Date: 201409
Location: ZZZZ.ARTCC, FO
Flight conditions: IMC
Weather elements / visibility: Icing; Thunderstorm; Turbulence
Light: Dusk
Aircraft: EMB ERJ 145 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
ATC / advisory: Center ZZZZ
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness; Workload
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Deviation - Altitude Excursion From Assigned Altitude; Deviation - Track / Heading All Types; Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Became Reoriented; Flight Crew Took Evasive Action; Flight Crew Regained Aircraft Control

Narrative: Encountered severe turbulence en-route. Corrected aircraft upset and flight proceeded normally. Aircraft ahead said the ride ahead through the weather was smooth.


Second narrative: We got to ZZZ early enough to load pax and bags to be ready to go early. Plane was boarded and loaded 25 early. Called three times to get fuel. Station Ops called but dismissed it by saying 'you still have 25 minutes to go'. Crew replied that indeed that was the case; there was a cell moving towards the airport that would shut down ramp. Fuel showed up 10 to go; as soon as he was done; we had a chance to close and drop the break to push right before lightning struck and the ramp closed. That's the reason for the on time departure. Ramp was closed for about 25 minutes. During that time our destination airport went in to and out of a ground stop. At the end of our push; Ground came on frequency to inform us that there was another ground stop going to destination. We taxied out to wait at Ground's suggestion that it wouldn't be as long as advertised. We took off about almost two hours later than what we would have been able to depart had we got our fuel. As we were climbing out; the holes that were there when we came in to ZZZ had closed and the ones that were left were closing fast. We climbed steeply to get to FL370; at that point we were just about to top the weather so we said that we could start working our way towards our next navaid. We had still been cleared for right and left deviations to get through the weather and Direct navaid when able.  We stayed in IMC. Radar wasn't helping so Captain asked me to message DISP to ask for help finding our way though. DISP suggested a route that would take us south first then towards our next navaid. We listened and headed south after we were on our way for about 10-20 seconds we entered severe turbulence; icing; sheer; rain. We had went into a mature thunderstorm. The plane ballooned up to 37500 and then dropped to 34500 within less than a minute; engines were at idle to stop from overspeeding; that didn't help. Plane rolled 70 degrees to right; declutter came up with nose down and roll. Captain and I couldn't hear each other or understand with the rain being as loud as it was coupled with the static coming over the radio. Couldn't hear ATC at all. I tunneled out for maybe 5 seconds while i was trying to wrap my head around what was going on. I got on controls with captain and we tried to just maintain wings level. At that point windshield froze over; windshield heat couldn't keep up with the icing at first. A little after that we saw blue sky and headed for it. Once we got out; CA called FA to make sure no one was hurt. We switched ATC Centers and they took our information. Returned to FL370 and went to the next navaid to start arrival in to ZZZ1.Threats: Long day.  Was now 11 hours later with a 3 hour sit before the ZZZ turn.  My experience level with severe turbulence; time crunch getting out of ZZZ.  Last leg of a long four day.Errors: should have tried to talk to dispatch earlier than in cruiseUAS: Uncontrollable A/C for a few secondsSuggestions:Slow down on last leg even with outside factors pushing I.E.; ATC; Weather OpsBetter on board radar; more attentive dispatchers; more motivated ground handling During the event; react quicker be proactive


Synopsis: An EMB-145 crew lost control of the aircraft at FL370 in an embedded thunderstorm. They descended 2;000 FT below assigned altitude before recovering and returning to the assigned aircraft and track.