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; Kristovich et al. (2017) ; data available online at http://data.eol.ucar.edu/master_list/?project=OWLeS ], occurred during the winter of 2013/14. Stemming from the successes of the exploratory LLAP project, the OWLeS project sought to examine 1) the kinematics and dynamics of LLAP bands, 2) upwind and downwind lake influences (i.e., heat and moisture fluxes and advection) on lake-effect convection, and 3) orographic influences on lake-effect convection. The original OWLeS proposal planned for eight
; Kristovich et al. (2017) ; data available online at http://data.eol.ucar.edu/master_list/?project=OWLeS ], occurred during the winter of 2013/14. Stemming from the successes of the exploratory LLAP project, the OWLeS project sought to examine 1) the kinematics and dynamics of LLAP bands, 2) upwind and downwind lake influences (i.e., heat and moisture fluxes and advection) on lake-effect convection, and 3) orographic influences on lake-effect convection. The original OWLeS proposal planned for eight
structural failures, and contributing to several fatalities. Since these snowbands are so narrow, the gradient in snowfall can be quite sharp, such as in the 17–19 November 2014 storm where regions just a few kilometers from the snow maximum only had snow totals of ~15 cm ( National Weather Service 2014 ). Heterogeneities within snowbands, such as mesoscale and misoscale vortices, can locally impact snowfall rates and wind speeds, but the type, frequency of occurrence, kinematics, genesis mechanisms, and
structural failures, and contributing to several fatalities. Since these snowbands are so narrow, the gradient in snowfall can be quite sharp, such as in the 17–19 November 2014 storm where regions just a few kilometers from the snow maximum only had snow totals of ~15 cm ( National Weather Service 2014 ). Heterogeneities within snowbands, such as mesoscale and misoscale vortices, can locally impact snowfall rates and wind speeds, but the type, frequency of occurrence, kinematics, genesis mechanisms, and
thermodynamic and wind profiles of the observed LLAP band reasonably well throughout the event. Therefore, model output can be used to gain insight into the dynamic and kinematic environment during this event. c. IOP7 analysis 1) WCR observations Vertical profiles of WCR reflectivity, w , and u normal from three flight legs (1, 3, and 5) in IOP7 are presented in the top three panels of Figs. 6 – 8 . Along leg 1, flown farthest west over the lake, the WCR observations show a well-organized LLAP band just
thermodynamic and wind profiles of the observed LLAP band reasonably well throughout the event. Therefore, model output can be used to gain insight into the dynamic and kinematic environment during this event. c. IOP7 analysis 1) WCR observations Vertical profiles of WCR reflectivity, w , and u normal from three flight legs (1, 3, and 5) in IOP7 are presented in the top three panels of Figs. 6 – 8 . Along leg 1, flown farthest west over the lake, the WCR observations show a well-organized LLAP band just
the charging layer includes a temperature range between −5° and −40°C. See the text for more detailed descriptions, especially for the lightning types (flash type IC* is defined in section 3d ). 2) IOP5 storm kinematics, microphysics, and lightning In qualitative terms, IOP5 was a very convective storm (i.e., scattered cells of KTYX reflectivity maxima of 35–40 dB Z and frequent graupel reports). The NLDN detected a total of three CG strokes and one IC pulse between 2206 and 2220 UTC, all having
the charging layer includes a temperature range between −5° and −40°C. See the text for more detailed descriptions, especially for the lightning types (flash type IC* is defined in section 3d ). 2) IOP5 storm kinematics, microphysics, and lightning In qualitative terms, IOP5 was a very convective storm (i.e., scattered cells of KTYX reflectivity maxima of 35–40 dB Z and frequent graupel reports). The NLDN detected a total of three CG strokes and one IC pulse between 2206 and 2220 UTC, all having
2017 ; Steenburgh and Campbell 2017 ; Eipper et al. 2018 ). In particular, Eipper et al. (2018) found that cold air advection (CAA) in the upper portion of the boundary layer (BL) was strongly correlated with the inland penetration of lake-effect radar echoes. However, the influence of environmental baroclinity on the far-inland kinematic and dynamic structure of lake-effect snowbands has received little attention. Here we extend the investigation of Eipper et al. (2018) by evaluating
2017 ; Steenburgh and Campbell 2017 ; Eipper et al. 2018 ). In particular, Eipper et al. (2018) found that cold air advection (CAA) in the upper portion of the boundary layer (BL) was strongly correlated with the inland penetration of lake-effect radar echoes. However, the influence of environmental baroclinity on the far-inland kinematic and dynamic structure of lake-effect snowbands has received little attention. Here we extend the investigation of Eipper et al. (2018) by evaluating
