Date: 202012
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Weather elements / visibility: Snow
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Taxi
ATC / advisory: Tower ZZZ
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: Captain; Pilot Flying
Anomaly: Ground Event / Encounter Loss Of Aircraft Control; Ground Event / Encounter Weather / Turbulence; Ground Incursion Taxiway
Result: Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Airport; Human Factors; Weather
Primary problem: Weather

Narrative: After landing at ZZZ; during taxi from Runway XXL; the intersection at [Taxiway] 1 and 1X was braking action extremely poor. The Captain was unable to slow to turn and drifted through the intersection. With snow plows in the area to clear a route back to Taxiway 1 via 1Y; it was safer to not turn on the snow and ice and request the plows to clear a path to the Ramp.Cause - Poor taxiway conditions. Suggest quicker plowing at the Airport taxiways.


Second narrative: Landed ZZZ Runway XXL. Weather was near mins. ATIS was reporting RCC 5/5/5; with taxiways and aprons covered with snow covered icy patches. Prior aircraft reported braking action med-poor. The FO and I ran the numbers; after considering elevation; gross weight; and reported braking; the APS showed plenty of room to brake with a 1X;000 feet runway. After landing; we also reported 'medium to poor' braking action to Tower with the midfield having the poorest braking action. We taxied clear and had to advise Tower of our exit and position as visibility continued to drop. Clearance was given to taxi to ramp via [Taxiway] 2; left onto [Taxiway] 3; cross [Runway] XXR; right onto [Taxiway] 1 to 1Z; report clear of XXR. Taxi was slow as the taxiways had icy patches. We were also advised that the prior aircraft had taken 30 mins to taxi to their gate. On making left turn from [Taxiway] 2 to 3; it was readily apparent that the taxiways were indeed slippery as even a turn at 5 knots still allowed some traction issues. Upon nearing XXR westbound; we noticed XXR and [Taxiway 1] appeared snowed over (not cleared). After advising tower that we were clear XXR; and upon applying brakes for the turn northbound onto [Taxiway 1]; it became obvious the braking action was worse on the west side of the airport.  Once the aircraft came to a complete stop; we were past the centerline of [Taxiway] 1; or at least the best we could tell as the taxiways were covered with fresh snow (blue taxiway lights were visible). On a dry day with fillets; it would still be doable to make the turn. But with the taxiways in worse condition than I've ever experienced; we relayed to Tower the taxiway conditions and whether we could instead proceed straight via [Taxiway] X1 to X3 as the snow plow trucks were clearly visible on [Taxiway] X2. Tower advised the ground crew to clear [Taxiway] X2 to X3 and cleared us to the ramp.Cause - Bad weather; mainly icing under snow covered runways and taxiways.Allow PIREPs to more directly affect the RCC reported on ATIS. Even after we reported medium to poor braking action after the previous landing aircraft had reported the same; the ATIS was still indicating RCC of 5/5/5. This in my opinion is misleading and contrary to the whole purpose of reporting RCC's.


Synopsis: Air carrier flight crew reported a taxiway incursion in snow/icing condition and cited poor braking as a contributing factor.