Meteorology · Weather Charts — Prognosis
A surface 'prog' (prognostic) chart received by a vessel shows:
- AThe forecast positions of pressure systems, fronts, and isobars for a future time✓ Correct
- BThe current analyzed weather only
- COcean depths
- DMagnetic variation
Explanation
A prognostic chart forecasts the future arrangement of highs, lows, fronts, and isobars (e.g., 24/48/96 hours ahead), letting the navigator anticipate wind and sea and plan routing. The analysis chart shows the present situation.
Authority: Bowditch (Pub. No. 9), weather charts; NWS marine prog charts
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