2025 Atlantic Hurricane Season

[LibertyBell]

29 minutes ago, NorthHillsWx said:

Where in the world are you getting “lackluster or nonexistent tropical cyclone activity in the Atlantic” from the 2024 season? It was above average on every metric and featured some of the worst hurricane impacts we have ever seen. There were 5 MDR hurricanes and the Gulf was active as well. Sorry, I will not agree with you on this. 

You have to look at specific periods like the near the peak of the season.  The active period was early and late, but tropical activity was nonexistent at the time it was supposed to be busiest.  We had a complete shut out of all rainfall here in October.

We had the same Saharan Air Layer / dry air intrusion into the tropics, and it's only become even more extreme this year.  All the forecasts for a historically busy season completely busted and we ended up with an average season.

 

[Seminole]

18 hours ago, RaleighNC said:

Honest question - increasing SSTs would seem to make an AMO Inactive period more active than it otherwise would be, wouldn't it?

It makes plausible sense. 

[GaWx]

2 hours ago, LibertyBell said:

You have to look at specific periods like the near the peak of the season.  The active period was early and late, but tropical activity was nonexistent at the time it was supposed to be busiest.  We had a complete shut out of all rainfall here in October.

We had the same Saharan Air Layer / dry air intrusion into the tropics, and it's only become even more extreme this year.  All the forecasts for a historically busy season completely busted and we ended up with an average season.

 

Hey Liberty,

 2024 came in less active than, for example, the initial forecasts from CSU. But the season was still solidly above avg and it was a horrific season for the SE US:

2024 North Atlantic Summary
Named Storms  (vs 1991-2020 Normal)	Hurricanes  (vs 1991-2020 Normal)	Major Hurricanes  (vs 1991-2020 Normal)	Total ACE (x104 kt2)  (% Difference of 1991-2020 Normal)	Total Direct  Deaths	Total U.S.  Damagee ($million)
18 (+4)	11 (+4)	5 (+2)	161.5 (+32% )	274	124,125

 

[LibertyBell]

1 minute ago, GaWx said:

Hey Liberty,

 2024 came in less active than, for example, the initial forecasts from CSU. But the season was still solidly above avg and it was a horrific season for the SE US:

2024 North Atlantic Summary
Named Storms  (vs 1991-2020 Normal)	Hurricanes  (vs 1991-2020 Normal)	Major Hurricanes  (vs 1991-2020 Normal)	Total ACE (x104 kt2)  (% Difference of 1991-2020 Normal)	Total Direct  Deaths	Total U.S.  Damagee ($million)
18 (+4)	11 (+4)	5 (+2)	161.5 (+32% )	274	124,125

 

The intriguing thing about last year which is being repeated to a more extreme extent this year is the long period of inactivity when you expect things to be very active.  It was the tropical equivalent of a book end season, with big activity early and later in the season.  Do you have a monthly breakdown of tropical activity from last season, Larry? Thanks!

 

[LibertyBell]

28 minutes ago, Seminole said:

It makes plausible sense. 

Yes, otherwise we would be going into a 70s/80s type of inactive period right now.

[GaWx]

1 hour ago, LibertyBell said:

The intriguing thing about last year which is being repeated to a more extreme extent this year is the long period of inactivity when you expect things to be very active.  It was the tropical equivalent of a book end season, with big activity early and later in the season.  Do you have a monthly breakdown of tropical activity from last season, Larry? Thanks!

 

