Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 164; Flight Crew Type 8961
Situational Awareness
Deviation / Discrepancy - Procedural Clearance; Ground Excursion Taxiway
Flight Crew Became Reoriented
Airport; Weather; Human Factors
During taxi out for takeoff holding in line for departure at runway 23R with thunderstorms in vicinity and rain having just passed over airport; we were instructed to follow the aircraft in front of us onto 23R and back taxi. We queried controller if  the airport was being turned around for a 05L departure and ground said yes.  Aircraft we were following was going much faster and we saw him turn off to right near the end of the runway and tower then told us continue to follow him and turn off at taxiway B2. There was a lot of standing water on runway and taxiways and as we approached signage for B2 we agreed that this was our turnoff. I initiated a slow right turn and could not see any paint markings but this was not unusual for MEX as they have ungrooved runways and there is always standing water after it rains. As I was about to turn left onto taxiway B to continue to 05L I realized we had crossed to taxiway B on an island not B2. There were no obstructions on the island and I only saw one yellow light off my left side. The taxi was smooth and nothing abnormal was felt or seen. The striped yellow paint of the island was not visible until we were looking at it from a different angle.
A319 Captain reported being cleared to back taxi on Runway 23R at MMMX and exit at Taxiway B2. Standing water from a recent thunderstorm made taxiway lines invisible and the aircraft was inadvertently taxied across an 'island' on the way to Taxiway B.