HYDROMETEOROLOGY RESEARCH

Zhang, J., K. Howard, C. Langston, S. Vasiloff, B. Kaney, A. Arthur, S. Van Cooten, K. Kelleher, D. Kitzmiller, F. Ding, D. J. Seo, E. Wells, C. Dempsey, 2011: National Mosaic and Multi-sensor QPE (NMQ) System: Description, Results, and Future Plans. Bulletin of the American Meteorological Society, 92, 1321-1338.

The National Mosaic and Multi-sensor QPE (Quantitative Precipitation Estimation), or “NMQ”, system was initially developed from a joint initiative between the National Oceanic and Atmospheric Administration's National Severe Storms Laboratory, the Federal Aviation Administration's Aviation Weather Research Program, and the Salt River Project. Further development has continued with additional support from the National Weather Service (NWS) Office of Hydrologic Development, the NWS Office of Climate, Water, and Weather Services, and the Central Weather Bureau of Taiwan. The objectives of NMQ research and development (R&D) are 1) to develop a hydrometeorological platform for assimilating different observational networks toward creating high spatial and temporal resolution multisensor QPEs for f lood warnings and water resource management and 2) to develop a seamless high-resolution national 3D grid of radar reflectivity for severe weather detection, data assimilation, numerical weather prediction model verification, and aviation product development.

Through about ten years of R&D, a real-time NMQ system has been implemented (http://nmq.ou.edu). Since June 2006, the system has been generating high-resolution 3D reflectivity mosaic grids (31 vertical levels) and a suite of severe weather and QPE products in real-time for the conterminous United States at a 1-km horizontal resolution and 2.5 minute update cycle. The experimental products are provided in real-time to end users ranging from government agencies, universities, research institutes, and the private sector and have been utilized in various meteorological, aviation, and hydrological applications. Further, a number of operational QPE products generated from different sensors (radar, gauge, satellite) and by human experts are ingested in the NMQ system and the experimental products are evaluated against the operational products as well as independent gauge observations in real time.

The NMQ is a fully automated system. It facilitates systematic evaluations and advances of hydrometeorological sciences and technologies in a real-time environment and serves as a test bed for rapid science-to-operation infusions. This paper describes scientific components of the NMQ system and presents initial evaluation results and future development plans of the system.

Zhang, J., Y. Qi, 2010: A real-time algorithm for the correction of bright band effects in radar-derived precipitation estimation. J. Hydrometeorology, 11, 1157-1171.

The bright band (BB) is a layer of enhanced reflectivity due to melting of aggregated snow and ice crystals.
The locally high reflectivity causes significant overestimation in radar precipitation estimates if an appropriate
correction is not applied. The main objective of the current study is to develop a method that automatically
corrects for large errors due to BB effects in a real-time national radar quantitative precipitation estimation
(QPE) product. An approach that combines the mean apparent vertical profile of reflectivity (VPR) computed
from a volume scan of radar reflectivity observations and an idealized linear VPR model was used for
computational efficiency. The methodology was tested for eight events from different regions and seasons in
the United States. The VPR correction was found to be effective and robust in reducing overestimation errors
in radar-derived QPE, and the corrected radar precipitation fields showed physically continuous distributions.
The correction worked consistently well for radars in flat land regions because of the relatively uniform spatial
distributions of the BB in those areas. For radars in mountainous regions, the performance of the correction is
mixed because of limited radar visibility in addition to large spatial variations of the vertical precipitation
structure due to underlying topography.

Zhang, J., Y. Qi, D. Kingsmill, K. Howard, 2010: Radar-based quantitative precipitation estimation for the cool season in northern California: case studies from the NOAA Hydrometeorological Testbed (HMT).. Proc. The World Environmental and Water Resources Congress 2010, Providence, RI, USA, Amer. Soc. Civil Engineers, 4639-4647.

The Hydrometeorological Testbed (HMT; http://hmt.noaa.gov) of the National Oceanic and Atmospheric Administration (NOAA) is a demonstration project intended to accelerate the infusion of new technologies, models, and scientific results from the research community into daily forecasting operations of the National Weather Service (NWS) and its River Forecast Centers (RFCs). The project focuses on the development and use of hydrometeorological instrumentation and models to aid forecasters, hydrologists and water resource managers in their decision-making process. The HMT plan calls for a sequence of regional demonstrations in vitally important watersheds in different parts of the United States. The first demonstration in the sequence (HMT-West) began in December 2005 in northern California’s American River Basin above Sacramento (Fig.1). This presentation focuses on one of the critical aspects of HMT: quantitative precipitation estimation (QPE). Two cases to be discussed occurred over the periods 30 December 2005 to 1 January 2006, and 13 to 15 January 2006. Scanning radar data were collected from several 10-cm National Weather Service (NWS) WSR-88D (Weather Surveillance Radar – 1988 Doppler) radars, one 3-cm polarimetric Doppler radar and one 5-cm mobile Doppler radar. The current study is focused on generating radar-based QPE from the WSR-88Ds for the two events. The impact of vertical profile of reflectivity (VPR) on radar-derived QPE in the complex terrain of northern California was analyzed and a variety of radar QPE techniques were applied to improve the precipitation estimates. Rain gauge observations after careful quality control were used to assess the accuracy of various radar precipitation estimates.

