NATL: IMELDA - Models

[tolakram]

12z Canadian
https://i.postimg.cc/9X8Tnwpg/floop-gdps-2025092412-sfcwind-mslp-watl.gif

Magical power we have in SE Florida

Sent from my Pixel 9 using Tapatalk

Indeed, the power of complacency. I sincerely hope there's no surprises this year because this joke attitude is often taken the wrong way, as we've seen with past posters on here using diagrams and climate change to tell us why SE Florida will never be hit again. Obviously a lot of us don't think this is funny.

[wzrgirl1]

I agree and considering how close the Euro ensembles have this going to the coast, it wouldn't take much of a shift west to put tropical storm winds on our coast if indeed it forms into a named system.

[BobHarlem]

12z euro is something else.

[got ants?]

12z Canadian
https://i.postimg.cc/9X8Tnwpg/floop-gdps-2025092412-sfcwind-mslp-watl.gif

Magical power we have in SE Florida

Sent from my Pixel 9 using Tapatalk

Indeed, the power of complacency. I sincerely hope there's no surprises this year because this joke attitude is often taken the wrong way, as we've seen with past posters on here using diagrams and climate change to tell us why SE Florida will never be hit again. Obviously a lot of us don't think this is funny.

Having lived here, I can tell you why those beliefs persist. In my 66 years, not only has South Florida exploded in co struction, but we actually see how it changed our weather patterns first hand. Its used to rain every afternoon in the summer, all the way to the coast, now, it still does that, but 20 miles inland. Then its hurricane history that shows them avoiding populated areas. Hurricane Andrew was predicted to hit Hollywood/Ft Laud, but made a beeline south of where the concrete wall starts.. And we've more than doubled since Andrew. Though I'd never say never, I have my doubts..

[wzrgirl1]

Magical power we have in SE Florida

Sent from my Pixel 9 using Tapatalk

Indeed, the power of complacency. I sincerely hope there's no surprises this year because this joke attitude is often taken the wrong way, as we've seen with past posters on here using diagrams and climate change to tell us why SE Florida will never be hit again. Obviously a lot of us don't think this is funny.

Having lived here, I can tell you why those beliefs persist. In my 66 years, not only has South Florida exploded in co struction, but we actually see how it changed our weather patterns first hand. Its used to rain every afternoon in the summer, all the way to the coast, now, it still does that, but 20 miles inland. Then its hurricane history that shows them avoiding populated areas. Hurricane Andrew was predicted to hit Hollywood/Ft Laud, but made a beeline south of where the concrete wall starts.. And we've more than doubled since Andrew. Though I'd never say never, I have my doubts..

Perhaps I am misunderstanding this post but are you saying that the construction itself changed the weather patterns? Can you please elaborate?

[LarryWx]

The 12Z EPS, like 0Z and 12Z of yesterday, actually has an uncomfortably high # of members (10+/20%+) hitting the SE US 9/28-10/4, which is earlier than the 10/5-7 12Z Euro freakish US hit.

One thing that’s a bit concerning is the forecasted MJO phase 2 by both GEFS and EPS for 9/27-10/3. As I posted about last month, phase 2 has had (whether inside or outside the circle) by a wide margin the highest % (after taking into account % of days in each phase) of Conus Jul-Sept MH hits and along with phase 8 the highest % of H hits since 1975.

[BobHarlem]

12z euro ensembles

[TomballEd]

12z euro is something else.

https://i.postimg.cc/7YpNKtMZ/floop-ecmwf-full-2025092412-sfcwind-mslp-atl.gif

Quite the ridge building over the top as well.

[StormWeather]

The 12Z EPS, like 0Z and 12Z of yesterday, actually has an uncomfortably high # of members (10+/20%+) hitting the SE US 9/28-10/4, which is earlier than the 10/5-7 12Z Euro freakish US hit.

One thing that’s a bit concerning is the forecasted MJO phase 2 by both GEFS and EPS for 9/27-10/3. As I posted about last month, phase 2 has had (whether inside or outside the circle) by a wide margin the highest % (after taking into account % of days in each phase) of Conus Jul-Sept MH hits and along with phase 8 the highest % of H hits since 1975.

The U.S east coast also hasn’t truly be tested (with new building codes and improvements having come about in the last 20 years) since Hurricane Jeanne in 2004 (the last MH to landfall on the east coast). IF this does end up becoming a MH in the future (if it forms at all) then this may be the test.

[TomballEd]

The 12Z EPS, like 0Z and 12Z of yesterday, actually has an uncomfortably high # of members (10+/20%+) hitting the SE US 9/28-10/4, which is earlier than the 10/5-7 12Z Euro freakish US hit.

One thing that’s a bit concerning is the forecasted MJO phase 2 by both GEFS and EPS for 9/27-10/3. As I posted about last month, phase 2 has had (whether inside or outside the circle) by a wide margin the highest % (after taking into account % of days in each phase) of Conus Jul-Sept MH hits and along with phase 8 the highest % of H hits since 1975.

The U.S east coast also hasn’t truly be tested (with new building codes and improvements having come about in the last 20 years) since Hurricane Jeanne in 2004 (the last MH to landfall on the east coast). IF this does end up becoming a MH in the future (if it forms at all) then this may be the test.

