Definition
A computer-prepared aviation weather forecast that provides predicted wind direction, wind speed, and air temperature at specified altitudes for selected locations across the country, valid for stated time periods. Wind direction is given as the true direction (degrees true) from which the wind is blowing, wind speed is in knots, and temperature is in degrees Celsius. Forecasts are typically issued for altitudes such as 3,000, 6,000, 9,000, 12,000, 18,000, 24,000, 30,000, 34,000, and 39,000 feet. Wind data is omitted for levels within 1,500 feet of the station's elevation, and temperatures are omitted for the 3,000-foot level and for any level within 2,500 feet of the station elevation.
Plain English
A forecast that tells pilots what the wind and air temperature will be at different heights above the ground, so they can plan their flight before takeoff.
Context Anchor
Seen during preflight weather planning, especially when comparing possible cruise altitudes or estimating time and fuel for a route.
Derivation
“Aloft” means “up in the air” or “above the ground.” In this term, it reminds you that the forecast is for conditions at altitude, not for surface wind and temperature.
Why Pilots Care
These forecasts let pilots pick altitudes with favorable winds for fuel savings and smoother air while avoiding icing levels.
Analogy
It is like checking the weather on different floors of a tall building instead of only at the front door. The air where you will actually fly may be very different from the air on the ground.
Intuition Check
Do not read this as a report of current surface weather. It is a forecast for winds and temperatures at selected altitudes above the ground along the flight-planning area.
Example Sentence 1
Before departure, the pilot reviewed the winds/temperatures aloft forecasts and chose 9,000 feet for a stronger tailwind.
Example Sentence 2
Winds/temperatures aloft forecasts showed a temperature inversion that could produce icing between 6,000 and 8,000 feet.