Facilitating Access to Boundary-Layer Conditions in Mountainous Regions

Government agencies, educational institutions, commercial firms, and the public have contributed substantively to increasing the availability of in-situ environmental observations near the surface throughout the nation. Diverse applications require access to low latency, high quality data. The National Mesonet Program of the National Weather Service provides access via Synoptic Data/MesoWest to over 12,000 actively reporting stations in the 11 western states and Alaska for research and educational applications. New sensor technologies are broadening what is possible to study in both urban and rural locales. While weather conditions everywhere are influenced by the characteristics of the underlying surface, those at most locations in the western United States are typically impacted to a greater degree by variations in topography and surface state.

Synoptic Data API services provide access to observations that have been subjected to a battery of data quality checks. Distinguishing between physically plausible extreme events from erroneous observations in mountainous regions is difficult to do when the data are obtained from dozens of sources. Differing sensor types, deployment techniques, exposure and siting standards, reporting frequencies, and additional characteristics all need to be considered. Meteorologically-relevant extrema are identified using data mining techniques applied to records from a few to over 10 years. For example, the frequency of occurrence of rapid temperature falls and rises in basins resulting from variations in the temporal evolution and coverage of cold-air pools will be contrasted to the typical time rates of change and amplitudes of temperature falls associated with cold fronts in the western United States.