GaWx

Other 12Z: Icon goes OTS again JMA hints at OTS but not sure since only to 72 UKMET goes OTS again like the Icon although it goes further NW than prior runs before going OTS NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 42 HOURS FORECAST POSITION AT T+ 42 : 23.3N 76.7W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 28.09.2025 48 24.2N 76.7W 1007 33 0000UTC 29.09.2025 60 25.2N 77.4W 1004 34 1200UTC 29.09.2025 72 26.7N 77.8W 1003 38 0000UTC 30.09.2025 84 28.2N 77.6W 1001 36 1200UTC 30.09.2025 96 28.9N 78.5W 996 42 0000UTC 01.10.2025 108 28.7N 77.8W 994 40 1200UTC 01.10.2025 120 28.5N 76.6W 992 38 0000UTC 02.10.2025 132 28.7N 74.3W 991 46 1200UTC 02.10.2025 144 28.9N 72.2W 991 54 0000UTC 03.10.2025 156 28.7N 69.6W 992 63 1200UTC 03.10.2025 168 28.6N 68.4W 995 52

Hopefully Humberto overachieving increases the chance that 94L will be more influenced by it in a way that helps the SE US.

0Z EPS: 29 of 50 hit SE US with ~10-11 as hurricanes Night night!

0Z GEFS: 14 of 30 members with SE US landfall with one of those 14 a hurricane

0Z Euro stalls for 48 hours just offshore SC/GA before turning back WNW into Beaufort, SC and not til Thu night!

0Z Euro much different vs prior Euros

0Z: So far, similar to 12Z with GFS hitting Myrtle Beach while Icon, CMC, and UKMET again all Fujiwara 94L safely OTS JMA only goes out to 72 at 0Z…so, can’t tell much Euro is next —————- 0Z UKMET: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 48 HOURS FORECAST POSITION AT T+ 48 : 22.5N 76.7W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 28.09.2025 48 22.5N 76.7W 1004 39 1200UTC 28.09.2025 60 24.8N 76.1W 1003 41 0000UTC 29.09.2025 72 25.6N 76.6W 1000 42 1200UTC 29.09.2025 84 26.5N 77.1W 999 40 0000UTC 30.09.2025 96 27.3N 77.3W 997 43 1200UTC 30.09.2025 108 27.3N 77.3W 995 43 0000UTC 01.10.2025 120 27.1N 75.4W 992 44 1200UTC 01.10.2025 132 27.3N 73.5W 989 44 0000UTC 02.10.2025 144 28.8N 70.0W 984 52 1200UTC 02.10.2025 156 30.8N 65.1W 979 69 0000UTC 03.10.2025 168 34.6N 57.8W 972 76

The chances of this being a cat 4 H are very low as of now even with favorable MJO phase 2 being forecasted. The bigger risk as it appears now is the catastrophic flooding risk from a very slow moving storm, even if it were to landfall as just a TS. TS Chantal caused major flooding from record 24 hour rainfall in parts of NC.

Per WxBell (may be different from others like TT): -Of the 18Z 30 GEFS/50 EPS members, I count ~25% that bring a lowest SLP of <1000 mb onto the E coast, but I see no lowest SLP <990 mb on the GEFS on land. -There do appear to be 7 EPS members that are hurricanes/<990 mb hitting.

That’s what I meant when I mentioned those scenarios. It appears the best chance for a Fujiwara to do that is for Humberto to be at a higher latitude than 94L. This is based on viewing 100s of ensemble members from different runs along with operationals.

The best bet for the SE to avoid a hit and the potential flooding catastrophe would be if 94L were to move away from there more slowly than the model consensus and let Humberto get to a higher latitude than it. Also, the same would probably be the case if Humberto were to move more quickly. Then hopefully Humberto would pull 94L away.

In case you missed it and are interested in the AmericanWx Ryder Cup contest (four are in it so far), here’s the link (deadline 7AM tomorrow):

18Z Euro: hits near NC/SC border:

Thanks for posting. This NY Post headline is so misleading. If the Fujiwhara Effect is strong enough, that would actually be the best way for the SE to avoid a landfall. Thus, I hope Fujiwhara is strong. The stronger combined storm on those models/ensemble members doing that avoids the US in the vast majority of cases. The NY Post is not a good source for news, regardless. It borders on tabloid.

