFS runs have been showing a CAG like storm forming in the western Caribbean. CMC has been showing it a lot too and now EPS is hinting it at. Where it goes from there is a toss up but the fact that it forms on many models is what's important. 

[Bhs1975]

Quite a few of the GFS runs have been showing a CAG like storm forming in the western Caribbean. CMC has been showing it a lot too and now EPS is hinting it at. Where it goes from there is a toss up but the fact that it forms on many models is what's important. 

If it does it will be over the highest OHC in the basin.

[tiger_deF]

On 8/12/2023 at 5:09 PM, tiger_deF said:

I think the chances of an August shutout are looking more and more likely...

Looks like I was wrong about August at least! The basin looks to be getting quite active over the next couple of weeks. Two areas that I think present distinct threats to land:

1. The westernmost portion of the decaying monsoon trough. Model support has quickly grown over the past day, and there is currently a massive convective burst taking place over the center of the disturbance, shown below. Models take this system right over the antilles/PR.

 

2. The wave currently coming off of Africa. Model support is also growing, with the 00z GFS developing the system in a few days. The Bermuda high appears much more stout than it has been, and the GFS takes the system across the entire Atlantic, recurving extremely close to the east coast. With 98L acting as a sacrificial lamb to SAL, the local environment looks very conductive for development.

[WxWatcher007]

6 hours ago, tiger_deF said:

Looks like I was wrong about August at least! The basin looks to be getting quite active over the next couple of weeks. Two areas that I think present distinct threats to land:

1. The westernmost portion of the decaying monsoon trough. Model support has quickly grown over the past day, and there is currently a massive convective burst taking place over the center of the disturbance, shown below. Models take this system right over the antilles/PR.

 

2. The wave currently coming off of Africa. Model support is also growing, with the 00z GFS developing the system in a few days. The Bermuda high appears much more stout than it has been, and the GFS takes the system across the entire Atlantic, recurving extremely close to the east coast. With 98L acting as a sacrificial lamb to SAL, the local environment looks very conductive for development.

Newly designated 90L has been the most consistently convectively active of the three MDR disturbances, and it looks to be organizing nicely this morning. I expect odds to increase. Definitely worthy of an invest tag. 

[cptcatz]

90L is looking nice this morning.  Will be interesting to see how far west it tracks.  I feel like models don't have a good handle on it.

[Bhs1975]

90L is looking nice this morning.  Will be interesting to see how far west it tracks.  I feel like models don't have a good handle on it.

Yeah they want to snatch it up and send it back east.


.

[WxWatcher007]

There’s supposed to be troughing which should allow a more NW heading eventually but everything looks complicated and messy out there. 98L should develop and I think 90L will too, but poor 99L looks to be a disappointment. 

It looks fine for an invest on visible, but there’s still work to do. 90L benefits tremendously from being further south with limited influence from SAL and shear. 

[WxWatcher007]

Also, posting for posterity because we have constant complaining from some about the NHC naming every swirl. 

 

[CheeselandSkies]

On 8/17/2023 at 5:24 PM, Scott747 said:

Those posts have gone away because it's the same schtick as it always is.

In a nutshell that poster has cancelled the rest of August and September. Also October will be cancelled along with 2024, 2025 and beyond.

I was relatively new to the forum then but I thought that poster might have learned some humility after making a post essentially cancelling 2017 mere days before Harvey regenerated, to be quickly followed by Irma, Jose, Maria, etc. Little did I know how wrong I was.

[WxWatcher007]

Alright folks, it's just about that time to ring the bell. After a dead period late July through most of August, right on cue the basin is alive. 

With a caveat. 

Let's start here. 

Despite our dead period, we've been pretty active for a Nino, which means anything near normal activity. In fact, today is the first day we go BN ACE this season according to Brian McNoldy. 

 

I only say this because now is really when the rubber needs to meet the road in determining what kind of season we have, which I'll talk about more when I do my peak season forecast.

For now, though, let's take our first look around the basin in quite some time. 

 

There are five areas to watch. The basin is active in the sense that there are legitimate disturbances out there--the basin is filled with them--but the overall environment for development, and certainly high end development, remains relatively hostile. Let's go one by one. 

Western Atlantic Orange--WxW007 Development Odds: 60% 

I've been watching this one for a while now, and while it still needs a lot of work, the guidance continues to believe that this will consolidate enough over the Gulf to allow for some modest development. We all know the water in the Gulf is warm, and actually some of the warmest on the globe this year.

However, I think the availability of moisture in the Gulf, and just enough of a window with lower shear will allow for development before a landfall in the western Gulf coast near the TX/Mexico border. Time is a factor. Let's see how coherent this disturbance is as it passes Florida. 

