• Arritt, R. W., T. D. Rink, M. Segal, D. P. Todey, C. A. Clark, M. J. Mitchell, and K. M. Labas, 1997: The Great Plains low-level jet during the warm season of 1993. Mon. Wea. Rev., 125, 21762192, doi:10.1175/1520-0493(1997)125<2176:TGPLLJ>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Augustine, J. A., and F. Caracena, 1994: Lower-tropospheric precursors to nocturnal MCS development over the central United States. Wea. Forecasting, 9, 116135, doi:10.1175/1520-0434(1994)009<0116:LTPTNM>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Browell, E. V., and et al. , 1997: LASE validation experiment. Advances in Atmospheric Remote Sensing with Lidar, A. Ansmann et al., Eds., Springer-Verlag, 289–295.

  • Carbone, R. E., J. D. Tuttle, D. A. Ahijevych, and S. B. Trier, 2002: Inferences of predictability associated with warm season precipitation episodes. J. Atmos. Sci., 59, 20332056, doi:10.1175/1520-0469(2002)059<2033:IOPAWW>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Clark, A. J., W. A. Gallus, and T. C. Chen, 2007: Comparison of the diurnal precipitation cycle in convection-resolving and non-convection-resolving mesoscale models. Mon. Wea. Rev., 135, 34563473, doi:10.1175/MWR3467.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Coleman, T. A., and K. R. Knupp, 2011: Radiometer and profiler analysis of the effects of a bore and a solitary wave on the stability of the nocturnal boundary layer. Mon. Wea. Rev., 139, 211223, doi:10.1175/2010MWR3376.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Colman, B. R., 1990: Thunderstorms above frontal surfaces in environments without positive CAPE. Part I: A climatology. Mon. Wea. Rev., 118, 11031122, doi:10.1175/1520-0493(1990)118<1103:TAFSIE>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Coniglio, M. C., J. Y. Hwang, and D. J. Stensrud, 2010: Environmental factors in the upscale growth and longevity of MCSs derived from Rapid Update Cycle analyses. Mon. Wea. Rev., 138, 35143539, doi:10.1175/2010MWR3233.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Crook, N. A., and M. W. Moncrieff, 1988: The effect of large-scale convergence on the generation and maintenance of deep moist convection. J. Atmos. Sci., 45, 36063624, doi:10.1175/1520-0469(1988)045<3606:TEOLSC>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Crook, N. A., R. Carbone, M. W. Moncrieff, and J. W. Conway, 1990: The generation and propagation of a nocturnal squall line. Part II: Numerical simulation. Mon. Wea. Rev., 118, 5065, doi:10.1175/1520-0493(1990)118<0050:TGAPOA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Davis, C. A., K. W. Manning, R. E. Carbone, S. B. Trier, and J. D. Tuttle, 2003: Coherence of warm-season continental rainfall in numerical weather prediction models. Mon. Wea. Rev., 131, 26672679, doi:10.1175/1520-0493(2003)131<2667:COWCRI>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Davis, C. A., and et al. , 2004: The Bow Echo and MCV Experiment: Observations and opportunities. Bull. Amer. Meteor. Soc., 85, 10751093, doi:10.1175/BAMS-85-8-1075.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Fovell, R. G., G. L. Mullendore, and S.-H. Kim, 2006: Discrete propagation in numerically simulated nocturnal squall lines. Mon. Wea. Rev., 134, 37353752, doi:10.1175/MWR3268.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • French, J., and M. D. Parker, 2010: The response of simulated nocturnal convective systems to a developing low-level jet. J. Atmos. Sci., 67, 33843408, doi:10.1175/2010JAS3329.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Fritsch, J. M., and G. S. Forbes, 2001: Mesoscale convective systems. Severe Convective Storms, Meteor. Monogr., No. 50, Amer. Meteor. Soc., 323–358, doi:10.1175/0065-9401-28.50.323.

    • Crossref
    • Export Citation
  • Fritsch, J. M., and R. E. Carbone, 2004: Improving quantitative precipitation forecasts in the warm season: A USWRP research and development strategy. Bull. Amer. Meteor. Soc., 85, 955965, doi:10.1175/BAMS-85-7-955.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Haertel, P. T., R. H. Johnson, and S. N. Tulich, 2001: Some simple simulations of thunderstorm outflows. J. Atmos. Sci., 58, 504516, doi:10.1175/1520-0469(2001)058<0504:SSSOTO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Haghi, K. R., D. Parsons, and B. Blake, 2015: Forecasting bores during PECAN 2015: A case study. 16th Conf. on Mesoscale Processes, Boston, MA, Amer. Meteor. Soc., 13.5. [Available online at https://ams.confex.com/ams/16Meso/webprogram/Paper274581.html.]

