Weather Analysis and Forecasting
Core concepts
Learn surface and upper-air chart analysis: isobar spacing and gradient, isallobars, thickness, and the 500 hPa pattern. Understand the use of soundings and hodographs, stability indices (LI, CAPE, CIN, shear), and the interpretation of numerical model output including ensembles and spaghetti plots. Study forecast verification concepts (bias, skill scores, probability of detection) and nowcasting based on radar and satellite. Recognise the analysis–forecast cycle and the role of the forecaster in adjusting model guidance.
Traps
Questions may confuse a model's initial analysis with its forecast. Beware of reading a hodograph incorrectly (direction is where the wind comes from). Do not equate high CAPE with severe weather without shear. Distinguish a watch from a warning.
Worked example
A sounding shows CAPE = 2500 J/kg, CIN = 25 J/kg, and 0–6 km shear of 25 m/s. The combination of strong buoyancy and shear favours organised storms, including supercells. Using the rule of thumb that a CAPE of 1000 J/kg supports strong updraughts, this profile indicates a significant severe-weather potential.