NATL: IMELDA - Models

[BobHarlem]

12z canadian still running, but it's backed off landfall monday night and gets more sucked up into Humberto. GFS gets 94l into the Gulf after the SC landfall at 168 hours.

[Powellrm]

What a unique set up the ICON is suggesting. As someone said, that would be a nightmare scenario for Bermuda. ICON seems like it’s on its own with this scenario, and seemingly sticking to it. I wonder what it’s picking up on that others may not be factoring in as much.

[BobHarlem]

12z Canadian out to 144 hours

[Teban54]

12z canadian still running, but it's backed off landfall monday night and gets more sucked up into Humberto. GFS gets 94l into the Gulf after the SC landfall at 168 hours.
https://i.imgur.com/H7OjrbB.png

This is actually more in line with yesterday's 12z CMC and prior runs (with the only different being a complete merger of the two storms, unique on this run). For CMC, the SC landfall at 0z today was an anomaly.

[Kingarabian]

24 hour trend seems to be a SECONUS landfall. OTS still is a good option as well. Difficult forecast for the NHC since models are showing potential landfall in less than 5 days.

[aspen]

12z Canadian out to 144 hours
https://i.postimg.cc/PqCBKW6z/floop-gdps-2025092512-sfcwind-mslp-atl.gif

Top 5 Canadian model run right there with Humberto devouring 94L.

[GCANE]

I have seen maybe a couple TCs interact close enough where there is some discernable Fujiwhara effect; but never to the extent that ICON and CMC is showing.
I have a hard time swallowing this.

[Kingarabian]

Assuming ensemble runs will continue to be all over the place.

[Zonacane]

I think it would be beneficial if we focused on what we do know based on the complexity of this forecast.
1. This storm is going to move north into the Bahamas
2. Conditions are going to be favorable for significant intensification in the Bahamas. The exact amount is uncertain, but I would wager a high end major hurricane is possible.

Everything after that looks like a clusterf***

[GCANE]

So, GFS is forecasting a huge slot of dry air south of 94L when in the Bahamas.
https://www.tropicaltidbits.com/analysi ... atl_16.png

If 94L does a Fuji loop then, it will be creamed by that dry air.
ICON and CMC are not taking this into account.
I am sticking with GFS.

[Zonacane]

So, GFS is forecasting a huge slot of dry air south of 94L when in the Bahamas.
https://www.tropicaltidbits.com/analysi ... atl_16.png

If 94L does a Fuji loop then, it will be creamed by that dry air.
ICON and CMC are not taking this into account.
I am sticking with GFS.

Is the GFS projecting SW shear?

[GCANE]

So, GFS is forecasting a huge slot of dry air south of 94L when in the Bahamas.
https://www.tropicaltidbits.com/analysi ... atl_16.png

If 94L does a Fuji loop then, it will be creamed by that dry air.
ICON and CMC are not taking this into account.
I am sticking with GFS.

Is the GFS projecting SW shear?

Basically no directional shear.

[tolakram]

GFS has this forming in 24 hours where the circulation comes together at the lower right of this sat view.

https://weather.cod.edu/satrad/?parms=s ... =undefined

[LarryWx]

12Z UKMET: At hour 120, 993 mb Humberto, which is within only 500 miles ENE of 1000 mb 94L, causes 94L (which had been moving mainly NNW) to then get sucked toward it as 94L then suddenly turns SSE, then ESE, and then ENE to well OTS (near 27N, 72W)

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 54 HOURS
FORECAST POSITION AT T+ 54 : 21.1N 76.5W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
0000UTC 28.09.2025 60 22.2N 76.2W 1006 31
1200UTC 28.09.2025 72 23.5N 76.9W 1006 32
0000UTC 29.09.2025 84 24.1N 77.4W 1004 33
1200UTC 29.09.2025 96 25.9N 78.3W 1004 39
0000UTC 30.09.2025 108 25.8N 77.8W 1002 38
1200UTC 30.09.2025 120 26.4N 78.1W 1000 37
0000UTC 01.10.2025 132 25.4N 77.6W 999 37
1200UTC 01.10.2025 144 25.0N 76.5W 997 43
0000UTC 02.10.2025 156 25.4N 74.8W 995 46
1200UTC 02.10.2025 168 26.9N 72.2W 991 47

——————
So far at 12Z for major operationals

-GFS hits just S of Georgetown, SC, Mon PM (9/29) as a H (with strong support from GEFS, it’s most ominous run by far yet for SE US)
-Icon, UKMET, CMC thanks to Fujiwhara go safely OTS from SE US
-Euro next
-JMA only out to 72 so far (can’t tell yet)

[TomballEd]

I have seen maybe a couple TCs interact close enough where there is some discernable Fujiwhara effect; but never to the extent that ICON and CMC is showing.
I have a hard time swallowing this.

IIRC, a K storm absorbed an I or J storm early 2000s

[LarryWx]

12Z Euro landfalls just SW of NC/SC border near Myrtle Beach.

[TomballEd]

There is some uncertainty, in my mind, whether 94L develops closer to the deep convection, to say the models may have trouble until a well defined center develops.

[tolakram]

[tolakram]

[tolakram]

The AI version still has a stall then east, then west, and then east.