  • Heideman, K. F., and J. M. Fritsch, 1988: Forcing mechanisms and other characteristics of significant summertime precipitation. Wea. Forecasting, 3, 115130, doi:10.1175/1520-0434(1988)003<0115:FMAOCO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Jirak, I. L., and W. R. Cotton, 2007: Observational analysis of the predictability of mesoscale convective systems. Wea. Forecasting, 22, 813838, doi:10.1175/WAF1012.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Johnson, A., X. Wang, and S. Degelia, 2015: Real-time multi-scale GSI-based ensemble data assimilation and forecasting in support of the 2015 PECAN field campaign. 37th Conf. on Radar Meteorology, Norman, OK, Amer. Meteor. Soc., 211. [Available online at https://ams.confex.com/ams/37RADAR/webprogram/Paper275889.html.]

  • Jorgensen, D. P., T. R. Shepherd, and A. S. Goldstein, 2000: A dual-pulse repetition frequency scheme for mitigating velocity ambiguities of the NOAA P-3 airborne Doppler radar. J. Atmos. Oceanic Technol., 17, 585594, doi:10.1175/1520-0426(2000)017<0585:ADPRFS>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kain, J. S., and et al. , 2013: A feasibility study for probabilistic convection initiation forecasts based on explicit numerical guidance. Bull. Amer. Meteor. Soc., 94, 12131225, doi:10.1175/BAMS-D-11-00264.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Karstens, C. D., and et al. , 2015: Evaluation of a probabilistic forecasting methodology for severe convective weather in the 2014 Hazardous Weather Testbed. Wea. Forecasting, 30, 15511570, doi:10.1175/WAF-D-14-00163.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kincer, J. B., 1916: Daytime and nighttime precipitation and their economic significance. Mon. Wea. Rev., 44, 628633, doi:10.1175/1520-0493(1916)44<628:DANPAT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Knupp, K., 2006: Observational analysis of a gust front to bore to solitary wave transition within an evolving nocturnal boundary layer. J. Atmos. Sci., 63, 20162035, doi:10.1175/JAS3731.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Koch, S. E., W. Feltz, F. Fabry, M. Pagowski, B. Geerts, D. O. Miller, and J. W. Wilson, 2008: Turbulent mixing processes in atmospheric bores and solitary waves deduced from profiling systems and numerical simulation. Mon. Wea. Rev., 136, 13731400, doi:10.1175/2007MWR2252.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Laing, A. G., and J. M. Fritsch, 2000: The large-scale environments of the global populations of mesoscale convective complexes. Mon. Wea. Rev., 128, 27562776, doi:10.1175/1520-0493(2000)128<2756:TLSEOT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Li, Y., and R. B. Smith, 2010: The detection and significance of diurnal pressure and potential vorticity anomalies east of the Rockies. J. Atmos. Sci., 67, 27342751, doi:10.1175/2010JAS3423.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Maddox, R. A., 1980: Mesoscale convective complexes. Bull. Amer. Meteor. Soc., 61, 13741387, doi:10.1175/1520-0477(1980)061<1374:MCC>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Maddox, R. A., C. F. Chappell, and L. R. Hoxit, 1979: Synoptic and meso-a scale aspects of flash flood events. Bull. Amer. Meteor. Soc., 60, 115123, doi:10.1175/1520-0477-60.2.115.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Mapes, B. E., 1993: Gregarious tropical convection. J. Atmos. Sci., 50, 20262037, doi:10.1175/1520-0469(1993)050<2026:GTC>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Mapes, B. E., T. T. Warner, and M. Xu, 2003: Diurnal patterns of rainfall in northwestern South America. Part III: Diurnal gravity waves and nocturnal convection offshore. Mon. Wea. Rev., 131, 830844, doi:10.1175/1520-0493(2003)131<0830:DPORIN>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Marsham, J. H., S. B. Trier, T. M. Weckwerth, and J. W. Wilson, 2011: Observations of elevated convection initiation leading to a surface-based squall-line during 13 June IHOP_2002. Mon. Wea. Rev., 139, 247271, doi:10.1175/2010MWR3422.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McFarquhar, G. M., M. S. Timlin, R. M. Rauber, B. F. Jewett, J. A. Grim, and D. P. Jorgensen, 2007: Vertical variability of cloud hydrometeors in the stratiform region of mesoscale convective systems and bow echoes. Mon. Wea. Rev., 135, 34053428, doi:10.1175/MWR3444.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Parker, M. D., 2008: Response of simulated squall lines to low-level cooling. J. Atmos. Sci., 65, 13231341, doi:10.1175/2007JAS2507.1.