The MJO for 9/27 through 10/3 or 10/4 is again being forecasted by GEFS and EPS to be in phase 2, which is about tied for the most dangerous phase along with 8 for Conus H landfalls and by a large margin has been the most dangerous for Conus MH landfalls (inside or outside the circle). MH Conus landfalls since 1974 during phase 2 -Ida (2021) -Michael (2018) -Irma (2017) -Harvey (2017) -Ivan (2004) -Bret (1999) -Emily (1993) -Hugo (1989) -Frederic (1979) -Eloise (1975) -Carmen (1974) That’s 11 of 29 (38%) of all Conus MH hits since 1974 just during phase 2. These were all during Jul-Oct. During Jul-Oct 1974-2024, 16% of days were in phase 2. So, even after taking into account the fact that the # of days in phase 2 has been about the largest of any one phase along with phase 1, the 38% of all MH hits is still very high. If phase 2 were instead a neutral influence, one would expect the # of MH hits during phase 2 to be only ~3-5. GEFS EPS

But wouldn’t a further W track of Humberto mean a slower latitude gain, which would then mean a higher chance for 94L to get N of Humberto’s latitude and would thus reduce the chance for 94L to get pulled OTS by Humberto? I hope not but am wondering.

The 12Z EPS, while still scary for the SE US with ~60% hitting and ~50%+ of those hitting being strong TS+, isn’t quite as ominous as the 0Z, which had ~75% hitting the SE. About 40% of members are strongly affected by Fujiwhara with Humberto.

Based on the 12Z ops and individual GEFS/GEPS members, the best bet for the SE US to not get hit thanks to Fujiwhara is for 94L to not be moving too fast and thus never get N of Humberto’s latitude. Helping also would be for it to be significantly weaker than Humberto.

12Z Euro

Also, the UKMET, one of the top tier models, interacts with Humberto and goes well OTS from the SE US per my post above this.

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 HOURSFORECAST POSITION AT T+ 54 : 21.1N 76.5WLEAD CENTRAL MAXIMUM WINDVERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)-------------- ---- -------- ------------- -------------0000UTC 28.09.2025 60 22.2N 76.2W 1006 311200UTC 28.09.2025 72 23.5N 76.9W 1006 320000UTC 29.09.2025 84 24.1N 77.4W 1004 331200UTC 29.09.2025 96 25.9N 78.3W 1004 390000UTC 30.09.2025 108 25.8N 77.8W 1002 381200UTC 30.09.2025 120 26.4N 78.1W 1000 370000UTC 01.10.2025 132 25.4N 77.6W 999 371200UTC 01.10.2025 144 25.0N 76.5W 997 430000UTC 02.10.2025 156 25.4N 74.8W 995 461200UTC 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): edit now out to 192: thanks to Fujiwara, no US landfall as the 2 storms combine

Tropical Weather Outlook NWS National Hurricane Center Miami FL 200 AM EDT Thu Sep 25 2025 Eastern Caribbean Sea (AL94): A tropical wave centered near the Dominican Republic continues to produces widespread disorganized showers and thunderstorms. The wave is expected to move west-northwestward around 10 to 15 mph, spreading heavy rainfall and gusty winds across Puerto Rico and the Dominican Republic through today. The system is then expected to slow down and turn northwestward when it reaches the southwestern Atlantic. A tropical depression is likely to form when the disturbance is in the vicinity of the Bahamas late this week. Interests in Puerto Rico, the Dominican Republic, Haiti, the Turks and Caicos Islands, and the Bahamas should monitor the progress of this system. * Formation chance through 48 hours...medium...50 percent. * Formation chance through 7 days...high...80 percent. Forecaster Bucci

The 0Z EPS is by far the most ominous for the SE US (including some that get into the Gulf) with a whopping ~75% of the members hitting or skimming. Some of these are very weak (not full TCs) while ~1/3 of the hits are strong.

0Z Euro, just like the 0Z CMC, hits Georgetown, SC, on Monday evening (probably because it was further N than Humberto) though it isn’t as strong as the CMC (989 mb per WxBell): So, of major 0Z ops, Euro and CMC hit Georgetown while UKMET, GFS, and Icon stay well offshore.

But the 0Z GFS has 94L no stronger than the high 980s while it has Humberto ~25 mb stronger (~963 mb). Were you aware of that? So, considering that, wouldn’t it make sense for Humberto to dominate?