poor sampling, radar echoes associated with the shoreline band extend quasi-continuously downstream, eventually connecting with the LLAP system over eastern Lake Ontario, which is better sampled by the KTYX radar. Over northeastern Lake Ontario, a secondary area of lake-effect precipitation extends east-southeastward from Point Petre, merging with the primary LLAP system near the east shore. The kinematic features noted above persist through 1200 UTC 11 December when the 3-km HRRR analysis provides
poor sampling, radar echoes associated with the shoreline band extend quasi-continuously downstream, eventually connecting with the LLAP system over eastern Lake Ontario, which is better sampled by the KTYX radar. Over northeastern Lake Ontario, a secondary area of lake-effect precipitation extends east-southeastward from Point Petre, merging with the primary LLAP system near the east shore. The kinematic features noted above persist through 1200 UTC 11 December when the 3-km HRRR analysis provides
) understand the dynamical and microphysical processes controlling the finescale kinematic structures and electrification processes of intense long-fetch LeSs; 6) provide in situ validation of operational (S band) and research (X band) dual-polarization hydrometeor type classification and lake-effect snowstorm QPE; and 7) understand the influence of downwind topography on LeSs generated over Lake Ontario. A large number of advanced observational facilities were deployed during intensive observation periods
) understand the dynamical and microphysical processes controlling the finescale kinematic structures and electrification processes of intense long-fetch LeSs; 6) provide in situ validation of operational (S band) and research (X band) dual-polarization hydrometeor type classification and lake-effect snowstorm QPE; and 7) understand the influence of downwind topography on LeSs generated over Lake Ontario. A large number of advanced observational facilities were deployed during intensive observation periods
instability or intensity maximizes near the coast, an inland precipitation maximum may occur. The expected signature of hydrometeor advection in profiling radar data is unclear, since it will depend on the details of hydrometeor trajectories and, in turn, the details of airflow kinematics and hydrometeor terminal fall speeds. This study uses observations to better constrain the role of the above mechanisms in producing inland variations in snowfall rate. Section 2 describes the profiling radar datasets
instability or intensity maximizes near the coast, an inland precipitation maximum may occur. The expected signature of hydrometeor advection in profiling radar data is unclear, since it will depend on the details of hydrometeor trajectories and, in turn, the details of airflow kinematics and hydrometeor terminal fall speeds. This study uses observations to better constrain the role of the above mechanisms in producing inland variations in snowfall rate. Section 2 describes the profiling radar datasets
structural differences within the LLAP band as the circulation, clouds, and precipitation are advected inland and respond to the changing lower boundary conditions. We hypothesize that the development of a strong, solenoidally driven secondary circulation, intensified by latent heat release, is essential for such a well-organized LLAP band. To support this hypothesis, high-resolution airborne dual-Doppler (DD) radar observations are presented that exhibit the 2D kinematic structure in a vertical plane
structural differences within the LLAP band as the circulation, clouds, and precipitation are advected inland and respond to the changing lower boundary conditions. We hypothesize that the development of a strong, solenoidally driven secondary circulation, intensified by latent heat release, is essential for such a well-organized LLAP band. To support this hypothesis, high-resolution airborne dual-Doppler (DD) radar observations are presented that exhibit the 2D kinematic structure in a vertical plane
large-scale kinematic and thermodynamic changes occurring over the Great Lakes region and occurred shortly following or concurrently with the development and intensification of surface troughs A and B and associated convergence zones. Niziol et al. (1995) discuss similar modulation of lake-effect storms by upper-level and surface troughs. By 0000 UTC 12 December, the 500-hPa short-wave trough axis was over Lake Huron ( Fig. 8c ) and surface trough A was over Lake Ontario ( Fig. 8d ). The
large-scale kinematic and thermodynamic changes occurring over the Great Lakes region and occurred shortly following or concurrently with the development and intensification of surface troughs A and B and associated convergence zones. Niziol et al. (1995) discuss similar modulation of lake-effect storms by upper-level and surface troughs. By 0000 UTC 12 December, the 500-hPa short-wave trough axis was over Lake Huron ( Fig. 8c ) and surface trough A was over Lake Ontario ( Fig. 8d ). The
