Tuesday, 31 July 2001: 11:00 AM
Forecast guidance from high resolution nests in the NCEP Meso Eta Model
Tests are underway of forecast runs of various high resolution nests within the operational Meso Eta Model. Under consideration are four regional nests (Eastern, Central, Western, and Alaskan) as well as 6+ smaller nests over the contiguous U.S. (Northwest, North Central, Southeast, etc.), Hawaii, and Puerto Rico. The current horizontal gridpoint spacing of the operational parent model is 22 km while the nests are running with 10 km spacing (Alaska is run at 12 km). When the Meso Eta moves to 12 km late in 2001, the nests will move to roughly 7 to 8 km and will become nonhydrostatic as well. Forecasts will be to 48 hours. Due to computational and time constraints, all nests will not be run all the time. Instead individual nests may be run at a particular cycle each day or in some instances a region or regions could be selected because a very significant event is anticipated to occur there. Examples will be shown of nested forecasts for several types of weather events in different parts of the country.