ATL: HELENE - Models

[gulfcoastdave]

I’m leaving Tallahassee shortly. Definitely is the right decision. Those are terrible runs for this area!

Be safe. I'm riding it out.

I'm over near pensacola but my daughter lives in Tally and is leaving after work this afternoon.
Many business are staying open in tally
If the path is correct and tally takes a hit ,power will be out for awhile due to all the big trees

[WacoWx]

I think we should say Tally more often.

[tolakram]

There is a local thread FYI, let's keep models models.

https://www.storm2k.org/phpbb2/viewtopi ... 9&t=124348

[Steve]

Going back 4 ICON runs it's a bit farther west coming in but a hair farther east than the consensus. I'm guessing Helene is going to hit just east of Apalachicola somewhere in the 940's or 950's. FV3 Hires hits right at the center of the bay @ 968. I don't think that's a bad forecast for a mesoscale. Nam 12km is 952 also west-central part of the bay.

[ThunderForce]

So, this is a weird question, but does anyone know why the NHC's cone and the model track guidance on Tropical Tidbits are so much further west in comparison to the actual models? The latter shows many of the models (and therefore TVCN) to the left of their operational runs, which is pretty confusing.

[tolakram]

So, this is a weird question, but does anyone know why the NHC's cone and the model track guidance on Tropical Tidbits are so much further west in comparison to the actual models? The latter shows many of the models (and therefore TVCN) to the left of their operational runs, which is pretty confusing.
https://i.postimg.cc/VNf0ydSb/09-L-tracks-latest.png

Mainly because not all of those models have the same skill. They use skill based methods to determine track, which is why they are usually more accurate than any individual model. There are exceptions, of course, but not many. They also tend to move the line slowly if models start moving around, as they sometimes tend to do. It's not perfect, which is why the cone is more important than the line. Remember the cone is actually a circle around each forecast point that represents historical error percentages at that time point. These circles are resized every year based on past performance.

[BIFF_THE_UNRULY]

breathing much easier in Tampa right now. Looks like our winning streak will continue.

[shah83]

12z GFS is thoroughly scary. It's not as disrupted by the front as earlier models are, and it has an absolutely enormous hurricane windfield approaching landfall.

[tolakram]

12Z GFS


12Z ICON

[tolakram]

GFS trend


ICON trend

[Stellar]

The flooding in Atlanta and Charlotte will be of concern....ground there is already saturated with rain today and tomorrow.

[shah83]

I also kind of suspect that we will have wave issues, a la Ivan, on top of that surge.

[ScottNAtlanta]

The flooding in Atlanta and Charlotte will be of concern....ground there is already saturated with rain today and tomorrow.

The track will be crucial for that. If it is west of Atlanta it will be much worse that if it passes east. As it is, looks like it might go right over us. Actually, it has been very dry in Atlanta, but the frontal passage will drop from 2 to 3 inches of rain before Helene even gets here.

[SouthFLTropics]

HAFS-A coming in with a pretty sizeable shift right at 33 hours. Hope that's not the start of a trend. Keep paying attention for any of you that said Tampa was in the clear.

EDIT - Actually it may be an optical illusion with the model but it sure does appear to shift right. It might just be increased convection.

[aspen]

HWRF and HAFS-A/B all show Helene mixing out the dry slot by late this afternoon or early evening, with a compact, healthy eyewall forming overnight as RI commences. All show a high-end Cat 4 or a Cat 5.

[Bocadude85]

HAFS-A coming in with a pretty sizeable shift right at 33 hours. Hope that's not the start of a trend. Keep paying attention for any of you that said Tampa was in the clear.

EDIT - Actually it may be an optical illusion with the model but it sure does appear to shift right. It might just be increased convection.

Definitely a hair east of the 6z.. the closer to the Florida west central coast the higher the surge I would imagine.

[tolakram]

[BIFF_THE_UNRULY]

I think we should say Tally more often.

When I lived there we called it Tally Wally. It was awhile ago.

Back when you could get a Pepperoni Pizza for $5. Locals in Tallahassee call a pepperoni pizza a "Hot Carl" for some reason. Great place

You just walk up to the counter and order it.

[Emmett_Brown]

12Z GEFS has a couple strong members that are east near Cedar Key. But the ensemble mean is pretty much unchanged from 6Z

[BIFF_THE_UNRULY]

The flooding in Atlanta and Charlotte will be of concern....ground there is already saturated with rain today and tomorrow.

Given the storms speed and projected strength. Atlanta and swathes of Georgia could get some really serouis weather they are not designed to get. Reminds me of Opal somewhat. 100mph winds hundreds of miles inward