Tropical Depression Nine

[nycwinter]

jumping the gun a bit to early..

[Nibor]

5 hours ago, WxWatcher007 said:

Taking a look at our coming PTC. Thanks to @Nibor for showing me how to post larger gif animations. 

You can clearly see both the gradual organization and headwinds for the coming PTC 9. To the north, you can see arc clouds still radiating out of the area, indicating the presence of some dry air. You can also see some of the thunderstorm tops being sheared, although it does look like in recent frames that things may have slackened some.  

It's easier to see the larger scale spin, and recon is on the way to examine how well defined a low level center there is. For a relatively short term forecast, there is still a lot to be figured out. 

 

[WxWatcher007]

5 minutes ago, nycwinter said:

jumping the gun a bit to early..

Yeah we have a long way to go…

[Coach McGuirk]

It's been such a dead season, I want to believe. 

[WxWatcher007]

Humberto is a little west of track and is now forecast to become our second category five hurricane of the season. 

[wncsnow]

A stall off the coast is fine with us in Helene ravaged WNC. 

[RaleighNC]

58 minutes ago, Coach McGuirk said:

It's been such a dead season, I want to believe. 

want to believe what? 

[Coach McGuirk]

5 minutes ago, RaleighNC said:

want to believe what? 

Damn it, don't you watch the X-Files?  

[GaWx]

0Z Icon is again OTS.

[GaWx]

0Z GFS also likely not going to hit the US based on 78 but we’ll see.

[MJO812]

3 minutes ago, GaWx said:

0Z GFS also likely not going to hit the US based on 78 but we’ll see.

Looking like the stall offshore is real

[GaWx]

0Z:

Icon stays OTS as has been case every run

GFS stays OTS 2nd run in a row

JMA goes out only 72 but implies it would again get pulled into Humberto and stay OTS

UKMET stays OTS as (like the Icon) has been the case every run:

 NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER  30 HOURS
              FORECAST POSITION AT T+ 30 : 23.5N  77.1W

                        LEAD                 CENTRAL     MAXIMUM WIND
      VERIFYING TIME    TIME   POSITION   PRESSURE (MB)  SPEED (KNOTS)
      --------------    ----   --------   -------------  -------------
    1200UTC 28.09.2025   36  23.5N  77.3W     1004            38
    0000UTC 29.09.2025   48  25.0N  77.5W     1002            38
    1200UTC 29.09.2025   60  26.5N  78.0W     1001            38
    0000UTC 30.09.2025   72  28.1N  78.3W      998            43
    1200UTC 30.09.2025   84  28.3N  78.5W      995            42
    0000UTC 01.10.2025   96  27.6N  76.9W      993            38
    1200UTC 01.10.2025  108  27.4N  74.6W      991            45
    0000UTC 02.10.2025  120  27.8N  71.6W      989            45
    1200UTC 02.10.2025  132  28.3N  68.0W      987            48
    0000UTC 03.10.2025  144  28.8N  63.5W      989            66
    1200UTC 03.10.2025  156  29.8N  59.3W      994            54
    0000UTC 04.10.2025  168  30.3N  56.7W      997            41

———————

CMC next

[Coach McGuirk]

58 minutes ago, Coach McGuirk said:

Damn it, don't you watch the X-Files?  

Everyone here wants a hurricane to hit.  We are all weenies. 

[Rd9108]

Looks like another fish storm

[GaWx]

0Z CMC stays OTS unlike 12Z, which looped back to NC

 So far, all OTS with only Euro left

[WxWatcher007]

17 minutes ago, GaWx said:

0Z CMC stays OTS unlike 12Z, which looped back to NC

 So far, all OTS with only Euro left

Canadian starts out that way, but then gets trapped under the ridge and a much weaker version of future Imelda gets pulled into New England. 

Verbatim stuff aside, if this becomes a situation where it will be a close scrape of the SE coast, we’ll need to pay close attention to the orientation of this ridge and whether it closes off an escape route as Imelda tries moving eastward. I was always skeptical of Imelda getting well inland and I brought the ridging closing the escape route up as a possibility yesterday. While I’d be skeptical of some sort of threat further north, it really seems like anything is on the table. 

