Flight winds

Wind and temperature at flight levels.

Sample content — not an operational product

The flight level data on this page is not yet published from the GMS forecast system. The figures on this page are illustrative and must not be used for any weather, marine or safety decision.

Forecast winds — Grenada area

Flight level	Approx. altitude	Wind	Temperature
FL050	5 000 ft	070° 18 kt	+18 °C
FL100	10 000 ft	080° 20 kt	+9 °C
FL180	18 000 ft	090° 16 kt	−5 °C
FL240	24 000 ft	100° 14 kt	−18 °C
FL300	30 000 ft	120° 18 kt	−36 °C
FL390	39 000 ft	150° 24 kt	−56 °C

Why the wind turns with height

Near the surface the easterly trades dominate. Higher up, the flow shifts as the trade layer gives way to the upper circulation — which is why a route can have a headwind at one level and a tailwind at another.

The depth of the trade layer varies day to day, and its top is often marked by a temperature inversion that also caps shower development.