  • Peters, J. M., and R. S. Schumacher, 2015: Mechanisms for organization and echo training in a flash-flood-producing mesoscale convective system. Mon. Wea. Rev., 143, 10581085, doi:10.1175/MWR-D-14-00070.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Pinto, J. O., J. A. Grim, and M. Steiner, 2015: Assessment of the High-Resolution Rapid Refresh Model’s ability to predict large convective storms using object-based verification. Wea. Forecasting, 30, 892913, doi:10.1175/WAF-D-14-00118.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Pitchford, K. L., and J. London, 1962: The low-level jet as related to nocturnal thunderstorms over Midwest United States. J. Appl. Meteor., 1, 4347, doi:10.1175/1520-0450(1962)001<0043:TLLJAR>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Pu, B., and R. E. Dickinson, 2014: Diurnal spatial variability of Great Plains summer precipitation related to the dynamics of the low-level jet. J. Atmos. Sci., 71, 18071817, doi:10.1175/JAS-D-13-0243.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Raymond, D. J., and R. Rotunno, 1989: Response of a stably stratified flow to cooling. J. Atmos. Sci., 46, 28302837, doi:10.1175/1520-0469(1989)046<2830:ROASSF>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rodwell, M. J., and et al. , 2013: Characteristics of occasional poor medium-range weather forecasts for Europe. Bull. Amer. Meteor. Soc., 94, 13931405, doi:10.1175/BAMS-D-12-00099.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rottman, J. W., and J. E. Simpson, 1989: The formation of internal bores in the atmosphere: A laboratory model. Quart. J. Roy. Meteor. Soc., 115, 941963, doi:10.1002/qj.49711548809.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rotunno, R., J. B. Klemp, and M. L. Weisman, 1988: A theory for strong, long-lived squall lines. J. Atmos. Sci., 45, 463485, doi:10.1175/1520-0469(1988)045<0463:ATFSLL>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Schmidt, J. M., and W. R. Cotton, 1990: Interactions between upper and lower tropospheric gravity waves on squall line structure and maintenance. J. Atmos. Sci., 47, 12051222, doi:10.1175/1520-0469(1990)047<1205:IBUALT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Schumacher, R. S., 2009: Mechanisms for quasi-stationary behavior in simulated heavy-rain-producing convective systems. J. Atmos. Sci., 66, 15431568, doi:10.1175/2008JAS2856.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Schumacher, R. S., and R. H. Johnson, 2009: Quasi-stationary, extreme-rain-producing convective systems associated with midlevel cyclonic circulations. Wea. Forecasting, 24, 555574, doi:10.1175/2008WAF2222173.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Smith, A. M., G. M. McFarquhar, R. M. Rauber, J. A. Grim, M. S. Timlin, B. F. Jewett, and D. P. Jorgensen, 2009: Microphysical and thermodynamic structure and evolution of the trailing stratiform regions of mesoscale convective systems during BAMEX. Part I: Observations. Mon. Wea. Rev., 137, 11651185, doi:10.1175/2008MWR2504.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Stensrud, D. J., 1996: Effects of persistent, midlatitude mesoscale regions of convection on the large-scale environment during the warm season. J. Atmos. Sci., 53, 35033527, doi:10.1175/1520-0469(1996)053<3503:EOPMMR>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Surcel, M., M. Berenguer, and I. Zawadzki, 2010: The diurnal cycle of precipitation from continental radar mosaics and numerical weather prediction models. Part I: Methodology and seasonal comparison. Mon. Wea. Rev., 138, 30843106, doi:10.1175/2010MWR3125.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Trenberth, K. E., A. Dai, R. M. Rasmussen, and D. B. Parsons, 2003: The changing character of precipitation. Bull. Amer. Meteor. Soc., 84, 12051217, doi:10.1175/BAMS-84-9-1205.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Trier, S. B., C. A. Davis, and D. A. Ahijevych, 2010: Environmental controls on the simulated diurnal cycle of warm-season precipitation in the continental United States. J. Atmos. Sci., 67, 10661090, doi:10.1175/2009JAS3247.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Tripoli, G. J., and W. R. Cotton, 1989a: Numerical study of an observed orogenic mesoscale convective system. Part I: Simulated genesis and comparison with observations. Mon. Wea. Rev., 117, 273304, doi:10.1175/1520-0493(1989)117<0273:NSOAOO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Tripoli, G. J., and W. R. Cotton, 1989b: Numerical study of an observed orogenic mesoscale convective system. Part II: Simulated genesis and comparison with observations. Mon. Wea. Rev., 117, 273304, doi:10.1175/1520-0493(1989)117<0273:NSOAOO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Tuttle, J. D., and C. A. Davis, 2006: Corridors of warm season precipitation in the central United States. Mon. Wea. Rev., 134, 22972317, doi:10.1175/MWR3188.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wallace, J. M., 1975: Diurnal variations in precipitation and thunderstorm frequency over the conterminous United States. Mon. Wea. Rev., 103, 406419, doi:10.1175/1520-0493(1975)103<0406:DVIPAT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wang, Z., and et al. , 2011: Observations of boundary layer water vapor and aerosol structures with a compact airborne Raman lidar. Fifth Symp. on Lidar Atmospheric Applications, Seattle, WA, Amer. Meteor. Soc., 3.6. [Available online at https://ams.confex.com/ams/91Annual/webprogram/Paper187254.html.]

