Potential Tropical Cyclone Nine and Hurricane Humberto

[Blountwolf]

Morning look - Humberto opens an eye, and 94L remains a disorganized mess in Haiti.

 

[Blountwolf]

0Z ECMWF overnight was a bit of a nightmare scenario - Imelda reaches the coast coming very close to landfall, Humberto's influence catches her, stalls forward motion and pulls her eye away from the coast, then loses her, Imelda strengthens and makes a landfall. Kept the huge rain totals close to coast, but dropped 30+ inches there.


06Z ECMWF running now. Looks like a VERY Humberto-dominant run. 94L is faster paralleling the FL coast, struggles to consolidate until right before landfall, but then stays together longer as Humberto is further behind and doesn't catch up as soon. Spins out over the mountains. Similar to 06Z GFS.


06Z GFS is a SC hit, and stalling in the mountains and dropping 9 inches.


The more runs I see like this, the less I like what I am seeing. I fear the effects in the mountains are going to be bad again.

 

[Blountwolf]

I note with interest the NAM is spitting out a scenario with Imelda much closer to the Florida coast. Something to keep an eye on.



HRRR now in range at the end of its run.

 

[Clancy]

Well, 94L is definitely locked into impacting somewhere along the Atlantic Bight. Biggest questions are how strong it gets and what happens after landfall. Latest HAFS has it stalling out over Georgia.

 

[Atlantic]

Ummmm

(At 5 am EST (my time), the core was fully built yet. Now at 10 am EST my time the eye appears to rapidly trying to clear out)

5 am this morning (about the time I woke up)



Now

 

[Blountwolf]

Well, 94L is definitely locked into impacting somewhere along the Atlantic Bight. Biggest questions are how strong it gets and what happens after landfall. Latest HAFS has it stalling out over Georgia.

HAFS is a lot further south than the globals - closer to Savannah for landfall. Interesting.

 

[Blountwolf]

Ummmm

(At 5 am EST (my time), the core was fully built yet. Now at 10 am EST my time the eye appears to rapidly trying to clear out)

5 am this morning (about the time I woke up)

Now

One gets the feeling Humberto is about to overperform predictions. Maybe it will absorb 94L as it does.

 

[slenker]

One gets the feeling Humberto is about to overperform predictions. Maybe it will absorb 94L as it does.

Hopefully, if this occurs, it minimizes impacts from moisture in the mountains. The last thing that region needs is a Helene repeat.

 

[N0mz]

Humberto cleared out an eye extremely quickly

 

[Blountwolf]

Hopefully, if this occurs, it minimizes impacts from moisture in the mountains. The last thing that region needs is a Helene repeat.

I really don't like saying this, but I am really concerned we're going to see exactly that - the stalling over N/GA scenario is nasty - it will pull Atlantic moisture into the mountains and orographic lift will squeeze it out.

 

[Blountwolf]

12Z NAM is a completely new scenario - different fujiwhara idea - 94L doesn't consolidate until well west, but then gets pulled sharply to the NE by a very strong Humberto.




This one tells an interesting story - the longer it takes for 94L to consolidate and move north, the more chance that Humberto is northeast of Imelda when it happens. That really changes a lot about the forecast if it is. NAM picks up on the fact that the two storms would rotate around each other counterclockwise. Not enough range on NAM to see much more than it beginning, but the end result would be totally different - and might mean both miss the coast entirely. Could also mean Humberto rotating west if Imelda strengthens a lot, but hopefully not anywhere near enough to reach the coast itself.

 

[Blountwolf]

12ZGFS is another SC hit with Imelda north west of Humberto, dumps 13+in in SC and hangs around SC/NGA again.

 

[TornadoFan]

 

[Blountwolf]

Thought some might find this handy:

Global Model Release Times (Central Time)

GFS | Init: 00/06/12/18 UTC | Delay: ~4–6 hrs
00Z → 6–8 PM CT
06Z → 12–2 AM CT
12Z → 6–8 AM CT
18Z → 12–2 PM CT

ECMWF | Init: 00/06/12/18 UTC | Delay: ~8–10 hrs
00Z → 6:30–7:30 PM CT
06Z → 12:30–1:30 AM CT
12Z → 6:30–7:30 AM CT
18Z → 12:30–1:30 PM CT

UKMET | Init: 00/12 UTC | Delay: ~6–8 hrs
00Z → 6–8 PM CT
12Z → 6–8 AM CT

CMC / GEM | Init: 00/12 (+06/18) UTC | Delay: ~6–8 hrs
00Z → 6–8 PM CT
12Z → 6–8 AM CT


Hurricane / Tropical Cyclone Models

HWRF | Init: 00/06/12/18 UTC | Delay: ~6–8 hrs
00Z → 6:30–8:30 PM CT
06Z → 12:30–2:30 AM CT
12Z → 6:30–8:30 AM CT
18Z → 12:30–2:30 PM CT

HAFS / HFAS | Init: 00/06/12/18 UTC | Delay: ~6–8 hrs
Similar to HWRF timing

HMON / GFDL | Init: 00/06/12/18 UTC | Delay: ~6–8 hrs
Similar to HWRF timing

 

[Blountwolf]

Ugh. 12ZHAFS solution is now to stall Imelda off Savannah and basically leaves her there. Another completely new scenario. Gotta love fujiwhara.

12ZHWRF landfalls in NW SC, then loops it counterclockwise through NC and reemerges it (greatly weakened) into the Atlantic about where it went in.

 

[Blountwolf]

18ZGEM-GDPS is really fascinating - models a scenario where I rolls up, parks off Savannah, gets pulled east out to sea 100 miles or so by Humberto, then Humberto "loses it's pull" on Imelda and Imelda then reverses direction and makes landfall in SW NC... at 180 hours out. Canada's model isn't as high res as the HWRF or HAFS, but in this case I think seeing as a possibility all the outlier potential scenarios is the best call, because frankly - this is weird.

 

[TornadoFan]

[td]

Special Message from NHC ​

[/td]​

[td]

Fri, 26 Sep 2025 20:16:06 +0000 ​

[/td]​

NHC will initiate advisories on Potential Tropical Cyclone Nine (formerly AL94), located near eastern Cuba, at 500 PM EDT (2100 UTC).​

 

[Atlantic]

Potential Tropical Cyclone time!

 

[TornadoFan]

Humberto has been upgraded to a Cat 3 with maximum sustained winds of 115 MPH

 

[Atlantic]

Major Hurricane Humberto is now forecast to peak at 130 kts (150 mph) according to the NHC, and I won’t be surprised if Humberto manages to become a Category 5 and outperform the forecast as it has continued to do.