ATL: FLORENCE - Models

[Hypercane_Kyle]

I have to believe a 911mb storm would interact with a ridge differently than a ~950mb one the ECMWF is showing. We shall see... 12z FV3-GFS coming in slightly west, too, along with the 12z UKMET. Nobody in SC/NC are out of the woods yet.

[hurricaneCW]

Got to love how the Gfs has a Cat 5 near 40N as it's moving OTS.

[LarryWx]

12Z UKMET: at hour 132 is a whopping 271 miles WNW of its 0 UKMET hour 144 although it is still far N of its runs prior to today's 0Z

GLOBAL MODEL DATA TIME 1200UTC 09.09.2018

HURRICANE FLORENCE ANALYSED POSITION : 24.4N 55.9W

ATCF IDENTIFIER : AL062018

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 09.09.2018 0 24.4N 55.9W 986 60 ****vs actual of 24.4N, 56.1W
0000UTC 10.09.2018 12 24.4N 57.4W 981 62
1200UTC 10.09.2018 24 24.8N 59.3W 972 65
0000UTC 11.09.2018 36 25.6N 61.5W 972 68
1200UTC 11.09.2018 48 26.5N 64.6W 965 73
0000UTC 12.09.2018 60 27.7N 67.9W 958 75
1200UTC 12.09.2018 72 29.1N 71.0W 953 84
0000UTC 13.09.2018 84 31.1N 73.4W 948 81
1200UTC 13.09.2018 96 32.8N 75.5W 942 86
0000UTC 14.09.2018 108 34.2N 76.9W 928 91
1200UTC 14.09.2018 120 34.9N 78.3W 962 54
0000UTC 15.09.2018 132 35.5N 79.1W 983 37 *****0Z was at 33.5N, 75.0W
1200UTC 15.09.2018 144 36.4N 79.2W 990 29

Doesn't it seem to be gaining lat rather fast over the initial 36hrs?

Yes, tonight's motion will be critical. Also, note that this run has it stronger early.

[eastcoastFL]

12Z UKMET: at hour 132 is a whopping 271 miles WNW of its 0 UKMET hour 144 although it is still far N of its runs prior to today's 0Z

GLOBAL MODEL DATA TIME 1200UTC 09.09.2018

HURRICANE FLORENCE ANALYSED POSITION : 24.4N 55.9W

ATCF IDENTIFIER : AL062018

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 09.09.2018 0 24.4N 55.9W 986 60 ****vs actual of 24.4N, 56.1W
0000UTC 10.09.2018 12 24.4N 57.4W 981 62
1200UTC 10.09.2018 24 24.8N 59.3W 972 65
0000UTC 11.09.2018 36 25.6N 61.5W 972 68
1200UTC 11.09.2018 48 26.5N 64.6W 965 73
0000UTC 12.09.2018 60 27.7N 67.9W 958 75
1200UTC 12.09.2018 72 29.1N 71.0W 953 84
0000UTC 13.09.2018 84 31.1N 73.4W 948 81
1200UTC 13.09.2018 96 32.8N 75.5W 942 86
0000UTC 14.09.2018 108 34.2N 76.9W 928 91
1200UTC 14.09.2018 120 34.9N 78.3W 962 54
0000UTC 15.09.2018 132 35.5N 79.1W 983 37 *****0Z was at 33.5N, 75.0W
1200UTC 15.09.2018 144 36.4N 79.2W 990 29

Doesn't it seem to be gaining lat rather fast over the initial 36hrs?

Yes, tonight's motion will be critical. Also, note that this run has it stronger early.

Thats very interesting. Recon just put the center a bit south again so i wonder if the contiued south of west movement will effect the models later.

[dspguy]

As of right now, is every major model all focused on the area between Myrtle Beach and OBX? I know that each model is merely showing the consensus of its ensembles. However, that's a pretty small area for all these major models to be honed in on with ~120 hours to go. Where's that chart that shows approximate error when 12, 24, 36, 120 hours out? I'm just impressed they are currently (and unfortunately!) honed in on a fairly small area with only 120 hours to go. Of course, it could always change.

[p1nheadlarry]

What about the stall and all the rain? Look at the 500mb, regardless of where the center ends up. Where is it going to go?

THe other question is what happens if Florecnce is slower.. that next ridge is likely to trap it.

