Narrative:

We were on a heading diverting north of ZZZ at FL340 when the first officer side pitot froze up. Right at this time we both saw lightning flashes and smelled something burning (may have been ozone). EICAS showed an sps [stall protection system] advanced and mfd had a cas message. Airspeed on first officer side started dropping and eventually went to zero and displayed no data (X's). Autopilot failed and we requested a descent to get down to an altitude where the temperatures would be above freezing. Our alternate was ZZZ1 and we declared an emergency and told center that we wanted to divert there. In the descent the pressurization failed. We notified dispatch and maintenance that we were diverting. We told the flight attendant that we were diverting and made an announcement to the passengers. Once we got around 10;000 the pitot unfroze and the aircraft was back in a desirable aircraft state. We continued with the diversion to ZZZ1 and landed uneventfully. Taxi to gate and called maintenance control to have contract maintenance sent to the aircraft. Pitot system frozen (air data computer failure) with convective weather nearby. Other than exiting freezing conditions I don't think there was much more we could do. Our destination airport had gone into holding for the same line of weather we were trying to avoid and we were not going to head into holding with an air data computer failure & possible lightning strike.

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Original NASA ASRS Text

Title: EMB-145 Captain as flying pilot reports loss of the First Officer's airspeed indication at FL340 along with lightening and a burning smell. Captain elects to divert to an alternate and an emergency is declared. During descent the pressurization system failed and the First Officer's airspeed indicator begin working.

Narrative: We were on a heading diverting north of ZZZ at FL340 when the First Officer side pitot froze up. Right at this time we both saw lightning flashes and smelled something burning (may have been ozone). EICAS showed an SPS [Stall Protection System] Advanced and MFD had a CAS message. Airspeed on First Officer side started dropping and eventually went to zero and displayed no data (X's). Autopilot failed and we requested a descent to get down to an altitude where the temperatures would be above freezing. Our alternate was ZZZ1 and we declared an emergency and told Center that we wanted to divert there. In the descent the pressurization failed. We notified Dispatch and Maintenance that we were diverting. We told the Flight Attendant that we were diverting and made an announcement to the passengers. Once we got around 10;000 the pitot unfroze and the aircraft was back in a desirable aircraft state. We continued with the diversion to ZZZ1 and landed uneventfully. Taxi to gate and called Maintenance Control to have Contract Maintenance sent to the aircraft. Pitot system frozen (ADC Failure) with convective weather nearby. Other than exiting freezing conditions I don't think there was much more we could do. Our destination airport had gone into holding for the same line of weather we were trying to avoid and we were not going to head into holding with an ADC failure & possible lightning strike.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.