The basic weather launch commit criteria on the pad at liftoff must be:
- Launch can not take off is 24 hour average temperature has been below 41 degrees.
- The peak wind speed allowable is 30 knots.
- When the wind direction is between 100 degrees and 260 degrees, the peak speed varies for each mission and may be as low as 24 knots.
- None at the launch pad or within the flight path.
- Do not launch if lightning has been detected within 10 nautical miles of the pad or the planned flight path within 30 minutes prior to launch.
- Direct visual observation of the Shuttle is required through 8,000 feet. This requirement may be satisfied using optical tracking sites or a forward observer
- the vehicle integrity can be observed without interruption through 6,000 feet.
- the thickness of the clouds must be less than 500 feet