Timing/location is key. Going to still have forward momentum with lowish friction, what will the vertical wind profile of the environment will be, etc

[LarryWx]

12Z UKMET: at hour 132 is a whopping 271 miles WNW of its 0 UKMET hour 144 although it is still far N of its runs prior to today's 0Z

GLOBAL MODEL DATA TIME 1200UTC 09.09.2018

HURRICANE FLORENCE ANALYSED POSITION : 24.4N 55.9W

ATCF IDENTIFIER : AL062018

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 09.09.2018 0 24.4N 55.9W 986 60 ****vs actual of 24.4N, 56.1W
0000UTC 10.09.2018 12 24.4N 57.4W 981 62
1200UTC 10.09.2018 24 24.8N 59.3W 972 65
0000UTC 11.09.2018 36 25.6N 61.5W 972 68
1200UTC 11.09.2018 48 26.5N 64.6W 965 73
0000UTC 12.09.2018 60 27.7N 67.9W 958 75
1200UTC 12.09.2018 72 29.1N 71.0W 953 84
0000UTC 13.09.2018 84 31.1N 73.4W 948 81
1200UTC 13.09.2018 96 32.8N 75.5W 942 86
0000UTC 14.09.2018 108 34.2N 76.9W 928 91
1200UTC 14.09.2018 120 34.9N 78.3W 962 54
0000UTC 15.09.2018 132 35.5N 79.1W 983 37 *****0Z was at 33.5N, 75.0W
1200UTC 15.09.2018 144 36.4N 79.2W 990 29

Could it be moving faster this run?

Yes, mainly tonight this run is faster. Also, it is stronger, which is much closer to reality.

[p1nheadlarry]

Got to love how the Gfs has a Cat 5 near 40N as it's moving OTS.

Which is why I don’t think the track is too unrealistic, but this runaway diabatic feedback without ocean coupling will probably calculate stronger beta drift, so left of the GFS (which the storm is currently on pace to do) seems most likely for now, imo.

[PTPatrick]

I wouldn’t hang my hat on any solution given the predicted collapse in steering in the vicinity of the coast. It’s unlikely any model will be correct this far out yet. Everthing from a cat 4 wiping out myrtle beach or Wilmington to a pesky coast hugger and flood erosion event is possible. ObX is used to these stragglers and the one common theme thru history is if you have a stall near the obx they don’t tend to stay very strong for long.

[toad strangler]

UKMET visuals

[LarryWx]

12Z GEFS mean significantly NE of prior runs.

[Ptarmigan]

I looked at the GFS 10 day rainfall forecast model. It has a total of nearly 76 inches of rain!
https://weather.us/model-charts/standar ... 1200z.html

It is offshore. The Carolinas get a lot of rain.

[Raebie]

I looked at the GFS 10 day rainfall forecast model. It has a total of nearly 76 inches of rain!
https://weather.us/model-charts/standar ... 1200z.html

It is offshore. The Carolinas get a lot of rain.

OBX would be totally submerged.

[GTStorm]

12Z GEFS mean significantly NE of prior runs.

So is CMC, and looks like 12z HWRF is a little north of 6z, so far....

[Ptarmigan]

I looked at the GFS 10 day rainfall forecast model. It has a total of nearly 76 inches of rain!
https://weather.us/model-charts/standar ... 1200z.html

It is offshore. The Carolinas get a lot of rain.

OBX would be totally submerged.

It is like Harvey all over again.

The GFS is the only one forecasting huge rainfall totals. Most have around 20 to 25 inches of rain, which is still a lot.

[Aric Dunn]

You also have to keep in mind the ridge that will eventually move this.. has not even build in yet.. still a number of factors we must wait for to have some solid faith in the models.

[seahawkjd]

I looked at the GFS 10 day rainfall forecast model. It has a total of nearly 76 inches of rain!
https://weather.us/model-charts/standar ... 1200z.html

It is offshore. The Carolinas get a lot of rain.

OBX would be totally submerged.

It is like Harvey all over again.

The GFS is the only one forecasting huge rainfall totals. Most have around 20 to 25 inches of rain, which is still a lot.

That's still half our yearly rain total in a very short period of time and would cause horrible flooding. The GFS totals are just unthinkable.

[LarryWx]

12Z CDN ens mean NE of its 0Z run. Weaker 500 mb ridge unlike 12Z GEFS' stronger one.

[toad strangler]

 https://twitter.com/hurricanetrack/status/1038842229677334529

[Aric Dunn]

Next synoptic Gulfstream flight is in the air. 00z models again will be key.. especially since the ridge should begin to build in over the next 24hrs and hopefully the upper sampling can get some good data.