2025 Tropical Tracking Thread

[Paleocene]

18 hours ago, Weather Will said:

WB 18Z GEFS on the 19th has a cluster in the Gulf and off the Atlantic coast heading out to sea. EURO AI ensemble has a similar cluster in Gulf and Atlantic but the Atlantic tracks are closer to the coast. 

 

 

12z GEFS today still has the cluster in the atlantic at about 240 hours. only a couple members head west for the gulf

[Weather Will]

WB 12Z EPS flashing red for Mid Atlantic coast....

[WxWatcher007]

It’s still really far out. Worth a casual eye though. 
 

[Weather Will]

11 minutes ago, WxWatcher007 said:

It’s still really far out. Worth a casual eye though. 
 

Yes, especially since I will be on the shore the last two weeks of August.  It has been 50 years or so since I had to evacuate while on vacation in OC.

[Weather Will]

NHC at 8pm.  Eastern Atlantic is the wave to watch.

[Weather Will]

WB 0Z EPS tropical storm and hurricane probabilities  through day 10.

[Weather Will]

WB 0Z ensemble low locations at 0Z Friday.

[dailylurker]

GFS has JAWS music playing at the end of its run. 

[WxUSAF]

1 hour ago, dailylurker said:

GFS has JAWS music playing at the end of its run. 

Trade seems to be early fall cold front with gorgeous weather or cat 5 up the Bay

[Weather Will]

12Z EPS probs thru Day 10 keep it off the coast.

[H2O]

Anything that high up will likely be a recurve

[jewell2188]

Is this the year after a long overdue hurricane drought for the mid Atlantic ????

[JenkinsJinkies]

2 hours ago, jewell2188 said:

Is this the year after a long overdue hurricane drought for the mid Atlantic ????

We can go decades without a hit from an actual hurricane. Most of the time it’s remnants or tropical storms that make their way here.

[Weather Will]

Still over 10 days out, but interesting to see the GFS and AI so close at Day 12-300 hrs. (18Z WB)

[WxWatcher007]

4 hours ago, H2O said:

Anything that high up will likely be a recurve

Agree. It needs to be hugging or very near the Antilles.

[Weather Will]

WB 0Z ensembles in 12 days at 6Z Friday 22nd: GEFS a fish storm. EPS has a few members taking a more southern route.  AI is on to something or got drunk last night and has members from Texas to Mid Atlantic.  

[WxWatcher007]

There’s going to be windshield wipers too on the ensembles.

[Weather Will]

NHC Special Weather Statement:

NWS National Hurricane Center Miami FL
935 AM EDT Sun Aug 10 2025

For the North Atlantic...Caribbean Sea and the Gulf of America:

Special outlook issued to update discussion of the disturbance 
located southeast of the Cabo Verde Islands (AL97).

Eastern Tropical Atlantic (AL97):
Updated:  Recently received satellite-derived wind data indicate 
that a well-defined low pressure system has formed about midway 
between the west coast of Africa and the Cabo Verde Islands with 
maximum winds of about 35 mph.  Although the associated shower and 
thunderstorm activity still lacks some organization, only a small 
increase in the organization could lead to the formation of a 
tropical depression before the low moves near or across the Cabo 
Verde Islands tonight and on Monday.  Regardless of development, 
locally heavy rainfall and gusty winds are possible today and Monday 
across the Cabo Verde Islands, and interests there should monitor 
the progress of this system.

Even if a tropical depression does not form over the next day or so, 
environmental conditions appear conducive for later development, 
and a tropical depression is likely to form by the middle to latter 
portion of this week while moving west-northwestward at 15 to 20 mph 
across the eastern and central tropical Atlantic.  
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 7 days...high...80 percent.

[frd]

5 minutes ago, Weather Will said:

NHC Special Weather Statement:

NWS National Hurricane Center Miami FL
935 AM EDT Sun Aug 10 2025

For the North Atlantic...Caribbean Sea and the Gulf of America:

Special outlook issued to update discussion of the disturbance 
located southeast of the Cabo Verde Islands (AL97).