 

Invest 90L--Development Odds: 70%

I am bullish on this disturbance, and I have been for a while. While there was a debate on whether the monsoon trough would even break down, the western end of the trough remained convectively active. As the MT broke apart into three distinct areas, this one remained south, which is critical because it has thus far evaded the overwhelming influence of SAL and shear. 

It's not great, but it's just enough IMO, a theme of this post as we look around this part of the basin. The models may be playing catch up with this one, but let's see what the trends are today. Last night's intense convective burst was helpful IMO. This is one to watch in the Antilles, because as it moves into the Caribbean if it isn't sheared we should see stronger convection as it organizes some. Long term fate is uncertain. 

Invests 98L & 99L--Development Odds: 50%

The water vapor says it all. These two were the leaders in the clubhouse, but you have everything you need to know by my combining the two in a quick paragraph. They're too north and they're struggling in a hostile environment. 98L is about to get sandblasted by shear and SAL. While 99L looks like it has a well established LLC, it's sheared and it's only going to get worse. If I had to place bets, the NHC designates 98L eventually but it's a minimal TS at best. Meh. 

New Wave on the Block--Development Odds 50%

Another wave is poised to exit Africa, and it is another vigorous one. With 98L and 99L likely to be sacrificial waves at the end of the day, this may pave the way for this wave (or a subsequent one) to have better development odds, provided they don't get decapitated by shear. Even then, these strong waves that are forecast to come off into September may find a more favorable environment west if the SAL and TUTT shear persists in the MDR. Some guidance is latching onto this idea, but we'll see. 

[olafminesaw]

Lots of fish activity

[ldub23]

50 minutes ago, olafminesaw said:

Lots of fish activity

But  less  fishy than 06Z

 

 

[Stx_Thunder]

On 8/16/2023 at 9:07 AM, Great Snow 1717 said:

The effects of El Nino and SAL on the Atlantic hurricane season

In a Good nutshell. Usually is most of the time 

[yoda]

Well we have a 36 hour TD... so yay?

[hlcater]

12 hours ago, WxWatcher007 said:

 

Nice analysis here. Think of all the waves, the one with the best odds of being notable long term is the AEW just now leaving Africa. I think 90L develops into a TD/TS over the next day or so but dry air and westerly shear courtesy of the TUTT should keep a lid on that one. There is a chance that it stays disorganized and slides far enough south to avoid getting picked up and drawn northward, but the vigor of the wave currently kinda argues against that. Would expect it to be pulled up into the western atlantic with perhaps a rainfall threat in Hispaniola as it does so.

[cptcatz]

Interesting little shift west on the 18z EPS...

[WxWatcher007]

98L and 90L look close to TDs, maybe 98L a little ahead. 

[Normandy]

The NHC’s lack of propensity to name obvious tropical cyclones is starting to get annoying.  It took them far too long to name Emily and the day before TD 6.  Just because it’s in the open ocean doesn’t mean you don’t initiate advisories when it’s an obvious TC

[WxWatcher007]

After languishing in the MDR, we have Tropical Storm Emily. 

 

Tropical Storm Emily Discussion Number   1
NWS National Hurricane Center Miami FL       AL072023
1100 AM AST Sun Aug 20 2023

The large area of low pressure we have been monitoring 
over the last several days to the west of the Cabo Verde Islands 
has finally developed a well-defined circulation per recently 
received satellite wind data. In addition, the scatterometer wind 
data also suggest the system has developed a robust wind field on 
its northern semicircle, with ASCAT-B/C both showing believable 
wind retrievals in the 40-45 kt range. Therefore, advisories are 
being initiated on Tropical Storm Emily this morning with maximum 
sustained winds of 45 kt, which is in good agreement with the latest 
1200 UTC TAFB Dvorak fix. 

The estimated motion of the tropical storm is slowly off to the 
west-northwest, at 300/9 kt. Over the next several days, Emily 
should maintain a general west-northwestward motion as it remains 
steered by a low-level ridge centered to its north. A gradual turn 
to the north is anticipated after Emily becomes a remnant low, 
rounding the southern periphery of this subtropical ridge. The track 
guidance is in fairly good agreement on this scenario, and the 
initial track forecast lies in between the simple and corrected 
consensus aids.

Emily might already be near its peak intensity, as vertical wind 
shear is expected to substantially increase over the cyclone in the 
next 24-36 hours as it remains embedded in a fairly dry mid-level 
environment. While it is possible a bit more intensification occurs 
today, it seems more likely the system will soon succumb to the 
increasingly hostile environment over the next several days. Both 
the GFS and ECMWF suggest Emily will cease to produce organized 
convection in about 48 hours, and the official intensity forecast 
shows it becoming a post-tropical remnant low at that time. There is 
some chance the environment becomes more favorable again in 4-5 
days, but a regeneration scenario will not be shown in the official 
forecast for now. 



