Meteorology for Air Traffic Control
Decoding the products
METAR is the routine observation, SPECI marks a significant change, TAF is the aerodrome forecast, and trend groups (BECMG, TEMPO, NOSIG) qualify the observation. Visibility and RVR are in metres, wind in degrees true and knots, QNH in hectopascals. QNH gives altitude above mean sea level, QFE gives height above the aerodrome reference point, and standard pressure 1013.25 hPa (QNE) is used above the transition altitude.
Gulf-specific weather matters: radiation fog forms under light winds with a small temperature/dewpoint spread; shamal winds bring dust and reduced visibility; thunderstorms and microbursts generate wind shear and outflow; convective cloud tops can sit well above cruising levels even on very hot days.
Traps
Using QNH when the question asks for height above the aerodrome; confusing transition altitude (fixed, in feet) with transition level (variable, a flight level); treating RVR and meteorological visibility as interchangeable; confusing SIGMET (significant en-route weather) with AIRMET (less severe, area forecast).
Rule of thumb
'High to low, look out below' - flying from high pressure into low pressure without resetting the altimeter leaves the aircraft lower than indicated; the same applies warm to cold. Fog is likely when temperature minus dewpoint is 2 degrees C or less with light wind.
Worked example
Aerodrome elevation 100 ft, QNH 1003 hPa. Since 1 hPa is about 8 ft near the surface, the altimeter over-reads by roughly 10 hPa x 8 = 80 ft if left at 1013; the aircraft is about 80 ft lower than the subscale suggests. Controllers must expect crews to level off using the current QNH.