Eastern Tropical Atlantic (AL97):
Updated:  Recently received satellite-derived wind data indicate 
that a well-defined low pressure system has formed about midway 
between the west coast of Africa and the Cabo Verde Islands with 
maximum winds of about 35 mph.  Although the associated shower and 
thunderstorm activity still lacks some organization, only a small 
increase in the organization could lead to the formation of a 
tropical depression before the low moves near or across the Cabo 
Verde Islands tonight and on Monday.  Regardless of development, 
locally heavy rainfall and gusty winds are possible today and Monday 
across the Cabo Verde Islands, and interests there should monitor 
the progress of this system.

Even if a tropical depression does not form over the next day or so, 
environmental conditions appear conducive for later development, 
and a tropical depression is likely to form by the middle to latter 
portion of this week while moving west-northwestward at 15 to 20 mph 
across the eastern and central tropical Atlantic.  
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 7 days...high...80 percent.

 

Look at these water temps, wow ! 

 

 

 

[WxWatcher007]

On 8/3/2025 at 1:54 PM, WxWatcher007 said:

Tropical Overview 8/3

Things have been quiet for most of the season despite three named storms so far. ACE is well below normal, but at this point in the season ACE doesn't really mean much. We have approximately 90% of the season to go, and the peak of the season, which begins around August 20, is right around the corner. 

There are several factors that have contributed to the quiet start. In recent high activity/hyperactive years, we've seen activity in the tropical Atlantic before climatology makes the region favorable. Think Beryl of last year. That was not the case this year, as a hostile atmospheric pattern, stability, and lower sea surface temperature anomalies (SSTAs) have left the tropical Atlantic devoid of activity, even in the face of historically low Saharan Air Layer intrusions (SAL) during its usual annual peak. 

Meanwhile, the PAC has been hot. And continues to be so as a favorable phase of the MJO passes through the region. 

Before more favorable atmospheric conditions move into the Atlantic we are already seeing homebrew starting to percolate off the East Coast. With a favorable MJO in the coming weeks, the window will begin to crack open in the Atlantic. At this time I am tracking three distinct possibilities.

(As I wrote this the NHC designated area two as a lemon and area three as an orange)

 

1. Invest 95L Off the Southeast Coast

The first area of interest is already likely in the early TC genesis stage. A current non-tropical low is trying to detach from a frontal boundary off the southeast coast, and is looking more and more like it's trying to become tropical with persistent convection firing now near an apparent center of circulation. This is a very common way to get TC genesis in the homebrew   region this time of year. 

This looks well on its way to developing before conditions become more hostile early in the week. It is not a threat to land, as these frontal system TCs tend to follow the weakness in the trough out to sea. It's interesting, but not overwhelmingly so. 

 

2. "Follow up" Development off Southeast Coast

Now this one is much more interesting, and has been for a while now. Yesterday most probably sat up as the happy hour GFS showed a strong system attempt to develop in the wake of 95L off the same frontal boundary, this time getting shunted back into the US. Well, although that run of the GFS was way too aggressive, the signal for some sort of follow up development has been on the guidance for a few days now. It's not terribly hard to see why, as the environment looks at least marginally favorable for some development. 

Vorticity

First--again, the frontal boundary is usually good for getting some vorticity spin up. So if something is far enough off the coast there should be some sort of spin that develops in the coming days. Both models pick up on this in the medium range. 

This is not enough for TC genesis. Which leads to the second favorable factor.

Instability

While the tropical Atlantic has been incredibly stable so far this season...

There has been no such issue off the East Coast...in fact, instability has been extremely high. 

What that tells me is that anything that does have spin and can develop an area of low pressure will have a chance to generate convection, which will only help with TC genesis odds as long as the system isn't hugging land the entire time. 

SSTa

Not much analysis needed here. I expect the the southwest Atlantic to be a hotbed of activity this season because that's where the heat is. Any low is going to have a shot with enough time and space to become tropical in this SSTa regime. 

