Dissemin is shutting down on January 1st, 2025

Published in

American Meteorological Society, Monthly Weather Review, 3(144), p. 1093-1114, 2016

DOI: 10.1175/mwr-d-15-0148.1

Links

Tools

Export citation

Search in Google Scholar

The utility of convection-permitting ensembles for the prediction of stationary convective bands

This paper is made freely available by the publisher.
This paper is made freely available by the publisher.

Full text: Download

Green circle
Preprint: archiving allowed
Green circle
Postprint: archiving allowed
Orange circle
Published version: archiving restricted
Data provided by SHERPA/RoMEO

Abstract

Abstract This study examines convection-permitting numerical simulations of four cases of terrain-locked quasi-stationary convective bands over the United Kingdom. For each case, a 2.2-km-grid-length, 12-member ensemble and a 1.5-km-grid-length deterministic forecast are analyzed, each with two different initialization times. Object-based verification is applied to determine whether the simulations capture the structure, location, timing, intensity, and duration of the observed precipitation. These verification diagnostics reveal that the forecast skill varies greatly between the four cases. Although the deterministic and ensemble simulations captured some aspects of the precipitation correctly in each case, they never simultaneously captured all of them satisfactorily. In general, the models predicted banded precipitation accumulations at approximately the correct time and location, but the precipitating structures were more cellular and less persistent than the coherent quasi-stationary bands that were observed. Ensemble simulations from the two different initialization times were not significantly different, which suggests a potential benefit of time-lagging subsequent ensembles to increase ensemble size. The predictive skill of the upstream larger-scale flow conditions and the simulated precipitation on the convection-permitting grids were strongly correlated, which suggests that more accurate forecasts from the parent ensemble should improve the performance of the convection-permitting ensemble nested within it.