Widebody; Low Wing; 2 Turbojet Eng
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 16
Situational Awareness; Time Pressure; Communication Breakdown
Conflict Airborne Conflict; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Separated Traffic; Flight Crew Returned To Clearance
Human Factors; Procedure; Weather
Aircraft X requested deviation west of 40 miles for weather. After probing clearance; I determined deviation could be approved at FL370 or FL390; and sent this information to pilot through HF. Pilot responded that he was beginning deviation without receiving a clearance. ATOP showed his position converging with another flight and the adjacent airway to the west at FL380. Established phone patch with Aircraft X through Commercial Radio and cleared him to immediately descent to FL370 and gave traffic. No alert was generated by ATOP; even though separation was diminished.Would have liked ATOP to show the conflict; although this did not affect my response.
ZNY Oceanic Controller is advised that a flight needs to deviate for weather. Controller sends information that deviation is approved at FL370 or FL390. Aircraft is at FL380 and deviates prior to receiving message and is a conflict for another aircraft at FL380.