Analysis of extreme rainfall and flooding in Cumbria 18-20 November 2009

Rainfall totals with this event exceeded long-term records by some 25%, which is a significant margin when those records have stood for over 100 years. Issued forecast guidance that utilised climatological tools alongside Global numerical weather prediction models over the preceding couple of days suggested totals close to previous record rainfall totals, and in light of this the event was reasonably well forecast, although the coarser models on their own did not capture rainfall as well, partly due to present resolution restrictions. However, the finerresolution models with a shorter lead-time were forecasting totals close to previous record values, although not the extreme values recorded.