Narrative:

I took over the position as the supervisor was allowing the d-side to leave the sector. The traffic had lessened to a manageable point. I sat down and began working. Weather had moved into the sector and aircraft were deviating and getting bad rides. I managed to keep up for some time. Eventually; traffic built back up and it was to a point where I could not effectively manage the airspace. I look up to ask for help; but the supervisor nor a controller in charge is anywhere to be found. I managed to get another controller who was getting on break to come and help me out. Another controller comes back and relieves him on the d-side. At this point there is a full page on the edst (en-route decision support tool). Still no supervisor. Continue to work the traffic and I take a handoff on aircraft X at FL350. Aircraft X checks in saying they have light chop. After a few minutes; aircraft X advises that they need to deviate left of course for weather. I clear aircraft X to 'deviate left of course when able proceed direct flm.' aircraft X reads back the clearance and proceeds to turn left about 10 degrees. A few minutes go by and aircraft X is now nearing I92 airspace. I initiate a handoff. At the same time I92 is handing off aircraft Y who is southbound at FL350. The current heading and clearance of aircraft X will put them about 12 miles behind aircraft Y. Right around bwg; a small area of weather appears and I notice that aircraft X has turned right to about an 80 or 90 heading. They are heading right for the aircraft Y. At this time my d-side is talking to I92 to figure out what is going on. I turn aircraft X 15 degrees left which is a 045 heading. I92 had also turned aircraft Y left an unspecified amount of degrees. After separation was ensured I asked aircraft X if they had been cleared to deviate left. The pilot responded with 'yes but there's stuff popping up out here so we went right.' I then told the aircraft that they need to advise before turning and that he had southbound traffic that he had turned towards creating a situation. It was a pilot deviation.I should have been better at watching the weather and issuing depicted weather. That being said I had to change the altitude limits of the weather just to see what was out there. FL350 and above showed minimal weather. The aircraft X should have also advised me of any other deviations that were need prior to turning. Pilots need to understand that they are not the only ones in the sky and that their actions have consequences. The pilot knew he was only clear to deviate left and chose to turn right anyway. Thirdly; the supervisor should have been in the control room. At the time all of this happened; I was still in the process of 'righting the ship' from being busy and alone on the sector before.

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Original NASA ASRS Text

Title: ZME Controller reported an aircraft was approved to deviate left for weather. Minutes later he noticed the aircraft was turning right into oncoming traffic without permission.

Narrative: I took over the position as the supervisor was allowing the D-Side to leave the sector. The traffic had lessened to a manageable point. I sat down and began working. Weather had moved into the sector and aircraft were deviating and getting bad rides. I managed to keep up for some time. Eventually; traffic built back up and it was to a point where I could not effectively manage the airspace. I look up to ask for help; but the supervisor nor a CIC is anywhere to be found. I managed to get another controller who was getting on break to come and help me out. Another controller comes back and relieves him on the D-Side. At this point there is a full page on the EDST (En-route Decision Support Tool). Still no supervisor. Continue to work the traffic and I take a handoff on Aircraft X at FL350. Aircraft X checks in saying they have light chop. After a few minutes; Aircraft X advises that they need to deviate left of course for weather. I clear Aircraft X to 'Deviate left of course when able proceed direct FLM.' Aircraft X reads back the clearance and proceeds to turn left about 10 degrees. A few minutes go by and Aircraft X is now nearing I92 airspace. I initiate a handoff. At the same time I92 is handing off Aircraft Y who is southbound at FL350. The current heading and clearance of Aircraft X will put them about 12 miles behind Aircraft Y. Right around BWG; a small area of weather appears and I notice that Aircraft X has turned right to about an 80 or 90 heading. They are heading right for the Aircraft Y. At this time my D-Side is talking to I92 to figure out what is going on. I turn Aircraft X 15 degrees left which is a 045 heading. I92 had also turned Aircraft Y left an unspecified amount of degrees. After separation was ensured I asked Aircraft X if they had been cleared to deviate left. The pilot responded with 'yes but there's stuff popping up out here so we went right.' I then told the aircraft that they need to advise before turning and that he had southbound traffic that he had turned towards creating a situation. It was a pilot deviation.I should have been better at watching the weather and issuing depicted weather. That being said I had to change the altitude limits of the weather just to see what was out there. FL350 and above showed minimal weather. The Aircraft X should have also advised me of any other deviations that were need prior to turning. Pilots need to understand that they are not the only ones in the sky and that their actions have consequences. The pilot knew he was only clear to deviate left and chose to turn right anyway. Thirdly; the supervisor should have been in the control room. At the time all of this happened; I was still in the process of 'righting the ship' from being busy and alone on the sector before.

Data retrieved from NASA's ASRS site 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.