Tuesday, 11 February 2003
Examining high wind events using satellite cloud cover composites over the Cheyenne, WY region
Cloud cover composites over the U.S. high plains/northern Rocky Mountain region have been derived from GOES 10 data for fall and winter season, 1997-2001. Each set of hourly composites have been derived using a different cloud detection method, including threshold methods from the visible, channel 4 (10 mm), and channel 2 (3.9 mm). Additional stratification into nine wind regimes by mean boundary layer wind speed and direction over Cheyenne, WY will also be determined from the 12 UTC analysis of the ETA model. From these composites, pre-event, event, and post-event conditions for past occurrences of high winds will be examined, searching for precursor cloud patterns that signal such events. Relevancy of this work for the Cheyenne NWS Forecast Office will be presented along with selected results.