Narrative:

I had just sat down to work sectors with heavy weather by the boundary of two sectors. Almost every aircraft in the sector airspace was deviating for weather. As I was sending clearances to other aircraft and getting multiple messages about moderate turbulence I received I got a message in my sector queue. Upon reviewing the message it alerted me to the fact that aircraft X was level at 35;000 ft. Instead of 34;000 ft. As shown in the coordination window between the sectors. The controller advised he had also just sat down at the sector.when I called the other controller to confirm altitude on aircraft X; the controller said that he was showing a radar hit of them level at 35;000 ft. When I alerted him that aircraft X was supposed to be at 34;000 ft.; the controller tried to reach aircraft X on frequency; but aircraft X was no longer on frequency. As soon as he said that I sent a cpdlc message to aircraft X to descend to and maintain 34;000 ft. Aircraft X had an immediate conflict with aircraft Y that started as soon as aircraft X progressed the boundary fix with an approximate crossing conflict of 4 minutes. While waiting for the aircraft X pilot to acknowledge their descent clearance via cpdlc; I called arinc and requested a phone patch with aircraft X. As I waited to be connected I probed aircraft Y to descend or climb; but was unable to move aircraft Y due to the fact they were deviating left of course; making the conflict with aircraft X worse; and also crossing traffic at both 34;000 ft. And 36;000 ft. While I waited to be connected via phone patch; aircraft X finally acknowledged their descent clearance. Upon connection of the patch aircraft X reported level at 34;000 ft. Aircraft X also had two other pieces of traffic at 35;000 ft. Eastbound that were more than 30 minutes out.upon review of the coordination between the previous controllers at the sectors it was confirmed that aircraft X was approved by the sector controller at 34;000 ft. And the controller had forgotten to descend him causing an immediate lack of separation. Ensure that all relief briefings are accurate and the post brief period of 5 minutes is ensured so that aircraft are at the correct altitude entering oceanic airspace.

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Original NASA ASRS Text

Title: Center Controller reported a traffic conflict between two aircraft when one aircraft had not been given clearance to descend.

Narrative: I had just sat down to work sectors with heavy weather by the boundary of two sectors. Almost every aircraft in the sector airspace was deviating for weather. As I was sending clearances to other aircraft and getting multiple messages about moderate turbulence I received I got a message in my sector queue. Upon reviewing the message it alerted me to the fact that Aircraft X was level at 35;000 ft. instead of 34;000 ft. as shown in the coordination window between the sectors. The Controller advised he had also just sat down at the sector.When I called the other Controller to confirm altitude on Aircraft X; the Controller said that he was showing a radar hit of them level at 35;000 ft. When I alerted him that Aircraft X was supposed to be at 34;000 ft.; the controller tried to reach Aircraft X on frequency; but Aircraft X was no longer on frequency. As soon as he said that I sent a CPDLC message to Aircraft X to descend to and maintain 34;000 ft. Aircraft X had an immediate conflict with Aircraft Y that started as soon as Aircraft X progressed the boundary fix with an approximate crossing conflict of 4 minutes. While waiting for the Aircraft X pilot to acknowledge their descent clearance via CPDLC; I called ARINC and requested a phone patch with Aircraft X. As I waited to be connected I probed Aircraft Y to descend or climb; but was unable to move Aircraft Y due to the fact they were deviating left of course; making the conflict with Aircraft X worse; and also crossing traffic at both 34;000 ft. and 36;000 ft. While I waited to be connected via phone patch; Aircraft X finally acknowledged their descent clearance. Upon connection of the patch Aircraft X reported level at 34;000 ft. Aircraft X also had two other pieces of traffic at 35;000 ft. eastbound that were more than 30 minutes out.Upon review of the coordination between the previous controllers at the sectors it was confirmed that Aircraft X was approved by the sector controller at 34;000 ft. and the controller had forgotten to descend him causing an immediate lack of separation. Ensure that all relief briefings are accurate and the post brief period of 5 minutes is ensured so that aircraft are at the correct altitude entering oceanic airspace.

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.