ATL: MARCO - Models

[northjaxpro]

Development on the ensembles starts around 4-5 days. With previous storms in the Atlantic this season, the GFS/ECMWF start to pick up on development about ~72 hours from actual development. We'll see if that trend continues. You can see on the GFS operational ensembles below, while not nearly as active as the GFS Para ensembles, if development occurs a track through the Yucatan Channel and even western Cuba is definitely in the cards. No/weak development likely will lead to a faster motion through the Yucatan Peninsula.

https://i.imgur.com/G9prvQi.png

What's right there in the Gulf causing this curve toward Florida, some sort of high pressure ridge?

CMC ICON and EURO show a trough positioned into the Central GOM .

[Blown Away]

It seems the models are backing off 97L and IMO it will remain weak/shallow and flow with easterlies into the Yucatan. Future 98L will be the problem IMO and still puzzled how the 06 GFS shows this as a Caribbean cruiser into S TX/Mexico and Euro is N of the islands. Unusual to see the GFS L of the Euro...

[northjaxpro]

It seems the models are backing off 97L and IMO it will remain weak/shallow and flow with easterlies into the Yucatan. Future 98L will be the problem IMO and still puzzled how the 06 GFS shows this as a Caribbean cruiser into S TX/Mexico and Euro is N of the islands. Unusual to see the GFS L of the Euro...

The GFS just has been off a lot thus far this season. CMC,on the other hand, has performed surprisingly well to this juncture.

[kevin]

Not directly related to 97L, but I'm looking at the Weathernerds TC ensemble forecasts to see what fraction of the ensemble members develop the storm. Does anyone know how many members are in each ensemble run for ECMWF, GFS and UKMET, respectively?

[Cpv17]

Not directly related to 97L, but I'm looking at the Weathernerds TC ensemble forecasts to see what fraction of the ensemble members develop the storm. Does anyone know how many members are in each ensemble run for ECMWF, GFS and UKMET, respectively?

ECMWF 51

GFS 21

UKMET 23

[GCANE]

12Z GFS is trending for a stronger Rossby Wave in the GoM.
Wave may have minimal development in the Carib.
Likely shredded in the GoM.

[Steve]

12Z's are starting to show some output.

ICON 180 hours shows 97L not much in the Gulf but the following wave is looking scary behind it.

[Kazmit]

Deepening north of the Yucatan.

[Steve]

GFS @ 156 hours


500mb GFS

[Steve]

GFS @ 174 hours


500mb (note ridge connected north of the system now)

[Steve]

GFS @ 196 hours (7am Tuesday) showing a TS landfalling around Houma, LA

[GCANE]

Spoke too soon.
GFS actually has a strong anti-cyclone over the system as it gets in the GoM and degrades the Rossby Wave.
Also seems to have an effect on the wave behind it.
Bottom line: way too early to tell what'll happen.

[Ivanhater]

I know all eyes are on the wave behind this one but we still need to watch this one

Sent from my SM-G955U using Tapatalk

[Steve]

Spoke too soon.
GFS actually has a strong anti-cyclone over the system as it gets in the GoM and degrades the Rossby Wave.
Also seems to have an effect on the wave behind it.
Bottom line: way too early to tell what'll happen.

Agreed. And the GFS hasn't been much help for these systems. It changes all the time and that's when it even acknowledges the spins exist. Per the discussion thread yesterday where I felt like this was the sacrifice for storms to come and others suggested the potential for a major, I disagreed though I don't argue hard against process in the western Gulf. Second system should be the stronger one in this scenario. GFS is starting to at least show the potential for the second system having it at 996mb off the NW coast of the Yucatan 1am next Wednesday. I'll keep watching that and report where it shows that feature landfalling.

[Steve]

GFS ultimately takes the second wave to Brownsville/State of Tamaulipas.

Of some interest, the CMC has both systems in the Gulf simultaneously. Not sure about that solution at 192 hours. It goes on to bring 97L toward Beaumont but then drops it south along the Texas Coast where the following wave makes landfall in NWFL as at least a solid 970mb Cat 2.

[FLpanhandle91]

CMC really liking Marco as the main player here for the central Gulf Coast.

[MississippiWx]

CMC really liking Marco as the main player here for the central Gulf Coast.

The wave closer to Africa may, in fact, be Laura. Many models have it developing before 97L.

[Kazmit]

CMC really liking Marco as the main player here for the central Gulf Coast.

The wave closer to Africa may, in fact, be Laura. Many models have it developing before 97L.

I hope so. It’s a powerful sounding name for a storm that will likely be quiet powerful.

[eastcoastFL]

GFS ultimately takes the second wave to Brownsville/State of Tamaulipas.

Of some interest, the CMC has both systems in the Gulf simultaneously. Not sure about that solution at 192 hours. It goes on to bring 97L toward Beaumont but then drops it south along the Texas Coast where the following wave makes landfall in NWFL as at least a solid 970mb Cat 2.
https://i.imgur.com/GNoWOoC.png

Yah I recall models early on having Michael headed that way as a TS. All options are still open this early

[GCANE]

12Z GFS is trending for a stronger Rossby Wave in the GoM.
Wave may have minimal development in the Carib.
Likely shredded in the GoM.

You love those rosby waves

I do.
They drive a majority of the weather. Just about all outside of the tropics - baroclinic.