Date of Award

January 2019

Document Type


Degree Name

Master of Science (MS)


Atmospheric Sciences

First Advisor

Mark Askelson


Unmanned Aircraft (UA) are being used more frequently and for an increased variety of purposes, from military use to medical deliveries, disaster and building infrastructure imagery, and agriculture. While the interest in and usage of UA grows, little is known about how often UA flight operations are impacted by different meteorological phenomenon. In this study, a 30-year climatology of surface stations and sounding observations are used to determine the likelihood of UA operations without weather-driven restrictions or grounding at five locations. The locations of Bismarck, ND, Riverton, WY, Oakland, CA, Albuquerque, NM, and Miami, FL are selected to represent different atmospheric and regional characteristics. Impacts from temperature, moisture, winds, and cloud base height are analyzed to determine the frequency with which thresholds, set utilizing previous studies on manned aircraft and testing of UA, are reached. Analysis of the surface data indicate that flight impacts vary by geographic location, season, and time of day. Temperature impacts primarily follow seasonal changes, whereas restrictions due to relative humidity and winds primarily follow diurnal variations. Analysis of sounding data produced similar restrictions overall, with impacts from relative humidity and winds changing with height. Data from soundings at the surface are consistent with surface data except for relative humidity, particularly in Miami, and wind speeds. Results from this study can be used to determine equipment required for UA in different regions, meteorological parameters that most impact flight, and the best time for UA operations based on meteorological impacts.