Question

After looking at the 1000 hPa maps for the initial time of the surface cyclone, I was 
curious since the forecast period is F00 - F30, is P1 considered to be initial time as 
well or is it 6 hours after the initial time?


Answer

P1 is considered to correspond to the time of F00
P2 - F06
P3 - F12
P4 - F18
P5 - F24
P6 - F30