ATL: FRANCINE - Models

[Teban54]

Model runs coming in weaker and weaker with each suite…a good sign for Louisiana overall. Misalignment with the upper level anticyclone should impart shear on the system, I’m sure mid level shear will become a hinderance as has been the case with Caribbean and Gulf storms commonly as of late. It being so close to continental dry air from the trough moving in also raises skepticism that this gets all that strong. Category 1 is probably the ceiling imo, maybe low end Cat 2 if it can beat these negative factors.

On the other hand, Francine is already at 995 mb (confirmed by eye drop). GFS has it at 1003 mb at this time, and the lowest it has ever shown for 18z 9/9 was 999 mb. HWRF and HMON were also underestimating its organization at 18z. Both HAFS models are the only ones that nailed it, and they show Cat 2-3 peak (albeit after some fluctuation in the next 12-24 hours).

[tolakram]

Model runs coming in weaker and weaker with each suite…a good sign for Louisiana overall. Misalignment with the upper level anticyclone should impart shear on the system, I’m sure mid level shear will become a hinderance as has been the case with Caribbean and Gulf storms commonly as of late. It being so close to continental dry air from the trough moving in also raises skepticism that this gets all that strong. Category 1 is probably the ceiling imo, maybe low end Cat 2 if it can beat these negative factors.

What model runs?

Latest hurricane models just now running.

[Frank P]

My bad 3090. I deleted that post. So what happened was it rotated around the west part of the area of interest and got absorbed into the mix. Pretty much the same thing happened with 91L coming up from the south/southeast. As they were converging there was already general spin which would likely birth a new center under the heaviest convection. The only way to see it is a super long water vapor loop at 6.9um. But the star.nesdis only goes back 240 images and uploads every 5 minutes. So we'd have to find another water vapor to show how they came into the overall low and merged. I been busy at work and haven't had time to see if recon closed off a center yet. But it was supposed to be later today when the consolidation would have taken place with a main low level center taking over.

Sory, but can't believe you are letting your work interfere with this developing situation..

[WiscoWx02]

Model runs coming in weaker and weaker with each suite…a good sign for Louisiana overall. Misalignment with the upper level anticyclone should impart shear on the system, I’m sure mid level shear will become a hinderance as has been the case with Caribbean and Gulf storms commonly as of late. It being so close to continental dry air from the trough moving in also raises skepticism that this gets all that strong. Category 1 is probably the ceiling imo, maybe low end Cat 2 if it can beat these negative factors.

What model runs?

Latest hurricane models just now running.

https://i.imgur.com/kfPE6YN.png

https://i.imgur.com/869dSc6.png

https://i.imgur.com/Nce6CTo.png

https://i.imgur.com/687Nw3Z.png

Yep the 12z as well as latest global model runs…most have come in weaker since last night. Dry air seems go be the main culprit, but from North America, not Africa haha

[Ubuntwo]

Model runs coming in weaker and weaker with each suite…a good sign for Louisiana overall. Misalignment with the upper level anticyclone should impart shear on the system, I’m sure mid level shear will become a hinderance as has been the case with Caribbean and Gulf storms commonly as of late. It being so close to continental dry air from the trough moving in also raises skepticism that this gets all that strong. Category 1 is probably the ceiling imo, maybe low end Cat 2 if it can beat these negative factors.

What model runs?

Latest hurricane models just now running.

https://i.imgur.com/kfPE6YN.png

https://i.imgur.com/869dSc6.png

https://i.imgur.com/Nce6CTo.png

https://i.imgur.com/687Nw3Z.png

Yep the 12z as well as latest global model runs…most have come in weaker since last night. Dry air seems go be the main culprit, but from North America, not Africa haha

Well vs. last night’s 0z, all 12z hurricane models are stronger save for the HAFS-A which still has a cat 2. I see what you mean on the globals, they halt intensification around low end hurricane due to shear injecting dry air into the core. It’s worth considering that the global models 12z initialization was too low considering what we are seeing now.

[Steve]

My bad 3090. I deleted that post. So what happened was it rotated around the west part of the area of interest and got absorbed into the mix. Pretty much the same thing happened with 91L coming up from the south/southeast. As they were converging there was already general spin which would likely birth a new center under the heaviest convection. The only way to see it is a super long water vapor loop at 6.9um. But the star.nesdis only goes back 240 images and uploads every 5 minutes. So we'd have to find another water vapor to show how they came into the overall low and merged. I been busy at work and haven't had time to see if recon closed off a center yet. But it was supposed to be later today when the consolidation would have taken place with a main low level center taking over.

Sory, but can't believe you are letting your work interfere with this developing situation..

Boss’ boss’ boss (head honcho) wanted information so I couldn’t watch the models start rolling in or recon. I did manage to get to Costco Zoological Gardens as they opened just in time for an extended wait for gas and a packed house inside.

[xtyphooncyclonex]

Model runs coming in weaker and weaker with each suite…a good sign for Louisiana overall. Misalignment with the upper level anticyclone should impart shear on the system, I’m sure mid level shear will become a hinderance as has been the case with Caribbean and Gulf storms commonly as of late. It being so close to continental dry air from the trough moving in also raises skepticism that this gets all that strong. Category 1 is probably the ceiling imo, maybe low end Cat 2 if it can beat these negative factors.

What model runs?

Latest hurricane models just now running.

https://i.imgur.com/kfPE6YN.png

https://i.imgur.com/869dSc6.png

https://i.imgur.com/Nce6CTo.png

https://i.imgur.com/687Nw3Z.png

Yep the 12z as well as latest global model runs…most have come in weaker since last night. Dry air seems go be the main culprit, but from North America, not Africa haha

None of those models have initialized Francine as having intensified to a 50 kt/995 mb storm with a developing eyewall and nascent eye at the moment. That's not how Francine seems to actually be acting... at all.

