Commercial Fixed Wing
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 6
Communication Breakdown; Human-Machine Interface; Situational Awareness
ATC Issue All Types; Airspace Violation All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Issued New Clearance
ATC Equipment / Nav Facility / Buildings; Aircraft; Procedure; Weather
Aircraft X departed Bozeman; climbing on the BOBKT-4 Departure procedure through about 7000 or 8000 feet the flight crew advised; due to weather ahead on the BOBKT-4; they wanted to turn to the south. Well; they were in my 9000 MVA; heading towards an 11000 MVA about 5 miles ahead and any turn except southwest or west was not going to work. I instructed the pilots; 'leaving niner thousand turn right heading 190; vector for weather [which we don't depict] and higher MVA's.' On hot days like today; Aircraft X's perform poorly. Evaluating their ground speed vs. rate of climb; I grew concerned that they were not going to reach 9000 and start the right turn and hit the 11000 MVA so I asked if they could 'provide their own terrain obstruction clearance through one one thousand' to which they replied; 'Negative. Nine thousand is about the best we can give you.' At this time they were struggling through 8800 so I changed the heading for the turn; out of 9000 to 250 to avoid the 11000 MVA and instructed them to 'make it a tight turn.' They were about 2-3 miles from a portion of the 11000 MVA and I needed the turn; like; now. They started turning but I wasn't feeling good about it and told them to keep the turn right; heading 270; which they acknowledged and complied as best they could. They were out of 10000 now. Aircraft X completed the 150* from H120 to H270 as I dialed the range on my scope in to about 20 miles. I watched the fused target drag the edge of the 9000/11000 line for a sweep or two as Aircraft X climbed through 10200 or so. I'm not certain if it was a violation of the 11000 MVA; so I submit this report in case it is flagged. The position symbol didn't encroach on the line delineating the 11000 MVA but the blue fused dot touched it. I think I'm good; but erring on the side of caution. Well; it would be really; really nice to have a weather feed on our Bozeman STARS sector! There were CWA's and SIGMETs out for the area east and southeast of BZN. The METAR and SPECI's at the field indicated lightning to the distant SE. This was the first departure I had in that direction (3 prior departures took VFR climbs on-course to the north so it sounded like it wasn't so bad out there). I didn't know how far 'distant SE' was. Turns out it was pretty close. That corner; 10-20nm to the southeast of BZN is a real bitch. We have a very narrow sliver of 9000 MVA then a jump to 11000 MVA right after it. It's an east/west canyon that the departure procedure flies through and through which RNAV approaches descend even below our MVA's. Once they're cleared on an approach; or on the BOBKT-4 we can't really touch them. Further; we always lose radar for a portion of those arrivals through the pass from 20 to 15 nm. It's disconcerting. When planes can't perform (due to heat like today or just a poor performing / non-turbojet aircraft) or they ask for something unexpected; we suddenly find ourselves painted into a corner. That's not a good feeling. These [airline] pilots conveyed urgency and it was clear they weren't about to turn to the east into the [weather]; so I had to get them out of there. I figure; if I'd had better awareness; (I was working on arrival sequence and using lots of vertical with overflights and pilots deviating 30 nm out of the way around weather over Livingston; also in our airspace) I would have queried the departure sooner to see how the climb-out corridor looked. Taking them off the BOBKT-4 is the last thing you want to do! They're low and outside the Primary DVA [Diverse Vector Area] anyway. Had I known that BOBKT-4 departures would put them directly into a storm within miles after departure; I'd have released Aircraft X with the Tower on a westerly heading within our DVA and right turns around for Billings on course and we wouldn't be having this discussion. In this scenario: I had nowhere to go but west and to impress upon the pilot how urgently he needed to make that right turn.
BOI TRACON Controller reported commercial fixed wing failed to turn adequately to avoid higher MVA. ATC sector does not display weather to assist aircraft safely avoid weather.