
Numerical weather prediction (NWP) has significantly enhanced the accuracy of weather forecasts & enabled the development of services specifically for mariners, including routeing advice & forecasts as ECDIS overlays. This practicalguide opens up the technology that now forms the basis of all modern weather forecasts so that mariners can recognise when they are being presented with NWP, establish its source & the characteristics & performance of the particular NWP model, & make informed judgements on suitability & use.