Date: 201701
Local time of day: 0001-0600
Location: KZAK.ARTCC, AK
Flight conditions: IMC
Weather elements / visibility: Thunderstorm
Aircraft: B787 Dreamliner Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
ATC / advisory: Center KZAK
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: Pilot Flying; First Officer
Anomaly: Deviation - Altitude Excursion From Assigned Altitude; Deviation - Speed All Types; Deviation - Track / Heading All Types; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action
Contributing factors: Aircraft; Human Factors; Weather
Primary problem: Ambiguous

Narrative: At FL360; and approaching 08N150W we entered a cumulous top that we were not aware of primarily due to our map scales being too large to see the radar return. We encountered moderate turbulence and strong up and down drafts. We scaled down our map displays and immediately requested a climb to FL370 and a course deviation; but only the altitude was approved. We were denied the course deviation due to traffic. We saw an immediate need to deviate to the right by only about 5 miles off course; which we did; and returned to our SLOP of R2 after passing the threat. Also; due to the up and down drafts being as strong as they were; our altitude deviated by about 200 feet and we got 4 overspeed warnings; which we observed to be about 5 knots.  The weather cell was small; but intense and rising rapidly. The whole event lasted around 3 minutes after which we checked on the cabin crew and found everyone to be okay.  Afterwards the airplane displayed status messages of 'Cruise Flap Fault' and 'Flaps Secondary Fault.'  On arrival and on descent; we got several EICAS messages regarding GPWS and Single Source ILS. The radar did not display weather until we were in it; when it finally displayed a large green area of what turned out to be moderate rain and turbulence. We were at 12;000 feet. The subsequent vectoring; ILS approach; and landing were uneventful and routine. The airplane suffered a lighting strike on departure on the previous leg and was inspected before we accepted it. We took a 3 hour delay for the inspection; which we were made aware of the night before. On takeoff and descent; my position was IRO on this leg in the right rear jumpseat. It has a very limited view; and it is very hard to hear communications between the crewmembers because of the location and the noise from the ventilation.


Second narrative: Near 08N 150W while cruising at FL360; we encountered an individual isolated thunderstorm cell that did not show on my radar screen due to the scale selected.  We noticed the cell visually just prior to entry and requested both a climb and lateral deviation from ATC via ACARS. We were given the climb to FL370; but denied lateral deviations due to traffic. While penetrating the storm; we encountered both overspeed warnings (approximately 4) as well as altitude deviations of approximately 200-300 feet. Despite being denied the lateral deviations by ATC; we did perform minor lateral deviations of less than 5 miles to avoid the core of the cell and returned to our slop offset immediately after exiting the cell. The entire event lasted approximately 2-3 minutes. Following the event; I checked with the flight attendant crew to ensure there were no injuries with the sudden turbulence.


Synopsis: B787 flight crew reported entering a small thunderstorm at night that they did not notice on Radar due to the large scale selected.