A severe storm struck Las Vegas, Nevada, on July 8, 1999 causing widespread flooding and leading to a loss of life. SSM/I and GOES satellite observations reveal that this event was associated with a moisture surge originating in the tropical eastern Pacific. An evaluation of SSM/I and GOES imagery from June through September 1999 indicates that several moisture surges occurred during the North American monsoon season, seldom reaching Las Vegas, but sometimes pushing tropical moisture as far north as Lake Tahoe. The ability to identify and track these surges offers possibilities for improved understanding of the conditions leading to devastating storm events in northwestern Mexico and the southwestern United States. ¿ 2000 American Geophysical Union