Category Five Hurricane Lee

[WxWatcher007]

The NHC has designated our AOI in the eastern Atlantic as Invest 95L. It already has a good look to it, with significant spin and some disorganized convection. 

 

Normally, I am more muted when we're at the invest stage, but not this time. I believe this is the strongest signal we've seen for a long track CV major hurricane in quite some time. 

Why? The environment ahead looks tremendous not just for tropical genesis but significant intensification in the MDR. 

First, it's the moisture. Unlike early August, where SAL and subsidence dominated the MDR, we have a more moist and unstable environment thanks to the presence of much stronger preceeding waves scouring out the SAL. 

Look at the dramatic rise in instability in the MDR since August. It's more than enough, as we've seen. 

Obviously the thermodynamic environment is excellent. We have strong SSTs and OHC through the MDR and basin. 

With a strong ridge building in over the Atlantic, wind shear should initially be low. That alone is enough for TC genesis. There is a long runway of low shear in the MDR.

(Edit: there are low trades initially, which means easterly shear, but I don’t think this will disrupt progression much after a few days)

However, what sets this apart from other setups, especially in recent years, is that it looks like the orientation of the steering pattern is going to create ideal conditions for ventilation. 

From Eric Webb

Folks, that's big time. All systems seem poised to allow for TC genesis, followed by an increasing level of organization and eventually, intensification. 

It's reflected on the guidance consistently. Each operational model has a strong system nearing the Antilles.

 

 

With a strong ridge over the Atlantic, the Antilles have to watch very closely, including Puerto Rico. Once this gets to the Antilles, as you can see above there is a lot of guidance that tries to round this around the ridge. All bets are off then, as we turn our attention toward the East Coast steering pattern relative to the Atlantic ridge. 

Climo always favors OTS at this stage, but given the presence of strong ridging showing up on the guidance, this may be one that we're watching for a while, especially as guidance tends to underplay the strength of ridging. This is also where we need to watch the orientation of troughing in the eastern US, but that'll be at least 7-10 days away. 

At the very least, this is likely to be a threat to the Antilles and a significant ACE producer. 

In my estimation, 95L has the best chance to be the strongest TC in the basin this season. 

 

[ineedsnow]

11 minutes ago, WxWatcher007 said:

The NHC has designated our AOI in the eastern Atlantic as Invest 95L

this has the chance to be the biggest of the season and the storm looks massive

[WxWatcher007]

Just updated the OP with an analysis  

[Ed, snow and hurricane fan]

Gert/Idalia could weaken the ridge enough to influence this.  Giving it enough latitude crossing the Atlantic making it easier for the trough offshore ECUSA to curve it so it misses the islands.  Maybe. 

 

Nice original post.

[WxWatcher007]

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

Gert/Idalia could weaken the ridge enough to influence this.  Giving it enough latitude crossing the Atlantic making it easier for the trough offshore ECUSA to curve it so it misses the islands.  Maybe. 

 

Nice original post.

Yeah I think the steering pattern is a bit messy right now. We’ll see where things stand as this reaches the Antilles.

[GaWx]

 The 12Z model consensus is weaker/delayed on TCG. Not only does the GFS have very little early in the run (GFS TCG is delayed til the Caribbean), the CMC is similar. Plus the last few ICONs have been weaker than recent days. Also, the last two UK (goes out 168) have no TC after many in a row with it. Trend? Mean further west if there is ever TCG?

[WxWatcher007]

33 minutes ago, GaWx said:

 The 12Z model consensus is weaker/delayed on TCG. Not only does the GFS have very little early in the run (GFS TCG is delayed til the Caribbean), the CMC is similar. Plus the last few ICONs have been weaker than recent days. Also, the last two UK (goes out 168) have no TC after many in a row with it. Trend? Mean further west if there is ever TCG?

It’d be hilarious if this struggled after my super bullish post  

In all seriousness though, I find it very hard to believe that easterly shear would overcome all the other favorable factors including peak climo to disrupt this invest to the point it’s weak across the entire basin, especially given how it looks currently on visible/IR. The overall environment looks excellent to me despite the early shear. 

Intensity also probably plays a role in track. 

