Northeast US Regional NEXRAD radar mosaics of winter storms from 1996-2023, part 1

This dataset contains over 14,000 hours of regional radar mosaics over the
northeast US from 600+ winter storm days between 1996-2023. Winter storm
days are defined when at least 2 out of 15 surface stations in the
northeast US (see attached map) produced at least 1 inch of snow over the
24 hour period. Sequences of these mosaics aid in analyzing the
precipitation area and the structures within winter storms. Radar
reflectivity data is combined from the first, lowest (0.5 degree)
elevation angle from 12 NEXRAD WSR-88D radars in the northeast US (see
attached). The scans occur every 5-10 minutes from each radar depending on
the radar scan settings.  The time label of the regional map is
based on the scan time central radar, KOKX (Upton, NY). Scans from other
radars in the region are used for that time as long as they are within 8
minutes of the KOKX scan. The polar radar data from each radar is
interpolated to a regional 1202 km x 1202 km Cartesian grid with 2 km grid
spacing covering 35.73-46.8 degN and 66.36-81.85 degW. Where the radar
domains overlap, we take the highest reflectivity value. For dates after
dual-polarization integration (2012 onwards), files contain the
correlation coefficient (RHO_HV) field and a binary field  that
can be used to “image mute” the reflectivity which reduces the visual
prominence of melting and mixed precipitation commonly mistaken for heavy
snow. Image muting is applied where radar reflectivity is ≥ 20 dBZ and
RHO_HV is ≤ 0.97. This product is different from other widely used radar
mosaics such as the MRMS produced by NOAA since it does not interpolate to
a constant altitude and thus preserves the finer scale details in the
reflectivity field. Because the data used to create these mosaics are not
interpolated to a constant altitude, the altitude varies over the region
(altitudes of radar scan used at each grid point are provided as a field
for each data file). This data set is specifically designed to analyze
fine-scale structures in winter storms. Part 1 contains files pre-dual
polarization integration (1996-2012)Part 2 contains files post-dual
polarization integration (2012-2023)