ATL: LEE - Models

[Senobia]

For the model runs that show a northern bend as it reaches PR, what are they picking up on that makes the system take such a drastic turn?

[Meteorcane]

For the model runs that show a northern bend as it reaches PR, what are they picking up on that makes the system take such a drastic turn?

I assume you mean the turn later in the forecast east of the Bahamas... that is caused by a fairly high amplitude trough (at least for this time of year) which moves into the eastern US/Western Atlantic early next week. This erodes the subtropical ridge to the north of the system which had kept it on a WNW heading. This is the EPS (European ensemble) 500mb mean height anomalies map for the day 6-10 forecast, you can see the blue (negative) height anomalies indicating the forecasted trough digging southward early next week (likely in response to a shortwave digging in from Canada, but this can't be explicitly inferred from an ensemble mean height field) which in turn cause the red (positive) height anomalies representing the oceanic ridge to erode away, providing a weakness for 95L to lift northward... and then likely turn NE later in the run given the troughs amplitude.

Will this pattern happen exactly as the Euro ensemble shows... probably not exactly but this general solution with some form of troughing near the east coat/west Atlantic does look like the most likely solution for early next week. There have a been deterministic runs of say the GFS would have showed a much less amplified pattern which would maybe open the door for a "ridge bridge" solution where the Oceanic ridge connects with the SW US ridge shunting the storm-track further north, which would be more concerning for the east coast... but this is definitely an outlier solution and the trough seems more likely.

[mantis83]

For the model runs that show a northern bend as it reaches PR, what are they picking up on that makes the system take such a drastic turn?

troughing/weakness in the west altantic which doesn't budge, it's there run after run

edit: 12z GFS trending towards euro now, misses islands entirely

[gatorcane]

The 12Z GFS shifted north and is stronger now taking the storm north of the islands and is close to the 00Z ECMWF and TVCN. The CMC also shifted north too and both models like the ECMWF turn a potentially powerful hurricane north into a weakness over the SW Atlantic next weekend with the CMC furthest west with the turn and ECMWF furthest east. 12Z models so far good news for the islands.

12Z GFS loop:

[Hypercane_Kyle]

The 12Z GFS shifted north and is stronger now taking the storm north of the islands and is close to the 00Z ECMWF and TVCN. The CMC also shifted north too and both models like the Euro turn a potentially powerful hurricane north into a weakness over the SW Atlantic next weekend. 12Z models so far good news for the islands.

Yeah, obviously too early to know with high certainty, but I am feeling increasingly confident this system will outright miss all landmass and go safely out to sea. Similar to Sam in 2021.

[cheezyWXguy]

That bend back to the west at day 10 on the 12z gfs is interesting. The trough that swept it out on previous runs lifts out too quickly to take 95L with it. Still don’t think it reaches the east coast this run as the next trough will likely pick it up, but this is something we’ll need to watch for as time goes on.

[SFLcane]

Well this is interesting....just about anything is possible this far out.

[AutoPenalti]

Well this is interesting....just about anything is possible this far out.

https://i.postimg.cc/Y9r2XbYF/hjhjhjhjhj.png

That doesn’t scream OTS to me.

[SFLcane]

Well this is interesting....just about anything is possible this far out.

https://i.postimg.cc/Y9r2XbYF/hjhjhjhjhj.png

That doesn’t scream OTS to me.

new trend ? we shall see

[jlauderdal]

Well this is interesting....just about anything is possible this far out.

https://i.postimg.cc/Y9r2XbYF/hjhjhjhjhj.png

That doesn’t scream OTS to me.

new trend ? we shall see

Medium to long range modeling struggling with the ridge, no way.

[SFLcane]

[aspen]

The 12z hurricane models develop 95L at 37-38W (HWRF), 40-41W (HMON), 44-45W (HAFS-A), and 38-39W (HAFS-B), respectively. That’s faster and further east than many runs from yesterday.

[Blown Away]

That doesn’t scream OTS to me.

new trend ? we shall see

Medium to long range modeling struggling with the ridge, no way.

HP around, finally getting nice breezes off the ocean. Slight season changes.

[jlauderdal]

new trend ? we shall see

Medium to long range modeling struggling with the ridge, no way.

HP around, finally getting nice breezes off the ocean. Slight season changes.

Felt like a windchill this morning on the bike ride, 70 dp the next few days, I would take 90-95 with a 70 dew 365 days a year.

Odds are for a recurve but lets give it another few cycles and see if things settle down, the leadup to our storm last week didnt have very consistent modeling.

I ran my generator yesterday for its monthly 20 min run...long way to go for Floridians.

[Spacecoast]

12z GEFS

[SFLcane]

Medium to long range modeling struggling with the ridge, no way.

HP around, finally getting nice breezes off the ocean. Slight season changes.

Felt like a windchill this morning on the bike ride, 70 dp the next few days, I would take 90-95 with a 70 dew 365 days a year.

Odds are for a recurve but lets give it another few cycles and see if things settle down, the leadup to our storm last week didnt have very consistent modeling.

I ran my generator yesterday for its monthly 20 min run...long way to go for Floridians.

[Nimbus]

Well this is interesting....just about anything is possible this far out.

https://i.postimg.cc/Y9r2XbYF/hjhjhjhjhj.png

That doesn’t scream OTS to me.

270 hours might not even be 95L

We were looking at a ridge decision last night at 168 hours near Puerto Rico.

[floridasun]

we know better by thur runs

[Nimbus]

Medium to long range modeling struggling with the ridge, no way.

HP around, finally getting nice breezes off the ocean. Slight season changes.

Felt like a windchill this morning on the bike ride, 70 dp the next few days, I would take 90-95 with a 70 dew 365 days a year.

Odds are for a recurve but lets give it another few cycles and see if things settle down, the leadup to our storm last week didnt have very consistent modeling.

I ran my generator yesterday for its monthly 20 min run...long way to go for Floridians.

That is true, the power went out for me with Idalia and I had waited till 96 hours before landfall to check my generator. You and Gums probably have the L8test inverter models but I'm running an old brushless that I haven't used more than 20 minutes since Irma. The capacitor was fried and I didn't dare use the Herm to ground from an AC capacitor because they don't have a self extinguishing outer case. Have some metal poly caps on the way for the next storm.

Spin up and ridge dilemma is for the islands at this point and I think the system may lose some of its moisture to the north and west for a while which would delay the spin up.

[chaser1]

we know better by thur runs

Exactly! Things will change. Gonna have to wait until we get a more defined COC anyway.