ATL: FLORENCE - Post-Tropical - Discussion

[TheDreamTraveler]

It's actually an animation if you click on it. It shows 3 of the ensembles including the latest.

 https://twitter.com/BenNollWeather/status/1038151712538685440

[Blown Away]

:uarrow: Then Flo is already at a lower latitude than any model has gone...

yepper and still chugging along south of west..

Yep you can see the naked LLC SW of the blob of convection heading WSW:

http://rammb.cira.colostate.edu/ramsdis ... display=12

WSW motion may delay arrival down the road:
1. Does does that allow ridge to build farther S and push Flo S?
OR
2. Does it allow ridge to retreat and allow Flo more east?

[MetroMike]

It's actually an animation if you click on it. It shows 3 of the ensembles including the latest.

 https://twitter.com/BenNollWeather/status/1038151712538685440

Levi Cowan notes that Florida is still in play. Not out of the woods by no means.

[gatorcane]

yepper and still chugging along south of west..

Yep you can see the naked LLC SW of the blob of convection heading WSW:

http://rammb.cira.colostate.edu/ramsdis ... display=12

WSW motion may delay arrival down the road:
1. Does does that allow ridge to build farther S and push Flo S?
OR
2. Does it allow ridge to retreat and allow Flo more east?

That is what I was wondering. Seems the ridge could build more west into the Carolinas if Flo wasn’t rounding the periphery allowing Flo to move more west. Note CMC and JMA hint at this scenario.

[TheDreamTraveler]

It's actually an animation if you click on it. It shows 3 of the ensembles including the latest.

 https://twitter.com/BenNollWeather/status/1038151712538685440

Levi Cowan notes that Florida is still in play. Not out of the woods by no means.

Yeah...at the end of the animation you see there are more tracks closer to Florida than yesterday from the 12z ensembles. But overall better agreement than before...though that isn't saying much right now lol

[toad strangler]

:uarrow: Then Flo is already at a lower latitude than any model has gone...

Lower than UKMET?

[tolakram]

COD Shortwave with Nighttime Microphysics turned on. Easier to see the low level clouds.

http://weather.cod.edu/satrad/exper/?parms=meso-meso2-ntmicro-200-1-10-1&checked=map&colorbar=undefined

[Blown Away]

:uarrow: Then Flo is already at a lower latitude than any model has gone...

Lower than UKMET?

I'm assuming Flo is @24.4N now, if that is accurate, I don't think the Ukmet got lower than that.

[beoumont]

By itself, I just don't necessarily believe that a strong Florence by herself would automatically result in a well entrenched strong blocking ridge to weaken unless a weakness in the higher latitude flow also contributed to the erosion of that high pressure ridge.

Over the years, I have observed that when a very major hurricane is moving w-wnw, and is approaching the end of a mid level high, the hurricane will move westward 6-12 hours longer than the NHC forecast (and most of the models) indicates the northward turn will begin. "The hurricane itself (mainly its massive outflow) is affecting its own environment by enhancing the ridge for that 6-12 hours." This, as opposed to the storm eroding the ridge.

[tolakram]

:uarrow: Then Flo is already at a lower latitude than any model has gone...

Lower than UKMET?

I think it's about on track, not much lower if at all.

[Aric Dunn]

:uarrow: Then Flo is already at a lower latitude than any model has gone...

Lower than UKMET?

I think it's about on track, not much lower if at all.

we can settle this debate if anyone wants to post the ukmet text from the 12z.

[toad strangler]

:uarrow: Then Flo is already at a lower latitude than any model has gone...

Lower than UKMET?

I'm assuming Flo is @24.4N now, if that is accurate, I don't think the Ukmet got lower than that.

Everything hinges on ridge placement and “shape”. Unexpected S of W progression combined with a flatter than modeled ridge spells big trouble for the S most zones. Obviously. Too many variables still on the table.

[Blown Away]

SAB confirms @24.5... In addition Flo moving ahead of NHC track... Definite WSW of NHC track... Also, I don't think the Ukmet ever got down to 24.5N...

[BobHarlem]

we can settle this debate if anyone wants to post the ukmet text from the 12z.

from https://www.metoffice.gov.uk/data/tropi ... wtnt80.txt

Low point is 24.4N, by this it's ahead of schedule for being that low though, by about 12-24 hours.

