U.S. West Coast States Adding New Observing Networks to Monitor Weather and Climate

The West Coast of North America is the first place in the northern hemisphere to feel the impacts of eastward-propagating midlatitude weather systems that form over the vast stretches of the Pacific Ocean. Satellite technology has allowed weather forecasters and other interested end users to detect these weather systems as they form over the data void oceans. But observations of some key storm phenomena are still unavailable, e.g., the strength of the baroclinically induced low-level jet in the warm sector side of the polar cold front. Also, satellite techniques that use microwave sensors often do not work near the coastline and over land because of the complex emissivity of land surfaces. Finally, a Pacific winter storms reconnaissance program, akin to the hurricane reconnaissance program held each year during the Atlantic hurricane season, does not exist. For these reasons and to provide a baseline to detect and monitor climate change impacts, the West Coast states, and in particular, California, are working with NOAA and other agencies to implement a 21st century observing system. This paper will motivate and describe California's new observing assets, give an update on the status of their implementation, and relay recent developments that have led to expanding some of these observing networks into Oregon and Washington.