Date: Mon, 23 Mar 1998 17:13:09 -0600 From: "Paul J. Roebber" Organization: University of Wisconsin at Milwaukee Mime-Version: 1.0 To: eegle-mod@wings.glerl.noaa.gov Subject: MM5 Winds for 1600 UTC 3/9/98 for comparison with GLCFS Winds X-Attachments: 1998/attach-19980323.gif Attached you will find a gif file of the MM5 wind field for 1600 UTC on 9 March 1998 for comparison with the GLCFS Winds. This map is produced from a 4h forecast on a 12 km model domain using the 1200 UTC AVN initial analysis (rather than the observations - however, the AVN would have used the obs in its data assimilation procedure so I don't think this would be much of a factor only 4h into the forecast). The contours in the center of Lake Michigan are 20 m/s (with a contour interval of 2 m/s and some smoothing for display). You will note some similarities with the GLCFS winds but also a number of discrepancies. Good model matches with obs include: station obs model 45002 37kt 37kt 17C 24kt 27kt GSRW3 39kt 37kt ESC 19kt 23kt MDW 19kt 23kt MNW 23kt 25kt TVC 25kt 23kt GRB 26kt 25kt Less good matches with the obs were at: station obs model SGNW3 41kt 27kt 20C 40kt 27kt Y09 15kt 25kt CGX 37kt 27kt Generally, the model wind field makes good sense and looks like an improvement over the "patchwork" of the GLCFS. However, I do have some concern over the "coarse grain" nature of the land use specification (19 km resolution) and terrain; I will probably undertake some experiments with other resolutions for this case to see how this affects things. Paul Roebber Content-Type: image/gif; x-mac-type="47494666"; x-mac-creator="4A565752"; name="Mar0916.gif" Content-Description: JPEGView Document Content-Disposition: inline; filename="Mar0916.gif" Attachment converted: Quadra HD:Mar0916.gif (GIFf/JVWR) (000127D8)