Storm Number	Storm Name	Typea	Datesb  (UTC)	Max.  Winds  (kt)	Min.  Pressure  (mb)	Accumulated  Cyclone  Energyc  (x104 kt2)	Direct  Deathsd	U.S.  Damagee ($million)	Tropical  Cyclone  Report  Status
1	Alberto	TS	19 Jun–20 Jun	45	992	0.8	2	125	Final
2	Beryl	MH	28 Jun–09 Jul	145	932	34.5	35	7,200	Final
3	Chris	TS	30 Jun–01 Jul	40	1005	0.1	5	0	Final
4	Debby	HU	03 Aug–08 Aug	70	979	4.9	12	2,500	Final
5	Ernesto	HU	12 Aug–20 Aug	85	967	14.4	3	0	Final
6	Francine	HU	09 Sep–12 Sep	90	972	4.8	0	1,300	Final
7	Gordon	TS	11 Sep–17 Sep	40	1004	1.3	0	0	Final
8	Eight	PTC	15 Sep–17 Sep	50	1004	0.0			Final
9	Helene	MH	24 Sep–27 Sep	120	939	7.0	176	78,700	Final
10	Isaac	HU	25 Sep–30 Sep	90	963	7.9	0	0	Final
11	Joyce	TS	27 Sep–30 Sep	45	1001	1.7	0	0	Final
12	Kirk	MH	29 Sep–07 Oct	130	928	23.7	0	0	Final
13	Leslie	HU	02 Oct–12 Oct	90	970	16.1	0	0	Final
14	Milton	MH	05 Oct–10 Oct	155	895	22.5	15	34,300	Final
15	Nadine	TS	19 Oct–20 Oct	50	1002	0.7	7	0	Final
16	Oscar	HU	19 Oct–22 Oct	75	984	4.5	8	0	Final
17	Patty	TS	01 Nov–04 Nov	55	982	2.3	0	0	Final
18	Rafael	MH	04 Nov–10 Nov	105	954	12.3	2	0	Final
19	Sara	TS	14 Nov–18 Nov	45	997	2.0	9	0	Final

 Yep, very active JJ, BN AS, very active ON.

[Wannabehippie]

oof. This is not a pretty picture for something to develop.Zero convection with that wave that just came off the coast, and has SAL mixed in with it.

[psv88]

This tropical season is a complete dud. Good for the insurance companies 

[GaWx]

1 hour ago, psv88 said:

This tropical season is a complete dud. Good for the insurance companies 

 Hopefully it ends up a complete dud! A dud is so overdue. Boring for tracking is a small price to pay for a safe season. But too early to know yet for sure, of course, as it takes only one and late seasons have gotten worse.
 
 Besides the good for insurers, it would obviously be even better for insureds that have suffered so much in recent years in the US and abroad like in 2024, 2022, and 2016-21.

 Euro Weeklies have been suggesting back to near the 20 year active avg starting ~9/22 and into mid Oct.

[NorthHillsWx]

Never count out October in the gulf but east coast is fighting climo into October for significant landfalls. Obviously there are exceptions 

[GaWx]

On 9/11/2025 at 11:42 PM, GaWx said:

 Like they’ve been showing almost every day for over a week and although they don’t get to above the active avg ACE like they showed 2 weeks ago, the Euro Weeklies still end the below avg ACE starting with the week that begins Sept 22nd. It rises to near the 20 year active avg then and that lasts for the 3 weeks going through Oct 12th. It still has the most active week of the next 4 to be 9/22-28 (with ~13.5 ACE) and the 2nd most active being 9/29-10/5. It’s projecting ~40 ACE 9/15-10/12. That would bring total ACE up to ~80. That would keep season to date ACE well below the active era’s avg of ~103 as of then.

Followup: Today’s EW for weeks 2-4 has significantly more ACE than that of the last 6 runs and is the most active for that 3 week period yet with AN/active each week. Whereas the run from 2 days ago had 40 ACE for 9/15-10/12, this new run has 8+16+13.5+10.5=48. It also shows increased risk to the SE US/Gulf 10/6-12.

[Chinook]

There's no storms except for Erin.

[NorthHillsWx]

Probably not tropical but the low off the Carolina coast could become quite strong when it moves ashore. Some guidance shows winds approaching 50 kts 

[GaWx]

For 60% orange in MDR

0Z UKMET: TS in middle of ocean again
NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 96 HOURS
FORECAST POSITION AT T+ 96 : 16.4N 45.5W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 17.09.2025 96 16.4N 45.5W 1005 41
0000UTC 18.09.2025 108 17.6N 47.7W 1005 45
1200UTC 18.09.2025 120 19.7N 49.9W 1006 44
0000UTC 19.09.2025 132 20.6N 51.6W 1006 40
1200UTC 19.09.2025 144 21.4N 53.0W 1005 36
0000UTC 20.09.2025 156 22.5N 53.5W 1004 46
1200UTC 20.09.2025 168 22.9N 55.4W 1002 45

