Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 3.5
Situational Awareness; Workload
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT; Inflight Event / Encounter Weather / Turbulence
Airspace Structure; Company Policy; Human Factors; Staffing; Weather
During weather deviations BOI Approach called to request approval for a routing and altitude of 10;000 feet on an aircraft. The route given to me seemed incomplete so I had to then ask the 'controller' where he would go after [fix]. I looked at the route which took the aircraft through several areas of precipitation that had been causing problems with aircraft. The route then took them through an area where the minimum IFR altitude would go to 10;900 feet. During the coordination I had several aircraft calling me; and the other lines lighting up for me. I told Approach 'Unable' and gave my initials and hung up the line. Approach then started proposing a new route over the line. I answered and told them 'Unable' again and that I didn't have time.  A few moments later my supervisor walked to my scope while on the phone; and said something along the lines of; 'Yeah; at 10;000 should work.' and hung up the phone. Approach then entered the routing and altitude into the NAS. Approach has now cleared; without my approval; an aircraft through known weather and through an MIA (Minimum IFR Altitude) 900 feet higher than the assigned altitude of the aircraft. It was my understanding that weather is the number one contributor to aircraft crashes in the NAS. The supervisor didn't know that the conversation had happened on the line between Approach and me so I truly don't believe it was his intent to go behind my back and approve an operation I had deemed unsafe. I was relieved from position before the handoff was accepted into my sector.I didn't realize calling the supervisor was an alternative to doing actual air traffic control. Unfortunately Handoff positions are not instantaneous; as we don't have the staffing to keep an eligible handoff controller in the control room at all times as the FAA locally deemed must be done due to safety; but is not so safe to keep doing if it means spending money.The moment of complexity was fleeting; so calling for a handoff would have been futile. It's disheartening to think the controller who knows what is happening in the sector and where it is and isn't safe to fly an aircraft can be so easily circumvented to have an aircraft put in an unsafe situation.
ZLC Center Controller reported denying a routing request to BOI Approach Control due to weather and terrain. Approach called the Center Controller's Supervisor who approved the route.