Abstract: We have calculated the seasonal variation of frequency of blocking and its geographical location by examining the grid point values of daily 500 mb geopotential height over the Northern Hemisphere for 15 consecutive years ...

Abstract: The NMC Global Spectral Model was integrated for one year. The model used is the same as the 1989 operational medium range forecast model except that the horizontal resolution was reduced from T80 to T40. Overall, the model ...

Abstract: The focus of this Paper is on the frequency and spatial distributions of blocking and persistent anomalies of geopotential height over the Southern Hemisphere. The analysis is based upon daily height fields at 1000 and 500 ...

Abstract: Local autocorrelation statistics for the Northern Hemisphere geopotential height field are presented for different seasons and tropospheric pressure levels. Values are generally much higher than those calculated from time ...

Abstract: In an effort to explain observed blocking phenomena, the work of Charney and DeVore (1979) and Hart (1979) has been extended to incorporate observed zonal topography in a barotropic nonlinear channel model. Multiple ...

Abstract: Relationships between the interannual variability of the U.S. summer precipitation regime and the intensification, weakening, or changes in position of the climatological-mean circulation features that organize this regime ...

Abstract: The moisture budget of the central United States during May is examined using multiyear (1985?89) assimilated datasets recently produced by NASA/DAO and NCEP/NCAR. Intercomparisons and comparisons with station observations ...

Abstract: The influence of the Great Plains low-level jet (LLJ) on summertime precipitation and moisture transport over the central United States is examined in observations and in assimilated datasets recently produced by the ...

Abstract: In preparation for the execution of the National Meteorological Center and National Center for Atmospheric Research (NMC/NCAR) Reanalysis Project, which will cover the period 1958?93, the impact of satellite data on both ...

Abstract: The NCEP and NCAR are cooperating in a project (denoted ?reanalysis?) to produce a 40-year record of global analyses of atmospheric fields in support of the needs of the research and climate monitoring communities. This ...