Not saying it is a certainty, and we definitely hope it comes as weaker. But this may show an underestimation ripple effect across different timeframes.

[duris]

Just as we're talking shifting west....

 https://x.com/robperillo/status/1833243274326511953

[tolakram]

I can't get the tweet to display right, but just as we're talking shifting west....

This is some news...after GRAF Model has been locked in for a SW LA/Vermilion Parish landfall for the last 24 hours, the latest run (18z) has shifted the forecast track more eastward toward St Mary Parish.

The GRAF model is usually the leader in forecast tropical systems paths (usually too fast with the motion of the storm)...and it remains faster (and more intense) than NHC forecast issued earlier today...again do not get locked into and anchor on a specific model run as guidance changes.

We'll see if the NHC nudges their forecast track a little farther east and ups their winds at landfall too with upcoming advisory at 4pm.

Francine could easily become a Category 2...and a major 3, can not be ruled out. #lawx #Francine

https://x.com/robperillo/status/1833243274326511953

It's an x.com link so use xpost instead of tweet. I didn't know what to call it, and for whatever reason some people still see twitter so we have both.

[duris]

I can't get the tweet to display right, but just as we're talking shifting west....

This is some news...after GRAF Model has been locked in for a SW LA/Vermilion Parish landfall for the last 24 hours, the latest run (18z) has shifted the forecast track more eastward toward St Mary Parish.

The GRAF model is usually the leader in forecast tropical systems paths (usually too fast with the motion of the storm)...and it remains faster (and more intense) than NHC forecast issued earlier today...again do not get locked into and anchor on a specific model run as guidance changes.

We'll see if the NHC nudges their forecast track a little farther east and ups their winds at landfall too with upcoming advisory at 4pm.

Francine could easily become a Category 2...and a major 3, can not be ruled out. #lawx #Francine

https://x.com/robperillo/status/1833243274326511953

It's an x.com link so use xpost instead of tweet. I didn't know what to call it, and for whatever reason some people still see twitter so we have both.

That explains it. Edited, thanks.

[Nimbus]

What model runs?

Latest hurricane models just now running.

https://i.imgur.com/kfPE6YN.png

https://i.imgur.com/869dSc6.png

https://i.imgur.com/Nce6CTo.png

https://i.imgur.com/687Nw3Z.png

Yep the 12z as well as latest global model runs…most have come in weaker since last night. Dry air seems go be the main culprit, but from North America, not Africa haha

None of those models have initialized Francine as having intensified to a 50 kt/995 mb storm with a developing eyewall and nascent eye at the moment. That's not how Francine seems to actually be acting... at all.

Not saying it is a certainty, and we definitely hope it comes as weaker. But this may show an underestimation ripple effect across different timeframes.

NHC said a deeper system would start to track NE sooner so once the new recon data gets into the model runs we should know by morning. Moving almost north now 340.

[NDG]

Both latest 18z ICON and GFS shifted to the east.

[MississippiWx]

New 18z GFS is well east of 12z. 18z Icon also moved east. This is the farthest east run I’ve seen either of them. We will see if it’s just an 18z fluke or a trend.

[NDG]

New 18z GFS is well east of 12z. 18z Icon also moved east. This is the farthest east run I’ve seen either of them. We will see if it’s just an 18z fluke or a trend.

Early tropical model tracks always seem to over react when a reformation is not in their short term forecast track, eventually they readjust.
So I wouldn't be surprised if they shift back to the east where they were at landfall on their 12z run.

[HurricaneBrain]

Never heard of a west reformation causing an east shift in the models. And what do you mean by the models moving back east? These are probably the easternmost runs yet.

New 18z GFS is well east of 12z. 18z Icon also moved east. This is the farthest east run I’ve seen either of them. We will see if it’s just an 18z fluke or a trend.

Early tropical model tracks always seem to over react when a reformation is not in their short term forecast track, eventually they readjust.
So I wouldn't be surprised if they shift back to the east where they were at landfall on their 12z run.

[NDG]

Never heard of a west reformation causing an east shift in the models. And what do you mean by the models moving back east? These are probably the easternmost runs yet.

New 18z GFS is well east of 12z. 18z Icon also moved east. This is the farthest east run I’ve seen either of them. We will see if it’s just an 18z fluke or a trend.

Early tropical model tracks always seem to over react when a reformation is not in their short term forecast track, eventually they readjust.
So I wouldn't be surprised if they shift back to the east where they were at landfall on their 12z run.

I am talking about the early tropical model runs, not global model runs.
18z runs were started after the reformation further west, thus a westward shift at landfall, as mentioned by the latest NHC discussion.

[Horn1991]

Early tropical model tracks always seem to over react when a reformation is not in their short term forecast track, eventually they readjust.
So I wouldn't be surprised if they shift back to the east where they were at landfall on their 12z run.

[/quote]

I believe NDG meant west.

[romeoblade]

Both latest 18z ICON and GFS shifted to the east.

https://i.imgur.com/V2PAwy2.gif

That's model will be sketchy for me, I recently moved back to Springfield, Louisiana and that puts me right on the east side. Already have fuel for the generators and tested them out earlier along with filling up my fresh water tank on my camper.

[NDG]

Both 18z HAFS-A & HAFS-B shifted to the east, HAFS-A looks to track right over Nola.

[Steve]

Both 18z HAFS-A & HAFS-B shifted to the east, HAFS-A looks to track right over Nola.

That’s like southeast of the city. Possibly an outlier? I don’t have a pc at home today so I haven’t looked at the late cycle 18z’s and can only post a link. Oh well. Late cycle not out for 18z yet.