The purpose of the NCEP Regional Reanalysis (RR) project is to produce a long-term set of consistent climate data at a regional scale, using a state-of-the-art data assimilation system. The NCEP RR project will create a 24 year (1979-2003) set of 3-hourly analyses over North America, using a 32-km version of the NCEP Eta Data Assimilation System (EDAS). The EDAS consists of successive 3-h analyses and forecasts using the Eta forecast model and the Eta 3-dimensional variational (3DVAR) analysis. The RR EDAS will assimilate most data types now used in the operational 12-km EDAS, including observed precipitation and satellite radiance data.

Although the NCEP RR effort has been designed primarily as a vehicle for climate studies, this project offers a unique opportunity for researchers to revisit noteworthy weather events which have occurred during the past quarter century. In this presentation, simulations using NCEP RR data for several well-documented weather events along the east coast of the U.S. will be shown. Of particular interest are those storms whose synoptic and mesoscale features have been the subject of exhaustive diagnostic study, such as the 18-20 February 1979 President's Day Storm, the 10-12 February 1983 "Megalopolitan" storm and the 13-14 March 1993 "Storm of the Century". Simulations using both the 32 km Eta model and 8-km version of the NCEP non-hydrostatic Meso model (NMM) will be presented to illustrate how well current NWP systems reproduce the synoptic and mesoscale structures in these storms, which were often poorly forecast in real-time.

Since several of these storms have been well documented in the meteorological literature, this study hopes to illustrate how much progress in NWP has been made in the last 25 years and to stimulate discussion on what still needs to be improved in mesoscale NWP systems.