WeatherSnow Flurries May Greet December
By Roberto Rondanelli
Lewis Fry Richardson, an English scientist and meteorologist, is considered the father of the numerical weather prediction. He pursued the problem through the inspection of the numerical solution of the equations of motion of the atmosphere. At Richardson’s time, it was believed that by archiving weather maps, it was possible to produce a sufficiently large sample of atmospheric states, and therefore forecasting was just a matter of finding an analog among the archived configurations.
Richardson’s approach was radically different. He thought that by knowing accurately the initial state of the atmosphere, he could integrate the equations of motion forward and produce a forecast based solely on the physical laws governing the atmosphere. In his treatise, he carried such a calculation. He integrated the equations over Europe to find a pressure tendency that was two orders of magnitude larger than real. His attempt has been replicated finding no mistake in his calculations. The unrealistic forecast was due to an imbalance in the initial state, and when data are properly filtered, a realistic forecast is achieved using his original procedure. He went even further devising a futuristic system in which 64.000 human computers could keep pace with the atmosphere. The basic idea of Richardson is at the heart of weather forecasting as we know it today.
Today: Mostly cloudy. Chance of showers increasing towards the evening. Low 50 F (10 C) High 58 F (14 C)
Wednesday: Rainy, breezy and unseasonably warm. Low 50 F (10 C) High 56 F (13 C)
Thursday: Rain tapering during the morning, then partly cloudy. Chance of flurries after midnight. Low 39 F (4 C) High 46 F (8 C).