92nd American Meteorological Society Annual Meeting (January 22-26, 2012)

Thursday, 26 January 2012
On the Land Surface Initialization for NWP Model At EMC
Hall E (New Orleans Convention Center )
Vince C. Wong, NOAA/NWS/NCEP, Camp Springs, MD

The MODIS_IGBP land-use satellite data has been implemented in NMMB, the next National Weather Services (NWS) operational mesoscale model. Parallel run with the present mesoscale operational model have been conducted since August last year. If one more final parallel test result is acceptable, NMMB will become the new operational mesoscale numerical weather prediction model this fall. Composited vertical profiles of temperature and moisture biases have been reduced with the new data. Model application of high-resolution maximum albedo for deep snow and snow-free albedo derived from MODIS satellite data have been used in the new and improved RRTM radiation scheme. In contrast to the single broad band albedo used in the operational model, the new data set involves four components (i.e., visible direct, visible diffusive, near infrared direct and near infrared diffusive). Solar zenith angle and snow age dependent albedos are also considered in the new model. High-resolution data of Green Vegetation Fraction (GVF) have been implemented in NMMB. Since cloudiness and data processing prevent real time GVF data being used for forecasting model, time extrapolation is needed to provide real time data. The present green-up and leaf falling period at each pixel will be estimated according to the trend of the recent GVF as well as the climatological GVF data. Time varying Leaf Area Index (LAI) has also been considered. Critical analyses of the impact of the aforementioned implementations to mesoscale numerical weather prediction models and precipitation processes will be discussed. Improved results of quantitative precipitation forecast (QPF) such as equitable threat score will also be discussed.

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