EMB-145 crew reported severe turbulence and altitude excursion at cruise when deviating around thunderstorms. The aircraft exited the area of weather and continued the flight without injuries.
Synopsis
EMB-145 crew reported severe turbulence and altitude excursion at cruise when deviating around thunderstorms. The aircraft exited the area of weather and continued the flight without injuries.
Narrative
In between waypoints ZZZZZ and ZZZZZ1 intersection at FL360; PF (Pilot Flying) and PM (Pilot Monitoring) have been keeping a close eye on a squall line passing through the sector. After some discussion we decided we would stay the course but looking for an opening that would provide the least turbulence. We heard a radio call between an Aircraft Y flight and ATC advising them that storms are below FL330 and that FL360 is fine. Upon hearing that we became sure of our decision to press on. About 10-15 mins later Aircraft Y had alerted ATC that they were experiencing moderate to severe turbulence and requested deviation to the right. We checked our radar and saw in the direction of our route that there was a section of the squall line with tops at FL400. We then discussed and agreed to also deviate to our right to avoid that section. About 10 mins after we encountered severe updraft with severe turbulence; showing extensive airspeed fluctuations; VSI +6000fpm for about 20 secs. AP (Autopilot) kicked off and we were unable to maintain altitude to a point we briefly hit FL390 before immediately pushed back down to FL360. We acted on training and PF flew the aircraft while I handled all other responsibilities. We asked ATC immediately for altitude relief which we got; deviated to our left to avoid the situation. CA (Captain) side PFD (Primary Flight Display) lost airspeed/altitude/VS information after about 1min with EICAS message showing IC1WOW INOP and SPS ADVANCED. We consulted the QRH on the two issues while hand flying with ISIS. Problem did not resolve following QRH. FO (First Officer) side instruments were working in conjunction with ISIS so we selected ADC2 and changed the AP couple side to FO side. Exited the storm and was able to continue enroute to our destination. No injuries reported. Cause: Inadvertent entry into an active developing cell with the information at hand. Suggestions: Choose the best path of least turbulence; stay at least 5000 ft. from top of cells to clear the storm; stay 20 NM away from storm cells. Make decision early to deviate for the best path as early as possible.
Second reporter narrative
We were between ZZZZZ and ZZZZZ1 intersection at FL360 above the storm cells. We discussed about deviation plans and consulted ATC. ATC advised storms are below FL330 and previous traffic stayed on course at FL360; so we decided to stay and keep monitoring the situation. Minutes later Aircraft Y in front of us at FL360 reported moderate turbulence and asked for higher; ATC told them unable FL370. Moments later we got into IMC and started moderate chops. We immediately asked for right deviation based on the info we had. After we turned; we encountered severe updraft showing extensive airspeed fluctuations; VSI +6000 fpm momentarily. Auto pilot kicked off. We were unable to maintain altitude so we immediately asked for and got the altitude relief from ATC. CA (Captain) side PFD (Primary Flight Display) lost airspeed/altitude/vs information. We hand flew using ISIS. Once airplane stabilized; PM (Pilot Monitoring) run QRH on the two EICAS messages IC1 WOW INOP & SPS ADVANCED; did not fix the issue. We saw FO (First Officer) side instruments are working so we selected ADC2 and changed the AP (Autopilot) couple side to FO side. This time autopilot stayed; we exit storm and were able to continue enroute. We advised ATC about the event and we were able to continue the flight. FA was in her seat during the event; no injuries and no object fell in cabin.Cause: We went into an activity developing cell inadvertently Suggestions: Stay at least 20 NM away from storm cell. If have to cross; make sure to clear the storm at least 5000 ft. Make decision to deviate as early as possible.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.