This work was funded by the NWS Aviation Weather Branch via Grant DG133W06CN0182, under the direction of Kevin Johnston, Cynthia Abelman, and Curt Neidhart and through the NextGen program under the guidance of Mark Miller. The success of this demonstration was due to the six years of support provided by the FWD staff in entering boundaries and monitoring the products in real time, and to Dan Megenhardt at NCAR who provided numerous engineering enhancements and excellent real-time support. Steven Fano, Gregory Patrick, William Bunting, Ted Ryan, and Lance Bucklew provided us with valuable and insightful feedback throughout the demonstration. Thomas Amis and the Fort Worth CWSU staff provided helpful commentary on the nowcast fields. Collaboration with Stephan Smith, Mamoudou Ba, Kenneth Sperow, Scott O’Donnell, Xuning Tan, John Crockett, and Lingyan Xin of NWS MDL made it possible to completely integrate this system into the WFO environment and provide the forecasters with tools on AWIPS, including the boundary tools developed by Dave Albo at NCAR. Karen Griggs provided terrific assistance with the figures. The three formal reviewers provided detailed, discerning, thoughtful reviews that really helped make the paper much more complete.
Bally, J., 2004: The Thunderstorm Interactive Forecast System: Turning automated thunderstorm tracks into severe weather warnings. Wea. Forecasting, 19, 64–72.
Benjamin, S., , Hu M. , , Weygandt S. , , and Devenyi D. , 2009: Integrated assimilation of radar, satellite, and METAR cloud data for initial hydrometeor/divergence fields to improve hourly updated short-range forecasts from the RUC, Rapid Refresh, and HRRR. Int. Symp. on Nowcasting and Very Short Term Forecasting, Whistler, BC, Canada, WMO, 3.1. [Available online at http://www.wmo.int/pages/prog/arep/wwrp/new/documents/WSN09_program_booklet.pdf.]
Casati, B., , Ross G. , , and Stephenson D. B. , 2004: A new intensity-scale approach for the verification of spatial precipitation forecasts. Meteor. Appl., 11, 141–154.
Davis, C., , Brown B. , , and Bullock R. , 2006a: Object-based verification of precipitation forecasts. Part I: Methodology and application to mesoscale rain areas. Mon. Wea. Rev., 134, 1772–1784.
Davis, C., , Brown B. , , and Bullock R. , 2006b: Object-based verification of precipitation forecasts. Part II: Application to convective rain systems. Mon. Wea. Rev., 134, 1785–1795.
Delanoy, R. L., , and Troxel S. W. , 1993: A machine intelligent gust front algorithm for Doppler weather radar systems. Preprints, Fifth Int. Conf. on Aviation Weather Systems, Vienna, VA, Amer. Meteor. Soc., 125–129.
Dixon, M., , and Wiener G. , 1993: TITAN: Thunderstorm Identification, Tracking, Analysis, and Nowcasting—A radar based methodology. J. Atmos. Oceanic Technol., 10, 785–797.
Done, J., , Davis C. , , and Weisman M. , 2004: The next generation of NWP: Explicit forecasts of convection using the Weather Research and Forecasting (WRF) model. Atmos. Sci. Lett., 5, 110–117.
Dye, J. E., , Winn W. P. , , Jones J. J. , , and Breed D. W. , 1989: The electrification of New Mexico thunderstorms. Part I. Relationships between precipitation development and the onset of electrification. J. Geophys. Res., 94 (D6), 8643–8656.
Ebert, E. E., 2008: Fuzzy verification of high resolution gridded forecasts: A review and proposed framework. Meteor. Appl., 15, 53–66.
Ebert, E. E., , and McBride J. L. , 2000: Verification of precipitation in weather systems: Determination of systematic errors. J. Hydrol., 239, 179–202.
Ebert, E. E., , Wilson L. J. , , Brown B. G. , , Nurmi P. , , Brooks H. E. , , Bally J. , , and Jaeneke M. , 2004: Verification of nowcasts from the WWRP Sydney 2000 Forecast Demonstration Project. Wea. Forecasting, 19, 73–96.
Fowle, M. A., , and Roebber P. J. , 2003: Short-range (0–48 h) numerical prediction of convective occurrence, mode, and location. Wea. Forecasting, 18, 782–794.
