This work was primarily supported by NSF Grant AGS-0750790. The second author was supported by NSF Grants OCI-0905040, AGS-0802888, AGS-0941491, AGS-1046171, and AGS-1046081. The authors thank Tian-You Yu, Richard Doviak, Dusan Zrnić, Jerry Brotzge, David Bodine, Daniel Michaud, and Boon-leng Cheong for their input during project meetings. The authors would also like to acknowledge Adam Clark for providing the ETS code used in this study.
Atlas, R., 1997: Atmospheric observations and experiments to assess their usefulness in data assimilation. J. Meteor. Soc. Japan, 75, 111–130.
Bean, B. R., , and Dutton E. J. , 1968: Radio Meteorology. Dover Publications, 435 pp.
Bodine, D., , Heinselman P. L. , , Palmer R. D. , , Cheong B. L. , , and Michaud D. , 2009: Survey of applications of radar refractivity retrievals. Preprints, 34th Conf. on Radar Meteorology, Williamsburg, VA, Amer. Meteor. Soc., P6.4. [Available online at https://ams.confex.com/ams/34Radar/techprogram/paper_155495.htm.]
Bodine, D., and Coauthors, 2011: Understanding radar refractivity: Sources of uncertainty. J. Appl. Meteor. Climatol., 50, 2543–2560.
Brewster, K. A., , Brotzge J. , , Thomas K. W. , , Wang Y. , , Xue M. , , Gao J. , , Weber D. , , and Howe K. , 2008: High resolution assimilation of CASA and NEXRAD radar data in near-real time: Results from spring 2007 and plans for spring of 2008. Preprints, 12th Conf. IOAS-AOLS, New Orleans, LA, Amer. Meteor. Soc., 15B.7. [Available online at http://twister.ou.edu/papers/BrewsterIOAS2008.pdf.]
Brewster, K. A., , Thomas K. W. , , Gao J. , , Brotzge J. , , Xue M. , , and Wang Y. , 2010: A nowcasting system using full physics numerical weather prediction initialized with CASA and NEXRAD radar data. Preprints, 25th Conf. on Severe Local Storms, Denver, CO, Amer. Meteor. Soc., 9.4. [Available online at https://ams.confex.com/ams/25SLS/techprogram/paper_176053.htm.]
Brock, F. V., , Crawford K. C. , , Elliott R. L. , , Cuperus G. W. , , Stadler S. J. , , Johnson H. L. , , and Eilts M. D. , 1995: The Oklahoma Mesonet: A technical overview. J. Atmos. Oceanic Technol., 12, 5–19.
Cheong, B. L., , Palmer R. D. , , Curtis C. , , Yu T.-Y. , , Zrnic D. S. , , and Forsyth D. , 2008: Refractivity retrieval using the phased array radar: First results and potential for multi-mission operation. IEEE Trans. Geosci. Remote Sens., 46, 2527–2537.
Crook, N. A., 1996: Sensitivity of moist convection forced by boundary layer processes to low-level thermodynamic fields. Mon. Wea. Rev., 124, 1767–1785.
Dabberdt, W. F., , and Schlatter T. W. , 1996: Research opportunities from emerging atmospheric observing and modeling capabilities. Bull. Amer. Meteor. Soc., 77, 305–324.
Deardorff, J. W., 1980: Stratocumulus-capped mixed layers derived from a three-dimensional model. Bound.-Layer Meteor., 18, 495–527.
Emanuel, K., and Coauthors, 1995: Report of the first Prospectus Development Team of the U.S. Weather Research Program to NOAA and the NSF. Bull. Amer. Meteor. Soc., 76, 1194–1208.
Fabry, F., , Frush C. , , Zawadzki I. , , and Kilambi A. , 1997: On the extraction of near-surface index of refraction using radar phase measurements from ground targets. J. Atmos. Oceanic Technol., 14, 978–987.
Gao, J., , Xue M. , , Brewster K. , , and Droegemeier K. K. , 2004: A three-dimensional variational data analysis method with recursive filter for Doppler radars. J. Atmos. Oceanic Technol., 21, 457–469.
Gao, J., , Brewster K. , , and Xue M. , 2008: Variation of radio reflectivity with respect to moisture and temperature and influence on radar ray path. Adv. Atmos. Sci., 25, 1098–1106.
Hu, M., , and Xue M. , 2007: Impact of configurations of rapid intermittent assimilation of WSR-88D radar data for the 8 May 2003 Oklahoma City tornadic thunderstorm case. Mon. Wea. Rev., 135, 507–525.
Hu, M., , Xue M. , , and Brewster K. , 2006a: 3DVAR and cloud analysis with WSR-88D level-II data for the prediction of Fort Worth, Texas, tornadic thunderstorms. Part I: Cloud analysis and its impact. Mon. Wea. Rev., 134, 675–698.
Hu, M., , Xue M. , , Gao J. , , and Brewster K. , 2006b: 3DVAR and cloud analysis with WSR-88D level-II data for the prediction of Fort Worth, Texas, tornadic thunderstorms. Part II: Impact of radial velocity analysis via 3DVAR. Mon. Wea. Rev., 134, 699–721.
Ide, K., , Courtier P. , , Ghil M. , , and Lorenc A. , 1997: Unified notation for data assimilation: Operational, sequential and variational. J. Meteor. Soc. Japan, 75, 181–189.
Koch, S. E., , Aksakal A. , , and McQueen J. T. , 1997: The influence of mesoscale humidity and evapotranspiration fields on a model forecast of a cold-frontal squall line. Mon. Wea. Rev., 125, 384–409.
