Accessibility navigation


Assessing spatial precipitation uncertainties in a convective-scale ensemble

Dey, S. R. A., Plant, R. S., Roberts, N. M. and Migliorini, S. (2016) Assessing spatial precipitation uncertainties in a convective-scale ensemble. Quarterly Journal of the Royal Meteorological Society, 142 (701). pp. 2935-2948. ISSN 1477-870X

[img]
Preview
Text - Accepted Version
· Please see our End User Agreement before downloading.

955kB

It is advisable to refer to the publisher's version if you intend to cite from this work. See Guidance on citing.

To link to this item DOI: 10.1002/qj.2893

Abstract/Summary

New techniques have recently been developed to quantify the location-dependent spatial agreement between ensemble members, and the spatial spread-skill relationship. In this paper a summer of convection permitting ensemble forecasts are analysed to better understand the factors influencing location-dependent spatial agreement of precipitation fields and the spatial spread-skill relationship over the UK. The aim is to further investigate the agreement scale method, and to highlight the information that could be extracted for a more long-term routine model evaluation. Overall, for summer 2013, the UK 2.2km-resolution ensemble system was found to be reasonably well spread spatially, although there was a tendency for the ensemble to be over confident in the location of precipitation. For the forecast lead times considered (up to 36 hrs) a diurnal cycle was seen in the spatial agreement and in the spatial spread-skill relationship: the forecast spread and error did not increase noticeably with forecast lead time. Both the spatial agreement, and the spatial spread-skill, were dependent on the fractional coverage and average intensity of precipitation. A poor spread-skill relationship was associated with a low fractional coverage of rain and low average rain rates. The times with a smaller fractional coverage, or lower intensity, of precipitation were found to have lower spatial agreement. The spatial agreement was found to be location dependant, with higher confidence in the location of precipitation to the northwest of the UK.

Item Type:Article
Refereed:Yes
Divisions:Faculty of Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
ID Code:66228
Uncontrolled Keywords:convective-scale ensemble forecasting neighbourhood verification spatial spread-skill
Publisher:Royal Meteorological Society

Downloads

Downloads per month over past year

University Staff: Request a correction | Centaur Editors: Update this record

Page navigation