Synoptic and Mesoscale Meteorology
Core concepts
Understand synoptic-scale systems: extratropical cyclones and their frontal structure (cold, warm, occluded, stationary), the Norwegian and Shapiro–Keyser cyclone models, and the life cycle of frontal waves. Study air masses and their source regions, frontal identification criteria (temperature gradient, wind shift, pressure trough, dew-point change), and the conveyor-belt model (warm and cold conveyor belts). Mesoscale phenomena include squall lines, mesoscale convective systems, supercells, gust fronts, sea/land breezes, mountain waves, and low-level jets. Know the role of the low-level jet in nocturnal convection and the structure of the subtropical and polar-front jets.
Traps
Frontal questions often hinge on the difference between a wind shift and a true thermal front. Occluded fronts are not always associated with the strongest precipitation. Distinguish a dryline from a cold front. Be careful with the direction of movement of systems relative to the steering flow and with the definition of a squall line versus a multicell cluster.
Worked example
A cold front moving east at 15 m/s crosses a station; the temperature drops 6 °C in 2 hours and the wind veers from SW to NW. The temperature gradient combined with the wind shift and pressure trough confirms the frontal passage. The post-frontal air mass, with lower θe, implies cold advection and a stabilising trend, although low-level convergence along the front may sustain showers.