Narrative:

While en route to sgu; la center told me to 'expect the visual approach' into sgu. When crossing over MMM; I noticed a significant down pour between me and the airport. I mistakenly thought I needed to remain in VMC since I was to expect the visual approach. In addition I was concerned about the possibility of downdrafts associated with the down-pour since the forecast had called for isolated thunderstorms. I decided to deviate course 20 degrees to the right and follow the ground-track for the VOR/DME-a approach into sgu to remain clear of the weather. By making the turn; I was able to remain in VMC. However; I turned into higher terrain where I would be unable to maintain 2;000 ft ground clearance without climbing. The controller queried me and I responded that I was turning to follow the VOR/DME-a ground track. Whereupon the controller had me climb and maintain 10;000 ft for terrain clearance. After a brief conversation with the controller; I realized that when I became uncomfortable about going through the down-pour (and associated downdrafts) I should have: 1) requested the VOR/DME-a approach into sgu (which would have kept me clear of the weather) before deviating from my clearance; or; 2) requested to deviate 20 degrees right of course for weather before turning. The controller didn't realize I was in VMC and was concerned when I turned into higher terrain; rightfully so. In the future; I will better communicate my concerns to ATC and I will request a different clearance if I'm uncomfortable with the one I received. In addition; I will not deviate from the clearance I received.

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Original NASA ASRS Text

Title: An pilot approaching SGU IFR was told to expect a visual approach then deviated from the ATC assigned track because of weather and after approaching high terrain was given a climb clearance.

Narrative: While en route to SGU; LA Center told me to 'expect the visual approach' into SGU. When crossing over MMM; I noticed a significant down pour between me and the airport. I mistakenly thought I needed to remain in VMC since I was to expect the visual approach. In addition I was concerned about the possibility of downdrafts associated with the down-pour since the forecast had called for isolated thunderstorms. I decided to deviate course 20 degrees to the right and follow the ground-track for the VOR/DME-A approach into SGU to remain clear of the weather. By making the turn; I was able to remain in VMC. However; I turned into higher terrain where I would be unable to maintain 2;000 FT ground clearance without climbing. The Controller queried me and I responded that I was turning to follow the VOR/DME-A ground track. Whereupon the Controller had me climb and maintain 10;000 FT for terrain clearance. After a brief conversation with the Controller; I realized that when I became uncomfortable about going through the down-pour (and associated downdrafts) I should have: 1) requested the VOR/DME-A approach into SGU (which would have kept me clear of the weather) before deviating from my clearance; or; 2) requested to deviate 20 degrees right of course for weather before turning. The Controller didn't realize I was in VMC and was concerned when I turned into higher terrain; rightfully so. In the future; I will better communicate my concerns to ATC and I will request a different clearance if I'm uncomfortable with the one I received. In addition; I will not deviate from the clearance I received.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.