2025 Global Model Runs Discussion (Out thru day 16)

[Cpv17]

18z Happy Hour GFS turns this wave behind Erin into a Cat 3 strike on the Lesser Antilles and Puerto Rico.

Pretty significant uptick in activity on the 18z GEFS as well. Quite a few members get into the Gulf.

[LAF92]

18z Happy Hour GFS turns this wave behind Erin into a Cat 3 strike on the Lesser Antilles and Puerto Rico.

Pretty significant uptick in activity on the 18z GEFS as well. Quite a few members get into the Gulf.

18z Euro AI gets that wave into the Gulf

[Teban54]

18z GFS ensembles seem to show two potential systems. I can't tell if some members are doing a merger off the two waves, or if there are three distinct waves showing up across the members. Regardless, the potential for land impact (not limited to US) seems much higher than with Erin.

[LarryWx]

0Z UKMET, which goes out to 168, has no followup TC to Erin unlike the prior runs.

[Woofde]

6z GFS showing some love for the wave about to leave Africa. It develops two MDR systems following Erin.

[WeatherBoy2000]

6z GFS showing some love for the wave about to leave Africa. It develops two MDR systems following Erin.https://uploads.tapatalk-cdn.com/20250815/90cdd1866bf856a69bc018db14a6ea40.jpg

The euro also has it, but the gfs and its ensembles are comparatively much more bullish atm.

[BobHarlem]

The 6z Operational GFS hits Daytona with a Cat 3 on the anniversary of Katrina, but the Euro just keeps it weak or undeveloped (still close to Central Florida though) around August 26-29th.

[AutoPenalti]

GFS Ensembles drop this further south or they just no longer develop it.

[LarryWx]

GFS Ensembles drop this further south or they just no longer develop it.

I’m seeing the 6Z GEFS differently. It looks unsettlingly pretty active to me in/near the SE/Gulf coast of the US during Aug 26-30.

-During this active period, GEFS has the MJO in/near phase 5. It’s not either of the 2 most active phases for H hits per day during Jul-Sep since 1975 (phases 2 and 8), but phase 5 has had the 3rd highest ratio of hits/day.

- During phase 5, these 10 Hs hit the Conus: Francine (2024), Ike (2008), Humberto (2007), Ophelia (2005), Isabel (2003), Bertha (1996), Fran (1996), Bob (1991), Elena (1985), and Babe (1977). Two areas were most impacted by these 10: NC (Ophelia, Isabel, Bertha, Fran, and Bob) and upper TX to FL panhandle (Francine, Ike, Humberto, Elena, and Babe).

[LAF92]

GFS Ensembles drop this further south or they just no longer develop it.

I’m seeing the 6Z GEFS differently. It looks unsettlingly pretty active to me in/near the SE/Gulf coast of the US during Aug 26-30.

-During this active period, GEFS has the MJO in/near phase 5. It’s not either of the 2 most active phases for H hits per day during Jul-Sep since 1975 (phases 2 and 8), but phase 5 has had the 3rd highest ratio of hits/day.

- During phase 5, these 10 Hs hit the Conus: Francine (2024), Ike (2008), Humberto (2007), Ophelia (2005), Isabel (2003), Bertha (1996), Fran (1996), Bob (1991), Elena (1985), and Babe (1977). Two areas were most impacted by these 10: NC (Ophelia, Isabel, Bertha, Fran, and Bob) and upper TX to FL panhandle (Francine, Ike, Humberto, Elena, and Babe).

https://x.com/hurricaneaddict/status/19 ... 5AKya8Pkyw
Matthew Gross gives a good explanation on what effects Erin could have on the future systems that follow

[cycloneye]

12z GFS has wave behind Erin developing and moves thru the NE Caribbean islands including Puerto Rico. This is below 10 days.

[LAF92]

12z GFS has wave behind Erin developing and moves thru the NE Caribbean islands including Puerto Rico. This is below 10 days.

https://i.imgur.com/UGw2128.gif

Day 9 approaching Cuba at 963mb

[Stratton23]

Day 10 moving into the gulf on the GFS as a major hurricane, misses the trough to its north as it moves out of the US, looks like trouble on this run lol

[LarryWx]

0Z UKMET, which goes out to 168, has no followup TC to Erin unlike the prior runs.

Unlike the 0Z, the 12Z UKMET is back with a followup AEW to Erin becoming a TD at 162 and nearly to a TS at 168 just N of the Virgin Islands moving WNW. This looks like the same AEW that Luis showed developing on the 12Z GFS but is ~500 miles further WNW than the GFS at 168, which is then only near 16N, 58W:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 162 HOURS
FORECAST POSITION AT T+162 : 18.9N 62.8W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 22.08.2025 168 19.4N 64.7W 1005 33

[BobHarlem]

post Erin wave run into the gulf

[eastcoastFL]

The system behind Erin in the GFS looks kinda scary. Looked like a fairly significant hurricane slamming into the treasure coast

[eastcoastFL]

post Erin wave run into the gulf
https://i.postimg.cc/KYjjZpCL/gfs-mslp-wind-watl-fh150-270.gif

Looks like I'm a run behind.

[Stratton23]

My concern is that soon to be major hurricane Erin actually might help to strengthen the bermuda high once it exits the atlantic, that is what is seen on the GFS, US got lucky with a recurve pattern with Erin, may not be as fortunate if that bermuda high does indeed strengthen again

[BobHarlem]

This GFS run better not do what I think it's about to do. (check date 20 years ago)

[Pelicane]

The ICON seemed to like the wave behind it more.