Improving a convection-permitting model simulation of a cold air outbreak

• Published in: Quarterly Journal of the Royal Meteorological Society
• Main Authors: Field, P. R., Cotton, R. J., McBeath, K., Lock, A. P., Webster, S., Allan, R. P.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2014
• Subjects: Norwegian Sea
• Online Access: https://centaur.reading.ac.uk/33435/; https://centaur.reading.ac.uk/33435/1/2116_ftp.pdf; https://doi.org/10.1002/qj.2116

A convection-permitting local-area model was used to simulate a cold air outbreak crossing from the Norwegian Sea into the Atlantic Ocean near Scotland. A control model run based on an operational configuration of the Met Office UKV high-resolution (1.5 km grid spacing) NWP model was compared to satellite, aircraft and radar data. While the control model captured the large-scale features of the synoptic situation, it was not able to reproduce the shallow (<1.5 km) stratiform layer to the north of the open cellular convection. Liquid water paths were found to be too low in both the stratiform and convective cloud regions. Sensitivity analyses including a modified boundary-layer diagnosis to generate a more well-mixed boundary layer and inhibition of ice formation to lower temperatures improved cloud morphology and comparisons with observational data. Copyright © 2013 Royal Meteorological Society and British Crown Copyright, the Met Office