GaWx

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?

0Z GEFS: the most threatening run yet to the SE US (even more than 18Z):

1. 0Z CMC Georgetown, SC hit with 975 mb H as not as strong Humberto (983 mb) doesn’t dominate: 2. 0Z GFS is safely OTS with Fujiwara from Humberto.

0Z UKMET: TD forms Mon night NW Bahamas, initially then drifts slowly NW followed by a stall and dissipation as the much stronger Humberto only ~500 miles east takes over: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 102 HOURS FORECAST POSITION AT T+102 : 25.0N 77.5W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 29.09.2025 108 25.9N 78.2W 1008 27 0000UTC 30.09.2025 120 26.1N 78.3W 1007 23 1200UTC 30.09.2025 132 26.1N 78.1W 1007 20 0000UTC 01.10.2025 144 CEASED TRACKING

0Z Icon: Humberto pulls 94L ESE to keep it safely away:

Big news from Australia’s BoM: their model progs have just switched from 3.4 to relative 3.4 (akin to RONI)! Relative Niño indices Traditional Niño index values were used at the Bureau of Meteorology until September 2025. From September 2025, the Bureau uses Relative Niño indices, which measure sea surface temperature anomalies in the tropical Pacific Ocean in the Niño regions, but calculated relative to the global tropical region temperature anomaly. This is to relate the indices more closely to the localised processes associated with ENSO, rather than larger-scale tropical SST features such as global warming. Example: The Relative Niño3.4 index calculation: Relative Niño3.4 = S x [(Niño3.4obs – Niño3.4clim) – (Tropical Meanobs – Tropical Meanclim)] Here’s the latest BoM relative 3.4 model prog for Relative 3.4, which has a low of -0.7C for OND: http://www.bom.gov.au/climate/ocean/outlooks/index.shtml?index=nino34#region=NINO34 @snowman19

Update: -Season’s ACE is now up to 57.2. -Gabrielle has exceeded earlier progs and is now on its own progged to get ACE to ~60. -Humberto has been declared and is progged to add ACE of ~13 through Sept 30th though with lots of uncertainty, including upside to ~17-20. -That would get ACE to ~73-80. -But that’s not necessarily all as models are now significantly more bullish on still another TC by late this week from Invest 94L. A great level of uncertainty rests with 94L at this very early stage. The upside limit on that through Sept 30 is ~~10. -So, current rough projections are significantly higher for ACE as of Sept 30th. In my quoted prog from 3 days ago, I had the upside at 65-70. That upside limit has since risen to ~83-90. That compares to the 1991-2020 average of 94 through Sept. 30. Thus, if this upside range of 83-90 were to verify, Sept 30th ACE could rise all the way to only a little below the active 30 year average! -Oct-Dec 30 year avg is 28. So, if we were to get to 90 as of Sept 30th, getting to an end of season well over 100 would then be favored along with a reasonable upside of ~130-140 vs 1991-2020 avg of 122. That upside potential is extra realistic because of 1. mainly favorable MJO progged for next few weeks 2. weak La Niña on RONI basis is correlated most to above avg ACE late season 3. Euro Weeklies are active @snowman19@PhiEaglesfan712

Tropical Weather Outlook NWS National Hurricane Center Miami FL 800 PM EDT Wed Sep 24 2025 For the North Atlantic...Caribbean Sea and the Gulf of America: Eastern Caribbean Sea (AL94): Showers and thunderstorms have become better organized since yesterday in association with a tropical wave centered near Puerto Rico. This 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 early tomorrow. 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, the Turks and Caicos Islands, and the Bahamas should monitor the progress of this system. * Formation chance through 48 hours...medium...40 percent. * Formation chance through 7 days...high...80 percent. Public Advisories on Humberto are issued under WMO header WTNT33 KNHC and under AWIPS header MIATCPAT3. Forecast/Advisories on Humberto are issued under WMO header WTNT23 KNHC and under AWIPS header MIATCMAT3. Forecaster Blake

I recommend folks who are curious follow the Invest 94L thread. If 94L isn’t pulled toward Humberto (via Fujiwhara), portions of the SE US may be in danger of a hit from 94L per the 12Z EPS, 18Z Icon, and others. In addition, the MJO is forecasted to be in phase 2 9/27-10/3. That has been the single most dangerous phase for the Conus overall since 1975 during Jul-Sept overall.

Example: 18Z Icon: no Fujiwhara and 94L gets stuck under the strengthening US Great Lakes ridge and subsequently turns NW toward C FL: Edit: And the GEFS/EPS are forecasting this to be during the potentially dangerous phase 2.