Date: 201508
Local time of day: 1801-2400
Location: MPZL.ARTCC, FO
Weather elements / visibility: Thunderstorm
Aircraft: Medium Large Transport; Low Wing; 2 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
ATC / advisory: Center MPZL
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness; Communication Breakdown
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action
Contributing factors: Weather; Human Factors; Equipment / Tooling; Chart Or Publication
Primary problem: Ambiguous

Narrative: We discovered after we took off that the weather SIG Chart that we had referenced during preflight (and checked to print) had not propagated to the file that saved onto either of our iPads. We were approaching Panamanian airspace and there was considerable weather ahead that required deviation. We did not recall this weather being indicated on the Significant (SIG) Chart; and when we looked for this chart (that is normally part of our printed flight briefing packet); neither of us could find it.We tried to contact Dispatch via ACARS to inquire what he was seeing but got no response. We picked our way through the storm system and continued on towards SEQM.  Well after we had passed the storms suddenly Dispatch began sending us ACARS messages and even an HF Selcal (that we answered; but could not hear anyone). By this point we were beginning our descent and these were distractions.During preflight the next night we were considering our gross weight and fuel load. We thought that we might be able to reduce our fuel somewhat in order to accommodate a few more passengers and increase our overall efficiency. However; in light of the previous night's experience; we first wanted to enquire about the weather enroute before we reduced our fuel. The SIG Chart had once again not shown any weather along our route of flight west of Panama. The SIG Chart had once again not propagated into the printed Flight Packet--either onto the iPads or on the station copies handed to us by SEQM Operations. We were concerned about whether the previous night's weather system had dissipated or moved on. We asked Dispatch specifically about it on the telephone. We were also concerned that for the second night in a row we could not seem to generate the SIG Chart or the Upper Wind map that we would normally reference in flight.Dispatch stated that there was no significant weather along our route of flight from [SEQM] to [our destination in the United States]. He basically assigned blame for the missing weather charts to the I.T. Department and said they'd look into it. According to this information we reduced our fuel load by approximately 2;000 LBS; and the extra passengers were boarded. We would land with a comfortable amount of fuel.On the climb out from [SEQM] we could see many lightning flashes coming from what appeared to be a long line of heavy storms running ESE-WNW from the ESV vortac; right smack across our route of flight. The radar painted it mostly yellow and red; with constant lightning. We were not expecting this. We picked our way through a hole in that line of weather. We informed Dispatch of this via ACARS; but received no reply.When we emerged on the other side of this line; we were facing a larger system of weather (i.e.; not a line but a large cluster of extremely active storms) stretching [130 miles ESE-WNW.] The radar was painting it mostly red and yellow; and there was constant lightning. We deviated up to 50 nm west of course to avoid this weather. We were far enough west that another aircraft had to relay communications with Panama. [Eventually] we sent another ACARS message to Dispatch.As we flew north; well west of course; we could see that this system was larger than we initially thought. It extended well up the western Panamanian and Costa Rican coastline. It showed no sign of diminishing. We deviated even further to the west; up to 80nm left of course; to stay out of it. Dispatch sent a message telling us that a Company aircraft was getting light-moderate near [southern Nicaragua] coming south. Based on what we were seeing; their ride was about to get a whole lot worse. We couldn't tell if anyone was getting through along our planned route of flight; but there were at least a few other aircraft deviating to the west with us. Passing abeam [southern Nicaragua] we could finally correct back to course. [MHTG] cleared us direct to [northern Belize.] At this point we were concerned at what we perceived as a lack of response from Dispatch. The storms had a great deal of lightning in them. The red-yellow cells were spaced tightly enough that there was no way to go but around the lot of them.We sent a message to Flight Operations informing what had just happened. We were both surprised that in his reply that there was little; if any; awareness of the weather we had just passed. What we saw and flew around should have been clearly visible on weather reporting services. It should have been a dominant consideration in planning our route of flight. It certainly dominated the execution of the first three hours of our flight.This pair of flights to/from [SEQM] was a Line Check for a special airport qual. Both Captains are highly experienced flying through this part of the world; day and night; in good and bad weather. We both know how to use weather radar; and this one was operating normally. The weather picture in the [weather briefing] was apparently profoundly different from the one in our cockpit. This is alarming to both of us.In summary we have three concerns. First; what happened to the SIG Charts that they did not propagate or print when we clicked PRINT ALL on the flight planning page? Second; what weather information was available to the Dispatcher who planned both of these flights? Third; what weather information was available in the [briefing] while we were actually inflight (and how much confidence do we have in its accuracy)?




Synopsis: Air Carrier Captain reported encountering unforecast severe weather on his flight from SEQM to the United States; and stated he did not get much help from Dispatch; either in the planning stage or enroute.