CPL Meteorology · Mock exam

On a synoptic chart, 3-hourly isallobars show a zone of −5 hPa centred 200 NM west of your destination. What does this indicate and how should it influence your flight planning?

• A.A −5 hPa isallobar is within normal diurnal variation and has no operational significance
• B.Pressure has fallen 5 hPa in the past 3 hours in that zone
• C.The zone of pressure fall marks the exact centre of a low-pressure system and will not move
• D.Pressure has risen 5 hPa in the past 3 hours — conditions are improving and the area is safe