ATL: FLORENCE - Models

[hurricaneCW]

Looks like the Euro is an outlier now, it's pretty far south and doesn't seem to slow down after LF.

I feel like this is because the Euro has a weaker hurricane versus say the Ukmet or Gfs (950s vs 930s) that would have a more pole-ward track.

[Brent]

Euro goes west inland

Interesting...

[AtlanticWind]

If Florence happen to stall a little earlier near SC/NC coast then drifted South could still be a problem
For Georgia and N Florida

[Aric Dunn]

lol .. back offshore and organizing again..

[TheDreamTraveler]

It's hard to see there but that says 47.8 inches

[galaxy401]

So...someone is going to get hit hard by the 50+ inches of rain. It's now becoming a question of what region it will be...

[Vdogg]

Everyone talks about the GFS, but it hasn’t been doing bad verification wise with this storm. And at the 96 and 120 hr marks, it’s been on par with or better than the Euro. It’s something to watch. I wouldn’t be too quick to discard it’s solutions.

https://twitter.com/wxreese/status/1039 ... 21313?s=21

[Hammy]

Everyone talks about the GFS, but it hasn’t been doing bad verification wise with this storm. And at the 96 and 120 hr marks, it’s been on par with or batter than the Euro. It’s something to watch. I wouldn’t be too quick to discard it’s solutions.

https://twitter.com/wxreese/status/1039 ... 21313?s=21

The biggest GFS error margins have historically been with storms north of 25 latitude, and turning them right far too quickly, as well as intensifying it too much in that area (which probably contributes to the track errors. )

[Brent]

[northjaxpro]

It is interesting that we have such good agreement this far away from the landfall point. Just for fun, I went back to a randomly chosen GFS run (I love TropicalTidbits, where would we be without this amazing tool).

The 0z 9/6 run of the GFS predicted that at 0z Monday 9/10 (as in now...) Florence would be near 27.8N, 57.3W. It got the longitude pretty close, but is pretty far off on the latitude... it was over 3 degrees too far N. So, it shows how far off it can be 4 days out.

So that is over 200 miles off closer to 250 miles.

That is correct. Hence, there is the margin of error. Landfall could easily be as far south as Charleston, SC instead of the current projected landfall near Wilmington, NC (the southern extext of the cone of uncertainty)

[GCANE]

COAMPS is still the best performing model over the last 24 hrs with 0 positional error.
Luckily, it is forecast some weakening before landfall with a dramatic slow down in forward speed.

[p1nheadlarry]

COAMPS is still the best performing model over the last 24 hrs with 0 positional error.
Luckily, it is forecast some weakening before landfall with a dramatic slow down in forward speed

FSU product, no?

[Shell Mound]

The 06Z GFS shifted farther NE and is stronger at landfall vs. 18Z.

[Nimbus]

The high cirrus clouds outline the upper level components fairly clearly.
There is still a weak cyclonic circulation west of Florence but you can see the huge anticyclonic ridge building north over Cuba.
That ridge may provide a little shear from the west once the low fills but will be key for steering.
Could slow the forecast and 25N is like the Korean 38th when it comes to model wars.
Just one more day before the local emergency management planners have to pull the trigger.
Seems like just yesterday Hugo made landfall at Fort Moultrie.

[GCANE]

On approach.
The PV Streamer is gone, almost perfect 355K PV ring, very conducive.
Inhibiting factor is the anticyclone just to Flo's SE, which would be tilting the vort column.
Need to keep an eye on this feature in future runs.

[Ken711]

So is the Euro the outlier with the 0z run, now that the UKMet has shifted NE? Are the other models seeing more north and poleward movement because they have Florence as a more intense hurricane?

[Ken711]

HMON 06z NE shift. Maybe the models with the exception of the Euro 0z run, are slowing shifting NE to the Outer Banks from Wilmington.

[invest man]

So is the Euro the outlier with the 0z run, now that the UKMet has shifted NE? Are the other models seeing more north and poleward movement because they have Florence as a more intense hurricane?

As a general rule I support the idea that the stronger is more N and the weaker more S. That is why I think we see the differences in the models. Euro weaker GFS stronger perhaps NHC between the 2 with strength placing their LF where they have it. One small caveat. Most of the time but certainly not always NHC will be closely in line with the TVCN (consensus model) and out 72 hours is fairly close to accurate. Just an observation. IM

[JtSmarts]

6Z HWRF SHIFTED TO MYRTLE BEACH/NC-SC BORDER

[tolakram]

6Z GFS