Date: 201605
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: Thunderstorm
Light: Daylight
Aircraft: MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise; Taxi
ATC / advisory: Center ZZZ; Ramp ZZZ
Aircraft component: Other Documentation
Component problem: Improperly Operated
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Workload; Training / Qualification; Situational Awareness; Distraction; Confusion; Communication Breakdown
Anomaly: Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Weight And Balance; Inflight Event / Encounter Fuel Issue; Inflight Event / Encounter Weather / Turbulence
Detector: Automation Aircraft Other Automation; Person Dispatch; Person Flight Crew
When detected: In-flight
Result: Flight Crew Diverted; Flight Crew Took Evasive Action; Flight Crew Became Reoriented
Contributing factors: Weather; Procedure; Manuals; Human Factors; Chart Or Publication; Company Policy
Primary problem: Human Factors

Narrative: Upon completion of pushback process; before taxi checklist and taxi call; ATC informed us of a full re-route. Captain entered the new re-route on the FMS while I copied on the dispatch release; my EFB and look into differences. Noticing the substantial differences; I ask the Captain (CA) if we needed to call dispatch for new numbers as the ones we had pertain to the old route. He replied that; that wasn't necessary and that we were 'Ok'. At me moment; his replied didn't seem right or make sense to me; so I kindly insist that we didn't had valid release numbers; route burn numbers and reliable weather information for our flight. In further; I insist that our W&B was also wrong because our calculated landing weight was based on the previous route burn and not the new route burn and unknown at the time. He insisted that we had a valid release at the time of 'push' and that we were 'off the gate'; instructing me to re-call for taxi instructions and to continue with the flight. His argument; years within the company and me being new at this carrier lead me to believe erroneously. So; I called for taxi.While climbing and almost immediately after takeoff (About 4;000 feet MSL) I notice the FMS had an 'INSUFFICIENT FUEL' message; the CA cleared the message as I was hand flying. His response to that was that 'it would fix it self; we would ask for shortcuts'. The CA emphatically ask ATC for 'shortcuts'; but one after the other he was turn down. The airspace was saturated with airplanes deviating south and to avoid the up-north weather over our original route.I started looking on our [operations manual] and to read about our procedures in this situation. I remember a discussion in ground school about company landing fuel preferences and to never plan to land with less than [a certain amount] of fuel. The FMS continue showing landing with [600 lbs. below minimum fuel weight] for the most part. We were fighting winds aloft that we never plan for; FL300; 267@70 - 255@81. We climb to FL320 as another carrier had a wind readout for us 245@65; that help[ed] a little. Again; I insisted to call dispatch; he finally did and on his second call we were informed that calculated landing fuel was [a thousand below the planned amount] of gas. CA informed dispatch of 'his' intention to divert.In retrospect; I think I should it done a better job on insisting for a phone call with dispatch to amend our flight release; receive accurate route weather/NOTAMS and to simply have an extra set of eyes while on the ground. Honestly; I don't remember this particular subject been discussed during training and I think we can do a better job in this area. I can't also find clear guidance for this subject on our Operating Manual.




Synopsis: A MD-80 First Officer reported receiving a full re-route for weather on the ground after pushback. The First Officer wanted a new flight release; the Captain did not. Inflight the FMS 'INSUFFICIENT FUEL' forced him to reconsider. The flight diverted for fuel enroute.