Discovering the mechanisms behind forecast busts

Numerical weather prediction occasionally presents “forecast busts", in which the forecast skill at five- to six-day lead time drops to almost zero across the world's leading NWP centres. Such failures can be linked via Rossby wave dynamics to an initial poor representation of Mesoscale Convective Systems upstream, which is in turn related to systematic difficulties in simulating moist convection. Our main research question is why errors in the representation of an MCS are normally benign for predictability but occasionally catastrophic? Answering this will provide insight into how multi-scale error growth in NWP systems depends on flow regimes.

Some links for this work:

Posters:

1. A poster comparing bust characteristics between forecasting centres, (presented by Kaustubh Mittal), at a Oxford model uncertainty workshop.
2. A poster identifying recent forecast bust events, (presented by Kaustubh Mittal), at a RMS student conference in the Met Office.
3. A poster introducing the project, (presented by Kaustubh Mittal), at the summer school on Fluid Dynamics of Sustainability and the Environment in Paris.