NOAA NWC - Irma National Water Model Streamflow Forecasts

The National Water Model (NWM) is a water forecasting model operated by the NOAA National Weather Service that continually forecasts flows on 2.7 million stream reaches covering 3.2 million miles of streams and rivers in the continental United States [1]. It operates as part of the national weather forecasting system, with inputs from NOAA numerical weather prediction models, and from weather and water conditions observed through the US Geological Survey's National Water Information System. Reference materials for the computational framework behind NWM is published by NCAR [9] [10].

The NWC generates NWM streamflow forecasts for the continental US (CONUS) with multiple forecast horizons and time steps. Due to the output file sizes, these are normally not available for download more than a couple days at a time [2]. A 40-day rolling window of these forecasts is maintained by HydroShare at RENCI [3], and a complete retrospective (August 2016 to the present) of the NWM Analysis & Assimilation outputs is maintained as well (contact [e-mail] for access).

An archive of all NWM forecasts for the period Aug 29 to Sept 17, 2017 has been compiled at RENCI [4] [5], available as netCDF (.nc) files totaling 6.8 TB. These can be browsed, subsetted, visualized, and downloaded (see [6] [7] [8]). In addition to these output files, we have uploaded to this HydroShare resource the input parameter files needed to re-run the NWM for the Irma period, or for any time period covered by NWM v1.1 and 1.2 (August 2016 to this publication date in August 2018). These parameter files are also made available at [1].

See README for further details and usage guidance. Please see NOAA contacts listed on [1] for questions about the NWM data contents, structure and formats. Contact [e-mail] if any questions about HydroShare-based tools and data access.

References
[1] Overview of the NWM framework and output files [http://water.noaa.gov/about/nwm]
[2] Free access to all National Water Model output for the most recent two days [ftp://ftpprd.ncep.noaa.gov/pub/data/nccf/com/nwm]
[3] NWM outputs for rolling 40-day window, maintained by HydroShare [http://thredds.hydroshare.org/thredds/catalog/nwm/catalog.html]
[4] Archived Irma NWM outputs via RENCI THREDDS server [http://thredds.hydroshare.org/thredds/catalog/nwm/irma/catalog.html]
[5] RENCI is an Institute at the University of North Carolina at Chapel Hill
[6] Live map for National Water Model forecasts [http://water.noaa.gov/map]
[7] NWM Forecast Viewer app [https://hs-apps.hydroshare.org/apps/nwm-forecasts]
[8] CUAHSI JupyterHub example scripts for subsetting NWM output files [https://hydroshare.org/resource/3db192783bcb4599bab36d43fc3413db/]
[9] WRF-Hydro Overview [https://ral.ucar.edu/projects/wrf_hydro/overview]
[10] WRF-Hydro User Guide 2013 [https://ral.ucar.edu/sites/default/files/public/images/project/WRF_Hydro_User_Guide_v3.0.pdf]

国家水文模型（NWM）是由美国国家海洋和大气管理局（NOAA）国家气象服务运营的水文预报模型，它持续预报美国大陆范围内涵盖320万英里河流和溪流的270万个流域的流量。该模型作为国家天气预报系统的一部分运行，其输入数据来源于NOAA数值天气预报模型以及通过美国地质调查局国家水文信息系统的观测到的天气和水文条件。NWM背后的计算框架的参考资料由美国国家大气研究中心（NCAR）发布[9][10]。国家水文中心（NWC）生成针对美国大陆（CONUS）的NWM流预测，涵盖多个预报时间和步长。由于输出文件的大小，这些数据通常无法一次性下载超过两天[2]。HydroShare在RENCI维护了一个40天的滚动预测窗口[3]，并保留了一个完整的回顾性（自2016年8月至今）的NWM分析与同化输出[4]。对于2017年8月29日至9月17日期间的所有NWM预报，已在RENCI整理存档[5]，并以总容量为6.8TB的netCDF（.nc）文件形式提供，可供浏览、子集、可视化和下载[6][7][8]。除了这些输出文件外，我们还上传了必要的输入参数文件到HydroShare资源中，以便重新运行NWM以模拟伊尔玛事件期间的数据，或覆盖NWM v1.1和1.2（自2016年8月至本出版日期2018年8月）的任何时间段的参数文件。这些参数文件也在[1]处提供。有关进一步的详细信息和使用指南，请参阅README文件。如对NWM数据内容、结构和格式有任何疑问，请参阅[1]上的NOAA联系人信息。如对基于HydroShare的工具和数据访问有任何疑问，请联系[e-mail]。