Shear

The key inhibitor here is shear. Often times with these frontal boundary systems near the coast you have shear and drier air that is lurking. That comes with the territory with the frontal boundary. Here it is unclear how favorable a shear environment this potential system will find, but guidance is hinting at a window of lower shear later this week taking hold. 

What makes this particularly interesting is the steering pattern. While the outcome is different in terms of where the area of vorticity goes, the pattern evolution is the same. In the wake of 95L a ridge builds in and traps whatever could develop along the coast. That's something to legitimately watch. Maybe not closely, yet, but at least with a casual eye.  

3. Central Atlantic Wave

This final area is highlighted as a lemon (now orange) by the NHC, but the wave hasn't yet left the coast of Africa. This is an area that should benefit from the coming MJO change, and it already has a few things going for it. 

First, as I mentioned earlier, SAL is at historic lows. Now, that doesn't mean that SAL isn't out in the Atlantic, because it is, but look at the coast of Africa. When this wave comes off, it will likely be in a pocket where there is very little SAL. It will be fighting stability in that part of the basin along with lesser SST anomalies, but that can be manageable with a vigorous enough wave. 

Timing and location are everything, and this one is still TBD on both. With the steering pattern likely changing with a ridge taking over, if this is able to get trapped under the ridge it will likely be moving into the most favorable conditions for a tropical wave yet this season. Just a little off and it's staying well out to sea. To be sure, I'm not calling for a US threat or anything at this time, but the NHC has a large geographical zone for development for a reason. There is higher than usual uncertainty on where this could develop.

This may be our first reasonably strong system of the year for two reasons. 

First, it is running into the aforementioned warm SW Atlantic. OHC is primed for a system ready to take advantage of it. Even the central Atlantic looks conducive for some strong activity again this year. 

Second, and potentially far more concerning, is the ensemble guidance that wants to totally wipe out unfavorable shear. This is a fairly stunning retreat of shear by the 00z EPS. 

So while I'm not necessarily expecting a super burst of activity, we now have plenty to track in advance of the start of peak season, with two areas that are worth watching...

 

 

Figure it's time to look at this again to see what happened. 

1. Invest 95L became Dexter, so that was a good call. 

2. The follow up disturbance off the East Coast never materialized, and was probably one of the worst forecasts I've had. As for why it gave a head fake, I think a combination of shear and dry air (the opposite of what I expected) kept convection from organizing and even generating on a consistent basis. Awful, awful call.  

3. The central Atlantic wave became 96L, but this call wasn't much better either. Simply put, MDR stability got it. It has been meandering for days in the open Atlantic, unable to generate consistent convection and organize. Not a good start. 

 

[WxWatcher007]

Now for the new...

Tropical Overview 8/10/25

1. Invest 97L
We're on the cusp of a true CV system developing, as 97L continues to organize just off the African Coast. 

It's still plenty disorganized, and is going to run into a cooler SST environment as it pops northwest (as posted above) but it's looking like one of the rare CVs set to develop in the basin. 

Ridging in the Atlantic will push this west, but how far west is TBD

Ensembles more or less agree that this will got to the northeast of the Antilles, but from there we have significant divergence based on whether there are any troughs imparting a weakness on the amplitude of the Atlantic ridge. That's the key part to all of this, and it cannot be resolved at this range, though with each day we learn a little more. 

If I had to place a lean on it, I would say OTS or Atlantic Canada due to how much latitude it gains by 60W, but there's a long way to go. 
 

2. Weak disturbance off FL Coast

This is more of a curiosity for me than anything, but there's a weak disturbance that's currently ideally positioned off the west coast of Florida. 

Obviously, SSTs are boiling but that's not enough to pique my interest. 

The disturbance is parked under an anti-cyclone, which provides the benefit of 1) upper divergence that maintains deep convection and 2) very low shear

The models don't do much with it, but if it had some time maybe it could become a little interesting? The big limiting factor is probably time, and the lack of a more robust surface reflection. Vorticity is modest, but that's not enough.