Evaluation of the Mesoscale Eta Model Over the Western United States

摘要

The skill of the Mesoscale Eta Model is evaluated over a 6-month period fromOctober 1, 1994 to March 31, 1995 over the western United States. This model will continue to undergo changes until and after its projected operational release in July 1995. Many diagnostics and error statistics are created to evaluate its performance as forecasts are received and archived at the University of Utah. These statistics are available on the Internet allowing researchers and operational forecasters access to them in near real-time. The Mesoscale Eta Model forecast initialized at 1200 UTC, 9 November 1994 is used as a case study to introduce many of the diagnostics developed to evaluate the model. A systematic evaluation of the average and root-mean-squared error over months and seasons reveals little significant bias in upper tropospheric fields such as 300 mb wind or 500 mb geopotential height. Moderate average errors are evident in lower tropospheric temperature. Accumulated precipitation over months and seasons indicates the model's spinup of precipitation during the first 12 hours of the forecast cycle. (MM).