Gremillion, M. S., , and Orville R. E. , 1999: Thunderstorm characteristics of cloud-to-ground lightning at the Kennedy Space Center, Florida: A study of lightning initiation signatures as indicated by WSR-88D. Wea. Forecasting, 14, 640–649.
Haiden, T., , Kann A. , , Wittmann C. , , Pistotnik G. , , Bica B. , , and Gruber C. , 2011: The Integrated Nowcasting through Comprehensive Analysis (INCA) system and its validation over the eastern Alpine region. Wea. Forecasting, 26, 166–183.
JPDO, 2007: Concept of operations for the next generation air transportation system. Version 1.2, Joint Planning and Development Office, Washington, DC, 226 pp.
Keenan, T., and Coauthors, 2003: The Sydney 2000 World Weather Research Programme Forecast Demonstration Project: Overview and current status. Bull. Amer. Meteor. Soc., 84, 1041–1054.
Marsigli, C., , Montani A. , , and Paccagnella T. , 2008: A spatial verification method applied to the evaluation of high-resolution ensemble forecasts. Meteor. Appl., 15, 127–145.
Mass, C. F., , Ovens D. , , Westrick K. , , and Colle B. , 2002: Does increasing horizontal resolution produce more skillful forecasts? Bull. Amer. Meteor. Soc., 83, 407–430.
McNeil, D., , and Freiberger P. , 1993: Fuzzy Logic—The Revolutionary Computer Technology That Is Changing Our World. Simon and Schuster, 319 pp.
Mueller, C., , Saxen T. , , Roberts R. , , Wilson J. , , Betancourt T. , , Dettling S. , , Oien N. , , and Yee J. , 2003: NCAR Auto-Nowcast System. Wea. Forecasting, 18, 545–561.
Nelson, E., , Roberts R. , , Saxen T. , , and Cai H. , 2006: The NWS/NCAR “Forecaster Over The Loop” Fort Worth operational demonstration: Human enhancement of a thunderstorm nowcasting system. Fifth Int. Conf. on Mesoscale Meteorology and Typhoon, Boulder, CO, East Asia Weather Research Association. [Available online at http://www.eol.ucar.edu/icmcs/program.html.]
Nelson, E., , Roberts R. , , Saxen T. , , Cai H. , , Pinto J. , , and Steiner M. , 2008: Evaluating the performance of different synoptic regime settings on the NCAR Auto-Nowcaster. Preprints, 13th Conf. on Aviation, Range and Aerospace Meteorology, New Orleans, LA, Amer. Meteor. Soc., 3.2. [Available online at https://ams.confex.com/ams/88Annual/techprogram/paper_132736.htm.]
Olson, D. A., , Junker N. W. , , and Korty B. , 1995: Evaluation of 33 years of quantitative precipitation forecasting at the NMC. Wea. Forecasting, 10, 498–511.
Pierce, C. E., and Coauthors, 2004: The nowcasting of precipitation during Sydney 2000: An appraisal of the QPF algorithms. Wea. Forecasting, 19, 7–21.
Pinto, J. O., , Dupree W. , , Weygandt S. , , Wolfson M. , , Benjamin S. , , and Steiner M. , 2010: Advances in the Consolidated Storm Prediction for Aviation (CoSPA). Preprints, 14th Conf. on Aviation, Range, and Aerospace Meteorology, Atlanta, GA, Amer. Meteor. Soc., J11.2. [Available online at http://ams.confex.com/ams/pdfpapers/163811.pdf.]
Purdom, J. F. W., 1976: Some uses of high resolution GOES imagery in the mesoscale forecasting of convection and its behavior. Mon. Wea. Rev., 104, 1474–1483.
Purdom, J. F. W., 1982: Subjective interpretations of geostationary satellite data for nowcasting. Nowcasting, K. A. Browning, Ed., Academic Press, 149–166.
Purdom, J. F. W., , and Marcus K. , 1982: Thunderstorm trigger mechanisms over the southeast United States. Preprints, 12th Conf. on Severe Local Storms, San Antonio, TX, Amer. Meteor. Soc., 487–488.
Roberts, N., 2008: Assessing the spatial and temporal variation in the skill of precipitation forecasts from an NWP model. Meteor. Appl., 15, 163–169.
Roberts, N., , and Lean H. W. , 2008: Scale-selective verification of rainfall accumulations from high-resolution forecasts of convective events. Mon. Wea. Rev., 136, 78–97.