VERIFYING TIME POSITION STRENGTH TENDENCY
-------------- -------- -------- --------
12UTC 07.09.2018 24.9N 51.4W MODERATE
00UTC 08.09.2018 24.6N 52.1W MODERATE LITTLE CHANGE
12UTC 08.09.2018 24.5N 53.4W MODERATE LITTLE CHANGE
00UTC 09.09.2018 24.4N 54.4W MODERATE LITTLE CHANGE
12UTC 09.09.2018 24.4N 55.6W MODERATE LITTLE CHANGE
00UTC 10.09.2018 24.6N 57.2W MODERATE LITTLE CHANGE
12UTC 10.09.2018 24.8N 59.6W MODERATE LITTLE CHANGE
00UTC 11.09.2018 24.7N 62.3W STRONG INTENSIFYING SLIGHTLY
12UTC 11.09.2018 25.1N 65.2W STRONG LITTLE CHANGE
00UTC 12.09.2018 25.8N 68.3W STRONG LITTLE CHANGE
12UTC 12.09.2018 27.2N 71.5W INTENSE INTENSIFYING SLIGHTLY
00UTC 13.09.2018 28.6N 74.3W INTENSE INTENSIFYING SLIGHTLY
12UTC 13.09.2018 30.4N 76.8W INTENSE INTENSIFYING SLIGHTLY

[eastcoastFL]

I am sticking with the Atlantic Beach/Morehead City/Ocracoke landfall.

Amazing area of NC, I hope I'm incorrect.

Im going on a limb for a rare GA landfall near the SC border.

I don't think the South shifting is done.

I'm sure it's possible, but then again the rest of the models could start honing in the OBX like the GFS seems to have done.

That's true but we are still very far out for the models to pick a solution and stick to it.

[J_J99]

It seems like the convection is racing down towards the nearly exposed center to cover it up...

[Aric Dunn]

we can settle this debate if anyone wants to post the ukmet text from the 12z.

from https://www.metoffice.gov.uk/data/tropi ... wtnt80.txt

Low point is 24.4N, by this it's ahead of schedule for being that low though, by about 24 hours.

VERIFYING TIME POSITION STRENGTH TENDENCY
-------------- -------- -------- --------
12UTC 07.09.2018 24.9N 51.4W MODERATE
00UTC 08.09.2018 24.6N 52.1W MODERATE LITTLE CHANGE
12UTC 08.09.2018 24.5N 53.4W MODERATE LITTLE CHANGE
00UTC 09.09.2018 24.4N 54.4W MODERATE LITTLE CHANGE
12UTC 09.09.2018 24.4N 55.6W MODERATE LITTLE CHANGE
00UTC 10.09.2018 24.6N 57.2W MODERATE LITTLE CHANGE
12UTC 10.09.2018 24.8N 59.6W MODERATE LITTLE CHANGE
00UTC 11.09.2018 24.7N 62.3W STRONG INTENSIFYING SLIGHTLY
12UTC 11.09.2018 25.1N 65.2W STRONG LITTLE CHANGE
00UTC 12.09.2018 25.8N 68.3W STRONG LITTLE CHANGE
12UTC 12.09.2018 27.2N 71.5W INTENSE INTENSIFYING SLIGHTLY
00UTC 13.09.2018 28.6N 74.3W INTENSE INTENSIFYING SLIGHTLY
12UTC 13.09.2018 30.4N 76.8W INTENSE INTENSIFYING SLIGHTLY

there we have it.. it is at the lowest point of all the models.. and still heading south of west it appears. if it reaches 24N I would suspect a more significant west shift..

[Spacecoast]

There are some 18z GEFS members that reach ~23.5. @ hr 78. Those particular southernmost members end with Ga/SC border landfall.

[johngaltfla]

Until Florence makes a definitive turn to the WSW/SW and the data from the Gulfstream comes in, I'm just going to remind everyone not to become complacent as major hurricanes have hit the Northeast also during this time period, aka, the Long Island Express:

[Blown Away]

Flo continues WSW at a decent clip... 00z models should be faster than 18z...