Vasiloff, S. V., K. Howard, 2009: Investigation of a severe downburst storm near Phoenix, Arizona, as seen by a mobile Dopper radar and the KIWA WSR-88D. Weather and Forecasting, 24, 856-867.

Vasiloff, S. V., K. Howard, J. Zhang, 2009: Difficulties with Correcting Radar Rainfall Estimates Based on Rain Gauge Data: A Case Study of Severe Weather in Montana on 16–17 June 2007.. Weather and Forecasting, 24, 1334-1344.

Zhang, J., K. Howard, S. Vasiloff, C. Langston, B. Kaney, A. Arthur, S. Van Cooten, K. Kelleher, D. Kitzmiller, F. Ding, D. J. Seo, M. Mullusky, E. Wells, T. Schneider, C. Dempsey, 2009: National Mosaic and multi-sensor QPE (NMQ) system: description, results and future plans. Preprints, The 34th Conference on Radar meteorology, Williamsburg, VA, USA, American Meteorological Society, 7A.1.

Zhang, J., Y. Qi, 2009: Correction of bright band effects in radar observations from plain areas. Preprints, The 34th Conf. on Radar Meteorology, Williamsburg, VA, USA, American Meteorological Society, P14.5.

Zhang, J., K. Howard, X. Xu, 2008: A warm season radar QPE algorithm using adaptive Z-R relationships. Proc. World Environmental and Water Resources Congress 2008, Honolulu, HI, USA, Amer. Soc. Civil Engineers, CD-ROM, 420.pdf.

Zhang, J., C. Langston, K. Howard, 2008: Three-dimensional radar mosaic integrating WSR-88Ds and Canadian radar network. Preprints, The 13th Conf. on Aviation, Range, and Aerospace Meteorology, New Orleans, LA, USA, Amer. Meteor. Soc., CD-ROM, P4.4.

Zhang, J., C. Langston, K. Howard, 2008: Bright Band Identification Based On Vertical Profiles of Reflectivity from the WSR-88D. Journal of Atmospheric and Oceanic Technology, 25, 1859-1872.

Zhang, J., K. Howard, P. L. Chang, P. T. Chiu, C. R. Chen, C. Langston, W. Xia, B. Kaney, P. F. Lin, 2008: High-Resolution QPE System for Taiwan. Data Assimilation for Atmospheric, Oceanic, and Hydrologic Applications, S. K. Park, L. Xu, Ed(s)., Springer-Verlag, 145-160.

Langston, C., J. Zhang, K. Howard, 2007: Four-Dimensional Dynamic Radar Mosaic. Journal of Atmospheric and Oceanic Technology, 24, 776-790.

Vasiloff, S. V., K. H. Howard, 2007: Investigation of a severe microburst near Phoenix, Arizona as seen by a mobile Doppler radar and the KIWA WSR-88D. Extended Abstracts, 13th Conference on Aviation, Range and Aerospace Meteorology, New Orleans, LA, USA, AMS, p4.7.

Vasiloff, S. V., B. Kaney, C. Langston, W. Xia, 2007: The National Severe Storms Laboratory QPE verification system. Extended Abstracts, 24th Conference on IIPS, New Orleans, LA, USA, AMS, 6B.12.

Vasiloff, S. V., D. J. Seo, K. W. Howard, J. Zhang, D. H. Kitzmiller, M. G. Mullusky, W. F. Krajewski, E. A. Brandes, R. M. Rabin, D. S. Berkowitz, H. E. Brooks, J. A. McGinley, R. J. Kuligowski, B. G. Brown, 2007: Improving QPE and Very Short Term QPF: An Initiative for a Community-Wide Integrated Approach. Bulletin of the American Meteorological Society, 88, 1899-1911.

Accurate quantitative precipitation estimates (QPE) and very short term quantitative precipitation forecasts (VSTQPF) are critical to accurate monitoring and prediction of water-related hazards and water resources. While tremendous progress has been made in the last quarter-century in many areas of QPE and VSTQPF, significant gaps continue to exist in both knowledge and capabilities that are necessary to produce accurate high-resolution precipitation estimates at the national scale for a wide spectrum of users. Toward this goal, a national next-generation QPE and VSTQPF (Q2) workshop was held in Norman, Oklahoma, on 28–30 June 2005. Scientists, operational forecasters, water managers, and stakeholders from public and private sectors, including academia, presented and discussed a broad range of precipitation and forecasting topics and issues, and developed a list of science focus areas. To meet the nation's needs for the precipitation information effectively, the authors herein propose a community-wide integrated approach for precipitation information that fully capitalizes on recent advances in science and technology, and leverages the wide range of expertise and experience that exists in the research and operational communities. The concepts and recommendations from the workshop form the Q2 science plan and a suggested path to operations. Implementation of these concepts is expected to improve river forecasts and flood and flash flood watches and warnings, and to enhance various hydrologic and hydrometeorological services for a wide range of users and customers. In support of this initiative, the National Mosaic and Q2 (NMQ) system is being developed at the National Severe Storms Laboratory to serve as a community test bed for QPE and VSTQPF research and to facilitate the transition to operations of research applications. The NMQ system provides a real-time, around-the-clock data infusion and applications development and evaluation environment, and thus offers a community-wide platform for development and testing of advances in the focus areas.