Roberts, R. D., , and Rutledge S. , 2003: Nowcasting storm initiation and growth using GOES-8 and WSR-88D data. Wea. Forecasting, 18, 562–584.
Roberts, R. D., and Coauthors, 2005: The NWS/NCAR Man-in-the-Loop (MITL) demonstration: Forecaster input into a thunderstorm nowcasting system. Preprints, World Weather Research Program Symp. on Nowcasting and Very Short Range Forecasting, Toulouse, France, WMO, 7.26. [Available online at http://www.meteo.fr/cic/wsn05/DVD/index.html.]
Roberts, R. D., , Nelson E. , , Pinto J. , , Saxen T. , , and Phillips C. , 2007: Status of nowcasting thunderstorm initiation: Where do we go from here? Preprints, 33rd Conf. on Radar Meteorology, Cairns, QLD, Australia, Amer. Meteor. Soc., 5.3. [Available online at http://ams.confex.com/ams/pdfpapers/123659.pdf.]
Roberts, R. D., , Nelson E. , , and Brown B. , 2009: A role for the forecaster in improving convection initiation nowcasts: Operational methodology and validation of approach. Int. Symp. on Nowcasting and Very Short Range Forecasting, Whistler, BC, Canada, WMO, 2.10. [Available online at http://www.wmo.int/pages/prog/arep/wwrp/new/documents/WSN09_program_booklet.pdf.]
Roberts, W., , and Cheatwood-Harris L. , 2010: The 2009 AutoNowcaster evaluation at the Ft. Worth/Dallas Weather Forecast Office. NWS NextGen Program Office Rep., 44 pp.
Roebber, P. J., , Schultz D. M. , , Colle B. A. , , and Stensrud D. J. , 2004: Toward improved prediction: High-resolution and ensemble modeling systems in operations. Wea. Forecasting, 19, 936–949.
Saxen, T. R., and Coauthors, 2008: The operational mesogamma-scale analysis and forecast system of the U.S. Army Test and Evaluation Command. Part IV: The White Sands Missile Range Auto-Nowcast System. J. Appl. Meteor. Climatol., 47, 1123–1139.
Smith, S. B., , Johnson J. T. , , Roberts R. D. , , Zubrick S. M. , , and Weiss S. J. , 1998: The System for Convection Analysis and Nowcasting (SCAN): 1997–1998 field test. Preprints, 19th Conf. on Severe Local Storms, Minneapolis, MN, Amer. Meteor. Soc., 790–793.
Steiner, M., , Bateman R. , , Megenhardt D. , , Liu Y. , , Xu M. , , Pocernich M. , , and Krozel J. , 2010: Translation of ensemble weather forecasts into probabilistic air traffic capacity impact. Air Traffic Control Quart., 18, 229–254.
Stensrud, D. J., , Brooks H. E. , , Du J. , , Tracton M. S. , , and Rogers E. , 1999: Using ensembles for short-range forecasting. Mon. Wea. Rev., 127, 433–446.
Stephenson, D. B., , Casati B. , , Ferro C. A. T. , , and Wilson C. A. , 2008: The extreme dependency score: A non-vanishing measure for forecasts of the rare events. Meteor. Appl., 15, 41–50.
Stuart, N. A., and Coauthors, 2006: The future of humans in an increasingly automated forecast process. Bull. Amer. Meteor. Soc., 87, 1497–1502.
Stuart, N. A., , Grumm R. , , Moore J. , , Pietrycha A. E. , , Reeves K. , , Abrams E. , , and Mass C. F. , 2007a: Reaching the goals outlined in the first forum. Bull. Amer. Meteor. Soc., 88, 1896–1897.
Stuart, N. A., , Schultz D. , , and Klein G. , 2007b: Maintaining the role of humans in the forecast process. Bull. Amer. Meteor. Soc., 88, 1893–1896.
Sun, J., , and Crook N. A. , 1997: Dynamical and microphysical retrieval from Doppler radar observations using a cloud model and its adjoint. Part I: Model development and simulated data experiments. J. Atmos. Sci., 54, 1642–1661.
Weisman, M. L., , and Klemp J. B. , 1982: The dependence of numerically simulated convective storms on vertical wind shear and buoyancy. Mon. Wea. Rev., 110, 504–520.
