Microphysical characterization of banded structures observed in cold-season extratropical cyclones

Observations acquired during the Profiling Of Winter Storms project (PlOWS) are used to characterize the microphysical properties of banded cloud and precipitation structures in cold-season extratropical cyclones. From 1 November to 15 December 2009 and from 15 January to 10 March 2010, cyclones were sampled by the National Center for Atmospheric Research C-130 aircraft over the central United States at a range of times within their life cycles. Horizontal flight legs, frequently conducted at a variety of altitudes, profiled the changing microphysical structure across the bands.

Cloud and precipitation particles were measured in situ with 3 two-dimensional optical array probes, two Forward Scattering Spectrometer Probes, and a Cloud Droplet Probe while a Cloud Spectrometer and Impactor probe provided measures of bulk mass content. Data from these probes are combined to characterize how particle number concentrations, size distributions, cross-sectional areas, median mass diameters, and mass contents varied horizontally relative to the banded structure's positions and vertically with altitude and air temperature. Data from the University of Wyoming Cloud Radar and Lidar are used to supplement the in situ measurements with extremely high-resolution profiles of particle characteristics through the banded structures. Implications of these measurements for characterizing precipitation growth mechanisms of the banded structures sampled during PlOWS will be discussed.