A320
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 200; Flight Crew Total 20000; Flight Crew Type 10000
Inflight Event / Encounter Weather / Turbulence
Flight Crew Diverted; General Declared Emergency
Weather; Aircraft
Un-forecast fog quickly developed during our approach into Airport ZZZ. The RVR at ZZZ was approximately 1;000 feet and holding steady. This Airbus is not authorized for autoland at ZZZ1 so our minimum visibility was 1800 RVR. Airport ZZZ1 was near minimums and just out of fuel range. Airport ZZZ2 was below minimums. The only airport within fuel range that had weather at or above minimums was Airport ZZZ3. ZZZ3 was long enough; wide enough; in the database; and we had charts. We notified dispatch we were going to divert to ZZZ3. Dispatch notified us that ZZZ3 is not approved for the Airbus and we would need to declare an emergency. We declared an emergency and landed at ZZZ3.
On final approach the weather at Airport ZZZ went below CAT 1 minimums and because of The Airbus limits we were not able to Autoland at ZZZ. Because of the un-forecast low visibility we needed to divert to a safe suitable airport. Airport ZZZ2 was also below minimums and we did not have adequate fuel to safely proceed to any other airports that were not in the area. We discussed our options with Dispatch and he suggested that we declare an emergency and divert to Airport ZZZ3 field. At the time of diversion ZZZ3 had weather that was above our landing minimums so we proceeded to ZZZ3 without incident.
A320 flight crew reports arriving at their destination in their CAT I restricted aircraft; to find the weather below minimums along with all nearby alternates. A suitable field is identified by Dispatcher and advises it is not approved for the A320; but could be used if an emergency was declared. Flight crew declares an emergency and lands.