[GaWx]

 Though boring for tracking, I think it’s absolutely fascinating what’s been going on this Sept so far. The last time Sept had no TC this far into the month was way back in 1992! It had its first Sep TC on Sep 17th. If 2025 doesn’t get a TD+ by Sep 17th (going to be close because of many models progging the current E MDR AEW to become a TD near or just after that day; also have to make sure the low off NC doesn’t do the same), then 2025 would have the latest 1st Sep TC since 1939’s Sep 23rd!

 Any predictions on whether either the current MDR AEW or the low off of NC will reach TD status by Sept 17th?

[MANDA]

35 minutes ago, GaWx said:

 Though boring for tracking, I think it’s absolutely fascinating what’s been going on this Sept so far. The last time Sept had no TC this far into the month was way back in 1992! It had its first Sep TC on Sep 17th. If 2025 doesn’t get a TD+ by Sep 17th (going to be close because of many models progging the current E MDR AEW to become a TD near or just after that day; also have to make sure the low off NC doesn’t do the same), then 2025 would have the latest 1st Sep TC since 1939’s Sep 23rd!

 Any predictions on whether either the current MDR AEW or the low off of NC will reach TD status by Sept 17th?

My hunch on low off NC is no but it is going to be interesting to watch it's track and see what it delivers to the Mid-Atlantic area in terms of rainfall and wind gusts.  As for the MDR region feature I'd say if it happens it will be after 9/17.  Things still look less than ideal for development in the MDR.  Slower development is the better hedge IMO.

[WEATHER53]

Just 10 days away 

[GaWx]

12Z runs regarding the MDR AOI:

--GFS/CMC/Icon all have this eventually as a H with GFS/CMC both recurving well E of Bermuda (Icon doesn’t go out far enough to tell)

-JMA has this as a TD at 48 and a TS at 72. This is stronger than the two prior 12Z runs that each had it as only a TD.

-Euro has a MH passing just SE of Bermuda

-UKMET again has this as a TS. This is a bit further W than recent runs but it’s still aiming a bit E of Bermuda as of 168:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 72 HOURS
FORECAST POSITION AT T+ 72 : 16.4N 47.4W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 17.09.2025 72 16.4N 47.4W 1006 40
0000UTC 18.09.2025 84 17.7N 48.8W 1006 42
1200UTC 18.09.2025 96 19.5N 52.1W 1006 44
0000UTC 19.09.2025 108 20.6N 54.3W 1006 40
1200UTC 19.09.2025 120 22.8N 55.1W 1006 44
0000UTC 20.09.2025 132 23.1N 57.0W 1005 43
1200UTC 20.09.2025 144 25.1N 57.7W 1003 46
0000UTC 21.09.2025 156 26.3N 58.6W 1001 49
1200UTC 21.09.2025 168 28.3N 59.3W 999 48

[WxWatcher007]

On 9/12/2025 at 6:55 AM, Seminole said:

Just some food for thought over the long haul. We have been in an AMO Active period since 1995. When you look at the history of AMO Active and Inactive periods those are historically 25 to 30 years long. Historically we are due to return to a AMO Inactive period and perhaps this is a transition year back to an AMO Inactive period.  

 

On 9/12/2025 at 4:35 PM, RaleighNC said:

Honest question - increasing SSTs would seem to make an AMO Inactive period more active than it otherwise would be, wouldn't it?

 

On 9/13/2025 at 11:30 AM, Seminole said:

It makes plausible sense. 

Maybe, but keep in mind that these large scale oscillations have a far reaching impact that go beyond SSTs. The atmospheric changes that provide cooling to the basin also impact things like steering patterns and shear. 

But with all that being equal, if you have large scale warming of the whole basin you'd still end up with what we've had going on this decade--stability issues across the basin and especially in the tropical Atlantic. You need contrasts between the MDR and subtropics to generate the instability necessary to keep waves convectively active.