I doubt it is directly related to climate change, but I remember when EC Florida and the Carolinas were the magnets and Opal type Gulf storms were memorable for being rare. If it swings back to ECUSA for major TC impacts, well, could be a cycle.

[KPILM]

The 12Z EPS, like 0Z and 12Z of yesterday, actually has an uncomfortably high # of members (10+/20%+) hitting the SE US 9/28-10/4, which is earlier than the 10/5-7 12Z Euro freakish US hit.

One thing that’s a bit concerning is the forecasted MJO phase 2 by both GEFS and EPS for 9/27-10/3. As I posted about last month, phase 2 has had (whether inside or outside the circle) by a wide margin the highest % (after taking into account % of days in each phase) of Conus Jul-Sept MH hits and along with phase 8 the highest % of H hits since 1975.

The U.S east coast also hasn’t truly be tested (with new building codes and improvements having come about in the last 20 years) since Hurricane Jeanne in 2004 (the last MH to landfall on the east coast). IF this does end up becoming a MH in the future (if it forms at all) then this may be the test.

I still drive past abandoned remnants of homes chewed up by Florence almost every day, I think that was a pretty good test.

[CrazyC83]

I think Humberto holds the key here. If Humberto is stronger, then I suspect this storm gets forced to the coast as it rotates north-northwestward. A weaker Humberto avoids the Fujiwhara and allows this system to follow it out to sea (although Bermuda may be in play).

[LarryWx]

The 12Z EPS, like 0Z and 12Z of yesterday, actually has an uncomfortably high # of members (10+/20%+) hitting the SE US 9/28-10/4, which is earlier than the 10/5-7 12Z Euro freakish US hit.

One thing that’s a bit concerning is the forecasted MJO phase 2 by both GEFS and EPS for 9/27-10/3. As I posted about last month, phase 2 has had (whether inside or outside the circle) by a wide margin the highest % (after taking into account % of days in each phase) of Conus Jul-Sept MH hits and along with phase 8 the highest % of H hits since 1975.

The U.S east coast also hasn’t truly be tested (with new building codes and improvements having come about in the last 20 years) since Hurricane Jeanne in 2004 (the last MH to landfall on the east coast). IF this does end up becoming a MH in the future (if it forms at all) then this may be the test.

These 9 MH hit the Conus during phase 2

Ida (2021)
Irma (2017)
Harvey (2017)
Ivan (2004)
Brett (1999)
Emily (1993)
Hugo (1989)
Frederic (1979)
Eloise (1975)

That’s 9 of 23 MH (39%) Jul-Sep hitting Conus just during phase 2. Out of 4,508 days during Jul-Sep 1975-2024 (1978 excluded because MJO unknown), there were 756 days during phase 2 or 17% of the days. The 17% is well under the 39%.

In addition to those 9 MH, these highly impactful H also hit during phase 2:

Hanna (2020)
Florence (2018)
Gustav (2008)
Katrina FL portion (2005)
Frances (2004)
Erin (1995)

[AJC3]

I think Humberto holds the key here. If Humberto is stronger, then I suspect this storm gets forced to the coast as it rotates north-northwestward. A weaker Humberto avoids the Fujiwhara and allows this system to follow it out to sea (although Bermuda may be in play).

While I agree that Humberto holds the key, I'd suspect the opposite is true for 2 reasons:

1. A stronger Humberto is likely to have a larger RMW, both of which would be MORE likely to cause a stronger binary interaction.

2. A stronger/larger Humberto will also cause greater erosion of the western flank of the Atlantic ridge to the north of 94L.

What would be useful in this regard is an ensemble correlation for both systems. Bifurcate the stronger ensemble members for Humberto from the weaker ones, then look at how this impacts the track/intensity of 94L.

[floridasun]

so, models going crazy because two system close each other

[Stratton23]

18z ICON had a much stronger ridge, upper low over the SE US is significantly weaker

[BobHarlem]

18z icon, bit of a left shift for both systems.

[AnnularCane]

18z icon, bit of a left shift for both systems.

https://i.postimg.cc/hPTC6nXz/floop-icon-2025092418-sfcwind-mslp-watl.gif

Looks like Humberto is chasing her.

[LarryWx]

I think Humberto holds the key here. If Humberto is stronger, then I suspect this storm gets forced to the coast as it rotates north-northwestward. A weaker Humberto avoids the Fujiwhara and allows this system to follow it out to sea (although Bermuda may be in play).

While I agree that Humberto holds the key, I'd suspect the opposite is true for 2 reasons:

1. A stronger Humberto is likely to have a larger RMW, both of which would be MORE likely to cause a stronger binary interaction.

2. A stronger/larger Humberto will also cause greater erosion of the western flank of the Atlantic ridge to the north of 94L.

What would be useful in this regard is an ensemble correlation for both systems. Bifurcate the stronger ensemble members for Humberto from the weaker ones, then look at how this impacts the track/intensity of 94L.

Upon closer inspection, 40% (20) of 12Z EPS members affect a portion of the SE with either a TC direct landfall, a skirting of the coast, or a weak remnant. Also, a clear majority of members that weren’t steered by a Fujiwhara from Humberto were in that 40%. So, whether or not Humberto pulls 94L into it might turn out to be the crucial factor for whether or not the SE US is threatened.

[Blown Away]

18z ICON