X1035384674-00367-71449</DOCNO> Precipitation-Type Forecast Algorithms Precipitation Type Forecast Algorithms A Comparison of the Eta and RUC Models OBJECTIVE: A better understanding of how the Eta and RUC models produce precipitation type output by: Reviewing classical thermodynamic profiles for specific winter precipitation types Evaluating the Eta's decision tree approach for precipitation type diagnosis Examining the RUC's bulk cloud microphysics approach Examples of observed soundings associated with different winter precipitation types: Snow sounding, Detroit, MI, 00 UTC Jan. 3, 1999 Ice pellet (graupel) sounding, Little Rock, AR, 12 UTC Dec. 23, 1998 Freezing rain sounding, Fort Worth, TX, 12 UTC Dec. 23, 1998 The Eta Model Approach If the coldest temperature in a saturated layer is -4C or less, the wet bulb temperature (Tw) profile is used to determine the precipitation type (snow or sleet) where the model is generating precipitation.
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precipitation type output
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the Eta's decision tree approach for precipitation type diagnosis
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the RUC's bulk cloud microphysics
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Type Forecast Algorithms Precipitation
Eta