Changes to the Operational “Early” Eta Analysis/Forecast System at the National Centers for Environmental Prediction

Abstract

This note describes changes that have been made to the National Centers for Environmental Prediction (NCEP) operational ''early'' eta model. The changes are 1) an decrease in horizontal grid spacing from 80 to 48 km, 2) incorporation of a cloud prediction scheme, 3) replacement of the original static analysis system with a 12-h intermittent data assimilation system using the eta model, and 4) the use of satellite-sensed total column water data in the eta optimum interpolation analysis. When tested separately, each of the four changes improved model performance. A quantitative and subjective evaluation of the full upgrade package during March and April 1995 indicated that the 48-km eta model was more skillful than the operational 80-km model in predicting the intensity and movement of large-scale weather systems. In addition, the 48-km eta model was more skillful in predicting severe mesoscale precipitation events than either the 80-km eta model, the nested grid model, or the NCEP global spectral model during the March-April 1995 period. The implementation of this new version of the operational early eta system was performed in October 1995.

Eta-CMAQ air quality forecasts for O<sub>3</sub> and related species using three different photochemical mechanisms (CB4, CB05, SAPRC-99): comparisons with measurements during the 2004 ICARTT study

“…The developmental Eta-CMAQ air quality forecasting system for O 3 , created by linking the Eta model (Rogers et al, 1996) and the CMAQ modeling system (Byun and Schere, 2006), was applied over a domain encompassing the eastern US (see Fig. 1) during summer 2004.…”

Assessment of bias-adjusted PM<sub>2.5</sub> air quality forecasts over the continental United States during 2007

“…Real-time O 3 forecasts using air quality models have been publicly available in the US for several years over different domains McKeen et al, 2005;Otte et al, 2005;Eder, et al, 2006), while real-time PM 2.5 forecasts are mainly in the developmental stage and not available to the general public. The NAQFC (Otte et al, 2005), developed by the National Oceanic and Atmospheric Administration (NOAA) and the US Environmental Protection Agency (EPA) couples NOAA's operational North American Mesoscale (NAM) weather prediction model (Black, 1994;Rogers et al, 1996; http://www.dtcenter.org/wrf-nmm/users) with EPA's Community Multiscale Air Quality (CMAQ) model (Byun and Schere, 2006). It has the capability to provide real-time forecasts for both O 3 and PM 2.5 .…”

Migration Routes of Satellite-Tracked Rough-Legged Buzzards from Japan: The Relationship between Movement Patterns and Snow Cover

“…The integration of data from the daily snow maps into the Eta Data Assimilation System used by the NWS National Centers for Environmental Prediction over North America began on 03 June 1998 (Environmental Modeling Center 1998). Figure 3 shows three Eta model horizontal grid domains over North America and extended areas at 48, 29, and 32 km resolution (Rogers et al 1999). Eta-32 is the most recent of the three grids implemented.…”