As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT TAXIING OUT OF MSN FOR DEPARTURE IN A HEAVY DOWN POUR WHEN THE AIR DATA COMP FAILED FLAGGING ALTIMETER, ALTITUDE ALERTER HORN AND FLAGS. TAXIED BACK TO WISCONSIN AIR. REMOVED AND REPLACED AIR-DATA COMPUTER, AIRCRAFT REMAINS RVSM COMPLIANT.