GaWx

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

@BarryStantonGBPsignal for Gulf activity midmonth is there. We’ll see is all I can say now.

Again, I’m not posting this because I’m trying to push it. Rather, I just want others to be aware of what WxBell, which has a large # of subs and thus a lot of visibility, is pushing via JB and to try to generate discussion: Looks Like Dr Viterito and I are Getting under someones skin This is an example of the kind of propaganda that was once reserved for other matters, but since a group of people now considers climate to be that kind of matter, they will do the same thing. The strategy, of course, is to say something that does have truth, but then do not fill in the entire picture. Naturally, the graphic attacks volcanoes and solar, both known for natural variability in the climate. But consider this. The cumulative buildup of heat in the ocean from increased solar and ( humor me here) some of the ideas on geothermal explain pretty nicely the buildup over the years of ocean heat. The sudden increase that Tonga and the el nino represented certainly added to it. You can't explain the jump from man-made causes, nor the significant drop that has started, so natural causes certainly explain much of the buildup But here is how the propaganda works. The pusher of the missive does not show the drop in 2025. ( Another favorite idea is to scream about Greenland falling into the sea when there happens to be a season where there is more than normal melt, but ignoring all the other years that have been occurring that have more than average snow and ice) Nor does the pusher fail to mention the drop off in MOSZA, and the drop in temperature seems to have some link. Nor can the pusher explain the record warmth in the north Pacific, the cooling in the NW Atlantic that is leading to the greatest difference at 40 north between the Pacific warmth and the NW Atlantic cooling on record. Gee, I wonder what could be causing the warmth where it is in the Pacific basin. must be a coincidence Or is there a magic CO2 fairy that bestows warmth where it so desires? BTW, the drop off in input in the Atlantic, though still warm, means it's quite a bit cooler Last year at this time current that is a pretty impressive drop off One may say, Joe, all you talk about is the opposite ideas of man-made warming. Well, that's because you have to be deaf or blind not to know their idea. It's all we are bombarded with, so I assume the reader knows the other side, because you can't help but know it. It's all you hear. Look at this "study" as an example of how this works. It's put out with loud fanfare and has none of the competing ideas that call it into question, even though the headline itself takes potshots at the very counters to it. And for good reason. Putting in competing ideas would lead to rational doubt. And that is not what propaganda is supposed to do. The only solution is to at least put other ideas out there, and give YOU the freedom to make the choice. In the end, the equation I put out 20 years ago when I started to get involved in this, still applies: The Sun, the oceans, stochastic events, and the very design of the system far overwhelm anything man can do to the climate and weather This has to really get people mad who think they can control the weather and climate and the fate of humanity.

The 12Z EPS has a notable signal for a TC formation (~25%) in the S Gulf with them moving mainly N to WNW and then hitting or threatening to hit from NE MX through TX/LA. But this could be mainly gone on the 0Z for all we know since this run looks much different vs earlier runs and its way out in the unreliable late week 2.

For the record but fwiw since it’s still well out in wild guessing land, the 12Z Euro directly hits Bermuda 9/14-5 as a MH as it moves NE.

12Z UKMET, after having it for the first run in a couple of days as a TD on the 0Z run (though it later weakened), is back to having the low too weak to be classified as a TC.

Barry, I’d rather not address those ITT, but that area may be active by midmonth. 12Z ICON is much weaker than and S of the 0Z run and has WSW motion to 15N, 49W at 168 well below a 600 dm H5 high at a steady state 1003 mb/TS.

Anything’s possible. It could blow up in especially the W half of the Caribbean if it gets to the E Car pretty weak. By the way, note that per Deepmind that the faster members are more of a threat to the Caribbean/further S.

The E MDR AOI is now red. This from Michael Lowry is a bit concerning at least for the E Caribbean: Models all over the map Forecast models generally agree on development, but the timing of and placement of development vary wildly, which of course affect the future track. On the one hand the American GFS is quick to develop the system this week along the northern lobe of the tropical wave and as a result move it farther north and turn it quickly into the Atlantic for next week, missing the islands to the north. On the other hand, the European model and Google DeepMind’s newest machine learning-based model that performed well during Hurricane Erin, take some time to develop the wave and do so on the southern side, which not surprisingly favors a track farther south and west and toward the eastern Caribbean for the middle part of next week. ——————— My concern is that Google Deepmind ensembles, which I know little about, did best with Erin per Lowry. As you can see, its 0Z 9/2 run has 6 of its members from the E MDR AEW in a very dangerous location. What I don’t know is how many total members it has. Lowry’s diagram makes it look like most members go toward the Caribbean, but there are only 6 that actually get there by hour 210. Many are slower (still well E) and 4 of them are turning WNW to NW (at the top of his yellow circle) and we can’t see where they go after hour 210. Also, there are two that are just starting to sharply recurve well E of the Caribbean but still within the MDR. But regardless, this ensemble’s avg trajectory does look more dangerous than the EPS and is totally different from the GEFS. @BarryStantonGBPPlease change this from 10/60 to 30/70. Thanks.

Wow, what a massive fold by GEFS to EPS in today’s MJO forecast! Whereas the EPS is similar to yesterday’s idea of not going to the right side (MC), GEFS abandoned the typical counterclockwise path that it had yesterday through MC and then to 6/7. Today, it remains in 2 through 9/11 and then crawls “backwards” up to 1 followed by 8 as of 9/16 (all mainly inside the circle, i.e., low amp). The EPS is very similar: Today’s (9/2) GEFS prog: Compare today’s GEFS to yesterday’s (9/1) GEFS prog: huge change! Thus, 9/2 EPS, which is very similar to 9/1 EPS, is very similar to 9/2 GEFS as it also ends up in low amp 8: