2025 Tropical Tracking Thread

[bncho]

59 minutes ago, JenkinsJinkies said:

Again, we’re getting a Feb 19-20 redux. This is the “throw us a bone” run and 0z will be even further south and east than 12z was.

there's no february 19-20 redux dude. we're not talking about a blizzard, we're talking about a hurricane.

[WxWatcher007]

Some evening analysis

4 minutes ago, WxWatcher007 said:

Although the convection is weak and disorganized, recon is now showing a much more well defined circulation, which if it holds will allow for gradual organization. 

Note how much tighter the circulation is in the image above, compared to some of the recon images posted earlier. You can also see a pocket of slightly stronger winds on the far eastern side of the system. Below you can see how the circulation is becoming better organized. Slowly. 

Convection is weak, but there has been some firing of stronger thunderstorms near the center. 

Shear has remained an issue through the day, but analysis shows that the shear may be abating, especially near the center. 

TD9 is in one of the best thermal environments in the entire Atlantic, so if it can start generating deep convection over its tightening center it should gradually intensify. 

While I am posting the SHIPS here, there looks to have been a bit of an uptick from hurricane guidance in overall intensity over the coming days. That's something we'll need to pay attention to, with the caveat that the trough and possible dry air will continue to lurk and will likely put a cap on intensity. 

 

Now for the track. There is increasing confidence that future Imelda will in fact turn away from the SE coast, but there is still a lot of uncertainty on how close the center gets to the coast and critically, the speed of the turn. Most guidance now turns the system away from the coast and accelerates it east into an Humberto created weakness. 

But within this evolving track forecast there are two diverging camps. The first, and most numerous, is one that easily follows Humberto out to sea. The second, which is led by the Euro and Euro AI to an extent, turns the system more slowly and allows a ridge to build over the top and close the escape route. The result is Imelda being turned back toward the coast. 

There aren't a lot of members that are held back, but the ones that do are pretty strong. 

So while it very well may be the case that this does turn and accelerate out to sea, there's still uncertainty. Remember, the models struggled with this inside of 100 hours. I'm not sure we should be locking in anything 5+ days out yet. Additional recon and finally having a well defined center should help with both track and intensity guidance. 

Finally, just because this is likely to stay offshore initially, that doesn't mean no impacts. TS force winds, coastal flooding, and flash flooding are still squarely hazards for coastal FL, GA, and the Carolinas. Just slight track changes could make the flood threat more impactful along the coast. 

 

[Weather Will]

What a complete fold by the EURO models.  Hail the new ICON/ Canadian Kings!!!  In all seriousness, I will not fall for the EURO snow storm looks this winter when the other models show nothing....

[CAPE]

8 minutes ago, Weather Will said:

What a complete fold by the EURO models.  Hail the new ICON/ Canadian Kings!!!  In all seriousness, I will not fall for the EURO snow storm looks this winter when the other models show nothing....

lol you will be all over it- posting snow maps every model cycle.

[WxWatcher007]

The Euro has been just another model for a long time now. Even though this turn was part of the envelope of possibilities, what’s particularly jarring was the Euro/GFS and their ensembles choosing the wrong path together inside 100 hours. That’s noteworthy imo. The AI models seem to have schooled the legacy guidance on this one. 

[Terpeast]

5 hours ago, WxWatcher007 said:

The Euro has been just another model for a long time now. Even though this turn was part of the envelope of possibilities, what’s particularly jarring was the Euro/GFS and their ensembles choosing the wrong path together inside 100 hours. That’s noteworthy imo. The AI models seem to have schooled the legacy guidance on this one. 

The AI models still have a long way to go, but they have been particularly good at predicting tropical cyclone tracks. 

[WxWatcher007]

23 minutes ago, Terpeast said:

The AI models still have a long way to go, but they have been particularly good at predicting tropical cyclone tracks. 

They have certainly earned my respect this season. 

[Weather Will]

5 minutes ago, WxWatcher007 said:

They have certainly earned my respect this season. 

Didn't the EURO AI have several runs run up the coast before caving to the ICON/Canadian?

[WxWatcher007]

26 minutes ago, Weather Will said:

Didn't the EURO AI have several runs run up the coast before caving to the ICON/Canadian?

Yes

[WxWatcher007]

Should've posted this yesterday but it actually makes more sense today as Imelda is on an intensification trend. Imelda adds to the list and should become a hurricane. Outside shot at a major. The peak season forecast is still up in the air, but with activity still expected on the models and in the areas I highlighted, I like where I sit. 

Peak Season Forecast (Aug 20-Oct 20)
Named Storms: 10 (4)
Hurricanes: 6 (2)
Major Hurricanes: 3 (2)

Fernand, Gabrielle (MH), Humberto (MH), Imelda

[87storms]

They have certainly earned my respect this season. 

Still kinda learning about AI, but after creating a few neural nets and slogging through understanding activation functions, gradient descent, loss functions, etc, it makes sense why these models (whatever architecture they’re using) could perform well on handling all the dimensions and chaos involved. It’s pure math and stats under the hood. The challenge will be dealing with the black box nature of deep learning algorithms, though I know explainable AI is becoming a thing. Computational cost is another topic as well.

[IronTy]

2 hours ago, 87storms said:

Still kinda learning about AI, but after creating a few neural nets and slogging through understanding activation functions, gradient descent, loss functions, etc, it makes sense why these models (whatever architecture they’re using) could perform well on handling all the dimensions and chaos involved. It’s pure math and stats under the hood. The challenge will be dealing with the black box nature of deep learning algorithms, though I know explainable AI is becoming a thing. Computational cost is another topic as well.