FORECAST POSITIONS AND MAX WINDS

INIT  20/1500Z 19.5N  38.8W   45 KT  50 MPH
 12H  21/0000Z 20.3N  39.9W   45 KT  50 MPH
 24H  21/1200Z 20.9N  41.6W   40 KT  45 MPH
 36H  22/0000Z 21.5N  43.6W   35 KT  40 MPH
 48H  22/1200Z 22.5N  45.8W   30 KT  35 MPH...POST-TROP/REMNT LOW
 60H  23/0000Z 23.6N  47.7W   30 KT  35 MPH...POST-TROP/REMNT LOW
 72H  23/1200Z 25.1N  49.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  24/1200Z 29.8N  50.3W   30 KT  35 MPH...POST-TROP/REMNT LOW
120H  25/1200Z 36.0N  51.0W   30 KT  35 MPH...POST-TROP/REMNT LOW

$$
Forecaster Papin

[MANDA]

13 minutes ago, WxWatcher007 said:

After languishing in the MDR, we have Tropical Storm Emily. 

 

Tropical Storm Emily Discussion Number   1
NWS National Hurricane Center Miami FL       AL072023
1100 AM AST Sun Aug 20 2023

The large area of low pressure we have been monitoring 
over the last several days to the west of the Cabo Verde Islands 
has finally developed a well-defined circulation per recently 
received satellite wind data. In addition, the scatterometer wind 
data also suggest the system has developed a robust wind field on 
its northern semicircle, with ASCAT-B/C both showing believable 
wind retrievals in the 40-45 kt range. Therefore, advisories are 
being initiated on Tropical Storm Emily this morning with maximum 
sustained winds of 45 kt, which is in good agreement with the latest 
1200 UTC TAFB Dvorak fix. 

The estimated motion of the tropical storm is slowly off to the 
west-northwest, at 300/9 kt. Over the next several days, Emily 
should maintain a general west-northwestward motion as it remains 
steered by a low-level ridge centered to its north. A gradual turn 
to the north is anticipated after Emily becomes a remnant low, 
rounding the southern periphery of this subtropical ridge. The track 
guidance is in fairly good agreement on this scenario, and the 
initial track forecast lies in between the simple and corrected 
consensus aids.

Emily might already be near its peak intensity, as vertical wind 
shear is expected to substantially increase over the cyclone in the 
next 24-36 hours as it remains embedded in a fairly dry mid-level 
environment. While it is possible a bit more intensification occurs 
today, it seems more likely the system will soon succumb to the 
increasingly hostile environment over the next several days. Both 
the GFS and ECMWF suggest Emily will cease to produce organized 
convection in about 48 hours, and the official intensity forecast 
shows it becoming a post-tropical remnant low at that time. There is 
some chance the environment becomes more favorable again in 4-5 
days, but a regeneration scenario will not be shown in the official 
forecast for now. 



FORECAST POSITIONS AND MAX WINDS

INIT  20/1500Z 19.5N  38.8W   45 KT  50 MPH
 12H  21/0000Z 20.3N  39.9W   45 KT  50 MPH
 24H  21/1200Z 20.9N  41.6W   40 KT  45 MPH
 36H  22/0000Z 21.5N  43.6W   35 KT  40 MPH
 48H  22/1200Z 22.5N  45.8W   30 KT  35 MPH...POST-TROP/REMNT LOW
 60H  23/0000Z 23.6N  47.7W   30 KT  35 MPH...POST-TROP/REMNT LOW
 72H  23/1200Z 25.1N  49.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  24/1200Z 29.8N  50.3W   30 KT  35 MPH...POST-TROP/REMNT LOW
120H  25/1200Z 36.0N  51.0W   30 KT  35 MPH...POST-TROP/REMNT LOW

$$
Forecaster Papin

Will get a some minimal ACE points from this but so far this season it has been quantity over quality.

[WxWatcher007]

1 minute ago, MANDA said:

Will get a some minimal ACE points from this but so far this season it has been quantity over quality.

Yes, and a lot of that has to do with the hostility in the basin created by shear and SAL/subsidence, but keep in mind that the overwhelming majority of big ACE producers occur after Aug 20. Like almost 90% I think. That's why these next two weeks are critical IMO to what kind of season we have overall. Have to produce. 

