Hydrometeor assimilation using hourly-updated satellite cloud retrievals over North America in the Rapid Refresh
Stan Benjamin, NOAA/ESRL/GSD, Boulder, CO; and M. Hu, S. S. Weygandt, J. M. Brown, P. Minnis, and W. L. Smith Jr.
A 3-d hydrometeor assimilation technique developed originally for the Rapid Update Cycle has now been improved and applied over all of North American in the Rapid Refresh, the new hourly-updated assimilation/model in real-time testing toward the planned replacement of the RUC at NCEP in 2010.
As of early August 2009, GOES-based cloud retrievals from NASA Langley Research Center including cloud-top pressure, cloud-top pressure, liquid water path, and ice water path covering North America are assimilated, along with METAR multi-level cloud, visibility, and current weather observations, and 3-d radar reflectivity, correcting a previous 1-h forecast of 3-d multi-species hydrometeor fields. These initial tests as of early August are in an experimental RUC, and will now very soon be applied to the experimental Rapid Refresh, where CONUS-domain GOES cloud retrievals have been assimilated since early 2008. The North American GOES cloud data completely cover the RUC domain, and will cover about 90% of the Rapid Refresh domain. Quality checks for the cloud-top data using 1-h skin temperature forecasts are being modified for application to the arctic region to allow “warm stratus” in which cloud radiative temperatures are much warmer than the underlying surface, a situation not usually observed in the RUC domain over CONUS and southern Canada.
Further improvements to the RR/RUC hydrometeor assimilation were implemented into the operational RUC at NCEP in March 2009, with improved retention of observed hydrometeor data in short-range forecasts. These improvements and current status of hydrometeor assimilation in the Rapid Refresh within the NCEP Gridpoint Statistical Interpolation (GSI) assimilation system will be described in the conference.
Session 10, Expected Operational Improvements from NPP/NPOESS and GOES-R Data - II
Thursday, 21 January 2010, 3:30 PM-5:00 PM, B313
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