BMB-UCAR WRF 3D-Var project

Summary for 9 September22 September 2006

Reporting time (for this report): 25 September 2006

 

 

Task 5. Meteorological performance

5.1. BE

 

With the guidance from Hans, Shuiyong is preparing to use the horizontal scale-length of BE for 27-9 km domains of MM5 to adjust that of the nested BE of 9km for WRF, which is interpolated from the 27km WRF domain. No specific report for this part.

 

5.2. WRFDFI

 

Following the suggestions from Hans, Min has finished the codes of three options for moisture filtering for DDFI. Cycling experiments are running and a report will be provided next time.

 

5.3. Comparison

 

All (Min, Zuofang, Jiqin, Shuiyong and Zaiwen) are focusing on the verification for the operational precipitation forecasts of MM5 and the performance comparison between operational MM5 and pre-operational WRF runs during the summer of 2006. The results will be reported next time.

Task 6. Monitoring of pre-operational runs and case studies

 

6.1. Verification

 

The codes relating with vertical level verification has been prepared. But further tests will be performed.

 

6.2. OSE

 

From YongrunÕs comments on JiqinÕs work, GPSPW (O-B) distribution might be OK due to the limited 222 samples. The real-time data collecting system is under construction.

 

6.3. Cycling

 

A cycling script system is ready and the bug of the incompatibility between wrfvar and wrf model has been fixed by Yongrun. Cycling experiments have been performed.

 

However, the work was planned to start in October. No report is required.

 

6.4. Tuning

 

Shuiyong performed some tests on tuning WPS+wrfvar2.1+new WRF. But he found wrfvar failed to run with a floating overflow error. We need to figure out the problem.

A case simulation without wrfvar was also conducted. The results revealed that the high-temperature forecast was improved, while the low-temperature forecast was worsen when comparing with SI+old WRF. Further tuning is needed.

 

The tuning work was planned to start next year. No report is required from Zuofang.

 

6.5. MM5DFI

 

The work was planned to start next year. No report is required.

 

MinÕs suggestion:

Shall we postpone the next report time to 14 October 2006? The first week of October is the vocation time.