Meteorology for Air Traffic Control
What controllers must know
Controllers need to interpret METAR, TAF, SPECI, SIGMET, AIRMET and wind shear warnings, and to understand the effect of weather on operations. Know the meaning of visibility, RVR, ceiling, cloud base, and the criteria for VMC and IMC. Understand thunderstorm hazards, icing, turbulence, and the formation of mountain waves and downslope winds, which are significant in Bolivia's terrain.
Operational use
Know when to issue information on weather changes, when to expect a change of runway due to wind, and how to handle pilot reports of wind shear or severe turbulence. SIGMETs for volcanic ash and thunderstorms are especially relevant. Know the difference between a forecast and an observation, and the validity periods.
Traps in questions
Questions often test the interpretation of RVR versus visibility, or the meaning of a TEMPO or BECMG group in a TAF. Another trap is assuming a SIGMET is issued for all weather; it is issued for specified hazards. Watch for questions on the effect of wind shear on approach minima.
Rule of thumb
Read a METAR in order: wind, visibility, weather, cloud, temperature, pressure. Worked example: a METAR shows 25015G28KT 9999 SCT030 18/12 Q1015. Wind is from 250 at 15 knots gusting 28; visibility 10 km or more; scattered cloud at 3000 ft; temperature 18, dew point 12; QNH 1015. The gust spread suggests possible low-level turbulence.