  • Weckwerth, and et al. , 2004: An overview of the International H2O Project (IHOP_2002) and some preliminary highlights. Bull. Amer. Meteor. Soc., 85, 253277, doi:10.1175/BAMS-85-2-253.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Weisman, M. L., and R. Rotunno, 2004: “A theory for strong long-lived squall lines” revisited. J. Atmos. Sci., 61, 361382, doi:10.1175/1520-0469(2004)061<0361:ATFSLS>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Weisman, M. L., C. Davis, W. Wang, K. W. Manning, and J. B. Klemp, 2008: Experiences with 0–36-h explicit convective forecasts with the WRF-ARW model. Wea. Forecasting, 23, 407437, doi:10.1175/2007WAF2007005.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Weisman, M. L., and et al. , 2015: The Mesoscale Predictability Experiment (MPEX). Bull. Amer. Meteor. Soc., 96, 21272149, doi:10.1175/BAMS-D-13-00281.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Whiteman, D. N., and et al. , 2006: Raman Lidar Measurements during the International H2O Project. Part II: Case studies. J. Atmos. Oceanic Technol., 23, 170183, doi:10.1175/JTECH1839.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wilson, J. W., and W. E. Schreiber, 1986: Initiation of convective storms at radar-observed boundary-layer convergence lines. Mon. Wea. Rev., 114, 25162536, doi:10.1175/1520-0493(1986)114<2516:IOCSAR>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wilson, J. W., and R. D. Roberts, 2006: Summary of convective storm initiation and evolution during IHOP: Observational and modeling perspective. Mon. Wea. Rev., 134, 2347, doi:10.1175/MWR3069.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ziegler, C. L., 2013: A diabatic Lagrangian technique for the analysis of convective storms. Part II: Application to a radar-observed storm. J. Atmos. Oceanic Technol., 30, 22662280, doi:10.1175/JTECH-D-13-00036.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
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The 2015 Plains Elevated Convection at Night Field Project

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  • 1 University of Wyoming, Laramie, Wyoming
  • | 2 University of Oklahoma, Norman, Oklahoma
  • | 3 NOAA/National Severe Storms Laboratory, Norman, Oklahoma
  • | 4 National Center for Atmospheric Research, Boulder, Colorado
  • | 5 University of Oklahoma, Norman, Oklahoma
  • | 6 Millersville University of Pennsylvania, Millersville, Pennsylvania
  • | 7 NOAA/National Severe Storms Laboratory, Norman, Oklahoma
  • | 8 Howard University, Washington, D.C.
  • | 9 NASA Langley Research Center, Hampton, Virginia
  • | 10 Iowa State University, Ames, Iowa
  • | 11 University of Oklahoma, Norman, Oklahoma
  • | 12 University of Manitoba, Winnipeg, Manitoba, Canada
  • | 13 University of Oklahoma, Norman, Oklahoma
  • | 14 University of Alabama in Huntsville, Huntsville, Alabama
  • | 15 Center for Severe Weather Research, Boulder, Colorado
  • | 16 University of Illinois at Urbana–Champaign, Urbana, Illinois
  • | 17 NCAR, Boulder, Colorado
  • | 18 NASA Langley Research Center, Hampton, Virginia
  • | 19 North Carolina State University, Raleigh, North Carolina
  • | 20 NCAR, Boulder, Colorado
  • | 21 University of Illinois at Urbana–Champaign, Urbana, Illinois
  • | 22 Colorado State University, Fort Collins, Colorado
  • | 23 NOAA/National Severe Storms Laboratory, Norman, Oklahoma
  • | 24 Naval Postgraduate School, Monterey, California
  • | 25 University of Oklahoma, Norman, Oklahoma
  • | 26 University of Wyoming, Laramie, Wyoming
  • | 27 Center for Severe Weather Research, Boulder, Colorado
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Abstract

