Date: 201907
Local time of day: 1201-1800
Location: ZJX.ARTCC, FL
Weather elements / visibility: Thunderstorm
Aircraft: HS 125 Series
Flight plan: IFR
Flight phase: Descent
Airspace: Class A ZJX
ATC / advisory: Center ZJX
Second aircraft: Super King Air 200
Reporter organization: Government
Reporter function: Enroute
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Situational Awareness
Second reporter function: Enroute
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Inflight Event / Encounter Weather / Turbulence
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued New Clearance
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: Adverse weather over the Orlando complex forced all traffic over the east coast. Navy owned the Warning Areas over the water up to FL300. This created a small amount of airspace to work climbing and descending aircraft. Aircraft X was landing SUA and given a time to descend clearance to get under a SUA departure; Aircraft Y. The clearance was not complied with and separation was lost. I was the D-side in this scenario and my time was monopolized with coordination from outside facilities including the Navy. This situation could have been completely avoided had the facility been able to recall the Warning Areas over the water.


Second narrative: The Sector was impacted with thunderstorms and airspace constraints due to active SAA (Special Activity Airspace) on the east coast. Part of the SAA was active AOB (At Or Below) FL300 and the other portion was active AOB FL430. There was an attempt to resume departing aircraft from Orlando (F11) but that had to be shut down within 10 minutes due to traffic complexity; volume and weather. While I was organizing the traffic and recovering from the departures; the D-side and I realized we had a good window to get Aircraft X (level at FL 300) down for his restriction (center boundary AOB FL 220) landing Stewart (SUA). The timing was even more important because on our southern boundary there was an aircraft orbiting in a changing block altitude from FL250-270 and FL270-290. Additional we were working northbound; deviating overflights from ZMA that had to be issued new routes due to their inability to fly over the center of the state. Aircraft X had one piece of traffic which was Aircraft Y (level at FL250) on a northeast bound track; deviating from the weather and about 60 miles south of Aircraft X. I felt confident in the descent clearance issued to Aircraft X; 'descend to be at or below FL240 in 6 minutes or less; then descend and maintain FL220'. The pilot read this back and I had to move on. I also believe I finished these instructions with the information that this restriction was for northbound deviating traffic at FL250. After a few minutes of moving through work related to the other traffic; CA (Conflict Alert) flashed this pair of aircraft. Conflict Alert is a great tool and has saved a lot of potential traffic issues. Having said that; almost every time I use a time to climb or descend clearance that results in the desired separation; conflict alert goes off sometime in the process. I wasn't surprised when the alert started and I used this moment to remind Aircraft X that he had about 2.5 minutes left to get under the FL250 traffic. The pilot stated he would hurry down and the situation looked just the same as most tight; but going to work evolutions. A few moments later it became obvious to me that I had to turn these aircraft and started with 30 degrees left on Aircraft X. I also asked the pilot to report reaching FL240 as soon as possible. I then issued a traffic alert to Aircraft Y and turned this aircraft 30 degrees left with the word 'Immediately'. After regaining separation I cleared these aircraft back on course and continued to work through other traffic. I eventually read the 'Brasher' warning to Aircraft X because I felt he missed his time clearance and there was a possibility of a pilot deviation.Through this event I've learned I have to start giving a larger buffer while using time clearances. I'm aware that when I restated the time the pilot had left; I may have been off by 30 seconds and should have been more precise. I also realize there was ample opportunity to just stop Aircraft X above Aircraft Y. I didn't take that route because my 'Expectation Bias' felt this was going to work.I also recommend not putting aircraft and Controllers in this unsafe situation. The 7110.65 Appendix B. was drafted because Controllers were being asked to work aircraft near thunderstorms and through active SUA's (Special Use Airspace) while hoping the military would continue to approve point outs. Appendix B. was not being followed during this event. There seems to be a constant conflict between safety and keeping the customers moving through the NAS during thunderstorm season. I was trained with a 'make it work' attitude and we at ZJX make a lot of things 'work' with a large amount of accepted risk. In hind sight I feel I should have told my supervisor I should not be working these aircraft AOB FL310.


Synopsis: ZJX Controllers reported problems with separation and special use airspace during thunderstorm season.