Date: 202007
Local time of day: 0601-1200
Location: ZZZ.ARTCC, US
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Communication Breakdown; Situational Awareness; Workload
Anomaly: ATC Issue All Types; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Environment - Non Weather Related; Human Factors
Primary problem: Environment - Non Weather Related

Narrative: Departed ZZZ's XXR on the SID. ZZZ Departure gave us a climb to 15;000 feet; and handed us off to Center. We attempted to check in with no success. Other aircraft on frequency; were also not able to communicate with this frequency. After several minutes of cruising at 15;000 feet another aircraft on frequency said he was able to contact Center further east; and that they were at FL190. We continued on our route at 15;000 feet. More aircraft handed off from ZZZ Approach began to attempt to check in unsuccessfully. Two or three times we returned to ZZZ Approach to try and get another frequency to no avail. ZZZ Approach was saturated with radio traffic and was confused as to why we kept coming back to him. For approximately 15-20 minutes we flew on the route at 15;000 feet attempting to check in. Gradually; we could hear the Controller as we continued eastbound. Finally we had the Controller loud and clear and attempted to check in. The Controller was saturated with traffic working on multiple frequencies. For another 5-10 minutes we attempted to check in but were unable. The aircraft continuing to come onto the frequency made most calls blocked. As we continued on the route; a large line of weather running north/south of our course with tops over FL650 had solidified making any chance of flying through the line impossible. We needed a deviation to the north to end-run the line of severe storms by fling north; from our easterly course. We were unable to check in with Center as we approached 60 miles to the line of weather. I instructed the FO that when we got to forty miles from the line; we would PAN PAN the frequency; and turn north parallel to the weather. There were several aircraft to our 8 to 9 o'clock position that we were concerned about in the case of turning north. Turning south was not an option. Right at 40 miles; we were able to check in; and get a turn north. The Controller was doing the best he could. The volume of radio traffic on this frequency cannot be understated. Luckily; our dispatcher had included two alternates for our destination and we had the fuel to be able to continue for an extended time at 15;000 feet and FL190 which consumed far more fuel than planned. I managed the flight to reduce fuel consumption; monitored the destination weather closely and landed with plenty of fuel reserves. I give the event a 'serious' risk rating due to the surrounding aircraft that would have been involved in case of an unplanned turn by us in order to avoid severe thunderstorm penetration.The main causal factor is ATC's under-staffing due to COVID-19. Having flown during the last week of June; into the first week of July; I have noted ARTCC facilities being overworked. Calls are being missed; check-ins taking longer; and confusion caused by controllers assigned multiple frequencies. The level of air traffic has gone up dramatically over the last two weeks; especially starting in July. A possible contributing causal factor is the airline industry adding flights faster than ATC can handle them and a possible lack of coordination between the airline industry and the FAA's ATC.Airline should work with ATC management to discuss the added flights and the capabilities of ATC ARTCC's. Perhaps there is a way to better coordinate with vulnerable ARTCC's to alternate departures/arrivals to set a more manageable pace for controllers in their sectors.




Synopsis: Air carrier Captain reported communication issues with Center and attributed it to COVID-19 ATC staffing of facilities.