A Real-Time Online Data Product that Automatically Detects Easterly Gap-Flow Events and Precipitation Type in the Columbia River Gorge

Journal Article · 30 September 2018 · Journal of Atmospheric and Oceanic Technology

DOI: https://doi.org/10.1175/JTECH-D-18-0088.1 · OSTI ID:1477808

Neiman, Paul J. ^[1]; Gottas, Daniel J. ^[1]; White, Allen B. ^[1]; Schneider, William R. ^[2]; Bright, David R. ^[2]

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1. NOAA/Earth System Research Laboratory/Physical Sciences Division, Boulder, Colorado
2. NOAA/National Weather Service Forecast Office, Portland, Oregon

A real-time, hourly updated, online graphical data product that displays the depth and strength of easterly gap flow in the Columbia River Gorge using a 915-MHz Doppler wind profiler is presented. During precipitation events, this data product also displays observed precipitation accumulation and diagnosed precipitation type using measurements provided by a collocated heated tipping-bucket rain gauge, an optical disdrometer, and temperature and relative humidity sensors. Automated algorithms that determine the existence and depth of the gap flow, as well as precipitation type, are described. The Columbia River Gorge is the only major gap in the Cascade Mountains of Oregon and Washington. Consequently, both easterly and westerly directed gap-flow events are common in this region. Especially during late autumn and winter, easterly gap flow can cause hazardous and damaging weather (e.g., snow, freezing rain, and strong winds) in the Portland, Oregon–Vancouver, Washington metropolitan area. The product described here was developed to help forecasters at the Portland National Weather Service Forecast Office monitor cool-season easterly gap-flow events in order to provide situational awareness and guide warnings to the public about potential weather-related hazards.

• Research Organization: National Oceanic and Atmospheric Administration (NOAA), Silver Spring, MD (United States). Office of Oceanic and Atmospheric Research
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• Grant/Contract Number: EE0007605
• OSTI ID: 1477808
• Journal Information: Journal of Atmospheric and Oceanic Technology, Journal Name: Journal of Atmospheric and Oceanic Technology Journal Issue: 10 Vol. 35; ISSN 0739-0572
• Publisher: American Meteorological SocietyCopyright Statement
• Country of Publication: United States
• Language: English