The weather for tomorrows SpaceX CRS-2 launch predicts an 80% chance of favourable weather for the launch.
With scattered stratocumulus clouds between 4,000 and 6,000 feet and broken altocumulus between 14,000 and 18,000 there should be good visibility. The winds are predicted to be gusty, but below lift-off limits.
With a temperature of 60F it will be quite cool, but there is 0 chance of rain. The main concerns for violation of launch criteria are Thick Clouds and liftoff winds.