At ~ 7:38 Pm Westmoreland 911 dispatched Station 20 (Murrysville VFC) to establish a helicopter landing zone at the Station 20 Fire Grounds in support of Station 610 (Murrysville Medic One) and STAT MedEvac. Station 20 responded with Engine 20 (6 firefighters including Chief 20, Captain 20, and Sergeant 20), with 16 firefighters (including Assistant Chief 20) on station standby. Chief 20 established the command as Engine 20's crew established the landing zone. Medic 613 arrived with the patient, and the STAT MedEvac Aerial Ambulance arrived on scene. However inclement weather and patient status precluded the aerial evaluation, so Medic 613 transported the patient to a local trauma center. Engine 20 remained on station until the weather cleared so the aerial ambulance could take-off. Upon the departure of the aerial ambulance, Command 20 returned Engine 20 to service and station.