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Check a long Pacific route with the ensemble

Check a long Pacific route with the ensemble

First compute the route normally. On an eligible Pro route of at least seven days in the validated Transpac or Pacific Cup area, open Ensemble / robust and choose Run ensemble analysis.

This is a second opinion, not a replacement for the model consensus. It builds eight alternative routes from representative ECMWF ensemble forecasts and checks those routes, plus the consensus route, against all 50 members. Keep the tab open while it runs. Previously downloaded members are reused when possible. On a constrained connection, WX Navigator shows the exact estimated transfer and asks before downloading.

The result has four possible readings:

  • Robust alternative found means a materially different route reduced worst-third regret while staying within 3% of the fastest published-forecast route.
  • Forecast holds means the normal consensus route was also the best hedge.
  • No clear alternative means another route was too close to distinguish from solver or geometry noise. Treat the consensus route as primary.
  • Analysis incomplete means one or more routes could not be scored across the full matrix. No robust verdict is published, and the analysis can be retried rather than becoming the saved verdict.

The table shows worst-third regret: the average time lost versus the best candidate in the 17 member outcomes that were hardest for that route. It is a comparison across this candidate set, not an ETA promise or the probability of a particular weather outcome.

You can inspect a robust alternative on the chart. It is advisory and is never silently promoted to the main route, shared as the recommendation, or substituted for model consensus. Re-run the normal route when its forecast cycles change, then run ensemble analysis again if the decision still matters.

WX Navigator sends coarse device and phase diagnostics for this unusually heavy browser computation— such as browser family, memory bucket, cores, connection class, duration, processed members, transfer bytes and coarse peak memory when available. It does not send your route geometry, polar or forecast fields in these diagnostics. A random diagnostics identifier correlates the phases of one run; the ensemble session capability is never sent to analytics. Raw ensemble diagnostics are retained for 90 days.