Zhang, J., C. Langston, K. Howard, 2007: Brightband identification from vertical profile of reflectivity. Preprints, The 33rd International Conf. on Radar Meteorology, Cairns, Australia, Amer. Meteor. Soc., P8A.13.

Vasiloff, S. V., 2006: Comparison of 2 hour forecasts based on persistence and a cross-correlation technique. Preprints, 12th Conference on Aviation, Range, and Aerospace Meteorology, Atlanta, GA, USA, AMS, CD-ROM, 3.10. [Available from steven.vasiloff@noaa.gov, National Weather Center, 120 David L. Boren Blvd., Norman, OK, USA, 73072.]

The NCAR Weather Support to Deicing Decision Making System (WSDDM) uses a cross-correlation technique to produce radar echo motion vectors. These vectors are then used to forecast snow water equivalent precipitation based on future echo positions with the focus on airports. It has been shown that WSDDM 30 min forecasts have large skill compared to persistence forecasts (a persistence forecast assumes that the current state will continue). This paper carries this type of comparative analysis out to two hours. Data from winter storms in the upper Midwest are evaluated and point forecasts near Chicago and Minneapolis are determined for both methods. Various echo configurations are used for the tests and include rain/snow bands, echoes from different sectors of synoptic cyclones and echoes with various reflectivity intensities.

Zhang, J., S. Wang, 2006: An Automated 2D Multipass Doppler Radar Volocity Dealiasing Scheme. Journal of Atmospheric and Oceanic Technology, 23, 1239-1248.

Zhang, J., C. Langston, K. Howard, 2006: Vertical profiles of reflectivity for different precipitation regimes. Proc. The 4th European Conference on Radar in Meteorology and Hydrology, Barcelona, Spain, Servei Meteorologic de Catalunya, 225-228.

Zhang, J., K. Howard, S. Wang, 2006: Single radar Cartesian grid and adaptive radar mosaic system. Preprints, The 12th Conference on Aviation, Range, and Aerospace Meteorolog, Atlanta, GA, USA, Amer. Meteor. Soc., 1.8.

Zhang, J., C. Langston, K. Howard, B. Clarke, 2006: Gap-filling in 3D radar mosaic analysis using vertical profile of reflectivity. Preprints, The 12th Conference on Aviation, Range, and Aerospace Meteorology, Atlanta, GA, USA, Amer. Meteor. Soc., CD-ROM, P1.9.

Arthur, A. T., G. M. Cox, N. R. Kuhnert, D. L. Slayter, K. W. Howard, 2005: The National Basin Delineation Project. Bulletin of the American Meteorological Society, 86, 1443-1452.

Zhang, J., K. Howard, J. J. Gourley, 2005: Constructing three-dimensional multiple radar reflectivity mosaics: examples of convective storms and stratiform rain echoes. Journal of Atmospheric and Oceanic Technology, 22, 30-42.

Langston, C., J. Zhang, K. Howard, 2004: Four-dimensional dynamic radar mosaic. Preprints, 11th Conference on Aviation, Range, and Aerospace Meteorology, Hyannis, MA, USA, American Meteorological Society, CD-ROM, P5.11.

Langston, C., J. Zhang, 2004: An automated algorithm for radar beam occultation. Preprints, 11th Conference on Aviation, Range, and Aerospace Meteorology, Hyannis, MA, USA, American Meteorological Society, CD-ROM, P5.16.

Zhang, J., K. Howard, W. Xia, C. Langston, S. Wang, Y. Qin, 2004: Three-dimensional high-resolution national radar mosaic. Preprints, 11th Conference on Aviation, Range, and Aerospace Meteorology, Hyannis, MA, USA, American Meteorological Society, CD-ROM, 3.5.

Zhang, J., S. Wang, 2004: An automated 2-D multi-pass velocity dealiasing scheme. Preprints, 11th Conference on Aviation, Range, and Aerospace Meteorology, Hyannis, MA, USA, American Meteorological Society, CD-ROM, 5.5.

Zhang, J., S. Wang, B. Clarke, 2004: WSR-88D reflectivity quality control using horizontal and vertical reflectivity structure. Preprints, 11th Conference on Aviation, Range, and Aerospace Meteorology, Hyannis, MA, USA, American Meteorological Society, CD-ROM, P5.4.

Zhang, J., K. Howard, W. Xia, C. langston, S. Wang, Y. Qin, 2004: Three- and Four-Dimensional High-Resolution National Radar Mosaic. ERAD Publ. Ser., 2, 105-108.

Zhang, J., K. Howard, W. Xia, J. J. Gourley, 2003: Comparison of Objective Analysis Schemes for the WSR-88D Radar Data. Preprints, 31st International Conference on Radar Meteorology, Seattle, WA, USA, American Meteorological Society, 907-910.