Originally Posted by
NoelEvans
How does SFO cope when the weather is down to Cat I (or lower!) conditions? (LHR 'stumbles' when it gets below Cat I and increased approach spacing is needed, but copes quite well in Cat I.)
When visuals are not available in SFO they issue ground stops to the domestic US traffic planned into SFO. They then begin to cancel flights in addition to the ground stop. In general the regional jet flights are canceled first but airline op centers often make the call as they are given a number of operations that must be canceled and they decide which flights. City pairs like LAX-SFO also get hit hard as there are so many flights it makes rebooking easier. International operations are for obvious reasons not subject to any of this.