[WxWatcher007]

Did a deep dive on the Gulf and 90L in the MA subforum thread, but reposting the Gulf portion here:

Gulf Disturbance
I tagged yesterday's disturbance with 60% odds of eventual development when it was moving through the Bahamas and Florida, and now that it has reached the eastern Gulf I am even more bullish given today's satellite appearance. 

To be clear: this one needs some work and there's not a lot of time to do it. That said, the quick convective burst and indications that it's trying to form into a low makes it worth an invest tag to me. 

The environment overall looks favorable. There is very little shear present and that should remain the case as this moves west. 

 

Once again, we obviously know that the SSTs are not an issue, with literally some of the warmest water on Earth in the Gulf and a deep reservoir of OHC. 

Moisture looks solid not great, but given where the vorticity is trying to tighten and the convective bursts we're seeing, I don't think drier continental air is a limiting factor yet. We'll see. 

I think time is the greatest limiting factor here, but kind of like Hanna a few years ago, if this can get a good organizational burst today/tonight that could bode well for another named storm to develop as this enters the western Gulf and the TX/Mexico border early Tuesday. Again, not a lot of time, and nothing can happen until there's a legitimate low, which we do not have yet. 

[Great Snow 1717]

18 hours ago, yoda said:

Well we have a 36 hour TD... so yay?

[GaWx]

2 hours ago, Normandy said:

The NHC’s lack of propensity to name obvious tropical cyclones is starting to get annoying.  It took them far too long to name Emily and the day before TD 6.  Just because it’s in the open ocean doesn’t mean you don’t initiate advisories when it’s an obvious TC

 The opposite was often said in years like 2020, naming too many. So, this may be an overreaction by the NHC to then.

[GaWx]

 With Emily, 2023 is at 6 storms to date.

Regarding 1991-2020 averages:

- 6th storm date 8/29: so ahead by 9 days despite El Niño 

- 2+ more storms are likely to be named by then, which would mean 8+ by 8/29. 8th storm average date isn't til 9/9. 9th not til 9/16.

- 1st H forms 8/11 and 2nd forms 8/26. So, pretty close to average for that with a decent shot at the 2nd H of 2023 by 8/26. Invest 90L appears to be the best candidate for this right now.

- 1st MH date 9/1. With the higher than normal # of systems for late August being monitored, there's a decent shot for the first MH by 9/1. Invest 90L may be the best candidate for this possibility, but we'll also need to see what the E MDR may produce.

 

https://www.nhc.noaa.gov/climo/

[WxWatcher007]

Not worth much verbatim, but both the GFS and Euro at 12z went back to hinting at some type of activity in the Gulf next week. Been causally looking at that since earlier in the week. Euro gone wild at 12z so nobody should take that seriously obviously, but that's the risk with that type of pattern IMO. 

[olafminesaw]

Definitely wouldn't think the upcoming period will be totally dead

[GaWx]

Bell ringing day last year vs this year:

Last year: very quiet despite moderate La Niña 

 

This year just about as many systems at one time as ever despite moderate El Niño:

[Ed, snow and hurricane fan]

4 hours ago, GaWx said:

Bell ringing day last year vs this year:

Last year: very quiet despite moderate La Niña 

 

This year just about as many systems at one time as ever despite moderate El Niño:

Did we have 2 systems upgraded to named storms in a single day last year?  Of course not.  I think we'll have 3 named storms in 3 days, but the numbers will be 3/1/0 for August, Maybe 4/1/0.  I think a below normal numbers and ACE season, but nothing like the LDub season cancel.  Gulf has poor steering and shear/dry air, but I'd bet money on a major hurricane landfalling Florida in October.  The OHC will still be immense in 2 months, and normal (climatological) mean steering favors Gulf to Florida.  Probably not a storm with enough lifespan to make ACE normal, but a short lived Cat 3 or 4 is a Cat 3 or 4.  Looking for a model that supports thay, none so far.

[LongBeachSurfFreak]

57 minutes ago, Ed, snow and hurricane fan said:

Did we have 2 systems upgraded to named storms in a single day last year?  Of course not.  I think we'll have 3 named storms in 3 days, but the numbers will be 3/1/0 for August, Maybe 4/1/0.  I think a below normal numbers and ACE season, but nothing like the LDub season cancel.  Gulf has poor steering and shear/dry air, but I'd bet money on a major hurricane landfalling Florida in October.  The OHC will still be immense in 2 months, and normal (climatological) mean steering favors Gulf to Florida.  Probably not a storm with enough lifespan to make ACE normal, but a short lived Cat 3 or 4 is a Cat 3 or 4.  Looking for a model that supports thay, none so far.

I wouldn’t write off Franklin for a major. Plenty of warm water in its later life, and that area loves to produce majors historically