[LongBeachSurfFreak]

5 minutes ago, WxWatcher007 said:

It’d be hilarious if this struggled after my super bullish post  

In all seriousness though, I find it very hard to believe that easterly shear would overcome all the other favorable factors including peak climo to disrupt this invest to the point it’s weak across the entire basin, especially given how it looks currently on visible/IR. The overall environment looks excellent to me despite the early shear. 

Intensity also probably plays a role in track. 

I’m right on board with you. I think this has the potential to be a huge ACE maker, and another prolific swell producer for the east coast. 

[Ed, snow and hurricane fan]

36-48 hours shear drops significantly and heat content rises, although SSTs are above 28C the entire forecast on the latest SHIPS.  Whether the Greater Antilles actually effects 95L, too far out in time and the land interaction may or may not affects intensity.  Eyeballing mid-point of the ensembles at 174 hours, ensemble mean looks to be near or over NE Caribbean and into one of the Greater Antilles.  At that time, other than 12Z being a little slower to spin up 95L, not a huge swing between 6Z and 12Z ensembles at hour 180.  I do wish WxNerds ensemble page adjusted the forecast time when flipping through the runs.

 

 

[GaWx]

1 hour ago, WxWatcher007 said:

It’d be hilarious if this struggled after my super bullish post  

In all seriousness though, I find it very hard to believe that easterly shear would overcome all the other favorable factors including peak climo to disrupt this invest to the point it’s weak across the entire basin, especially given how it looks currently on visible/IR. The overall environment looks excellent to me despite the early shear. 

Intensity also probably plays a role in track. 

12Z Euro is strongest of the 12Z models as of 120 and pretty close to earlier runs.

[yoda]

3 minutes ago, GaWx said:

12Z Euro is strongest of the 12Z models as of 120 and pretty close to earlier runs.

Until it weakens at 144

[GaWx]

5 minutes ago, yoda said:

Until it weakens at 144

Yep although it still is the strongest of the 12Z runs at 144. Also, the 0Z Euro had similar weakening 132-156 followed by restrengthening. I'll be looking to see if the 12Z is similar.

[yoda]

1 minute ago, GaWx said:

The 0Z Euro had similar weakening 132-156 followed by restrengthening. I'll be looking to see if the 12Z is similar.

1004mb at 168 passing north of all the islands 

[Windspeed]

It’d be hilarious if this struggled after my super bullish post  
In all seriousness though, I find it very hard to believe that easterly shear would overcome all the other favorable factors including peak climo to disrupt this invest to the point it’s weak across the entire basin, especially given how it looks currently on visible/IR. The overall environment looks excellent to me despite the early shear. 
Intensity also probably plays a role in track. 

I don't think so. This is one heck of a healthy wave with evident broad turning in the low levels with an MLC already associated with the concentrated convection. With all of struggles over the MDR this season, regardless of the few systems that formed early, this one looks a go. Should be a long-tracking major hurricane. The big question isn't necessarily going to be if this can become a strong hurricane, but if it will end up a threat for the Lesser and Greater Antilles. Not mentioning the CONUS yet because it's just too early to know how/if the WAR will be there or break down.

[GaWx]

11 minutes ago, yoda said:

1004mb at 168 passing north of all the islands 

Down to 994 at 192. 

[yoda]

1 minute ago, GaWx said:

Down to 994 at 192. 

989 at 216.  00z was 986 and 12z yesterday was 969

[yoda]

Moving NW at 240... preparing to recurve at 972mb

[Windspeed]

Both initial runs of the HAFS A and B have an intensifying hurricane by 100-126.

[GaWx]

 The 12Z EPS at 228 is similar to the 0Z EPS at 240 with <20% of members threatening the NE Caribbean, Bahamas, or CONUS. Of those that do, two appear to be cat 4-5 with a 923 and a 933 as of 240 both moving WNW near/toward the Bahamas.
 Bermuda is still threatened by a good # and there are once again many Hs.

[LongBeachSurfFreak]

Hopefully this avoids the cold wake left by Franklin. I would love to see a long track major just miss. Major swell producing event as I’ll be on vacation from my real job and life guarding full time at Jones beach Ny. Timing couldn’t be better. 

[Ed, snow and hurricane fan]

1 hour ago, Windspeed said:

Both initial runs of the HAFS A and B have an intensifying hurricane by 100-126.

What is the difference between the A and B?

