Forecast Improvements
Other Agency – Contribution to WRF Model Development by CAPS
Funding Agency/Type: FAA via NSSL and CIMMS Task III
Objectives
Complete further revisions and testing of the generalized cloud analysis
package within GSI for stratiform clouds (using GOES cloud top and METAR
cloud data) and begin an initial treatment for convective clouds at the
parameterized scale assimilating radar reflectivity.
Accomplishments
Progress this year has included the design and development of an initial
version of a new generalized cloud analysis package within the GSI, the
updating of all cloud analysis packages to the latest GSI version, the
testing and verifying of each component of the cloud analysis, and determination
of the impacts of the different cloud analysis packages when used in
the hourly assimilation cycles.
The new generalized cloud analysis combined the strengths of the ARPS and RUC cloud analysis with several improvements. It is able to build three-dimensional distributions of cloud and hydrometeors fields and adjust in-cloud temperature based on METAR data, NESDIS cloud products, and NSSL radar reflectivity mosaic. The new cloud analysis was tested thoroughly using the 13 March 2006 central U.S. squall lines case under the RUC CONUS environment through both cold start and hourly assimilation cycles.
This project is ongoing.
Publications
Hu, M., and M. Xue, 2007: Implementation and evaluation of cloud analysis
with WSR-88D reflectivity data for GSI and WRF-ARW. Geophys.
Res. Lett.,
34, L07808, doi:10.1029/2006GL028847.
Hu, M., and M. Xue, 2007: Impact of configurations of rapid intermittent assimilation of WSR-88D radar data for the 8 May 2003 Oklahoma City tornadic thunderstorm case. Mon. Wea. Rev., 135, 507-525.
Hu, M., S. Weygandt, M. Xue, and S. Benjamin, 2007: Development and testing of a new cloud analysis package using radar, satellite, and surface cloud observations within GSI for initializing rapid refresh. 18th Conf. on Numerical Weather Prediction and 22nd Conf. on Weather Analysis and Forecasting, Park City, UT, Amer. Meteor. Soc.
Analyzed (a) composite cloud cover (column maximum) at 0000 UTC 13 March 2006 with all available data, and west-east cross section of (b) the analyzed cloud cover; (c) background cloud water + cloud ice; and (d) analyzed cloud water + cloud ice along indicated line in (a).