This says the TVCN is a combination of: AVNI (GFS), EMXI (ECMWF, or Euro), HWFI (HWRF), CTCI (NRL COAMPS-TC w/GFS initial boundary conditions), and EGRI (UKMet)
https://www.nhc.noaa.gov/modelsummary.shtml
Hurricane Center has wind products here...
https://www.nhc.noaa.gov/refresh/graphics_at1+shtml/145000.shtml?tswind120#wcontents
https://www.nhc.noaa.gov/refresh/graphics_at1+shtml/145000.shtml?mltoa34#contents
Latest UKMet run (12z) moves it thru Jacksonville, NC / Emerald Isle area, then into SE portion of VA. Previous run at 00z brought it into Cape Hatteras
5AM NHC Disco...
The upper-level environment is expected to improve to significantly
during the next 12 h and beyond with the current 20 kt of
southwesterly shear forecast to give way to shear of less than 10
kt. By 72 h and beyond, light shear from the southeast and east
along with the development of strong upper-level outflow jets to
the north of Florence is expected to create an environment that
favors significant and possibly even rapid strengthening. The new
NHC intensity forecast has been increased over the previous advisory
in anticipation of these very favorable dynamical conditions
developing, and now shows Florence becoming a hurricane by Sunday
and a major hurricane in 3 days, followed by additional
strengthening over the very warm Atlantic waters of at least 29 deg
C that are about 2 deg C above normal right now. The consensus
models IVCN and HCCA were closely followed, which are a little
below the FSSE model.
FORECAST POSITIONS AND MAX WINDS
INIT 08/0900Z 24.5N 54.2W 55 KT 65 MPH
12H 08/1800Z 24.6N 55.0W 60 KT 70 MPH
24H 09/0600Z 24.6N 56.0W 65 KT 75 MPH
36H 09/1800Z 24.6N 57.2W 75 KT 85 MPH
48H 10/0600Z 24.9N 59.0W 90 KT 105 MPH
72H 11/0600Z 26.0N 64.0W 105 KT 120 MPH
96H 12/0600Z 28.0N 70.2W 120 KT 140 MPH
120H 13/0600Z 30.9N 75.8W 125 KT 145 MPH
It's an abbreviation for 500mb...the movement and evolution of upper atmosphere waves are big pieces of the puzzle when it comes to forecasting and these are most commonly tracked at the 500mb level (5H or h5).
It's looks like both the HRRR and the NAM 3km pivot the precip shield and back-build the trailing large band associated with the upper wave overnight and swing it through overnight and into the AM
You can see on the CC radar a surge of warmth as the snow vs other line races up to I-85 in the upstate and NE from there to Mooresville area. Basically, the atmosphere can feel Mack's warmth coming up from Columbia
Looking at the HRRR, it does show this surging warm nose (not to be mistaken with the pre-storm warm bubble) and it hangs in the upstate to CLT corridor until overnight into sunrise unfortunately
The benefactor of this surge will be those just to the north of it who are cold enough for snow, maybe Hickory to Morganton to Winston
The 3km NAM has convective shower/thunderstorm cells rolling through SE GA into S SC, so the model is indicating that those storms could rob the moisture transport into central NC...we'll see
GFS and Euro both roll comma head precip through NE GA into the western Carolinas in the overnight to late morning timeframe....should keep the snowy mood going in those regions. This makes sense given that the trough axis is still as far west as the Mississippi/Alabama border at 4AM. It won't fully clear out until that trough axis swings through. Accumulations will be more efficient once the sun goes down...it makes a difference.
GSP update, ha...
.NEAR TERM /THROUGH TODAY/...
As of 1230 AM EST Friday: No changes. Will address the near term
with the new fcst package. Suffice to say the wheels have not
fallen off...yet.