Mesoscale Parallel Experiment Log
- Experiment Name
Eta-32 with assimilation of merged Stage II/Stage IV precipitation analyses
- Parallel Slot
- Control Slot
- Start date of parallel experiment
- 12Z 2002/11/19
- End date of parallel experiment
- 12Z 2003/01/13
- Environmental Modeling Center scientists
- Abstract (including Motivation, Hypothesis and Method)
The 32-km EDAS/Eta parallel system is being used to test the assimilation of
the merged Stage II/IV precipitation analysis.
Since its implementation in July 2001, the ETA/EDAS
precipitation assimilation uses the NCEP Stage II hourly
precipitation analysis as the source of observed precipitation.
Another hourly precipitation analysis now available is
the NCEP Stage IV analysis, which is a mosaicked product
based on the regional multi-sensor precipitation analyses
produced by the 12 CONUS River Forecast Centers.
Both analyses are based on hourly radar and gauge
observations, Stage IV benefits from some manual quality
control at the RFCs, while the Stage II, produced directly
at NCEP from hourly radar/gauge data, are more timely.
For this experiment, both Stage II and Stage IV are used in the
Eta/EDAS precipitation analysis. Since Stage IV is
generally considered to be of higher quality, during the data-preparation
stage prior to running each EDAS segment,
we merge the two analyses as outlined below. For each hour
that will be covered by the upcoming EDAS segment,
we use the available Stage IV analysis as the primary data source,
and fill in any missing-data area in the Stage IV
analysis (individual RFCs send out their hourly analyses
at different times through out the day, so at the time the data
is needed by the Eta model, the Stage IV coverage might not be complete.
Please see the
Q&A for more details about
the timeliness of the Stage IV) with the available Stage II.
An example of the merged product can be found at
- Experiment changes log
- Background links
- Evaluation of parallel results
Daily forecast maps
Daily forecast stats
Verification of precipitation and against rawinsondes / surface data
Mesoscale Parallel Home Page
Page Last Modified: 19 November 2002