Meteorology
Meteorology tests the weather knowledge needed for VFR decision-making: pressure and altimetry, wind, stability, cloud, icing, thunderstorms, fronts, METAR/TAF interpretation and Israeli local weather patterns.
Pressure and altimetry
- QNH is the altimeter setting that reads elevation above mean sea level at the aerodrome; QFE reads height above the aerodrome reference point; QNE is the standard setting 1013.25 hPa used above the transition altitude.
- “High to low, look out below”: flying toward lower pressure without resetting the altimeter makes true altitude lower than indicated.
- About 1 hPa corresponds roughly to 27 ft near sea level, but use the chart or computer for flight planning.
Weather systems and hazards
- Cumulonimbus brings turbulence, hail, icing, lightning, microbursts and wind shear; give it a wide berth.
- Structural icing requires visible moisture and temperatures near or below freezing; carburettor icing can occur in warmer air.
- In Israel, Mediterranean winter systems bring rain, thunderstorms and low cloud; summer brings stable conditions, sea breezes and occasional sharav heat lows with reduced visibility and turbulence.
- METAR gives observed conditions; TAF gives forecast conditions with validity periods and probability groups.
Worked example
You are cruising at 3,000 ft indicated with the altimeter set to 1013 hPa, but the local QNH is 1003 hPa. The pressure is lower than the altimeter setting assumes, so the true altitude is lower than indicated by about 270 ft. Terrain clearance must be based on QNH, not the standard setting, below the transition altitude.
Traps that cost marks
- Setting QNE below the transition altitude.
- Reading a TAF probability group as a certainty.
- Flying into a microburst on a visual approach.
- Assuming icing only occurs at very low temperatures.