Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Fuel Issue; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Issued New Clearance; Flight Crew Diverted; General Declared Emergency
Aircraft; Company Policy; Human Factors; Weather
Enroute; sent several ACARS messages to Dispatch; [planned destination] weather bad; [planned] alternate also bad; ZZZ weather good. No response except; while descending on [our destinations] arrival; 'stick with [the planned alternate];' if you go into holding; try to get a hold of me. My response was 'no.' On downwind; thunderstorm on short final approach; with only ten minutes of hold fuel; diverted to ZZZ. I also had attempted several phone calls to Dispatch on internet cockpit phone; but it did not work. We asked ATC Center to call Dispatch; they took the phone number; but wasn't sure if they had time to call. After a few minutes; still no response from Dispatch; so [we] declared emergency; per company policy of ZZZ not being filed alternate [and] not approved by Dispatch. Landed ZZZ; got fuel; continued to [our original destination]. We need a better means to contact Dispatch. [We] sent numerous ACARS messages; no response until arrival at [our destination]. Internet phone is unreliable. Of the five or six times I have tried to use it; it has only worked once.
Air carrier Captain reports inability to contact his Dispatcher directly to advise of a weather diversion to an airport other than the filed alternate.