Meteorology
Meteorology
This domain tests weather theory and practical interpretation for Philippine operations: ITCZ, monsoons, typhoons, thunderstorms, altimetry, METAR/TAF and hazard avoidance.
Weather systems. The ITCZ brings widespread convective cloud and rain near the equator. The southwest monsoon (habagat) brings moist winds and rain from June to September; the northeast monsoon (amihan) brings cooler, drier air from December to February. Typhoons form over warm ocean water, have a calm eye, and their dangerous quadrants are usually the right-front in the Northern Hemisphere. Thunderstorms produce severe turbulence, icing, hail, microbursts and wind shear; avoid them by at least 20 nm and do not attempt to fly beneath.
Altimetry and reports. QNH is the altimeter setting that gives elevation when on the ground; QFE gives height above a reference point. “High to low, look out below”: flying from high pressure to low pressure without resetting the altimeter makes the true altitude lower than indicated. METAR is an observed report; TAF is a forecast; TEMPO and BECMG describe temporary and gradual changes.
Worked example
You set QNH 1013 at departure, then fly into an area where QNH is 1005 without resetting. The altimeter over-reads by about 8 hPa × 30 ft = 240 ft, so your true altitude is about 240 ft lower than indicated - a terrain risk in mountainous areas.
Traps
Do not confuse QNH with QFE. Do not treat a TAF as an observation. Do not use the typhoon eye as a safe passage; the winds return suddenly.