2025 Global Model Runs Discussion (Out thru day 16)

[Fancy1002]

I know it doesn’t go far enough to tell, but it looks like the icon is joining the party with leaning into a central or west Caribbean development. Let’s see if the cmc follows suit.

[cycloneye]

A good 3 part thread to read.

 https://x.com/yconsor/status/1977747426736754770



 https://x.com/yconsor/status/1977748146651283802



 https://x.com/yconsor/status/1977748292185276874

[mrbagyo]

Could this be the one?

[zzzh]

Some AI ensemble members show development in the central/western Caribbean. Zero show development in the MDR.

[LarryWx]

Still a good ensemble signal in the west Carib from the GFS and Canadian at the end of their runs. However the GFS and to a lesser extent the Canadian has consistently shown a signal there often all season long so I dont think its anything to worry about for now.

The wave the models show possibly developing and heading towards PR is something we may need to keep an eye on...interesting enough the ICON has been the southern outlier...it will be interesting to see what it does when its forecast range takes it it PR's longitude.

Along with Happy Hour Icon, the Happy Hour GFS, like the 12Z, 0Z, and 5 runs before, has this. It hits Virgin Islands with a cat 1 H 10/22-3.

Edit: I just looked at 12Z UKMET maps. Although the text already told me there was no TC from this, the H5 vorticity and precip maps are closer to a TCG than prior runs. If this trend continues, the often genesis shy UKMET may have an actual TCG from this within the next run or two.

Sure enough, the 0Z UKMET has this as a TD going just N of due W at a rather brisk pace through the middle of the Lesser Antilles on Sunday (10/19): keep in mind that this is a top tier model that is sometimes genesis shy

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 150 HOURS
FORECAST POSITION AT T+150 : 13.5N 57.7W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 19.10.2025 156 13.8N 59.5W 1010 32
0000UTC 20.10.2025 168 14.1N 62.8W 1009 34

Also, the Icon (0Z) has it yet again.

Consistent with the 0Z, the 12Z UKMET has the followup MDR system moving WNW through the central Lesser Antilles on 10/19 and then into the far E Caribbean:


NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 138 HOURS
FORECAST POSITION AT T+138 : 13.9N 57.2W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 19.10.2025 144 14.2N 59.0W 1010 33
0000UTC 20.10.2025 156 14.6N 61.9W 1010 34
1200UTC 20.10.2025 168 15.1N 64.9W 1009 35

[Fancy1002]

Am I seeing it wrong, or does it look like Lorenzo hanging around on the GFS, is splitting the Bermuda high from the east coast high enough to give future Melissa a path to head north in the central Caribbean rather than being pushed into the western Caribbean. Any more west and Miami might be in trouble.

[Fancy1002]

It seems the cmc is just determined to stick with this odd timing scenario.

[zzzh]

Am I seeing it wrong, or does it look like Lorenzo hanging around on the GFS, is splitting the Bermuda high from the east coast high enough to give future Melissa a path to head north in the central Caribbean rather than being pushed into the western Caribbean.

Lorenzo is tiny, it doesn't have significant impact on steering. The main reason is the east coast trough that pulls it north

[Fancy1002]

This GFS run is looking a bit ominous so far.

[Fancy1002]

Am I seeing it wrong, or does it look like Lorenzo hanging around on the GFS, is splitting the Bermuda high from the east coast high enough to give future Melissa a path to head north in the central Caribbean rather than being pushed into the western Caribbean.

Lorenzo is tiny, it doesn't have significant impact on steering. The main reason is the east coast trough that pulls it north

To my knowledge, it’s not about the size of the storm, it’s about a low pressure system interrupting the connection between two high-pressure systems.

[Fancy1002]

Looks like a strong four or a weak five ramming into west Central Cuba, also a good amount west of the 06 run. Let’s see if that’s a continuing trend later today.

[Fancy1002]

If anyone has access to it, could you post IR picture at the 324 hour mark

[SouthFLTropics]

Today's 18z Happy Hour GFS may possibly be one of the most anticipated of the year so far based on the last two runs. You know the board will light up when it shows a major strike on South Florida, even if it is two weeks into fantasyland.

[boca]

Today's 18z Happy Hour GFS may possibly be one of the most anticipated of the year so far based on the last two runs. You know the board will light up when it shows a major strike on South Florida, even if it is two weeks into fantasyland.

I think we had one or possibly two fantasy mode cane strikes this year far below the normal model cane strikes from last years.

[caneseddy]

12z Euro drops it on this run...doesnt even start to develop into a tropical entity until its right on the coast with Nicaragua and then sends it to the Pacific where it starts developing.

12 CMC sends a hurricane north of the islands and out to sea like every storm this year

[Fancy1002]

Half of the GFS ensemble members develop near or before the lesser Islands and head north, while the others don’t develop until they get to the Western Caribbean and then explode heading in a bunch of random directions

[Teban54]

Posting the 12z GFS run that people had mentioned above: