18th Conference on Weather and Forecasting, 14th Conference on Numerical Weather Prediction, and Ninth Conference on Mesoscale Processes

Tuesday, 31 July 2001
Operational evaluation of the new sea-surface temperature analysis implemented at NCEP
James L. Partain, NOAA/NWS/NCEP, Camp Springs, MD
A new real-time global SST analysis (RTG_SST) has been developed specifically for use by the NCEP numerical weather prediction models. Each daily analysis product uses the most recent 24-hours of in situ and satellite-derived surface temperature data and provides a global SST field on a 0.5-degree (latitude, longitude) grid. The RTG_SST was implemented January 30, 2001 and now provides the sea surface temperature fields for the Meso Eta Model. It is anticipated that it will soon replace the lower-resolution, 7-day Reynolds-Smith 1-degree global SST analysis in the Operational AVN/MRF Global Analysis/Forecast Systems.

In support of the operational implementation of this new SST analysis, in late January 2001 the NCEP Marine Prediction Center (MPC) conducted an operational evaluation of both the operational ETA model (which was utilizing the lower-resolution Reynolds-Smith analysis) and the experimental ETA ("ETA-X") model (utilizing the new RTG_SST analysis). Both models were run simultaneously in real-time parallel mode on the IBM SP supercomputer at NCEP, which greatly facilitated the evaluation by the MPC forecasters.

The results of the MPC evaluation will be presented in full in this presentation. In particular, focus will be given to cases from both the eastern Pacific ocean and the western Atlantic ocean where significant differences between the ETA and ETA-X were noted. In general, both MPC forecasters and EMC modelers were surprised to find the extent of change and positive impact the ETA-X displayed, particularly in the eastern Pacific where little or no impact was expected to result from the new RTG_SST analysis.

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