EMB ERJ 145 ER/LR
Flight Crew Air Transport Pilot (ATP)
Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Unstabilized Approach; Inflight Event / Encounter Fuel Issue; Inflight Event / Encounter Weather / Turbulence
Flight Crew Diverted
Company Policy; Weather
Departed for [our destination] with no adverse weather in METAR or TAF. During the arrival ATC notified us of a significant wind shift causing a runway change; planned Runway XX changed to Runway XY. We had plenty of time and briefed for the new runway. We continued our approach and inside the final approach; we encountered an increasing performance windshear. A missed approach was executed and no altitude was lost. Initially we had planned to come back around for another approach until we noticed our fuel on board and realized another missed approach would put us in a critical situation; possibly forcing us to land with windshear present. A quick check for nearby airports and a check with dispatch resulted in an unplanned divert to [nearby airport]. We climbed to 10;000; declared minimum fuel and proceeded to [nearby airport]. During the diversion we saw the FMS had us planned to land with 1;000 LBS Fuel On Board (FOB) and [we advised ATC of] emergency fuel [situation]. We delayed our descent to conserve fuel and landed with approximately 1;300 LBS.Unforecasted weather was the obvious threat. Also; the minimum fuel load contributed to the situation. I really can't see any errors that were made. As for the Unwanted Aircraft State (UAS); it was definitely landing at an unplanned alternate well under minimum fuel.I feel the fuel loads should be increased when flying into mountainous terrain as mountain wave can cause windshear. I believe this is what happened to us and I'm not sure what else; as a crew; we could have done different. We had briefed our windshear procedures prior to joining the final approach but with no alternate planned; our choices were very limited in the event of a go around. The cost index fuel planning works most of the time; but certain areas should not be planned with those numbers in mind.
[Report narrative contained no additional information.]
EMB-145XR flight crew reported a low fuel situation resulted from a wind-shear induced go-around and diversion to an alternate.