Yours too, eh?  I also have a neural net processor.  Too bad it's set to read-only from the factory.  

[87storms]

Yours too, eh?  I also have a neural net processor.  Too bad it's set to read-only from the factory.  

lol, literally taking a class rn on deep learning and neural nets (one more paper left on GANs). There’s a lot of free code out there to use. MNIST has been my dataset of choice…aka the “hello world” of neural networks. It’s fascinating stuff, but very computationally expensive. I have no idea what AIFS uses, but I imagine it’s not trivial.

[WxWatcher007]

Peak Season Forecast (Aug 20-Oct 20)
Named Storms: 10 (4)
Hurricanes: 6 (3)
Major Hurricanes: 3 (2)

Fernand, Gabrielle (MH), Humberto (MH), Imelda (H)

[WxWatcher007]

From my peak season forecast:

“As the EPS suggests, we could start seeing favorable conditions return even earlier in the peak period, but I think a conservative expectation of things to heat up with the MJO after the 20th is the best route. That would make the September 20-October 20 period most active.”

 

 

[WxWatcher007]

Northeast flow from the two hurricanes triggering flood advisories. Along the coast. 

[WxWatcher007]

Closing the book on September. I'll have an update on what to watch for in October tomorrow. 

[87storms]

28 minutes ago, WxWatcher007 said:

Closing the book on September. I'll have an update on what to watch for in October tomorrow. 

In a spiritual kinda way, I feel like hurricanes are acting proportional to how our pattern has been the last few years...downsloping, nw flow, ots...not all the time, but that seems like the base state, even more so than usual.  We're due for a nor'easter pattern.

[WxWatcher007]

We've made it to October, and with Imelda in its final act and just under three weeks left in the peak season forecast, it's time to take a look at what comes next. 

Peak Season Forecast (Aug 20-Oct 20)
Named Storms: 10 (4)
Hurricanes: 6 (3)
Major Hurricanes: 3 (2)

Fernand, Gabrielle (MH), Humberto (MH), Imelda (H)

First, there's still plenty of potential left in the basin. Although climo is quickly shifting westward, we still see robust AEWs moving into the basin, and one of those will actually be an area of interest discussed below. Yes, there is dry air/SAL in the tropical Atlantic, but look at the ITCZ and the convection we have there. This will go a long way toward ensuring the survival of the coming waves. 

 

A key part of what happens the rest of the period will center around intraseasonal forcing. Will the MJO remain in a favorable state for TC genesis and landfall risk? Will we get a CCKW that enhances the opportunity for waves to develop? The signals are mixed, but I think we will remain in a favorable period overall through the end of October. As I stated in my peak season forecast, I still think we rapidly end the season at the end of the month however. 

In terms of getting more NS and H, the basin continues to be primed for it, with SST anomalies still robust throughout the Atlantic. As we shift toward activity in the climo favored spots off the SE coast, Gulf, and Caribbean--especially the western Caribbean, there is plenty of fuel for low to moderate end activity. 

The picture becomes more complicated when looking at high end activity, however. To be sure, there is plenty of OHC, especially in the western part of the basin.

But a deeper look shows that there are more localized regions where higher end activity is more likely. 

 

I don't think this changes much, but we definitely have to watch out for another potential MH if it gets into these zones of anomalously high OHC. 

Finally, we have been extremely lucky that nothing has formed in the Caribbean. Between anomalously high OHC and exceptionally low shear, we've been avoiding disaster--seriously. Now that climo is shifting into this region, we need to closely monitor 1) the development of a CAG by mid-October and 2) any tropical waves getting to the Caribbean. There is a strong signal for anomalously low wind shear to return--though this year has been incredibly conducive in the wind shear category. 

 

Alright, so what are we watching? I have three areas of interest. 

 

1. Tropical Atlantic Wave 
The Tropical Atlantic has been more of a bust this season as expected, in large part due to the prevalence of dry and stable air along with SAL. This has been an issue throughout the decade. However, those conditions are more limited now, and an active wave train has moistened a good part of the MDR. There is a strong cross guidance signal that a wave emerges and finds hospitable conditions in the ITCZ. This should eventually lead to some level of development, as evidenced by the models. I am bullish on development.

 

2. SE Coast/Gulf
This is the second lemon by the NHC, and it's no surprise given that there has been a signal for a few days now. In the wake of Imelda, we have a boundary that is left behind, and along it we have some vorticity trying to spin up. Now, whether that becomes a low is unclear, but we do know that climo starts to favor these kinds of things in October. The limiting factors are proximity to land, and time. Whatever develops should cross Florida and into the Gulf, but is unlikely to meander there with time to develop into anything serious. This probably has a decent chance of development, though not nearly as high as area #1. It's worth a casual eye. 

 

3. Caribbean CAG
This is the one to watch, even though there isn't a significant development signal, yet. Toward the middle of the month, guidance is starting to show the development of a Central American Gyre, which favors slow, but gradual tropical genesis. The CPC has picked up on it, and recent years have shattered the mold on what CAGs can become. Recently, they've become some of our most destructive storms.

With wind shear expected to drop significantly and the thermal environment in the Caribbean, along with the increased tendency for troughing in the east around this time, our next significant threat may very well come from this region.