[Ed, snow and hurricane fan]

The Euro and GFS ensembles (and their ops) aren't that radically different in a week, really, but the difference in huge in impact.  GFS looks like an E Caribbean threat, Euro only about 200 miles apart, but suggests Bermuda may the only land that keeps 95L a pure fish.  And Bermuda is a small enough target it could be pure fish food.

[Windspeed]

What is the difference between the A and B?

Set of different data sets loaded. One also will use raw GFS for the UFS, while the other will simultaneously be used with sampled atmospheric data from reconnaissance. Obviously, that is only when recon is flying. Mainly to see the differences in output. That's really all I know; someone else may also want to chime in...

Dr. Sundararaman (Gopal) Gopalakrishnan discussed this is a recent Weather Geeks podcast if you want to listen to him speak. It's a more evolved simulation platform with multi-outputs versus the older HWRF, which will likely be retired in a few years.

[MattPetrulli]

These are pretty far south compared to the Euro. Would favor a recurse atm, but definitely don't think it's auto fish or anything. Especially if it ends up weaker than modeled, which is becoming a bit more possible today, and heads more south/west than currently projected.

[WxWatcher007]

It may very well remain no threat to land, but this is a very important reminder, visualized:

 

[Floydbuster]

 

[shaggy]

Icon and cmc at 0z are stronger(albeit not tbat strong) and more threatening to the islands

[GaWx]

21 minutes ago, shaggy said:

Icon and cmc at 0z are stronger(albeit not tbat strong) and more threatening to the islands

After two runs without TCG being noted on the UKMET, the new run (0Z) has TCG. So, together with a much stronger CMC vs 12Z, there is some reversal of recent runs' weakening trends despite the 0Z GFS being similar to its recent weaker runs.

0Z UKMET: moving WNW at 15 just N of Leewards at 168:
NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER  84 HOURS
              FORECAST POSITION AT T+ 84 : 14.8N  44.0W

                        LEAD                 CENTRAL     MAXIMUM WIND
      VERIFYING TIME    TIME   POSITION   PRESSURE (MB)  SPEED (KNOTS)
      --------------    ----   --------   -------------  -------------
    1200UTC 06.09.2023   84  14.8N  44.0W     1010            24
    0000UTC 07.09.2023   96  15.7N  45.9W     1009            27
    1200UTC 07.09.2023  108  16.4N  47.8W     1008            29
    0000UTC 08.09.2023  120  17.2N  50.6W     1008            26
    1200UTC 08.09.2023  132  17.8N  53.7W     1008            29
    0000UTC 09.09.2023  144  18.3N  56.3W     1007            27
    1200UTC 09.09.2023  156  18.6N  59.6W     1007            31
    0000UTC 10.09.2023  168  19.5N  62.1W     1005            32

[shaggy]

31 minutes ago, GaWx said:

After two runs without TCG being noted on the UKMET, the new run (0Z) has TCG. So, together with a much stronger CMC vs 12Z, there is some reversal of recent runs' weakening trends despite the 0Z GFS being similar to its recent weaker runs.

0Z UKMET: moving WNW at 15 just N of Leewards at 168:
NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER  84 HOURS
              FORECAST POSITION AT T+ 84 : 14.8N  44.0W

                        LEAD                 CENTRAL     MAXIMUM WIND
      VERIFYING TIME    TIME   POSITION   PRESSURE (MB)  SPEED (KNOTS)
      --------------    ----   --------   -------------  -------------
    1200UTC 06.09.2023   84  14.8N  44.0W     1010            24
    0000UTC 07.09.2023   96  15.7N  45.9W     1009            27
    1200UTC 07.09.2023  108  16.4N  47.8W     1008            29
    0000UTC 08.09.2023  120  17.2N  50.6W     1008            26
    1200UTC 08.09.2023  132  17.8N  53.7W     1008            29
    0000UTC 09.09.2023  144  18.3N  56.3W     1007            27
    1200UTC 09.09.2023  156  18.6N  59.6W     1007            31
    0000UTC 10.09.2023  168  19.5N  62.1W     1005            32

Gfs op run doesn't seem to match its ensembles which are coming in with a strong signal for a storm to be threatening the northern islands so far. We will see what the rest of the run shows.

[Ed, snow and hurricane fan]

Still a long way out, but GFS and Euro ensembles look fishier today than yesterday.  Still more than a few members are in the NW Caribbean.  First visible, impressive looking although I can't see a closed circulation.  It is probably getting close.