GaWx

1. 0Z Euro has no TC from this. That weak low into CHS late is home-grown. 2. 6Z GFS is way OTS, even E of Bermuda. 3. 6Z Icon is much weaker at the Lesser Antilles at 120.

0Z: -The UKMET is again too weak with the low to classify it as a TD. -The 0Z CMC is similar to the GFS in being further S than its prior run and is close to the 0Z GFS as of 144.

The Gulf storm and the storm ahead of Invest 91L/likely future Gabby may end up being one and the same for all we know now.

For the record, today’s 12Z JMA moves much more quickly as it gets near Bermuda at 192! What’s up with that? This is actually consistent with yesterday’s 12Z JMA.

They’re ensemble members. They don’t depict them with names.

990s-950s/TS to cat 3

Yeah, ones in Gulf may very well be from MDR AEW ahead of 91L.

Check this out from the Happy Hour GEFS: I don’t think that any of these are from Invest 91L, but I’m not saying it’s drunk either. I think these are from a legit system ahead of 91L. Are they from the system between 45W and 50W?

The 12Z EPS has one member from 91L hit FL, another headed toward the Gulf, and a couple of others not far from hitting the NE US as they recurve. But overall, that’s still pretty quiet for CONUS. Interestingly, there’s more Conus hits from other systems, mainly homegrown stuff.

Hey Manda, Your posts are appreciated but please go here for discussion devoted to Invest 91L:

12Z: -Euro: has a TS in the MDR that later weakens to a weak low as it crosses the Lesser Antilles and then goes through Caribbean disorganized/very weak -UKMET: no TC again/low too weak to be classified a TD

RONI-ONI differences have been slowly dropping since late in 2024 and especially since FMA: 2024: JJA -0.54 JAS -0.52 ASO -0.54 SON -0.55 OND -0.55 NDJ -0.54 DJF -0.53 2025: JFM -0.51 FMA -0.49 MAM -0.43 AMJ -0.38 MJJ -0.32 JJA -0.29

This thread is for forecast discussions and speculation regarding the upcoming winter.

- I predicted 139 ACE in the contest before the season started. -There's still a long way to go based on it being La Niña and also considering that recent La Niña seasons have been more backended than in the past. -IF ACE ends up low, I’ll give you kudos. If not I hope you’ll be humble and admit you were wrong.

For the record, the 0Z Euro center stays just offshore S FL as it recurves to northward motion 100 miles offshore at 360. Of course, the 360 hour position on an operational has very little credibility. Only 3 of the 50 0Z EPS members come within 300 miles of S FL from this with none hitting there throughout the run. One out of 50 (2%) threatens to hit S FL from this system while still near Andros Island at 360. Another member develops from what looks like something else that’s moving NE from near S FL.

0Z: -Icon is a little SW of the 12Z with it at 18N, 55W at 180 moving WNW -The UKMET on again off again is now back to off with the low not strong enough to be classified a TD. -Early in the GFS run, it’s a little N of the 18Z position at 138 hours.

Looks like canonical Niña. I’m looking for JB to cool this down for his final outlook considering he tends to do that when it isn’t cold along the NE coast. Also, here’s some big hints within this that he will do just that: August 29, 2025 The threat of a cold winter looms. Plenty of blocking is expected over the Arctic. A prominent Alaskan ridge should lead to plenty of cold air. Another Thanksgiving to Christmas cold period is on the table, but this time it may not break. The heart of the winter looks coldest relative to average, but there are questions as to how it starts and ends.

Thank you, Don! One thing worthy of continued discussion I think is why it’s so persistently blazing hot in places like the NW Pacific. Why there and why so strong there? That seems strange to me. Any thoughts about that?

12Z UKMET: N of 0Z…aiming for just N of Leewards NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 96 HOURS FORECAST POSITION AT T+ 96 : 13.8N 43.4W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 07.09.2025 96 13.8N 43.4W 1012 25 0000UTC 08.09.2025 108 13.9N 46.1W 1011 28 1200UTC 08.09.2025 120 13.9N 48.8W 1010 28 0000UTC 09.09.2025 132 14.3N 51.3W 1009 31 1200UTC 09.09.2025 144 15.6N 53.6W 1010 32 0000UTC 10.09.2025 156 16.8N 56.0W 1010 32 1200UTC 10.09.2025 168 17.8N 58.6W 1010 34

I know of only the Gulf for near midmonth right now. I don’t know what Yaakov is referring to for a 2nd area as it’s paywalled.

I’m not aware of any other notable potential threat to the US as of yet. The MDR 30/70 has only a relatively small chance as of this very early period though that obviously could change later. That one could threaten the E Caribbean, too, though it’s still not a high threat as of now. Beyond that, who knows but a weak La Niña and recent late season activity means be extra wary for late Sept/first half of Oct.

Good point about the 0Z GEFS in the Gulf. I suspect that considering the model consensus, very warm Gulf, and yesterday’s progged MJO having phase 1 or 8 then on GEFS and EPS (I haven’t seen today’s yet) that that area will likely have a H or MH threat near midmonth.

Not surprisingly after a sudden uptick on yesterday’s 12Z EPS for the W Gulf late in week 2, the 0Z backed down notably, especially for TX threats although it still has a couple of W Gulf TCs with a 955 into LA and a 990 mb into MX. The 12Z had had ~8 TS+ including a 927 into LA, 968 into TX, and 961 into MX along with 3 hurricanes threatening at the end still in the Gulf.

0Z UKMET: This run is back to a TD. Once formed, it remains the same strength. It is significantly further S than the prior run with a TD (24 hrs ago). At 168, it’s on a trajectory toward the Leewards only 150 miles away: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 132 HOURS FORECAST POSITION AT T+132 : 13.3N 51.7W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 08.09.2025 132 13.3N 51.7W 1011 27 0000UTC 09.09.2025 144 14.1N 54.6W 1010 29 1200UTC 09.09.2025 156 15.0N 57.4W 1011 31 0000UTC 10.09.2025 168 16.0N 59.5W 1010 31