Weisman, M. L., , Davis C. , , Wang W. , , Manning K. W. , , and Klemp J. B. , 2008: Experiences with 0–36-h explicit convective forecasts with the WRF-ARW model. Wea. Forecasting, 23, 407–437.
Weygandt, S., , Benjamin S. , , Smirnova T. , , Brundage K. , , Alexander C. , , Hu M. , , Jamison B. , , and Sahm S. , 2009: Evaluation of the High Resolution Rapid Refresh (HRRR): An hourly updated convection resolving model utilizing radar reflectivity assimilation from the RUC/RR. Int. Symp. on Nowcasting and Very Short Range Forecasting, Whistler, BC, Canada, WMO, 3.17. [Available online at http://www.wmo.int/pages/prog/arep/wwrp/new/documents/WSN09_program_booklet.pdf.]
White, A., , Neiman P. , , Gottas D. , , Gutman S. , , and Jankov I. , 2009: A coastal atmospheric river monitoring and early warning system. Int. Symp. on Nowcasting and Very Short Range Forecasting, Whistler, BC, Canada, WMO, 4.11. [Available online at http://www.wmo.int/pages/prog/arep/wwrp/new/documents/WSN09_program_booklet.pdf.]
Wilks, D. S., 2006: Statistical Methods in the Atmospheric Sciences. 2nd ed. Academic Press, 627 pp.
Wilson, J. W., , and Schreiber W. E. , 1986: Initiation of convective storms by radar-observed boundary layer convergent lines. Mon. Wea. Rev., 114, 2516–2536.
Wilson, J. W., , and Megenhardt D. L. , 1997: Thunderstorm initiation, organization, and lifetime associated with Florida boundary layer convergence lines. Mon. Wea. Rev., 125, 1507–1525.
Wilson, J. W., , and Roberts R. D. , 2006: Summary of convective storm initiation and evolution during IHOP: Observational and modeling perspective. Mon. Wea. Rev., 134, 23–47.
Wilson, J. W., , Ebert E. E. , , Saxen T. R. , , Roberts R. D. , , Mueller C. K. , , Sleigh M. , , Pierce C. E. , , and Seed A. , 2004: Sydney 2000 Forecast Demonstration Project: Convective storm nowcasting. Wea. Forecasting, 19, 131–150.
Wilson, J. W., , Feng Y. , , Chen M. , , and Roberts R. D. , 2010: Nowcasting challenges during the Beijing Olympics: Successes, failures, and implications for future nowcasting systems. Wea. Forecasting, 25, 1691–1714.
Wong, W.-K., , Yeung L. H. Y. , , Wang Y.-C. , , and Chen M. , 2009: Towards the blending of NWP with Nowcast–Operation experience in B08FDP. Int. Symp. on Nowcasting and Very Short Range Forecasting, Whistler, BC, Canada, WMO, 4.5. [Available online at http://www.wmo.int/pages/prog/arep/wwrp/new/documents/WSN09_program_booklet.pdf.]
Xue, M., , Wang D. , , Gao J. , , Brewster K. , , and Droegemeier K. K. , 2003: The Advanced Regional Prediction System (ARPS), storm-scale numerical weather prediction and data assimilation. Meteor. Atmos. Phys., 82, 139–170.
The Nowcasting Working Group of the World Meteorological Organization (WMO) World Weather Research Program has defined nowcasting as follows: forecasting with local detail, by any method, over a period from the present to a few hours ahead; this includes a detailed description of the present weather.
In lieu of lightning data, which were not available in the FOTL-ANC system, convective storms are defined as storms reaching radar echo intensities ≥35 dBZ. This designation is based partially on studies by Dye et al. (1989) and Gremillion and Orville (1999), who have shown that the onset of storm electrification generally occurs >5 min after storm echoes of 30 dBZ or greater have reached subfreezing levels.
All times are listed in UTC; subtract 5 h for Fort Worth, TX, central daylight time.
Storm extrapolation nowcasts of existing storms are obtained using the radar-based TITAN (Dixon and Wiener 1993) algorithm. Storm extrapolation and persistence are the typical benchmark nowcasts against which all other short-term precipitation nowcasts are compared (e.g., Mueller et al. 2003; Ebert et al. 2004, Pierce et al. 2004; Wilson et al. 2004; Saxen et al. 2008).
Hereafter, FOTL-ANC (ANC) notations are used to represent human (no human) involvement in producing the nowcasts.