Summary for 23 September – 13 October 2006
Reporting time (for this report): 15 October 2006
Shuiyong re-calculated the BE for 27 and 9km domains using SI+ wrfvar (BE interpolation) + WRFv2.1 with the operational model forecasts in August 2006. The interpolated 9km BE was also tuned using the factors 1.5/1.5/2/2/2. He analyzed the structure of 9km BE and performed single-point observation and AWS+GPS data assimilation experiments. According to the results of experiments, except for specific humidity, the BE structures are reasonable for most of the variables except humidity, which needs more time to investigate.
Min has performed
the cycling tests for the three options of moisture filtering for DDFI. But no
report is prepared this time.
Min and Zuofang has
submitted a report about the verification for the operational precipitation
forecasts of MM5 for the summer of 2006. The results showed that the scores of
the forecasts initiating from 1200UTC are better than those from 0000UTC for
whatever the verification thresholds, that is, using the interpolated AVN
analysis as initial condition may lead to better precipitation forecasts skill
than objective analysis on the background of AVN forecasts. In addition, the
forecast skills for precipitation under different types of synoptic systems are
verified. In general, the precipitation forecast skills are greatly improved
comparing with last year, which can be regarded as the results of the improved
model configurations and the shift of background from T213 to AVN.
The performance
comparison between operational MM5 and pre-operational WRF runs during the
summer of 2006 is still ongoing. The results will be reported next time.
The codes relating with vertical level verification has been prepared. But further tests will be performed.
Jiqin has confirmed
the types of observation data we can acquire and decode in real-time. The
real-time data collecting system will be ready in short time. She also made a
plan for the OSE task: 1) to get some idea about the number and distribution of
observations which can be absorbed by WRFVAR; 2) to get some idea about the
observation quality with statistics of O-B; 3) simple correction for
observation bias; 4) numerical experiments.
But thereÕre still
some problems need to resolve: 1) is there any difference between the GTS data
collected from BMB and from NCAR? 2) what is the framework the OSE numerical
experiments will be performed under (WRFSI+WRF or WPS+WRF)?
Dr HuangÕs
comments: Jiqin should start her GTS experiments using the latest system: WPS+WRF according to Shuiyong's
definition.
Min started to work on the operational cycling system script. But no report is prepared this time.
Yongrun found the
problem in the interface of WPS and WRFVAR. WPS gave the overshooting in
terrain interpolation along the coastal line, so there are many negative values
in terrain field and PHB. This caused the floating point in WRFVAR. Yongrun
provided a GEOGRID.TBL file as a temporary solution to this problem. He
promised to fix the WRFVar code to account for the negative terrain values in
near future.
No report is required from Zuofang.
The work was planned to start next year. No report is required.
Next
report time: 27 October, 2006.