n12365
Pre-takeoff checklist
I have never understood why the 24 hour forecast prog chart is never valid 24 hours from when it is issued. I could understand if it was 30 minutes less than a full 24 hours, but the attached 24-forecast is valid 19 hours and 15 minutes from when it was issued. This is significantly less than 24 hours. It is still a useful tool, but I think it would be more appropriate to call it the 18 hours forecast. Can anyone help me understand this?