Downscaling the ERA5 reanalysis for ‘Hurricane’ Debbie (1961): evidence of both cold-conveyor belt and sting jets

Given the deficiencies apparent in the ERA5 reanalysis for this case (including a
mean sea-level pressure (MSLP) centre in the vicinity of Ireland less deep and dis-
placed compared with observations, as outlined in Graham and Smart, 2021) we
have sought to downscale the reanaly-sis data to higher resolution using the
Weather Research and Forecasting (WRF) model. The WRF model was initialised with hourly data from the ERA5 Back Extension (BE) reanalysis in two runs, starting at 1800 UTC on 14 September, and again at 1800 UTC on 15 September 1961, respectively. The first six hours of output from each run were discarded as ‘spin-up’ and the output concatenated to obtain 48 hours of continuous data.