Date: 201310
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: Marginal
Weather elements / visibility: Fog
Light: Night
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Landing
ATC / advisory: CTAF ZZZ
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Fatigue; Communication Breakdown; Situational Awareness; Time Pressure
Anomaly: Flight Deck / Cabin / Aircraft Event Other / Unknown; Inflight Event / Encounter Weather / Turbulence; Inflight Event / Encounter Fuel Issue
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Executed Go Around / Missed Approach; Flight Crew Diverted; General Declared Emergency; General Flight Cancelled / Delayed
Contributing factors: Human Factors; Airport; Company Policy; Weather
Primary problem: Weather

Narrative: Last leg of our day; the Captain and I reviewed the flight release prior to departure. Our destination was currently reporting a beautiful VFR evening; with the TAF not showing the overcast to move into the area until early morning. We were due to arrive prior to midnight. Dispatch planned us with a normal 'VFR Type' planned fuel with no alternate; expecting to land with about 2;300 LBS (1 hour). As a crew we agreed we could complete the flight safely and off we went.About 15 minutes out we were informed that a flight 10 minutes ahead of us didn't get a visual on the field till they were about five miles from it. The weather was obviously starting to move in much sooner than forecast. As luck would have it; the ILS was OTS this night; and the lowest you could get down on any other approach was about 1;300 AGL. The clouds were beginning to form much lower than this however. Prior to commencing descent; we checked the AWOS; and it was still reporting VFR. As we approached the field; we were able to get a visual on it at about five miles as well; as we set up on a right downwind for [Runway] 14. We called the field and switched to CTAF. The way the clouds were forming made it so that looking straight down onto the field allowed you to see it quite plainly; however; as we rolled out onto a 4 mile final we had absolutely nothing in sight. We initiated a go-around and began to size up our options. We very briefly contemplated attempting to set up for an approach to Runway 32; but we checked the AWOS during our go-around and the current conditions were now being reported at 1/4 SM; 200 OVC! The combination of the surrounding terrain/night condition; the rapidly changing weather; the critical fuel state; and the uncertainty of actually being able to land here at all made us very quickly decide that we needed to divert ASAP. We started a climb out towards the VOR north of the airport; re-contacted Center; and asked for the current weather at a normal airport a hundred miles north of us. Thankfully it was showing 10 SM/CLR; so we decided that this was our best option. We ran some rudimentary numbers; contacted Dispatch; and figured that we would land with 1;300 LBS. We declared a fuel emergency with Center and proceeded direct. We referenced our performance flip cards and flew at max range cruise speed. The Captain left me to fly while he coordinated with the company; station ops; the flight attendants and then informed the passengers. We landed shortly thereafter with 1;250 LBS (about 30 minutes fuel). The passengers were all provided hotels for the night and we ended up flying them back to their original destination the next morning.I have run through the events of last night several times in my head now; and I feel that we acted appropriately and efficiently once we realized we were in a dangerous situation. I feel that the Captain and I worked very cohesively once we were subject to the pressure of time; and I cannot look back on our actions and say that I would do anything differently with regards to that. I really feel like we handled this emergency by the book; and we reacted exactly as we are trained. I do; however; feel like I should have known better before we even left the ground. Although the release looked fine and legal; airports like this one are notorious for rapidly forming overcast layers at this hour of the night. I probably should have seen this one coming; but as the routine schedule pressures; fatigue; and complacency factors surely effected our secure belief that this situation would not happen to us this night. Another contributing factor that didn't help our cause was the fact that the Captain was a Midwest based crewmember; who rarely flies west and didn't necessarily know the 'personality'; so to speak; of airports in mountainous; often moist terrain. This was a place where I really should have advocated more early on. I remember flying in and out of there many times during my firstyear on the job; and I recall it being the norm that we would take extra fuel; regardless of what Dispatch had to say; and regardless of what the release looked like. I know my story is probably a common one; but I cannot help but feel extremely humbled by this. I believe that I learned more in one night than perhaps I have in my entire last year on the job.




Synopsis: A CRJ flight crew dispatched with minimum VFR reserves found their destination in mountainous terrain below minimums and had to divert and declare a fuel emergency. They landed at their diversion station with about 1/2 hour of fuel remaining.