Lin, Y.-L., , Farley R. D. , , and Orville H. D. , 1983: Bulk parameterization of the snow field in a cloud model. J. Climate Appl. Meteor., 22, 1065–1089.
Liu, H., , and Xue M. , 2006: Retrieval of moisture from slant-path water vapor observations of a hypothetical GPS network using a three-dimensional variational scheme with anisotropic background error. Mon. Wea. Rev., 134, 933–949.
Lord, S. J., , Kalnay E. , , Daley R. , , Emmitt G. D. , , and Atlas R. , 1997: Using OSSEs in the design of the future generation of integrated observing systems. Preprints, First Symp. on Integrated Observation Systems, Long Beach, CA, Amer. Meteor. Soc., 45–47.
McLaughlin, D., and Coauthors, 2009: Short-wavelength technology and the potential for distributed networks of small radar systems. Bull. Amer. Meteor. Soc., 90, 1797–1817.
McPherson, R. A., and Coauthors, 2007: Statewide monitoring of the mesoscale environment: A technical update on the Oklahoma Mesonet. J. Atmos. Oceanic Technol., 24, 301–321.
Montmerle, T., , Caya A. , , and Zawadzki I. , 2002: Short-term numerical forecasting of a shallow storms complex using bistatic and single-Doppler radar data. Wea. Forecasting, 17, 1211–1225.
Schenkman, A., , Xue M. , , Shapiro A. , , Brewster K. , , and Gao J. , 2011a: Impact of CASA radar and Oklahoma Mesonet data assimilation on the analysis and prediction of tornadic mesovortices in a MCS. Mon. Wea. Rev., 139, 3422–3445.
Schenkman, A., , Xue M. , , Shapiro A. , , Brewster K. , , and Gao J. , 2011b: The analysis and prediction of the 8–9 May 2007 Oklahoma tornadic mesoscale convective system by assimilating WSR-88D and CASA radar data using 3DVAR. Mon. Wea. Rev., 139, 224–246.
Shimose, K., , Xue M. , , Palmer R. D. , , Gao J. , , Cheong B. L. , , and Bodine D. J. , 2013: Two-dimensional variational analysis of near-surface moisture from simulated radar refractivity-related phase change observations. Adv. Atmos. Sci., 30, 291–305.
Skamarock, W. C., , Klemp J. B. , , Dudhia J. , , Gill D. O. , , Barker D. M. , , Wang W. , , and Powers J. G. , 2005: A description of the Advanced Research WRF version 2. NCAR Tech. Note NCAR/TN-468+STR, 88 pp.
Sun, J., 2005: Convective-scale assimilation of radar data: Progress and challenges. Quart. J. Roy. Meteor. Soc., 131, 3439–3463.
Sun, W.-Y., , and Chang C.-Z. , 1986: Diffusion model for a convective layer: Part I: Numerical simulation of a convective boundary layer. J. Climate Appl. Meteor., 25, 1445–1453.
Tong, M., , and Xue M. , 2005: Ensemble Kalman filter assimilation of Doppler radar data with a compressible nonhydrostatic model: OSS experiments. Mon. Wea. Rev., 133, 1789–1807.
Weckwerth, T. M., , and Parsons D. B. , 2006: A review of convection initiation and motivation for IHOP_2002. Mon. Wea. Rev., 134, 5–22.
Weckwerth, T. M., , Wilson J. W. , , and Wakimoto R. M. , 1996: Thermodynamic variability within the convective boundary layer due to horizontal convective rolls. Mon. Wea. Rev., 124, 769–784.
Weckwerth, T. M., and Coauthors, 2004: An overview of the International H2O Project (IHOP_2002) and some preliminary highlights. Bull. Amer. Meteor. Soc., 85, 253–277.
Weckwerth, T. M., , Pettet C. R. , , Fabry F. , , Park S. , , LeMone M. A. , , and Wilson J. W. , 2005: Radar refractivity retrieval: Validation and application to short-term forecasting. J. Appl. Meteor., 44, 285–300.
Xue, M., , and Martin W. J. , 2006a: A high-resolution modeling study of the 24 May 2002 case during IHOP. Part I: Numerical simulation and general evolution of the dryline and convection. Mon. Wea. Rev., 134, 149–171.
Xue, M., , and Martin W. J. , 2006b: A high-resolution modeling study of the 24 May 2002 case during IHOP. Part II: Horizontal convective rolls and convective initiation. Mon. Wea. Rev., 134, 172–191.
Xue, M., , Droegemeier K. K. , , and Wong V. , 2000: The Advanced Regional Prediction System (ARPS)—A multi-scale nonhydrostatic atmospheric simulation and prediction model. Part I: Model dynamics and verification. Meteor. Atmos. Phys., 75, 161–193.
Xue, M., and Coauthors, 2001: The Advanced Regional Prediction System (ARPS)—A multi-scale nonhydrostatic atmospheric simulation and prediction tool. Part II: Model physics and applications. Meteor. Atmos. Phys., 76, 143–165.
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.
As in Shimose et al. (2013), we use the term phase change to refer to the difference in phase of a target between two different times and phase change difference (PCD) to refer to the phase difference between two consecutive targets aligned along the same radial.
Note that the short 10-min assimilation cycles have the potential of introducing imbalance noise that may take longer than 10 min to settle down in the forecast model, although convective-scale data assimilation studies (e.g., Hu and Xue 2007) have successfully used such short intervals. A digital filter (Lynch and Huang 1992) can be applied in the forecasting step to reduce potential noise.