The central Great Plains region in North America has a nocturnal maximum in warm-season precipitation. Much of this precipitation comes from organized mesoscale convective systems (MCSs). This nocturnal maximum is counterintuitive in the sense that convective activity over the Great Plains is out of phase with the local generation of CAPE by solar heating of the surface. The lower troposphere in this nocturnal environment is typically characterized by a low-level jet (LLJ) just above a stable boundary layer (SBL), and convective available potential energy (CAPE) values that peak above the SBL, resulting in convection that may be elevated, with source air decoupled from the surface. Nocturnal MCS-induced cold pools often trigger undular bores and solitary waves within the SBL. A full understanding of the nocturnal precipitation maximum remains elusive, although it appears that bore-induced lifting and the LLJ may be instrumental to convection initiation and the maintenance of MCSs at night.

To gain insight into nocturnal MCSs, their essential ingredients, and paths toward improving the relatively poor predictive skill of nocturnal convection in weather and climate models, a large, multiagency field campaign called Plains Elevated Convection At Night (PECAN) was conducted in 2015. PECAN employed three research aircraft, an unprecedented coordinated array of nine mobile scanning radars, a fixed S-band radar, a unique mesoscale network of lower-tropospheric profiling systems called the PECAN Integrated Sounding Array (PISA), and numerous mobile-mesonet surface weather stations. The rich PECAN dataset is expected to improve our understanding and prediction of continental nocturnal warm-season precipitation. This article provides a summary of the PECAN field experiment and preliminary findings.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

CORRESPONDING AUTHOR E-MAIL: Bart Geerts, geerts@uwyo.edu

A supplement to this article is available online (10.1175/BAMS-D-15-00257.2)

This article is included in the Plains Elevated Convection At Night (PECAN) Special Collection.

Abstract

The central Great Plains region in North America has a nocturnal maximum in warm-season precipitation. Much of this precipitation comes from organized mesoscale convective systems (MCSs). This nocturnal maximum is counterintuitive in the sense that convective activity over the Great Plains is out of phase with the local generation of CAPE by solar heating of the surface. The lower troposphere in this nocturnal environment is typically characterized by a low-level jet (LLJ) just above a stable boundary layer (SBL), and convective available potential energy (CAPE) values that peak above the SBL, resulting in convection that may be elevated, with source air decoupled from the surface. Nocturnal MCS-induced cold pools often trigger undular bores and solitary waves within the SBL. A full understanding of the nocturnal precipitation maximum remains elusive, although it appears that bore-induced lifting and the LLJ may be instrumental to convection initiation and the maintenance of MCSs at night.

To gain insight into nocturnal MCSs, their essential ingredients, and paths toward improving the relatively poor predictive skill of nocturnal convection in weather and climate models, a large, multiagency field campaign called Plains Elevated Convection At Night (PECAN) was conducted in 2015. PECAN employed three research aircraft, an unprecedented coordinated array of nine mobile scanning radars, a fixed S-band radar, a unique mesoscale network of lower-tropospheric profiling systems called the PECAN Integrated Sounding Array (PISA), and numerous mobile-mesonet surface weather stations. The rich PECAN dataset is expected to improve our understanding and prediction of continental nocturnal warm-season precipitation. This article provides a summary of the PECAN field experiment and preliminary findings.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

CORRESPONDING AUTHOR E-MAIL: Bart Geerts, geerts@uwyo.edu

A supplement to this article is available online (10.1175/BAMS-D-15-00257.2)

This article is included in the Plains Elevated Convection At Night (PECAN) Special Collection.

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