Question about WRF real-time forecasting

[Hen Go]

Taking "NCAR ARW WRF 15km Forecast (WRF Real-Time Forecasting)" as an example.
It says "The WRF 15 km realtime forecast is a 72 h forecast initialized from the 00 and 12 UTC 0.5 degree NCEP GFS and uses WRF V3.5 code."

i wonder the model Initialized at 2023-09-25 00Z to make the 72h forecast, uses GFS0925.00 only, or uses GFS0925.00, GFS0925.06 (assuming the time interval of the GFS it uses is 6 hr)... to GFS0925.72

 

[Ming Chen]

WRF needs the GFS forecast products as input for running future forecast. Therefore, you will need GFS0925.00, GFS0925.06, GFS0925.00, GFS0925.12 etc. to produce initial and lateral forcing data.

 

[Hen Go]

WRF needs the GFS forecast products as input for running future forecast. Therefore, you will need GFS0925.00, GFS0925.06, GFS0925.00, GFS0925.12 etc. to produce initial and lateral forcing data.

Thanks for your kind reply,
and another question is that does this forecast require spin-up time period or it just straightly use the GFS data at 00z to initiate the simulation process