Definition
A prediction of expected atmospheric conditions for a specific location and time period, issued by a recognized meteorological service. In aviation, weather forecasts include products such as Terminal Aerodrome Forecasts (TAFs), Area Forecasts, Winds and Temperatures Aloft Forecasts, and Significant Weather Prognostic Charts, each covering different scales of time and geography relevant to flight planning.
Plain English
A professional prediction of what the weather will be like at a certain place and time. Pilots use these predictions to plan a flight before they go.
Context Anchor
Seen during preflight planning when a pilot checks expected weather along the route, at the destination, and at possible backup airports.
Derivation
From 'fore' (before) and 'cast' (to throw or project) — literally 'to throw ahead.' The word captures the idea of projecting current conditions forward in time to predict what comes next.
Why Pilots Care
Weather forecasts determine whether a flight can be conducted under VFR or IFR, help avoid hazardous conditions such as thunderstorms or low ceilings, and support legal and safe go/no-go decisions.
Intuition Check
Do not treat a weather forecast as a promise or as a current weather report. It is the best prediction for a certain time and place, and it should be compared with actual weather reports before and during the flight.
Example Sentence 1
During preflight, the pilot reviewed the weather forecast for the destination and found that conditions were expected to remain above approach minimums.
Example Sentence 2
An updated weather forecast showed increasing turbulence along the route, so the crew delayed departure.