1. Presentation to the Inter-Agency Committee for Hydrological Uses of Radar Data, University of Bristol, 5 August 2004 C.G.Collier University of Salford

3. Combining and comparing rainfall observing systems in hydrological modelling of a rural catchment G.L.Robbins 1, M.Grum 2 and C.G.Collier 1 1 Univ. Salford 2 PH-Consult, Denmark

4. Rainfall measurements relative strengths.

5. A simple model which, one step ahead, predicts the rainfall intensity to be a weighting of its immediate own current value with its neighbours

6. Schematic of a simple catchment model

7. Croal catchment and hydrometeorological network

8. Rainfall, observed river flow and forecast hydrographs after various time steps 13 September 2001

9. Error in peak flow magnitude and time of occurrence of peak flow

10. Assimilation of Doppler radial winds into a high resolution NWP model F.A.Rihan 1, C.G.Collier 1, S.P.Ballard 2 and S.J.Swarbrick 2 1 University of Salford 2 JCMM, Met Office

11. Impact of a strong velocity gradient across the pulse volume and instrumental noise on the Doppler wind spectrum

12. Schematic representation showing a convergence line moving from left to right. Gaussian noise represents the measurement error

13. Chilbolton (300m & 4 km res.) and 1 km NWP model radial winds 1 July 2003. Model at two elevations

14. Model radial winds at 4 km resoln.

15. Next steps Met Office to complete 3D-var (later 4D- Var) assimilation system Observing System Simulation Experiments (OSSEs)