Anomalous ridging does anomalous things. Sometimes.  

[Coach McGuirk]

Such a bizarre situation.  I don't think we know what will happen. 

[GaWx]

0Z Euro stays away from the US.

[NorthHillsWx]

Humberto being stronger and further west is why the models are showing more interaction/Imelda being pulled east. This is not set in stone hopefully no one lets their guard down but obviously this drastically reduces impacts if the offshore stall occurs. Huge difference in 100 miles at this range 

[NorthHillsWx]

These homebrew systems developing under ridges with weak steering flows are typically a pain in the ass to forecast in the southeast

[jlauderdal]

6 hours ago, Rd9108 said:

Looks like another fish storm

Its not going to be a fish, its rolling through the bahamas.  FISH=no landmass

[NorthHillsWx]

43 minutes ago, jlauderdal said:

Its not going to be a fish, its rolling through the bahamas.  FISH=no landmass

Also Bermuda is in play

[TampaMan]

Honestly this is a good thing if it goes OTS. Some of the early tracks and rainfall totals for the western Carolinas was devastating. As much as I’d like to see some wind and rain, this may be a saving grace for those folks in the mountains. 

[donsutherland1]

Courtesy of the Fujiwhara Effect, my thinking is that the stronger Humberto will pull what will become Imelda away from the coastline before U.S. landfall can occur and before ridging can rebuild overhead to break down the steering currents and later redirect Imelda toward U.S. landfall. The Bahamas and possibly Bermuda will need to closely monitor the developing tropical cyclone. There remains a degree of uncertainty.

[WxWatcher007]

As I hope we all learned yesterday, we’re nowhere near having all the answers on the medium and longer range track. From the very beginning we knew Humberto and the steering pattern made this a highly complex forecast and some of us kind of settled into believing a false consensus on the models(EPS/GEFS)—myself included. I don’t think we know what’s going to happen yet. We just have to keep monitoring and communicating the track uncertainty.

There’s also fairly substantial intensity uncertainty. Recon is in the PTC and is finding westerly winds now so it’s on an organizing trend even if the low is still broad. 

We will eventually have a defined enough center for a TC designation. Importantly, this is on the edge of the deep convection firing north of Cuba. In this kind of situation we have to watch for center reformations if deep convection continues, which here could significantly impact track. 

One thing is clear: the PTC is organizing at a steadier pace given the recon findings and satellite appearance.

[MJO812]

The stall looks legit. All the models show it.

[wthrmn654]

Cmc and euro ai want to bring it to the Mid Atlantic/ north east before all is said and done...... that's after wandering off the south east.  

 

Will have to keep an eye on that to see off that becomes a thing or not. 

[donsutherland1]

With the NHC now referring to Google DeepMind in some of its discussions, below is the latest Google DeepMind output for PTC9 at closest approach on the ensemble mean track:

[WxWatcher007]

SHIPS has some decent odds of RI occurring relative to climo. Maybe something to watch as the organizational trend continues today.

[Kevin Reilly]

59 minutes ago, WxWatcher007 said:

As I hope we all learned yesterday, we’re nowhere near having all the answers on the medium and longer range track. From the very beginning we knew Humberto and the steering pattern made this a highly complex forecast and some of us kind of settled into believing a false consensus on the models(EPS/GEFS)—myself included. I don’t think we know what’s going to happen yet. We just have to keep monitoring and communicating the track uncertainty.

There’s also fairly substantial intensity uncertainty. Recon is in the PTC and is finding westerly winds now so it’s on an organizing trend even if the low is still broad. 

We will eventually have a defined enough center for a TC designation. Importantly, this is on the edge of the deep convection firing north of Cuba. In this kind of situation we have to watch for center reformations if deep convection continues, which here could significantly impact track. 

One thing is clear: the PTC is organizing at a steadier pace given the recon findings and satellite appearance.

 

Looks like a center is going to form just north of Cuba on the north Cuban Coast / south of the Bahamas and lift north bound.