This material is based upon work supported by the National Science Foundation under Grant Nos. ATM0106776, ATM0109241, and NOAA/PACS NA06GP0451 to the University of Utah. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation or the National Oceanic and Atmospheric Administration.

The Utah Global Model (UGM) is a primitive equation, hydrostatic, baroclinic version of the global model described by Paegle (1989: A variable resolution global model based upon Fourier and finite element representation. Mon. Wea. Rev., 117, 583-606). It predicts vorticity, divergence, thermal and moisture fields on pressure-based sigma coordinates.

The approach is similar to that used by global models in operational centers, with the exception of numerical approximations of horizontal derivatives, which are based on Fourier series in longitude and finite elements in latitude. The present version has a 2.22 degree nodal spacing in latitude and 42 waves in longitude on 20 vertical levels, situated at sigma = .99, .98, .96, .94, .91, .88, .84, .78, .72, .66, .59, .53, .47, .41, .34, .28, .22, .16, .09 and .03. The model is initialized using temperature, wind, moisture and surface pressure obtained from the NCEP gdas2 (2.5 x 2.5 degree). The model is initialized with climatological heating rates (large scale condensation, deep convective, shallow convective, shortwave radiative and longwave radiative) from the NCEP/NCAR Reanalysis.

The figures under "Stream Function at Sigma .53 and Precipitation" show contours of stream function (rotational part of the wind field) at Sigma level .53 (contoured every 6e+06 (m*m)/s). This is roughly comparable to 500 mb geopotential height contours. The shaded regions show the predicted total precipitation (stratiform plus convective). The Hour 00 panel shows the initialized precipitation field, while the other panels display the 12-hour accumulated precipitation (inches). The areal coverage of precipitation appears to be excessive in the initial 12-hour spin-up period, and unrealistically limited and too localized at later times. For "Stream Function at Sigma .78 and Winds," values of the stream function are contoured every 2e+06 (m*m)/s, and the magnitude of the wind (m/s) at Sigma level .88 (corresponding to about 880 mb) is shaded.

**The UGM is an experimental model used primarily to address predictability questions (e.g. Vukicevic and Paegle 1989, Mon. Wea. Rev.; Paegle et al. 1997, Met. and Atmospheric Physics; Miguez-Macho and Paegle 2000, Mon. Wea. Rev.; Wang et al. 1999, Journ. of Geophysical Res.). It is generally less skillful by about 1 day when compared with real time global models run at major forecast centers.** The related research has been partly supported by NSF, NOAA/OGP and the USAF.