It’s nearly 70 years since Marshall and Palmer (1948) published their paper on the distribution of raindrops with size and the empirical scaling relationship equating the measured radar reflectivity, Z with the rainfall rate, R: Z= aRb. Since then, the relationship has been widely used to generate rainfall estimates from radar. With the roll-out of dual-polarisation to the UK radar network nearing completion, the Met Office is now making use of this new technology to improve radar rainfall estimates and supplement the Marshall–Palmer relationship.