2025 Atlantic Hurricane Season

[Seminole]

3 hours ago, cptcatz said:

September 20 Euro and GFS runs: no tropical development through October 6. lol at all the people saying the lid was gonna come off in the second half of September and early October. After Gabrielle that MDR is closed for the season, could still see a Caribbean/Gulf storm in October but this season will be a massive forecast bust.

Running out of time. Here in north Florida it has been very dry and less humid compared to September last year. Feels more like October than September. If nothing happens in the next couple of weeks it is probably time to turn the page on this season.

 

[WEATHER53]

2 hours ago, MJO812 said:

Another season where many forecasters had the east coast above average chance with alot of storms.  Just like winter outlooks, take the tropical outlooks with a grain of salt or maybe not do outlooks way far in advance. 

I’m wondering if the generally far better tropical forecasts have now fallen victim to the winter storms micro management that just does  not work  

[MJO812]

2 hours ago, GaWx said:

 Good. The lack of casualties, misery, and destruction so far is a great thing! We’ve had enough of this crap. But unfortunately Oct has produced really bad storms, especially in recent years. So, the jury is still far from coming back with a full verdict for the season.

 Although the chances are now pretty low, we still don’t know for sure that ACE won’t get to near the 30 yr 122 avg especially based on 2024, 2020, 2016, and 2005, but also on 1894, 1893, and 1878. However, all of these very active Oct+ years were more active through Sept though 2016 and 1894 not that much.

Homegrown storms will be the thing moving forward. The Atlantic basin should be closing shop soon.

[GaWx]

17 minutes ago, MJO812 said:

Homegrown storms will be the thing moving forward. The Atlantic basin should be closing shop soon.

Regarding TCs that hit Conus, the latest TCG date on record E of 50W is Sep 25 (1893).

[NorthHillsWx]

For what it’s worth all ops are very active in the central Atlantic over the next 2 weeks 

[GaWx]

 I continue to fear what late seasons are capable of producing based especially on the recent past. Having 3 of the 7 most active Oct-Dec periods ACEwise (70+) during just the last 9 seasons is not comforting at all. Moreover, 3 of the last 6 (50%) La Niña seasons (2024 per RONI counts as La Niña) were in these top 7! 

 The one somewhat comforting thing, however, is the relative slowness of 2025 so far and how that affects the chances for a highly active Oct-Dec. There appears to be some correlation between how active a season is prior to Oct and how active is a season Oct-Dec, which means that having a relatively slow season through Sep does appear to reduce the chance for a very active Oct-Dec (50+ ACE) somewhat vs that chance when pre-Oct isn’t slow:

Seasons with 50+ ACE during Oct-Dec:

Year/pre-Oct ACE/Oct+ ACE
2024: 78/84
2020: 106/75
2016: 59/80
2005: 171/75
1969: 93/57
1963: 49/63
1961: 134/55
1950: 157/54
1932: 87/82
1894: 59/76
1893: 159/73
1887: 123/59
1878: 84/97

 Per this list based on each era’s normal ACE, the pre-Oct ACE for these 13 very active Oct-Dec was as follows:

- 6 MA normal (2005, 1961, 1950, 1893, 1887, 1878)
- 3 AN (2020, 1969, 1932)
- 1 NN (1894)
- 3 BN (2024, 2016, 1963)

 So, 50+ Oct-Dec years have been heavily biased toward pre-Octs that were active.

Where is 2025 headed for pre-Oct? Through Gabrielle, the prog is for ~~55. Then there’s the current MDR orange. The consensus has this as TS Humberto by 9/26-7 and a H soon after. That would have a realistic potential of 10-15 ACE 9/26-30. So, that would get total 2025 pre-Oct ACE to as much as ~65-70. That compares to 94 for the 1991-2020 pre-Oct avg, which means 2025 pre-Oct will end up solidly BN just about regardless of what Gabrielle and Humberto do.

What does this tell me? With 2025 almost definitely headed for BN pre-Oct, the chance for a 50+ Oct-Dec is <50%. However, 2024, 2016, and 1963 as well as 3 of the most active 7 Oct-Dec on record having occurred just within the last 6 La Niña seasons also say don’t bet the farm on <50 for Oct-Dec at least as of yet.

[WxWatcher007]

NHC has now designated that lead wave as a lemon. The GFS and AI ensembles have been more bullish on development odds while the Euro has basically nothing until the 12z run.

 

[GaWx]

23 minutes ago, WxWatcher007 said:

NHC has now designated that lead wave as a lemon. The GFS and AI ensembles have been more bullish on development odds while the Euro has basically nothing until the 12z run.

 

 Yeah, the only 12Z op with this as a TC is the GFS though a few of its ensembles also have a TC (more noisy than earlier runs). Thus, I’m taking the GFS with a huge grain at least as of now.

[WxWatcher007]

32 minutes ago, GaWx said:

 Yeah, the only 12Z op with this as a TC is the GFS though a few of its ensembles also have a TC (more noisy than earlier runs). Thus, I’m taking the GFS with a huge grain at least as of now.

Definitely a grain of salt but anything in that region would be worth watching with uncertainty about the depth and orientation of next week’s trough. This is pretty similar to what I thought in my peak season outlook with activity concentrated in the SW Atlantic. 

The late month CAG signal seems muted for now. 

[WxWatcher007]

There’s no need for a thread quite yet imo. 

It does look like conditions are becoming more favorable in the western Atlantic. It’ll be interesting to see if the trend toward the leading wave and central Atlantic area continues to move toward development. 

[ineedsnow]

3 minutes ago, WxWatcher007 said:

There’s no need for a thread quite yet imo. 

It does look like conditions are becoming more favorable in the western Atlantic. It’ll be interesting to see if the trend toward the leading wave and central Atlantic area continues to move toward development. 

18z GFS not backing down

[Michelle Davies]

Why is the 18z GFS showing a Gulf storm out of nowhere?

[WxWatcher007]

1 minute ago, Michelle Davies said:

Why is the 18z GFS showing a Gulf storm out of nowhere?

Model noise most likely. Most ensembles have nothing there with the focus on the SW Atlantic over the next week to ten days. 

[Michelle Davies]

1 minute ago, WxWatcher007 said:

Model noise most likely. Most ensembles have nothing there with the focus on the SW Atlantic over the next week to ten days. 

I'm seeing the Euro and the Google models develop the mandarin into a potent hurricane. I wonder if the lemon and mandarin could possibly merge. What are your thoughts?