DYnamical and Microphysical Evolution of Convective Storms Thorwald Stein, Robin Hogan, John Nicol DYMECS

MetOffice Nimrod data Rainfall radar images 1km res 5min interval 1/32= mm/hr Rainfall [mm/hr] for 7 August :10:00 Centered around the Chilbolton radar location

0.5 mm/hr Labelling algorithm Threshold for minimum rainfall Threshold for minimum feature size (4km 2 )

2.0 mm/hr Labelling algorithm Threshold for minimum rainfall Threshold for minimum feature size (4km 2 )

1.0 mm/hr Labelling algorithm Threshold for minimum rainfall Threshold for minimum feature size (4km 2 )

1.0 mm/hr Keep label consistent between images (red) Register break ups (yellow) Highlight new storms (green) Store track (magenta) and lifetime

Per storm, store: – Area – Azimuth – Range – [u,v] – Centroid – Bounding box – Et cetera... Local rainfall maxima within storm (core, cell) work in progress

Scan scheduler: – Read nimrod scene – Prioritize storms – Issue radar commands Scan strategy: – 4 RHI scans through each core in (clockwise- most) storm 1 – PPI volume scan (10 PPIs) through storm 1 – Repeat for next storm (anti-clockwise) – Finish with low-level PPI back to th August Flooding South Wales

26 th August 2011 (Floods in South Wales)

Stats at 2deg/s 32 pulse pairs About 0.5% of all rays are missing (data not written?) At 1deg/s and 64 pulse pairs, <<1% is missing.

Erroneous scans

Further issues 1.No phase parameters beyond 180km 2.Radar error no position received occurs after 10-20% of commands 3.AR_NEW recorded in netCDF, not FRATE when WI>180